OROS Wiki - User contributions [en]

Addons:PV Diagram

2026-11-09T08:21:32Z

Lmagimel: /* How to use: */

[[category:WikiOros]]
=== [[File:PV.png|70px]] Add on : PV (pressure volume) diagram ===

A [https://en.wikipedia.org/wiki/Pressure%E2%80%93volume_diagram pressure–volume diagram] (or PV diagram, or volume–pressure loop) is used to describe corresponding changes in volume and pressure in a system.

[[File:Indicator_diagram_steam_admission.png|500px]]

The diagram records the pressure of steam versus the volume of steam in a cylinder, throughout a piston's cycle of motion in a steam engine. The diagram enables calculation of the work performed and thus can provide a measure of the power produced by the engine.

To exactly calculate the work done by the system it is necessary to calculate the integral of the pressure with respect to volume. One can often quickly calculate this using the PV diagram as it is simply the area enclosed by the cycle.

==Download==

Working with NVGate V15 or upper.
[https://partnerzone.digigram.com/s/yK8f5f45MynAnrL Version 1.0.108544 from january 2022 : diagram PV]

Include a model to demo with the correct settings.

==How to use: ==

[[File:PVdiagram2022.PNG|600px]]

*Define one (or more) channel as a pressure.
*Add this channel into Sync. order (SOA) plug in.
*On SOA plug in , average, domain, select: "Angular"
*Display Avg.block from SOA (Average time domain triggerd block of SOA)
*Open PV_Diagram.exe
*Click on refresh (right click) in available results if you do not see anything.
*Select the input.
*Compute once will display the PV diagram base once based the last triggerd block.
*"background computation, will continuously compute the diagram.

Addons:PV Diagram

2026-11-09T08:20:54Z

Lmagimel: Download link moved to Partner Zone (PV Diagram 1.0.108544)

[[category:WikiOros]]
=== [[File:PV.png|70px]] Add on : PV (pressure volume) diagram ===

A [https://en.wikipedia.org/wiki/Pressure%E2%80%93volume_diagram pressure–volume diagram] (or PV diagram, or volume–pressure loop) is used to describe corresponding changes in volume and pressure in a system.

[[File:Indicator_diagram_steam_admission.png|500px]]

The diagram records the pressure of steam versus the volume of steam in a cylinder, throughout a piston's cycle of motion in a steam engine. The diagram enables calculation of the work performed and thus can provide a measure of the power produced by the engine.

To exactly calculate the work done by the system it is necessary to calculate the integral of the pressure with respect to volume. One can often quickly calculate this using the PV diagram as it is simply the area enclosed by the cycle.

==Download==

Working with NVGate V15 or upper.
[https://partnerzone.digigram.com/s/yK8f5f45MynAnrL Version 1.0.108544 from january 2022 : diagram PV]

Include a model to demo with the correct settings.

==How to use: ==

[[File:PVdiagram2022.PNG|600px]]

*Define one (or more) channel as a pressure.
*Add this channel into Sync. order (SOA) plug in.
*On SOA plug in , average, domain, select: "Angular"
*Open PV_Diagram.exe
*Click on refresh (right click) in available results if you do not see anything.
*Select the input.
*Compute once will display the PV diagram base once based the last triggerd block.
*"background computation, will continuously compute the diagram.

NVGate Waterfall

2026-11-02T13:56:51Z

Lmagimel:

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|50px]] in the waterfall section :
[[Image:WTF_Ribbon.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[Image:WTF_Ribbon.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:55:56Z

Lmagimel: Reverted edits by Lmagimel (talk) to last revision by Credaelli

[[category:NVGate]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT Analyzer|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT Analyzer|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT Analyzer|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|50px]] in the waterfall section :
[[Image:WTF_Ribbon.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT_Analyzer#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT Analyzer|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT Analyzer|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT_Analyzer#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT_Analyzer#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT Analyzer|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[Image:WTF_Ribbon.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

NVGate Waterfall

2026-11-02T13:54:45Z

Lmagimel: Undo revision 12274 by Lmagimel (talk)

[[category:NVGate]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the display Tab, and click on [[Image:WTF_AddRemove.png|80px]] in the waterfall section :
[[Image:add_remove.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:53:54Z

Lmagimel: /* From the waterfall plug-in menu */

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the display Tab, and click on [[Image:WTF_AddRemove.png|80px]] in the waterfall section :
[[Image:add_remove.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:53:24Z

Lmagimel: /* From the waterfall plug-in menu */

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|80px]] in the waterfall section :
[[Image:add_remove.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:53:17Z

Lmagimel: /* From the waterfall plug-in menu */

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|40px]] in the waterfall section :
[[Image:add_remove.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:53:08Z

Lmagimel: /* From the waterfall plug-in menu */

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|20px]] in the waterfall section :
[[Image:add_remove.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:53:01Z

Lmagimel: /* From the waterfall plug-in menu */

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|200px]] in the waterfall section :
[[Image:add_remove.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:52:33Z

Lmagimel: /* From the waterfall plug-in menu */

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|700px]] in the waterfall section :
[[Image:WTF_Ribbon.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

NVGate Waterfall

2026-11-02T13:51:52Z

Lmagimel: /* From the waterfall plug-in menu */

[[category:NVGate]]
[[category:WikiOros]]
The Waterfall module is used to stack data from NVGate plug-ins, such as Spectra, 1/n Octave, RPM, DC, or any scalar data values into one graph. Data is displayed as slices that are synchronized and can be sorted by references (time, RPMs or DC channel). We can display 3D data or profile (2D).

====Overview====
The following scheme describes the waterfall slices collection behavior. When selected event (trigger) occurs, the latest computed data from each associated plug-in are collected into the current slice. Then data can be displayed into 2D (for scalar) and 3D graph in function of each reference.

[[Image:Waterfall_monitor_03.png|framed|none]]

''Stackable results''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="90%"
| 
|'''3D'''
|'''2D (profiles)'''

|-
|'''FFT'''
|* Triggered block * Weighted block * Inst. Spectrum * Average Spectrum * Inst. Cross Spectrum * Average Cross Spectrum * FRF H1 * FRF H2 * Coherence * Inst. Zoom Spectrum * Average Zoom Spectrum * Zoom Cross Spectrum * Zoom Average Cross * Zoom FRF * Zoom Coherence
|* Overall Power * Order x 

|-
|'''Sync. Order'''
|* Triggered block * Weighted block * Order Inst. Spectrum * Order Average Spectrum
|* Order x * Overall Power

|-
|'''1/n Octave'''
|* 1/n Octave * Average results: - AvNoct - MinOct - MaxOct
|* Overall level: OvrLin * Overall Weighted level: OvrWgt

|-
|'''Overall acoustic'''
| 
| - Lxypeak - Lxy inst * Lxy eq 1/8s * Lxy eq 1s * Lxy eq t ''X'' = Applied weighting (A or C), in case of Z selection (no weighting) X is not displayed. ''Y ''= Applied time filter (None, Fast, Slow or Impulse), If none is selected (no time filtering) Y is not displayed. t = Short time integration duration. T 

|-
|'''Tachometer'''
| 
|* Tach Angular Speed (ref) * Virtual Angular Speed (ref) * Ext Tach Angular speed (ref) * DC Tach speed (ref) * Combined tach speed (ref) * Fractionnal tach (speed)

|-
|'''Front end'''
| 
|
* DC (ref)
* CAN (ref)

|-
|'''Monitor'''
| 
|
* Monitor DC
* Monitor RMS
* Monitor Peak
* Monitor Peak-Peak
* Monitor Crest-Factor
* Monitor Skew
* Monitor Ktsis
* Monitor Max
* Monitor Min

|-
|'''Time domain'''
| 
|
* DC
* RMS
* Max
* Min
* Peak
* Peak-Peak
* Crest-Factor
* Ktsis

|-
|N.A.
| 
|
* Time (ref) always selected
* Slice (ref) always selected

|}

'''Computation SPUs'''

Unlike other plug-in, the memory of the waterfall depend on the capacity of the PC and others applications running on it. The depth of the waterfall is function of the free memory of your PC, and is limited to around 3 millions samples per DSP.

==Tutorial==

===Waterfall connection===
This section will show the different ways to add results into the waterfall.

====From the Show Result window====

The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a waterfall of the [[NVGate FFT|average spectrum]] for an acceleration input.

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Waterfall'' section :
[[Image:GoToResult_Waterfall.png|400px|none]] 

Then, select ''Avg. Spectrum'' and the first input. Finally, click on [[Image:DisplayButton.png]] to display the waterfall :
[[Image:GTR_Display_Waterfall.png|400px|none]] 

The 3D view of the waterfall is displayed. 

For more detail please see [[NVGate Software overview]]. 

See also the [[NVGate_RT60|RT60]] with interrupted source tutorial video, where this method is used. 

====From the graph window====
This method will allow you to add the result from a currently displayed [[NVGate_Display#Graph|graph]] into the waterfall. This will work with any result of NVGate [[NVGate Waterfall|compatible with the waterfall]]. As previously, we will add the [[NVGate FFT|Average spectrum]] ''' of all the channels''' into the waterfall. 

First of all, right-click on the grey border of the graph and go in the ''Add to Waterfall'' section :
[[Image:WTF_RightClick.png|700px|none]] 

* '''All Traces''' will add all of the traces in the graph into the waterfall
* '''Active Trace''' will only add the [[NVGate Active Trace|active trace]] of the graph into the waterfall.
 
Here, we will select '''All Trace''', as we want to add all the channels of the [[NVGate FFT|FFT plug-in]].
[[Image:WTF_RgtClick_AllTrace.png|700px|none]] 

All the traces have been added, and the waterfall can be displayed from the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:DisplayWTF.png|700px|none]] 

The ''3D view'' of the waterfall is now displayed in the current [[NVGate_Project_manager#Layout|layout]].

====From the waterfall plug-in menu====

Finally, results can be add into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png|50px]] in the waterfall section :
[[Image:WTF_Ribbon.png|700px|none]] 

This will open the waterfall menu. Here, select the result (''Avg. Spectrum''), the channels you want to add (in that example, all the channels), and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_AddResults.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

===Waterfall profile display===
We saw in the previous section that a waterfall collect all-along the acquisition results from NVGate plug-ins, like a spectrum, in a single graph. Now if we connect to the waterfall a plug-in that is not delivering a complete trace, but a single scalar value, the collection during the acquisition off all these successive scalar values will result in a simple curve in the waterfall. This is what is called a '''Profile''' in NVGate. 

A profile can be used to plot trend over the time for DC inputs, Overall RMS level and Bode plots of Orders over the RPM value of the shaft. 

In this section, I will show you how to display a profile of the [[NVGate_FFT#Display_available_results|Overall RMS level]] on a channel connected the the [[NVGate FFT|FFT 1 plug-in]]. I will present the three same methods presented in the previous section.
====From the Show Result window====
The [[NVGate_Software_overview#Step_2_Show_results|Show Results]] window is the most common way of adding a result in the waterfall. Here I will show you how to simply display a Profile of the [[NVGate FFT|overall level]] for an acceleration input. 

First, open the Show Result window, go in the ''FFT 1'' tab, and reach the ''Profile'' section :
[[Image:Profile_ShowResults.png|400px|none]] 

Then, select ''Order & Overall'' and the fist input. In the ''Tracked order'' section, select ''Overall''. Finally click on [[Image:DisplayButton.png|40px]] to display the waterfall :
[[Image:Profile_ConfigShowResult.png|400px|none]] 

The profile window is now displayed in the current [[NVGate_Project_manager#Layout|layout]], and you can run the acquisition. However, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the waterfall]] to contain all the data. To do so, double-click on the dark grey border of the graph, in the [[NVGate_FFT#Settings|FFT menu]], select ''Waterfall''. In the [[NVGate_Waterfall#Mode|''Mode'' tab]] of the waterfall, modify the ''Number'' parameter :
[[Image:Addapt_Depth.png|700px|none]] 

To change the profile reference , right click on the graph : select reference.

[[File:change_reference.png|700px]]

For more detail please see [[NVGate Software overview]], and the following sections. 

====From the graph window====
[[NVGate_Waterfall#From_the_graph_window|As we did for the standard waterfall]], we will now see how to add a scalar value in the waterfall to create a profile directly from the result window. 

Here, we have [[NVGate_FFT#Display_available_results|displayed the ''Overall level'']] an acceleration input from the [[NVGate FFT|FFT plug-in]] :
[[Image:FFT_Overall_scalar.png|200px|none]] 

Right_click on the border of the window and go in the ''Add to waterfall'' section. There is only one trace in the window here, so only ''Active trace is available. :
[[Image:Scalar_RightClick.png|400px|none]] 

After clicking on ''Active Trace'', the ''Overall Level is added in the waterfall. We will now use the same method to display the profile. go in the [[NVGate_Ribbons:_Display/Graph_Tab#Add.2Fremove_windows|Add/Remove windows]] menu of the[[NVGate Ribbons: Display/Graph Tab|Display/Graphs tab of the Ribbon]] :
[[Image:Display_WTF_Profile.png|700px|none]] 

The profile is now displayed in the current [[NVGate_Project_manager#Layout|layout]]. As previously, you may need to adapt the [[NVGate_Waterfall#Glossary|depth of the profile]].

====From the waterfall plug-in menu====

As for other results, scalar results can be added into the waterfall directly from the waterfall menu. To do so, go into the [[NVGate Ribbons: Analysis Tab|Analyses tab of the NVGate ribbon]], and click on [[Image:WTF_AddRemove.png]] in the waterfall section :
[[File:add_remove.png|400px]]
 

This will open the waterfall menu. Here, select the result (''Order & Overall''), the channels you want to add, and finally click on the green arrow [[Image:WTF_Arrow.png]] :
[[Image:WTF_Menu_Profile.png|700px|none]] 

After clicking on [[Image:WTF_Arrow.png]], the trace is added in the ''References and Profiles'' section :
[[Image:Profile_WTF_Menu_Final.png|700px|none]] 

Click on ''OK'', the results have been added to the waterfall. You can now display it with the method described in the previous section.

==Waterfall Display==
The Waterfall window offers a wide range of operation in order to go further in your measurement. It is possible to display XY and YZ sections as well as the extraction section.
From the Display/Graph tab and the 3D group, this group provides general purpose tools about the Waterfall 3D graphs.

[[File:waterfall_group_2022.PNG|300px]]

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:display_waterfall_sections.PNG|50px]]
| '''Display Waterfall sections''': This multi-action button enables selecting the areas of the Waterfall window to be displayed. The Waterfall window is composed of 4 main areas: 
[[File:Usersmanual_170.png|600px|]] 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_471.png|30px]]
|'''3D only''': Shows the 3D graph only. This graph can be a 3D plot or a color map.

|-valign="top"
|[[File:Reports_Tools_Ribbons_472.png|30px]]
|'''X/Y only''': Shows the X/Y extraction graph only. This graph contains the spectra at the cursor position and the X/Y sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_473.png|30px]]
|'''Y/Z only''': Shows the Y/Z extraction graph only. This graph contains the time (or ref) profile at the cursor position and the Y/Z sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_474.png|30px]]
|'''Extraction only''': Shows the Order/frequency extraction graph only. This graph contains the order/frequency profile at the cursor position and the extraction sections.

|-valign="top"
|[[File:Reports_Tools_Ribbons_475.png|30px]]
|'''All graphs''': Shows all the graphs in a matrix.
|} 

|-valign="top"
|[[File:display_type_waterfall.PNG|80px]]
| '''3D waterfall graph or ColorSpectrum view''': Enables selecting the type of view for the Waterfall window. 

{|border="0" cellspacing="0" cellpadding="4" width="100%" align="center"
|-valign="top"
|[[File:Reports_Tools_Ribbons_477.png|25px]]
|'''3D perspective''': Plot the spectra (or trigger blocks) in a true 3D space, taking in account the perspective. The global orientation of the gathered spectra can be changed using the rotate button. This type of view allows looking at the waterfall from any side.

|-valign="top"
|[[File:Reports_Tools_Ribbons_476.png|20px]]
|'''3D Isometric''': Plot the spectra (or trigger blocks) along a Z axis with the same scale whatever is the position. The Z axis angle is modified by the rotate button.
[[Image:Usersmanual_173.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_479.png|30px]]
|'''Frequency/time color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Frequency (Y) Vs Time (X) arrangement.

[[Image:Usersmanual_174.png|400px|none]]

|-valign="top"
|[[File:Reports_Tools_Ribbons_478.png|30px]]
|'''Time/frequency color map''': Plot the spectra (or trigger blocks) on 2D map with the color representing the point amplitude. This plot shows the Time (Y) Vs frequency (X) arrangement.
|} 

|-valign="top"
|[[File:Reports_Tools_Ribbons_480.png|20px]]
|'''Rotate''': Toggle the rotating mode. Allows rotating the 3D graphs with the mouse when enabled. Disabling this item return the mouse to the previous mode.

|-valign="top"
|[[File:Reports_Tools_Ribbons_481.png|20px]]
|'''Add section''': Add a copy of the cursor location in each of the 3 extraction graphs. Waterfall display provides extraction of section from the 3D space.

|-valign="top"
|[[File:Reports_Tools_Ribbons_482.png|20px]]
|'''Section manager''': Open the Waterfall ''Section manager'' dialog.
|} 

Cursors give information about the displayed Waterfall trace (current X, Y and Z coordinates are available from the ''Infotrace'').

Move the cursors either by using the drag & drop in the 3D view or by using the arrow pad of the keyboard (the cursor mode [[Image:Usersmanual_171.png]] must be selected).

'''Tip''': Move the mouse over the cross in the middle of the window and click in order to resize manually the graph window.

====References====
The waterfall data are arranged in accordance to the active reference. A reference is a scalar value (RPM, DC level, RMS, Parametric input) stored with the waterfall data.

Right click on the grey part of the graph to select the active reference.

[[Image:Usersmanual_40.png|700px|none]]

The displayed data are then sorted regarding the reference value.

[[Image:Usersmanual_175.png|framed|none]]

A threshold is available on a waterfall by pressing the <nowiki>’</nowiki>y<nowiki>’</nowiki> button (or <nowiki>’</nowiki>ctrl y<nowiki>’</nowiki> for more precision).


[[Image:Display_Graphs_Traces_76.png|framed|none]]

----

====Sections====
* [[Image:Reports_Tools_Ribbons_481.png]] Add section: Add a copy of the cursor location in each of the 3 extraction graph
Waterfall display provides extraction of section from the 3D space

[[Image:Display_Graphs_Traces_118.png|framed|none]]

These sections are linked with cursors of the 3D view:

* Fig1: for a fixed value of the X-axis of the 3D view,
* Fig2: For a fixed value of the reference
* Fig3: for a fixed value of the order (follow the evolution of an order) or frequency for order spectra waterfall.

During the acquisition, an autoscale is available on the z-axis (reference) if <nowiki>’</nowiki>z Adjust<nowiki>’</nowiki> is active.

[[Image:Display_Graphs_Traces_119.png|framed|none]]
* '''Add section: '''Creates a new section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall.
* '''Select YZ section: '''Selects the active trace in the YZ graph. Useful to get the value of the cursor for this section
* '''Select XY section: '''Selects the active trace in the XY graph. Useful to get the value of the cursor for this section
* '''Select extraction section: '''Selects the active trace in the extraction graph. Useful to get the value of the cursor for this section

The <nowiki>’</nowiki>Select Tacho<nowiki>’</nowiki> mode allows tracking an order in function of the selected tachometer. The extraction order could be done in function of the selected tacho. 4 Graphs are available for the windows allowing tracking different results:

*3D view: you can select by right-clicking on it an isometric view, a perspective view, a freq/time colormap or a time/freq colormap (useful to track orders). The 3D view is the default view.
* YZ section,
* Order extraction (only available if a tachometer is active).

[[Image:Display_Graphs_Traces_120.png|framed|none]]

The sections are displayed in these 2D views. The sections can be managed in the section manager windows. In the section manager, add section made a copy of each cursor (Frequency, Reference, Order) in all displayed windows. These memorized traces could be added to result by the <nowiki>’</nowiki>add to result selection.The waterfall sections can be saved as independent results (spectra, reference profiles, extracted profiles). The selection is achieved using the "Add to result selection" entry from the waterfall window contextual menu.

----

[[Image:Display_Graphs_Traces_121.png|framed|none]]

After being saved, the sections became independent results, reducing the amount of saved data when you are focusing only on extracted data.

====Section manager====
You can fine tune the section parameters by using the section manager available by right clicking on the Waterfall window. For example, you want to visualize the first order.
* [[Image:Reports_Tools_Ribbons_482.png]] Section manager: Open the waterfall section manager.
or, right click in the grey part of the graph and select Section manager.

[[Image:Usersmanual_176.png|framed|none]]

* Section manager: This dialog box is used to create and modify sections.
To modify a section, select the desired type and the desired section then modify the Section properties and click "Apply". To create a new section, Select the type, set the desired properties and click "Add". To remove a section, select the desired type and the desired section, then click "Remove".

[[Image:Display_Graphs_Traces_01.png]][[Image:Display_Graphs_Traces_69.png]][[Image:Display_Graphs_Traces_70.png]]

* Section properties: The XPos, ZPos, Freq or Order defines the position of the section in the Waterfall. When the "Advanced" box is checked, it defines the center of the band. The width is used when the "Advanced" box is checked. It defines the bandwidth.

The advanced sections are:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Type'''
|'''Sections'''
|'''Type of result'''
|'''Description'''

|-
|Power
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Calculates the power within the band

|-
|Peak
|YZ, Order and Frequency extraction sections
|Frequency, order and octave spectra
|Detects the highest value

|-
|RMS
|YZ sections
|Triggered and resampled block
|Calculates the RMS value within the band

|-
|Average
|YZ sections
|Triggered and resampled block
|Calculates the average value within the band

|-
|Min
|YZ sections
|Triggered and resampled block
|Detects the minimum value within the band

|-
|Max
|YZ sections
|Triggered and resampled block
|Detects the maximum value within the band

|} 

* ''Z-Operator'':

This Operator is available on XY extraction view and 3 operators are available: Min, Max and Arithmetic Average.

[[Image:Display_Graphs_Traces_71.png|framed|none]]

* ''Order Extraction'':

[[Image:Display_Graphs_Traces_02.png|framed|none]]

{|class="wikitable" style="background:white" border="0" cellspacing="2" width="100%"
| 
| 
| 

|}

[[Image:Display_Graphs_Traces_72.png|700px|none]]

This Operator take data spectrum by spectrum, for each spectrum there is a determination of the max value and of the corresponding order. Using this operator it is possible to detect on which orders it is useful to work. Note: The Max Order cannot be saved in result (not available in the <nowiki>’</nowiki>Add to result selection<nowiki>’</nowiki>).

====Save results====
This section gets you to select and save the Waterfall results.

Right click on the Waterfall window and select '''Add to result selection'''. A window that allows you to select the results to be saved is displayed:

* The entire Waterfall results
* The extraction section (in this case it is the order 2 section) independently
* The XY section independently
* The YZ section independently

[[Image:Usersmanual_13.png|framed|none]]

Click on '''OK'''.

[[Image:Usersmanual_12.png|framed|none]]

Click on: ''Measurement/Save/ Save Measurement'', your results selection will be automatically saved:

[[Image:Usersmanual_178.png|framed|none]]

==Settings==

<Youtube> https://www.youtube.com/watch?v=GzQiaU10iXo</Youtube>

=====Glossary=====
This section will explain specific vocabulary of the Waterfall.

* '''Slice''': this represents one acquisition of the Waterfall. A slice is a set of scalar and spectrum data acquired at the same time. The Waterfall is a stack slices.
* '''Depth''': this is the maximum number of slices you can acquire on the Waterfall.
* '''Section''': section at the current position of the cursor. The extraction section is created only if a tach has been selected in the Waterfall (see chapter 2 Display, Waterfall window menu).
* '''Reference''': A scalar collected by the waterfall acquisition that can put in order the slices. The reference corresponds to the X-axis of the profiles and the Z-axis of the 3D graphs.
* '''Profiles or 2D Results''': profiles of a scalar evolution in function of time or any reference associated with the waterfall
* '''Results 3D''': spectra collected by the waterfall acquisition putted in order by a reference. These types of results are displayed in 3D graphs (3D, isometric or color-spectrogram).

=====Channel=====
The different channels are available by putting selected inputs in the plug-in.

It contains the results to be picked up by the Waterfall.

The following window lets you select for each analysis plug-in, the channel related to the result.

[[Image:Waterfall_monitor_04.png|framed|none]]

* '''Source''': In the ASB the channels are different from other ASB channels, the source of channel 1 and following are the results. The source of channel 64 and previous ones are the references. By default the time reference is always associated with a result source.

[[Image:Waterfall_monitor_05.png|framed|none]]

=====Trigger=====
Contains the settings related to triggering events and how to start and stop signal computation.

* '''Start''': selects the event to start the waterfall acquisitions. This setting selects the event, which enable acquisition that is to say data collection does not operate while start event is no occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource. The start time corresponds to the zero of the waterfall time scale. By default start is set to "free run" this allows waterfall acquisition to start immediately after run.
* '''Stop''': selects the event to stop the waterfall acquisitions. This setting selects the event, which ends acquisition that is to say data collection, does not operate after stop event occurred. Any event can be chosen among the list of defined events. By default only the Free run and Manual events are available. Additional events can be defined in the "Event Definition" shared resource.
* '''Trigger''': selects the event that trigs waterfall acquisitions. This setting selects the event which trig acquisitions that is to say a new data collection occur each time trigger event occurred. If trigger is set to periodic (period 20ms) the Waterfall acquisition will operate as fast as possible, this can hang user interface during acquisitions. The first time a source is selected for the Waterfall, if trigger = Periodic, then the event corresponding to the availability of the source results is assigned to the trigger. Ex: Setting FFT1 spectra into the waterfall plug-in will set Trigger to <nowiki>’</nowiki>FFT1 result available<nowiki>’</nowiki>. By default the trigger is set to <nowiki>’</nowiki>Periodic<nowiki>’</nowiki> with a period of 20.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''List of events'''
|'''Description'''

|-
|Manual
|This event occurs when the user requests a manual trigger.

|-
|Events from Event module
|see Event module

|-
|FFTx result available
|This event is in the list if a signal is connected to an FFTx channel source. This event occurs when an FFT measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Oct result available
|This event is in the list if a signal is connected to an Octave channel source. This event occurs when an Octave measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Order x result available
|This event is in the list if a signal is connected to an Order x channel source. This event occurs when an Order x measurement starts. This event is generated at each calculation of a new spectrum in exponential averaging and at the end of averaging in linear.

|-
|Overall acoustic result available
|This event is in the list if a signal is connected to an Overall acoustic channel source. This event occurs when an Overall acoustic measurement starts. This event is generated at each new spectrum calculated (every 256 samplings) for CBT, Fast, Slow, Impulse and exponential averaging. For the others averaging this event is generated at the end of averaging on t.

|-
|Periodic 
|This event simplifies the instrument setup by shortcutting periodic event activation. Selecting periodic for the trigger will make appears the period setting.

|} 

There is two ways to trigger the waterfall:

* The analyzer is running, it keeps in memory last measurements. Then with the waterfall you can select some specific results (for example for rpm or time).
* The plug-in triggering, at the end of each average the plug-in send an event. The plug-in put the rhythm into the waterfall. This mode is the default mode.

=====Mode=====
Contains the settings related to the Waterfall display mode.

* '''Mode''':
'''Off''': the Waterfall is inactive. This mode is useful to check your signal and your settings before the analysis.

'''One shot''': the Waterfall is active between <nowiki>’</nowiki>start<nowiki>’</nowiki> and <nowiki>’</nowiki>stop<nowiki>’</nowiki>, there<nowiki>’</nowiki>s only one acquisition (for example: coast downs or run ups). The Waterfall ends on stop or when the number of slices is full.

'''Continuous''': this mode memorizes the n last slices (selected number of slices) before the stop event. This mode is similar to the <nowiki>’</nowiki>time to stop<nowiki>’</nowiki> mode of the recorder. This mode is different from the monitoring; the continuous mode is storage of measurement (for example: detection of ultimate strain).

* '''Number''': the number of Waterfall slices (from 2 to 100 000). If the Waterfall trigger is a Delta RPM event, the "Event number" of this Delta RPM event is assigned to the number of Waterfall slices.

The waterfall depth is managed automatically, allowing the user to get the larger slices/points number depending on the current available physical memory on the PC running NVGate. This functionality protects waterfall or profiles acquisition from memory overloads. That means the depth of the Waterfall is a function of slices weight (which depend on the type of analysis).

[[Image:Waterfall_monitor_06.png|framed|none]]

The area is fixed. If the slices weight are important, then the depth would be small.

The area is function of the free memory space available when you select to use the Waterfall. The memory space has to be exactly the same during all the measurement that means the measurement could hang if you start another application on your computer during the measure.

The acquisition/display and save memory usages are managed separately and are sequenced. It result a larger of data managed by the waterfall and secured acquisition.

NVGate takes advantage of 64bits PC memory (<nowiki>></nowiki> 2 GB) for larger memory allocation for the Waterfall. As NVGate remains a 32-bit application, PC memory is not used above 4 GB.

The following table summarizes the evolutions of the waterfall depth (for a given configuration: 32 ch 3,201 lines and PC):

For example a waterfall of 32 ch 3,201 lines handles up to:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|bgcolor = "#D9D9D9"|'''PC configuration'''
|align = "center" bgcolor = "#D9D9D9"|'''Slices'''

|-
|XP 32 bit 2GB RAM
|align = "center" bgcolor = "#92D050"|260

|-
|Win7 64 bit 4GB RAM
|align = "center" bgcolor = "#92D050"|640

|} 

NB: In the stand-alone mode, the depth is limited (about 3 million samples per DSP) due to the analyzer memory size.

'''Notes''':

- '''OVA''': if the waterfall trigger selected were « OvA Leq result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in Overall acoustic.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|short Leq (t)
|T/t

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|} 

- '''1/N Octave''': if the waterfall trigger selected were « Oct result available », the slices number would depend on durations (average duration « T » and short duration « t ») from the sub module Average in 1/N Octave.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="40%" align="left"
|'''Average type'''
|'''Slices number'''

|-
|Linear, with repeat = End Of Averaging
|T

|-
|Linear, with repeat != End Of Averaging
|Independent

|-
|Repeat
|T/t

|-
|Exponential
|Indepedent

|-
|Constant BT
|Independent

|-
|short Leq 1/8s
|T/t

|-
|short Leq 1s
|T/t

|-
|Fast
|Independent

|-
|Slow
|Independent

|-
|Impulse
|Independent

|} 

The on line display uses more power and could slow displays but acquisitions and analyses remain real-time.

==Waterfall status==
All statuses are available to add to the control panel


[[Image:Waterfall_monitor_07.png|framed|none]]



======Waterfall======

[[Image:Waterfall_monitor_08.png|framed|none]]

The current plug-in status is synthesized in a special progress-bar. This status bar is automatically displayed in the <nowiki>’</nowiki>control panel<nowiki>’</nowiki> when the plug-in is active (i.e. as soon as at least 1 input is connected to the Waterfall plug-in). This status is called <nowiki>’</nowiki>Waterfall<nowiki>’</nowiki> and it is available in the status ASB tree (see customize control panel).

This status displays the slice number acquired in the waterfall, the plug-in state (Run, Paused or Stop) and the real-time status.

The way the status bar is displayed, depends on the mode selected:

* <nowiki>’</nowiki>One shot<nowiki>’</nowiki> mode: the progress bar is filled from left to right.
* <nowiki>’</nowiki>Continuous<nowiki>’</nowiki> mode: the progress bar is filled from right to left with flashing until the end of the acquisition.
* <nowiki>’</nowiki>Off<nowiki>’</nowiki> mode: the progress bar is empty with the text <nowiki>’</nowiki>Off<nowiki>’</nowiki> inside.

The color of the bar and of the writing let you know what happens during the acquisition:

* ''Green background and white or black text'': acquisition in real time.
* ''Red background and white or black text'': the current acquisition is not real time.
* ''Green background and red text'': the current acquisition is real time, but a previous acquisition was not real time.

======Trigger State======

The following scheme describes the different states of the measurement:

[[Image:Waterfall_monitor_09.png|framed|none]]

By default the trigger state is on <nowiki>’</nowiki>Stop<nowiki>’</nowiki> and waiting for a <nowiki>’</nowiki>Run<nowiki>’</nowiki> (start or trigger). Then the state become <nowiki>’</nowiki>Triggering<nowiki>’</nowiki> and is waiting for a start event, the states become <nowiki>’</nowiki>Block Triggering<nowiki>’</nowiki> and is now waiting for a trigger event for being in the <nowiki>’</nowiki>Running state.

The state is <nowiki>’</nowiki>Stop<nowiki>’</nowiki> after a stop event or at the end of averaging.

======Count======
This status displays the averaging count, that total number of slices already acquired.

======Real-time======
This status displays if the averaging is in real-time or not (i.e. the current block is analyzed or not). If the corresponding signal were not available at this time, the acquisition is not real-time. That means that the treatment is longer than the acquisition. There are three values for this state:

* '''<nowiki>’</nowiki>OK<nowiki>’</nowiki>''': The acquisition is real-time.
* '''<nowiki>’</nowiki>No<nowiki>’</nowiki>''': One previous acquisition was not real-time.
* '''<nowiki>’</nowiki>-<nowiki>’</nowiki>''': The acquisition is currently not real-time.
======% Block lost======
During an acquisition, results are stocked on the analyzer DSP in a buffer storage (limited to 4 MSample per DSP). If the depth of the waterfall is larger than this, then the PC must empty this buffer storage during acquisition (then the PC can store more results). The DSP to PC transfer takes place as soon as the waterfall acquisition starts depending on connection status (stand alone, poor quality). This process continuously empties the DSP memory. A block is lost if the DSP to PC transfer is not able to get it before the DSP memory is full.

In <nowiki>’</nowiki>one shot<nowiki>’</nowiki> mode and for depth smaller than X the acquisition is preferred to the displaying, i.e. the display takes place at the end of acquisition

In <nowiki>’</nowiki>continuous<nowiki>’</nowiki> mode or for depth larger than X, the displaying is preferred to the acquisition, in order to quickly see any changes during the measurement, some blocks may be lost.

======% Block transferred======
This status displays the percentage of block that the PC could have recovered from the DSP buffer storage.

Note that: %Block lost <nowiki>+</nowiki> %Block transferred = 100%.

==FAQ==
===FFT1 Tach vs EXT synch tach===

'''What’s the different between Ord1 Tach. and Tach.Ext Ang speed?'''

The waterfall and profile provide new capabilities that improve readability and accuracy: Tachometer centered on FFT/SOA blocks.

This allows centering tachometer speed at the center of the FFT/SOA trigger block(s). It is useful with long trigger blocks (High resolution analyses) to perfectly match the actual data with the order cursor or section.

With classical tach (ext tach angular speed):
The RPM is collected at the end of the analysis block.

[[File:ord_tach.PNG|500px]]

This situation leads to an offset in the waterfall calculation of the orders (cursors, sections). For a run up, as the angular speed is over evaluated, the order calculation is lower than the actual ones.

With centered tach (FFT Tach or ORD Tach):
The RPM is calculated as the average speed during the block duration to be synchronized with the analyzed data.

[[File:center.PNG|500px]]

With the centered tachometer, the orders calculations match more accurately the actual orders in waterfall.
The computation of the angular speed takes in account the averaging, triggering and overlap used in the plug-in.
The centered speed is calculated as:

CT = (RPM (end of block) + RPM (begin of block)) / 2

The RPM centering and averaging is done in the analysis plug-in prior to be connected to the waterfall. To use the centered tach simply add the said tachometer to the corresponding plug-in (FFTn or SOAn). These additional tachometers are available in the waterfall as soon as one of the result of the plug-in is added to the waterfall.

1. Add Tach to the Plug-in,

2. Add plug-in results (Spectra, orders, etc..) to the waterfall,

3. Display the waterfall,

4. Select the Plug-in Tach, as a tachometer and reference

[[File:fft_tach.PNG|400px]]

File:Add remove.png

2026-11-02T13:51:47Z

Lmagimel: File uploaded with MsUpload

File uploaded with MsUpload

Torsion and Twist Tool

2026-10-28T08:01:21Z

Lmagimel: New page: Torsion & Twist tool V3.0 beta (download on Partner Zone)

[[category:NVGate]]
[[category:WikiOros]]
The '''Torsion & Twist''' tool sets up NVGate for you when you measure '''torsional vibration''' with a toothed wheel or an encoder on the '''Ext Sync''' inputs.

It finds by itself the '''number of pulses per revolution''' and the '''missing teeth''' of your wheel, tells you if the signal is good, and writes the right settings into NVGate. No need to count teeth or to try settings by hand.

[[File:TorsionTwist_Measurement.png|800px]]

{|class="wikitable" style="width:100%;"
|style="background: #FFF4CE;"|'''Beta version''' — this tool is provided free of charge and delivered '''"as is"''', without warranty of any kind. Check the settings it writes before an important measurement. Your remarks are welcome: customer.care@oros.com
|}

__TOC__

----

== Download ==

Download [https://partnerzone.digigram.com/s/9NErtnZbc6wx2cY Torsion & Twist V3.0 beta] october 2026

Tested with NVGate V18.

== What you need ==

* A PC with '''NVGate''' open, in connected mode (the tool talks to NVGate by itself).
* An OROS analyzer with '''Ext Sync''' inputs, and the NVGate [[NVGate Torsional|torsional option]] to measure torsion.
* A wheel sensor (toothed wheel, encoder, tape...) connected to Ext Sync 1 and/or Ext Sync 2.

== Install ==

# Unzip the downloaded file anywhere (for example on the desktop).
# Double-click '''Torsion_Twist.exe'''. Nothing else to install.
# ''Optional:'' double-click '''install_to_nvgate.bat''' once. The tool then also appears in NVGate under '''Automation > Execute'''.

When the tool starts, the badge at the top right shows '''NVGate online''' in green: it is connected.

----

== Case 1 — The machine is running: AUTO SETUP ==

Use the '''Online''' tab.

[[File:TorsionTwist_Online.png|800px]]

# Start the machine (constant speed or run-up).
# In the table, tick '''Torsional''' for each Ext Sync input you use.
# Click '''AUTO SETUP'''. A small window shows 4 steps:
#* search the pulses (trigger level),
#* count the teeth and the gap (3 seconds of signal),
#* write the settings into NVGate,
#* check the torsion measured by NVGate.
# At the end you read '''Settings written and checked'''. NVGate is ready: press Run.

'''STOP''' stops at any time; your previous settings are then put back.

If the wheel has '''no missing tooth''', the tool cannot guess its number of pulses: a red row '''Pulses/rev, no gap''' appears. Type the number, or use '''Count pulses''' (see below), then click AUTO SETUP again.

== Case 2 — You already have a recording ==

Use the '''Measurement''' tab (picture at the top of this page). NVGate does not even need to be open to look at the result.

# On the left, the list shows your NVGate measurements that contain Ext Sync signals.
# '''Click a measurement''': in a second the table shows, for each Ext Sync input, the pulses per revolution, the missing teeth, the speed and the '''Signal quality'''.
# Click '''APPLY''' to write these settings into NVGate.
# Or click '''Post-analysis''' to replay the recording in NVGate with the right torsion settings.

Your recordings are only read, never modified.

== Reading the result ==

{|class="wikitable"
|-
!Row!!What it tells you
|-
|'''Pulses/rev''' / '''Missing teeth'''||Your wheel, as found by the tool (60 and 2 = a 60-2 wheel). "NVGate now: ..." means NVGate is set differently: APPLY corrects it.
|-
|'''Angular speed'''||The shaft speed, in rpm.
|-
|'''Signal quality'''||'''Green OK''': the signal is clean. '''Red''': the reason is written in the cell (move the mouse on it for details).
|-
|'''Torsion check'''||Green OK: the torsion computed by NVGate matches the pulses.
|}

== Count pulses (wheel without missing tooth) ==

'''From a recording''' (Measurement tab): click '''Count pulses''' and say where the speed comes from — a speed you type, another wheel of the recording, or a tach input of the recording.

'''On the machine''' (Online tab): open '''Autotach & count pulses''', click '''Count pulses''' and choose:
* '''I have the speed''': the machine turns at a known speed (typed, or given by another wheel or a tach). The tool computes the pulses per revolution.
* '''I don't know the speed''': turn the rotor '''one full turn by hand''', slowly, then click STOP. The tool shows the number of pulses counted.

The result goes into the '''Pulses/rev, no gap''' row; then use APPLY or AUTO SETUP.

== Twist & Torque ==

Use this tab when '''two wheels are on the same shaft''' (one at each end).

[[File:TorsionTwist_Twist.png|800px]]

* '''Twist 1 ON''': NVGate computes the angle between the two wheels. While NVGate runs, its mean value ('''DC''') and its '''Pk-Pk''' are shown.
* '''Torque coef. calculator''': type the shaft diameters, the distance between the sensors and the material; '''Apply to Twist 1''' gives you the torque instead of the angle.
* '''Reset DC''': sets the mean twist to zero (the analyzer stops; press Run again).

== Good to know ==

* '''Options''' (top right): the tool can also add the speed of each input and its speed profile in your NVGate layout.
* Very slow machines: below about '''60 rpm''' the tool says "speed too low".
* The short recordings made by AUTO SETUP are deleted afterwards: nothing is left in your project.
* The '''Log Window''' at the bottom explains each step and any problem.
* Do not change NVGate settings by hand while AUTO SETUP is running.
* More details: the '''README.txt''' file delivered with the tool.

See also: [[NVGate Torsional]].

File:TorsionTwist Twist.png

2026-10-28T08:01:21Z

Lmagimel: New page: Torsion & Twist tool V3.0 beta (download on Partner Zone)

New page: Torsion & Twist tool V3.0 beta (download on Partner Zone)

File:TorsionTwist Online.png

2026-10-28T08:01:21Z

Lmagimel: New page: Torsion & Twist tool V3.0 beta (download on Partner Zone)

New page: Torsion & Twist tool V3.0 beta (download on Partner Zone)

File:TorsionTwist Measurement.png

2026-10-28T08:01:20Z

Lmagimel: New page: Torsion & Twist tool V3.0 beta (download on Partner Zone)

New page: Torsion & Twist tool V3.0 beta (download on Partner Zone)

Human Vibration

2026-10-13T07:51:40Z

Lmagimel: BodyVibration download link updated to version 1.1 (October 2026)

The OROS '''Human Vibration''' tool allows users to evaluate the effect of vibration on the human body according to standards ISO 2631 and ISO 5349. These standards define measurement practices and vibration signal analysis to evaluate the effect on health and comfort of environmental and equipment vibrations on the Human body. 

<youtube>https://www.youtube.com/watch?v=Y-0GB23TsmI</youtube>

{|class="wikitable" style="width:100%;"
|style="background: #0000A0; text-align:center;"|<big>[https://www.oros.com/demo-request/ Schedule a demo]</big>
|style="background: red; text-align:center;"|<big>[https://www.oros.com/quote-request-form/ Get a quotation]</big>
|style="background: green; text-align:center;"|<big>[[FFT_Spectrum_Analyzer_Multipurpose#Full_technical_support|Contact support]]</big>
|}
 

==Standards compatible ==

The ISO 2631 describes the effects on health and comfort of vibration on the whole-body in transportation systems, and ISO 5349 for the effects on health of vibration on hands and arms when manipulating machine-tools or vibrating objects. In the following, we will see how to use OROS to evaluate these effects. 

This is a post analysis toolkit, operating alongside NVGate after the recording of the signal and will help you to calculate time-weighted signal of acceleration and specific indicators both defined in the standards. 
 
'''Standards compatible''': international standards about whole/body vibration including: ISO 5349, ISO 8041, ISO 2631-1 and ISO 2631-5. 

'''Whole/body Vibration Indicators include ''': VDV, MSDV, MTVV, Weighted raw, al(ISO 2631-5), D(ISO 2631-5) are available. RMS, Peak, Crest, peak-Peak, are available in [[NVGate Time Domain Analysis|NVGate TDA plug in]].
{| class="wikitable" style="margin: auto;"
|+style="caption-side:bottom;"|''Body vibration indicators''
|-
|style="height:30px; width:100px;"|<math>MTVV</math>
|Maximum Transient Vibration Value, represent the maximal RMS value of the signal
|-
|style="height:30px; width:100px;"|<math>VDV</math>
|Vibration Dose Value, taking into account the temporal shocks in the signal
|-
|style="height:30px; width:100px;"|<math>MSDV</math>
|Motion Sickness Dose Value, representing the comfort in transportation measurement
|-
|style="height:30px; width:100px;"|<math>D_k</math>
|The Acceleration Dose, representing the effect of the vibration on the spine
|-
|style="height:30px; width:100px;"|<math>A_w</math>
|Daily maximal exposure value (Calculated from Post processing in NVGate)
|-
|style="height:30px; width:100px;"|<math>Peak</math>
|Amplitude Peak of the vibration; maximal amplitude of the signal from the 0 (Calculated from Post processing in NVGate)
|-
|style="height:30px; width:100px;"|<math>Crest factor</math>
|Ratio between the Peak level and the RMS of the weighted signal(Calculated from Post processing in NVGate)
|}

'''Signal filtering including''':
{| class="wikitable" style="margin: auto;"
|+style="caption-side:bottom;"|''Time-weighting filters''
|-
|style="height:30px; width:100px;"|<math>W_k</math>
|Time weighting for the Z axis for whole-body measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_d</math>
|Time weighting for the X and Y axis for whole-body measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_h</math>
|Time weighting for the hand-arms measurement in any direction (ISO 5349-1)
|-
|style="height:30px; width:100px;"|<math>W_f</math>
|Time weighting for motion sickness measurement in the vertical direction (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_c</math>
|Time weighting for the X axis for whole-body measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_e</math>
|Time weighting for all rotational directions for whole-body measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_j</math>
|Time weighting for the Z axis for head comfort measurement (ISO 2631-1)
|}

==Download & install==
Download the program [https://partnerzone.digigram.com/s/L6stQDncrf6afE9 here] (version 1.1, October 2026). This version is compatible with OROS NVGate Software V12.10 or upper.

Once downloaded, you can unzip the folder and launch the installer program Setup_OROS_BodyVibration_Tool_vXX.exe. Follow the step of the program to properly install the software. 

The program will be installed in "C:\OROS\Programs\ExternalTools". Shortcuts are created on the main desktop, in the Windows Start program and in the "Link" repository of NVGate. This way you can directly run the program from NVGate.

==How to use==

<ol>
<li>Launch NVGate </li>
<li>Launch OROS_BodyVibration_Tool.exe </li>
<li>Open a project in NVGate </li>

[[File:Open_Proj.png]]
 
<li>In the tool, Click on list measurement to list all the measurements present in the project (only the measurements where the signal files are actually on the disk will be displayed. Ensure you have [[NVGate_Project_manager#Uploading.2FDownloading|downloaded signal from the OR3X disk]]) </li>
[[Image:List_Meas.png|400px|none]]
<li>Add the measurement you want to analyze in the "selected list" area using the ">>" button. Use the "<<" button to remove file if needed. </li>
[[Image:Add_Rmv.png|400px|none]]
<li>Click on "Select Directions" to set the direction and sensor for each channel (This step is not necessary if you only want the time-weighted signals). </li>
[[Image:Select_DOF.png|400px|none]]
<li>Select the weighting you want to apply on the time signal </li>
[[Image:Select_Filter.png|400px|none]]
<li>Select the weighting you want to apply for each direction X, Y and Z used for the indicators </li>
[[Image:Select_Process_Filt.png|400px|none]]
<li>Select the metrics you want to calculate </li>
[[Image:Select_Metric.png|400px|none]]
<li>Click on "Start Processing" </li>
[[Image:Strat_Proc.png|400px|none]]
<li>The processing is completed when a the following pop-up window appears. The results and weighted signal will have been added to the current NVGate project. See the next sections for details. </li>
[[Image:The_End.png|400px|none]]
</ol>

==Toolkit results==
===Spectral weighting===
This results are already inside NVGate, you need to do a right click on the spectrum grey part.
Weighting/More... then select the apropropriate weighting.
[[File:weighting filter.png|500px]]

===Time-weighted signal===
Studies of the effect of vibrations on the human body suggest that parts of the body don't have the same response to vibrations as others, and will be more sensitive to specific frequencies and transient component of vibration signal. In order to represent the sensitivity of the human body, ISO standards define time-weighting that must be applied to the signal according to the environmental conditions. The following section shows how to apply time-weighting filters to your signal using the toolkit.
====Time-weighting filters====
As defined in the standards, specific time weighting must be applied to the acceleration signal in order to represent the effect of vibrations on health and comfort. Here is the list of the different time-weighting filters implemented in the toolkit : 
{| class="wikitable" style="margin: auto;"
|+style="caption-side:bottom;"|''Time-weighting filters''
|-
|style="height:30px; width:100px;"|<math>W_k</math>
|Time weighting for the Z axis for whole-body measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_d</math>
|Time weighting for the X and Y axis for whole-body measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_h</math>
|Time weighting for the hand-arms measurement in any direction (ISO 5349-1)
|-
|style="height:30px; width:100px;"|<math>W_f</math>
|Time weighting for motion sickness measurement in the vertical direction (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_c</math>
|Time weighting for the X axis for whole-body measurement (ISO 2631-1; older version)
|-
|style="height:30px; width:100px;"|<math>W_e</math>
|Time weighting for all rotational directions for whole-body measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_j</math>
|Time weighting for the Z axis for head comfort measurement (ISO 2631-1)
|-
|style="height:30px; width:100px;"|<math>W_m</math>
|Time weighting for all directions for buildings vibration measurement (ISO 2631-2)
|}

Filters have been validated from 0.5 to 10kHz at 25.6kSample/second.

====Usage in the toolkit====
The toolkit allows you to calculate the filtered raw signal with any of the above weighting filters. This will allow you to display [[NVGate FFT|spectrums]] and calculate RMS via [[NVGate_Post_Analysis|post-analysis]] in NVGate.

To calculate the raw weighted signal, simply select the filters you want in the "Time signal filters" section:

[[Image:Filter2.png]]

Once the processing is completed, a new measurement containing the filtered signal for each selected filter is created in [[NVGate Project manager|NVGate Project Manager]] :

[[Image:Filtered_Sig.png|400px]]
 
You can then load the new signals in the player the same way as any NVGate signal. Each track of the signal is filtered with the corresponding filter. 

[[Image:Sig_In_ Player.png|800px]]

===Health and comfort indicator===
In addition to the time-weighting filters, the ISO standards present a series of specific metrics to evaluate the affect of vibrations on the Human body. The following section will present you how to use the toolkit to access these metrics.
====Indicators====

{| class="wikitable" style="margin: auto;"
|+style="caption-side:bottom;"|''Human vibration indicators''
|-
|style="height:30px; width:100px;"|<math>A_w</math>
|RMS of the weighted acceleration magnitude.
|-
|style="height:30px; width:100px;"|<math>a_v</math>
|Total RMS value calculated as a quadratic average of the three direction for each tri-axial sensor.
|-
|style="height:30px; width:100px;"|<math>A_h</math>
|RMS of the <math>W_h</math> weighted acceleration magnitude.
|-
|style="height:30px; width:100px;"|<math>Peak</math>
|Amplitude Peak of the vibration; maximal amplitude of the signal from the 0 (Calculated from Post processing in NVGate)
|-
|style="height:30px; width:100px;"|<math>Crest factor</math>
|Ratio between the Peak level and the RMS of the weighted signal(Calculated from Post processing in NVGate)
|-
|style="height:30px; width:100px;"|<math>MTVV</math>
|Maximum Transient Vibration Value, represent the maximal RMS value of the signal
|-
|style="height:30px; width:100px;"|<math>VDV</math>
|Vibration Dose Value, taking into account the temporal shocks in the signal
|-
|style="height:30px; width:100px;"|<math>MSDV</math>
|Motion Sickness Dose Value, representing the comfort in transportation measurement
|-
|style="height:30px; width:100px;"|<math>D_k</math>
|The Acceleration Dose, representing the affect of the vibration on the spine
|-
|style="height:30px; width:100px;"|<math>Se</math>
|The equivalent Static compression stress on the spine, caused by repeated shocks
|}

======Aw======

The <math>A_w</math> is the RMS of the weighted acceleration signal. The weighting is applied in accordance with the direction set for each channel and the weighting filter defined for the direction. 

For each channel, the <math>A_w</math> and <math>A_w(T)</math> will be calculated. The <math>A_w(T)</math> is the daily exposure value, defined as : 
<math display="block" forcemathmode="5">A_w(T) = A_w*k_{i}*\sqrt{\frac{T}{T_m}}</math>
 
With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter. the <math>k_i</math> factor is defined in the ISO 2631 as <math>k_X = k_Y = 1.4</math> and <math>k_Z = 1</math>.

When comparing result from one measurement point in the three direction, the maximum of the daily exposure value must be used as the total daily exposure value at that point : 
<math display="block" forcemathmode="5">A_w(T) = max(A_{wX}(T), A_{wY}(T), A_{wZ}(T)) </math>
 

======av======
The <math>a_v</math> is the total RMS vibration value of the weighted acceleration signal. This value will be automatically calculated with Aw indicator if a tri-axial sensor has been defined in the definition of direction window.

For each tri-axial sensor, the <math>a_v</math> will be calculated as a quadratic average of the weighted RMS value in the three directions : 

<math display="block" forcemathmode="5">a_v = \sqrt{{a_{vX}}^{2}*{k_{X}}^{2} + {a_{vY}}^{2}*{k_{Y}}^{2} + {a_{vZ}}^{2}*{k_{Z}}^{2}}</math> 
With <math>k_{X,Y,Z}</math> a factor defined in the ISO 2631 as <math>k_{X}=k_{Y}=1.4</math> and <math>k_{Z}=1</math>
 

======Ah======
The <math>A_h</math> is the RMS of the <math>W_h</math> weighted acceleration signal for hand-arms vibration measurement. For each channel, the <math>A_h</math> and <math>A_h(T)</math> will be calculated. The <math>A_h(T)</math> is the Daily exposure value, defined as : 

<math display="block" forcemathmode="5">A_h(T) = A_h*\sqrt{\frac{T}{T_m}}</math> 

With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter. 

If any sensor is defined, the total <math>A_h</math> and <math>A_h(T)</math> will be calculated for each sensor as a quadratic average of the three direction of the sensor : 
<math display="block" forcemathmode="5">A_{h Total} = \sqrt{{a_{hX}}^{2}*{k_{X}}^{2} + {a_{hY}}^{2}*{k_{Y}}^{2} + {a_{hZ}}^{2}*{k_{Z}}^{2}}</math>
 
and : 
 
<math display="block" forcemathmode="5">A_{h Total}(T) = \sqrt{{a_{hX}}^{2}*{k_{X}}^{2} + {a_{hY}}^{2}*{k_{Y}}^{2} + {a_{hZ}}^{2}*{k_{Z}}^{2}}*\sqrt{\frac{T}{T_m}}</math>
 
With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter, and <math>k_{X}=k_{Y}=k_{Z}=1</math>
 

======Peak======

This indicator is the [[NVGate_Time_Domain_Analysis#Available_results|peak amplitude]] of the vibration signal. It represents the maximum amplitude of the weighted signal. This indicator can be obtained in NVGate by [[NVGate Post Analysis|post-analysing]] the weighted signal with the [[NVGate Time Domain Analysis|TDA plugin of NVGate]].

======Crest Factor======

This indicator is the [[NVGate_Time_Domain_Analysis#Available_results|Crest Factor]] of the vibration signal. It represent the importance of the transient event in the signal as the ratio of the maximal Peak amplitude over the RMS level for the weighted signal. This indicator can be obtained in NVGate by [[NVGate Post Analysis|post-analysing]] the weighted signal with the [[NVGate Time Domain Analysis|TDA plugin of NVGate]].

======MTVV======
The MTVV is the Maximal Transient Vibration Value, is the maximum of the running RMS of the weighted acceleration. This value is calculated for each channel and is expressed in m/s².

The MTVV Tau is the integration time, expressed in seconds. This value can be edited before the calculation, but the ISO 2631 recommend to use 1 second. Therefore, this is the default value of this parameter.

======VDV======
The VDV is the forth power Vibration Dose Value. It is calculated as a cumulative sum of the weighted acceleration at the fourth power. The fourth power is used to give more weight to the transient event of the signal over the periodic event. Therefore, this indicator must be used to assess the effect of shock on human health and comfort. The VDV is calculated for each channel and expressed in m/s^(1.75). 

If the "VDVTexp" box is checked, an evaluation of the VDV value over a longer time period will be calculated of each channel as : 
<math display="block" forcemathmode="5">VDV_{X,Y,Z}(T) = VDV_{X,Y,Z}*k_{X,Y,Z}*\sqrt[4]{\frac{T}{T_m}}</math> 

With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter, and <math>k_{X}=k_{Y}=1.4</math>, and <math>k_{Z}=1</math>

======MSDV======
This metric is the Motion Sickness Dose Value, used to evaluate the ride comfort in in-vehicle measurement. It is expressed in m/s^(1.5). 

Although this value will be calculated for each direction, only the Z-direction will have a prominent relevance to assess ride comfort.
======Dk======
<math>D_k</math> is the acceleration dose. It is use to evaluate the effect of vibrations on the human spine, and calculated as the 6th root of the sum of the peaks in the acceleration signal raised at the 6th power. It is expressed in m/s². Peaks are defined as the absolute maximum of the acceleration signal between two zeros crossing. In the Z direction, only the positive peak will be considered, were all positive and negative peaks are used for the X and Y directions. 

Specific filters are used to weight the acceleration signal before calculating the <math>D_k</math>. These filter are different for the vertical and horizontal direction, and are defined for a sampling rate of 160 Sample/second. Therefore, we advise to [[NVGate Recorder|record]] the signal with a low [[NVGate_Front_End#Input_settings|sampling rate]] in NVGate. 

Assessing the affect of the vibration on human spine most is important when dealing with transportation vehicular, especially the driver seat. For a better evaluation, the ISO 2631-5 advises calculating the daily acceleration dose, defined as : 

<math display="block" forcemathmode="5">D_{X,Y,Z}(T) = D_{X,Y,Z}*\sqrt[6]{\frac{T}{T_m}}</math> 

This value will be calculated if the box "Dk Texp" is checked.

======Se======
The Se is the compressive stress on the human spine, expressed in MPa. It is calculated by the combination the Dk in the three direction. Therefore, it will only be calculated if sensors are defined in the "Select Direction" window. One value of Se will be calculated for each sensor by the formula : 
<math display="block" forcemathmode="5">Se = \sqrt[6]{\sum_{k=X,Y,Z}(D_{k}*m_{k})^6}</math> 

Where <math>m_{X} = 0,015</math> MPa/(m/s²), <math>m_{Y} = 0,035</math> MPa/(m/s²) and <math>m_{Z} = 0,032</math> MPa/(m/s²). 

To evaluate the lumbar stress over a daily exposition time, the Se(T) will also be calculated as : 
<math display="block" forcemathmode="5">Se(T) = \sqrt[6]{\sum_{k=X,Y,Z}(D_{k}(T)*m_{k})^6}</math> 

T being the total exposure duration represented by the "Reference time" parameter. 

====In the toolkit====
Before calculating the indicators in the toolkit, you must define a filter for each direction. Filters will be selected in accordance with the desired result (Hand-arms; Whole-Body, ..) and the direction of the measurement as specified in the table [[Human_Vibration#Time-weighting_filters|describing the filters]]. Filters will be applied to the signal before calculating the indicators, but the time-filtered signal will not be saved. 
[[Image:proc_filt.png]]
 
You will then need to enter the reference time you want to use to estimate the parameters on a greater duration. This duration must be entered in seconds. The default value is 288500 seconds, corresponding to an 8 hour exposition: 
[[Image:Ref_Time.png]]

You will finally need to enter the MTVV Tau value. The MTVV Tau is the integration time in seconds used for the calculation of the MTVV. The ISO 2631 recommends using 1sec. This is the default value of the setting. 

Once the filters are selected and the parameters competed, you can select the metrics you want to calculate by checking the different boxes. 
[[Image:all_proc.png]] 
You can then start the processing to calculate the indicators. 

Here, we are calculating all the indicators for the "Seat_Pad_Measurement" signal. This signal contains 3 Tracks, one for each channel X, Y and Z of a three axis accelerometer. As we want to calculate the multi-axis metrics, we also define a sensor on the three tracks, called "Seat_Pas_3axis". 
[[Image:Set_up_seatPad.png|500px]]
 
Once completed, the result can be found in the currently opened project in the [[NVGate Project manager]]. A new measurement called "NAME_OF_THE_Signal_out" containing the result is created. 

[[Image:ResInProjMAn2.png|300px]] 

Each indicator is calculated for each direction and for each track of the signal. The name of the result contains the name of the track, the considered direction and the filter used for that direction (except for the <math>D_k</math> which use specific filters). 
The following picture shows the indicators for the first track (SeatPadX) of the signal : 
[[Image:Resut_SeatPad.png|300px]]
 

For the metrics estimated on the "Reference Time", the name of the indicator is followed by "(Ref_Time_in_Second"). Here an example with the VDV metric, the name of the indicator is displayed in the window title : 
[[Image:VDV_andTexp.png|800px]]
 

The metrics combining the three directions (av, Se, Ah,...) are named as following : "METRICS_Name : Sensor". Here is an example for Se :

[[Image:Se.png|400px]]
 
You can then display the result in NVGate by double clicking.
 

====Unit in NVGate====
For acceleration measure, please only use m/s², otherwise, Aw, Ah and other indicators will not be calculated correctly.
If wished, you might change the unit after wise in NVGate, in [[NVGate_User_Preferences#Physical_quantity|Spare units of NVGate]].

To display the right unit for the MSDV;, VDV and Se indicators, you need to modify the [[NVGate_User_Preferences#Physical_quantity|Spare units of NVGate]] as :
* Spare1 : <math>m/{s}^{1.75}</math> for the VDV
* Spare2 : <math>m/{s}^{1.5}</math> for the MSDV
* Spare3 : <math>Pa</math> for the Se (you can adapt the display as MPa).
 
No formula needs to be entered as the calculations are already built-in to the toolkit. You will only need to enter the unit and your display preferences.
 

==Practical information about measurements==

This section will provide you with some practical information about Human Vibration evaluations.

Human vibrations are transmitted to the human body over a reasonable amount of time. This transmission mainly happens in vehicles during transportation, in buildings, and when using vibrating equipment and tools, such as electric drills and blowers. Since the last century, studies have shown that vibrations can have many affects on the human body, from discomfort and transportion sickness to serious health issues, including blood flow disorders to muscular and rheumatisms. 
Therefore, methods of measurement and evaluation of these vibrations have been developed over the years, and have translated into several standards for mechanical appliances to prevent discomfort and harm. 

===Type of measurement===
====Whole-Body Measurement====
Measurement procedures for whole-body vibration evaluation are described in ISO 2631. This type of vibration will mainly occur in transportation and in the workplace when working with big machinery. Therefore, the evaluation of the vibration will be carried out on the part supporting the human body, like backside and feet for a seated person and feet for a standing person. Sensors must be placed to assess vibration to these specific points. Measurement must be carried on the complete system. Meaning the user must be present during the measurement and operate the machine/vehicle as usual. The following picture, extracted from the standard, gives indication of the orientation of the sensors : 

[[Image:Axis_WholeBody.png]] 

For each point, the vibration must be measured in the three directions: X, Y and Z. As different weighting will be used for each direction, it is very important that each sensor is oriented according to the same directions. The Z direction must always be used in the direction of the human spine. 

Specific sensors must be used in order to detect vibration at the transmission point. For a seated person, [https://www.dytran.com/Model-5313A-Triaxial-Seat-Pad-Accelerometer-P2161/|Seat Pad accelerometer] allows you to acquire vibrations at the buttocks : 
[[Image:DytranSeatPad.png]] 
If necessary, the same kind of sensors can by used under the feet of a standing person. These sensor must be fixed to hold in place when the subject moves. For vibration transmitted to feet, standard accelerometers can also be placed on the floor. 
 
The length of the measurement should be representative of the whole exposure duration during a day. However, as it is not always possible to acquire long signal, the ISO 2631 specifies that measurement must be taken for at least 20 minutes, and 2h measurement are preferable. Using the OROS tool kit, long signals file can be take a lot of time to analyze. In order to analyze signal files longer than 30 minutes, we advise to : 
* Reduce the Sampling rate, as frequency bandwidth for Whole-body vibration will note exceed 1kHz.
* Split each sensor over several files.
 
Please contact OROS customer care team for additional advice.
 

====Hand-Arm Measurement====

Measurement procedures for hand-arm vibration evaluation are described in the ISO 5349. This type of vibration is transmitted to the body by the hands and the arms when using hand-tools and equipment, holding a vibrating object (like the steering wheel in a vehicle), or feeding a machine (wood cutting or turning). 

Here, the direction of the sensor is not important, however, at least two directions must be acquired at each point in the direction perpendicular to the handle axis. The most important part is to measure vibration at the contact point of the hand and the tool. Specific adaptors can be used to hold the accelerometer with the handle.

 
The length of the measurement should be representative of the whole exposure duration during a day. Therefore, it can vary from very short measurement (when feeding the machine) to longer measurement (steering wheel). 
Using the OROS tool kit, long signal files can take a lot of time to analyze. In order to analyze signal files longer than 30 minutes, we advise to : 
* Reduce the Sampling rate, as frequency bandwidth for Whole-body vibration will note exceed 1kHz.
* Split each sensors over several files.
 
Please contact OROS customer care team for additional advice.
 

The main indicator used for hand-arm vibration will be the Ah and Ah(8) metrics.

Hardware battery

2026-10-07T07:48:16Z

Lmagimel: Battery docs moved from SharePoint to Partner Zone (OROS/Fichiers wiki/batterie) + OR35TW UN38.3/IEC62133 and OR10 UN38.3/MSDS added

[[category:WikiOros]]
Let's find general information and FAQ about battery information.

Disclaimer: this page could be not up to date. Be aware than regulation about battery and transportation are quite complex and can change over time. Please follow the regulation of your country and your carrier for up to date information.

=MSDS=
==OR35V1 - OR36 V1 V2 TW and OR38 V1==

Nimh battery.

Manufacturer FORCEE : [https://partnerzone.digigram.com/s/PCmyf5ziw7nK74Q MSDS OR35V1 - OR36 V1 V2 TW and OR38 V1]

For OROS analyzer, Forcee use niMH panasonic cells iniside their battery, so here the MSDS from panasonic (You can use this MSDS as an alternative of Forcee one: [https://partnerzone.digigram.com/s/XcEqo7psZaYznk9 Panasonic cells inside OROS forcee battery]

== OR38 TW ==
NiMh Battery

Manufacturer GP[https://partnerzone.digigram.com/s/XnpjiKoAQNiPpTd MSDS OR38TW]

The battery is made by: 15 cells of : NIMH 1.2 V / 3800 mAh - Réf: GP380LAHV

==OR38V2==
Nimh battery.

Manufacturer can be GP or Forsee. Ask oros with your analyzer serial number, if you need to know the manufacturer.

Manufacturer GP: [https://partnerzone.digigram.com/s/XnpjiKoAQNiPpTd MSDS GP]

Manufacturer FORSEE: [https://partnerzone.digigram.com/s/PCmyf5ziw7nK74Q MSDS Forsee]

==OR35TW==
Lithium ion battery.

Battery ACCUWATT AWT 15/6-X : Li-ion 14.5 V - 6 Ah - 87 Wh.

[https://partnerzone.digigram.com/s/AXj9wE7Yq72XADC MSDS Lithium ions OR35 TW battery]

[https://partnerzone.digigram.com/s/bA3pksp3FHCxiT7 UN38.3 test report OR35 TW battery]

[https://partnerzone.digigram.com/s/JcFWjETLnt3Z93Z IEC 62133 test report OR35 TW battery]

==OR10==
Lithium ions battery.

[https://partnerzone.digigram.com/s/n5kLBQrrPrEQFfW OR10 - IEC62133 conformity test]

[https://partnerzone.digigram.com/s/KXZEAkzT82HsnXw OR10 - UN38.3 test report]

[https://partnerzone.digigram.com/s/kkymi237wQKn559 OR10 - MSDS battery]

==OR34==
Nimh Battery.

[https://partnerzone.digigram.com/s/beL5NRfMaQ95KHZ OR34 MSDS]

== External battery power gorilla==

[https://partnerzone.digigram.com/s/2Bx4CJGFMeAJcdE Technical documentation]

=Cargo transport=

==Nimh battery -OR34V1 - OR35V1 - OR36 and OR38 : V1,V2 , TW ==

No Restriction , nothing to declare.

==Lithium ion battery OR35TW and OR10==

It is Forbiden to transport a battery alone. The battery need to be inside the analyzer.

UPS FEDEX TNT : OK

DHL : you can can have some issue for lithium ion battety, we advice to avoid DHL for this.

Contact your carrier to inform him. Genreally speaking, on the shipping document you can thick a box and say you have lithium ion battery INSIDE the material.

Then you need to download this 2 documents below and put it on parcel.
[https://partnerzone.digigram.com/s/9tQCtf7rrfjYtxQ doc 1] and [https://partnerzone.digigram.com/s/mPkLkidtsyira23 doc 2]

= Traveling by airplane =

== Lithium ion battery : OR35TW and OR10 ==

Forbiden in “check it in”

Ok in hand luggage.

== Nimh batterie : OR34V1 - OR35V1 - OR36 and OR38 : V1,V2 , TW ==

OK to check it in.

OK in hand luggage.

=Certificate=
Ask us: customer.care@oros.com

NVGate Torsional

2026-10-02T08:06:55Z

Lmagimel: /* Frequency to RPM converter (Torsional inputs) */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 4 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4096. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 4 teeth.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval.
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.
* It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s: Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque (setting ''Physical qty.''). The coefficient is used to convert the read angle in torque. 

===coefficient===
When ''Physical qty.'' = '''Torque''', the setting ''Coef.'' appears. It is the torsional stiffness of the shaft and it must be entered in '''N·m per radian''' (N·m/rad), not in N·m per degree.
{|class="wikitable"
|'''Torque (N·m) = Coef. (N·m/rad) × twist angle (rad)'''
|}

* If the stiffness is known in N·m/°, multiply it by 57.3 (180/π). Example: 5000 N·m/° → enter ''Coef.'' = 286 479.
* Example measured on the bench: twist 5.5° (= 0.096 rad) with ''Coef.'' = 1000 → torque = 96 N·m (and not 5500 N·m).
* The ''Offset'' is an angle (in °), added to the twist '''before''' the coefficient: Torque = Coef. × (twist + Offset).

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

NVGate Torsional

2026-10-01T15:35:15Z

Lmagimel: /* Twist measurements (static and dynamic) */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 4 teeth.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval.
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.
* It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s: Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque (setting ''Physical qty.''). The coefficient is used to convert the read angle in torque. 

===coefficient===
When ''Physical qty.'' = '''Torque''', the setting ''Coef.'' appears. It is the torsional stiffness of the shaft and it must be entered in '''N·m per radian''' (N·m/rad), not in N·m per degree.
{|class="wikitable"
|'''Torque (N·m) = Coef. (N·m/rad) × twist angle (rad)'''
|}

* If the stiffness is known in N·m/°, multiply it by 57.3 (180/π). Example: 5000 N·m/° → enter ''Coef.'' = 286 479.
* Example measured on the bench: twist 5.5° (= 0.096 rad) with ''Coef.'' = 1000 → torque = 96 N·m (and not 5500 N·m).
* The ''Offset'' is an angle (in °), added to the twist '''before''' the coefficient: Torque = Coef. × (twist + Offset).

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

NVGate Torsional

2026-10-01T15:15:15Z

Lmagimel: /* Limits */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 4 teeth.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval.
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.
* It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s: Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

NVGate Torsional

2026-10-01T15:14:58Z

Lmagimel: /* Limits */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 4 teeth.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval.
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.
* It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

NVGate Torsional

2026-10-01T15:14:50Z

Lmagimel: /* Fractional missing pulses management */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 4 teeth.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval.
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.
*It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

NVGate Torsional

2026-10-01T13:28:32Z

Lmagimel: /* Limits */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See the [[#Quick guide for the operator: what to enter in NVGate|quick guide for the operator]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval.
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

NVGate Torsional

2026-10-01T13:28:13Z

Lmagimel: /* Check after setting */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See the [[#Quick guide for the operator: what to enter in NVGate|quick guide for the operator]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval.
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval. With a shorter gap (g = 0.6 tested), no setting gives a correct speed (spikes of 37 to 39 %).
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it (g = 2.05 set to 1 → +1.8 %).
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

NVGate Torsional

2026-10-01T13:27:39Z

Lmagimel: /* Annexe : Setting Pulse/rev and Missing teeth */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See the [[#Quick guide for the operator: what to enter in NVGate|quick guide for the operator]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval. With a shorter gap (g = 0.6 tested), no setting gives a correct speed (spikes of 37 to 39 %).
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it (g = 2.05 set to 1 → +1.8 %).
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

NVGate Torsional

2026-10-01T13:26:50Z

Lmagimel: /* Typical mistakes (example: 8 pulses, gap of 2.4) */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See the [[#Quick guide for the operator: what to enter in NVGate|quick guide for the operator]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

====Quick guide for the operator: what to enter in NVGate====
You only need to enter '''two numbers''' in the Ext. sync. settings: '''Pulse / rev''' and '''Missing teeth'''.

{|class="wikitable" style="width:100%;"
!Word!!What it means
|-
|'''Pulses on the shaft'''||The stripes (or teeth) that you can actually '''count''' on the shaft. The gap is not counted.
|-
|NVGate setting '''Missing teeth'''||How many pulses would fit in the gap. Keep only the '''whole number'''.
|-
|NVGate setting '''Pulse / rev'''||'''Pulses on the shaft + Missing teeth'''. It is '''not''' the number of stripes you count.
|}

[[File:Torsional_operator_8_pulses.png|900px|none]]

=====Three steps=====
# '''Count the pulses on the shaft.''' Example: '''8'''.
# '''Look at the gap: how many pulses would fit in it?''' Keep the whole number. Example: 2.4 → '''2''' (2.1 → 2, 2.9 → 2, 1.3 → 1).
# '''Enter in NVGate''': Missing teeth = '''2''' and Pulse / rev = 8 + 2 = '''10'''.

'''How to estimate the gap with a ruler''': measure the normal spacing between two stripes (from the start of one black stripe to the start of the next one), then the distance from the start of the last stripe before the gap to the start of the first stripe after it.
Pulses that fit in the gap = (that distance ÷ normal spacing) − 1. Example: 34 mm ÷ 10 mm − 1 = 2.4 → Missing teeth = 2.

=====Examples=====
{|class="wikitable" style="width:100%;"
!On the shaft!!Pulses counted!!Pulses that fit in the gap!!NVGate Missing teeth!!NVGate Pulse / rev
|-
|Piano tape (picture above)||8||2.4||'''2'''||'''10'''
|-
|Encoder 60-2 (60 teeth, 2 removed)||58||2||'''2'''||'''60'''
|-
|Encoder 24-1||23||1||'''1'''||'''24'''
|-
|Piano tape||37||1.7||'''1'''||'''38'''
|-
|Piano tape||45||2.9||'''2'''||'''47'''
|}

=====Check after setting=====
Run the shaft at a constant speed and look at the Tors signal: it must be '''flat''', with '''no spike once per revolution''', and its mean value must match the speed given by another sensor. If not, see the typical mistakes below.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

==Annexe : Setting Pulse/rev and Missing teeth ==
With a piano tape, the gap at the junction is never a whole number of teeth: it is, for example, 2.4 teeth, never exactly 2 or 3. NVGate handles such a fractional gap perfectly, '''provided that the two settings are chosen as described below'''.

[[File:Torsional_piano_tape_gap.png|800px|none]]
''Piano tape with P = 58 pulses present per revolution and a gap of g = 2.4 teeth''

=====What the two settings mean=====
{|class="wikitable" style="width:100%;"
!Setting!!Meaning
|-
|'''Pulse / rev''' (N)||Total number of tooth positions on one revolution, '''missing teeth included'''.
|-
|'''Missing teeth''' (m)||Number of missing teeth (the gap).
|-
|'''N − m'''||Number of pulses '''actually present''' on one revolution (P). This is the decisive value: it must match the real number of pulses.
|}

=====Setting rule=====
{|class="wikitable" style="width:100%;"
|style="background:#E8F0FA;"|
# '''Count P''', the number of pulses actually present on one revolution (black stripes of the tape, or pulses between two gaps on a recording).
# '''Measure g''', the gap length in teeth: '''g = (gap interval ÷ normal interval) − 1'''.
# '''Missing teeth = integer part of g'''. If g is within 0.1 of a whole number, use that whole number.
# '''Pulse/rev = P + Missing teeth''' — not the "nominal" number of stripes of the tape.
|}

'''Example''': 58 pulses present and a gap interval 3.4 times the normal interval → g = 2.4 → '''Missing teeth = 2''' and '''Pulse/rev = 58 + 2 = 60'''.

=====How to measure P and g on site=====
# Run the shaft at a roughly constant speed and record the Ext. sync. track for a few revolutions.
# On the recording, read the normal interval between two pulses and the interval across the gap. Compute g = (gap interval ÷ normal interval) − 1. Example: 3.4 ms ÷ 1.0 ms − 1 = 2.4 teeth.
# Count the pulses between two gaps: this is P.
# Check the result: at constant speed the Tors signal must be flat (no spike once per revolution), and its mean value must equal the speed given by another sensor (or by the same input in Tach mode).

=====What happens with a wrong setting=====
The following results were measured with NVGate 18.00.003 on an OR35, with synthetic pulse trains whose pulse instants are exactly known (58 pulses present per revolution, 1200 RPM constant, gap g from 0.6 to 4.0 teeth, 63 cases). Results are identical online (Ext. sync. input) and in post-processing (Signal Op.).

[[File:Torsional_missing_teeth_map.png|900px|none]]
''Error on the mean speed (%) depending on the actual gap g and on the settings. Colour = worst of mean and peak error. Left: Pulse/rev = P + m. Right: Pulse/rev kept at the nominal value 60.''

{|class="wikitable" style="width:100%;"
!Setting!!Example (g = 2.4, P = 58)!!Result
|-
|style="background:#5EF86D;"|'''Missing teeth = integer part of g''', Pulse/rev = P + m||m = 2, Pulse/rev = 60||Correct in all tested cases (g = 1.0 to 4.0): mean error < 0.002 %, peak error < 0.035 %
|-
|Missing teeth rounded up||m = 3, Pulse/rev = 61||Correct only when the decimal part of g is large enough (1.7 → 2, 2.4 → 3 are correct, but 1.3 → 2 gives −57 %)
|-
|style="background:#FBBCB7;"|One tooth less than the integer part||m = 1, Pulse/rev = 59||Speed '''too high by +1.6 to +2.9 %''', with no visible spike — the most misleading error
|-
|style="background:#FBBCB7;"|One or two teeth too many||m = 4, Pulse/rev = 62||Speed too low by −2 % up to '''−68 %''' (speed divided by two)
|-
|style="background:#FBBCB7;"|Missing teeth = 0 although there is a gap||m = 0, Pulse/rev = 58||Mean speed nearly correct, but a '''spike of 37 to 65 %''' once per revolution
|-
|style="background:#FBBCB7;"|Pulse/rev kept at the nominal value whatever m||Pulse/rev = 60, m = 3||Correct only if Pulse/rev − m equals P. Otherwise +0.7 to +3.6 %, or worse
|}

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval. With a shorter gap (g = 0.6 tested), no setting gives a correct speed (spikes of 37 to 39 %).
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it (g = 2.05 set to 1 → +1.8 %).
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

NVGate Torsional

2026-10-01T12:49:54Z

Lmagimel: /* Annexe : Setting Pulse/rev and Missing teeth */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See [[#Setting Pulse/rev and Missing teeth for a fractional gap|Setting Pulse/rev and Missing teeth for a fractional gap]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

==Annexe : Setting Pulse/rev and Missing teeth ==
With a piano tape, the gap at the junction is never a whole number of teeth: it is, for example, 2.4 teeth, never exactly 2 or 3. NVGate handles such a fractional gap perfectly, '''provided that the two settings are chosen as described below'''.

[[File:Torsional_piano_tape_gap.png|800px|none]]
''Piano tape with P = 58 pulses present per revolution and a gap of g = 2.4 teeth''

=====What the two settings mean=====
{|class="wikitable" style="width:100%;"
!Setting!!Meaning
|-
|'''Pulse / rev''' (N)||Total number of tooth positions on one revolution, '''missing teeth included'''.
|-
|'''Missing teeth''' (m)||Number of missing teeth (the gap).
|-
|'''N − m'''||Number of pulses '''actually present''' on one revolution (P). This is the decisive value: it must match the real number of pulses.
|}

=====Setting rule=====
{|class="wikitable" style="width:100%;"
|style="background:#E8F0FA;"|
# '''Count P''', the number of pulses actually present on one revolution (black stripes of the tape, or pulses between two gaps on a recording).
# '''Measure g''', the gap length in teeth: '''g = (gap interval ÷ normal interval) − 1'''.
# '''Missing teeth = integer part of g'''. If g is within 0.1 of a whole number, use that whole number.
# '''Pulse/rev = P + Missing teeth''' — not the "nominal" number of stripes of the tape.
|}

'''Example''': 58 pulses present and a gap interval 3.4 times the normal interval → g = 2.4 → '''Missing teeth = 2''' and '''Pulse/rev = 58 + 2 = 60'''.

=====How to measure P and g on site=====
# Run the shaft at a roughly constant speed and record the Ext. sync. track for a few revolutions.
# On the recording, read the normal interval between two pulses and the interval across the gap. Compute g = (gap interval ÷ normal interval) − 1. Example: 3.4 ms ÷ 1.0 ms − 1 = 2.4 teeth.
# Count the pulses between two gaps: this is P.
# Check the result: at constant speed the Tors signal must be flat (no spike once per revolution), and its mean value must equal the speed given by another sensor (or by the same input in Tach mode).

=====What happens with a wrong setting=====
The following results were measured with NVGate 18.00.003 on an OR35, with synthetic pulse trains whose pulse instants are exactly known (58 pulses present per revolution, 1200 RPM constant, gap g from 0.6 to 4.0 teeth, 63 cases). Results are identical online (Ext. sync. input) and in post-processing (Signal Op.).

[[File:Torsional_missing_teeth_map.png|900px|none]]
''Error on the mean speed (%) depending on the actual gap g and on the settings. Colour = worst of mean and peak error. Left: Pulse/rev = P + m. Right: Pulse/rev kept at the nominal value 60.''

{|class="wikitable" style="width:100%;"
!Setting!!Example (g = 2.4, P = 58)!!Result
|-
|style="background:#5EF86D;"|'''Missing teeth = integer part of g''', Pulse/rev = P + m||m = 2, Pulse/rev = 60||Correct in all tested cases (g = 1.0 to 4.0): mean error < 0.002 %, peak error < 0.035 %
|-
|Missing teeth rounded up||m = 3, Pulse/rev = 61||Correct only when the decimal part of g is large enough (1.7 → 2, 2.4 → 3 are correct, but 1.3 → 2 gives −57 %)
|-
|style="background:#FBBCB7;"|One tooth less than the integer part||m = 1, Pulse/rev = 59||Speed '''too high by +1.6 to +2.9 %''', with no visible spike — the most misleading error
|-
|style="background:#FBBCB7;"|One or two teeth too many||m = 4, Pulse/rev = 62||Speed too low by −2 % up to '''−68 %''' (speed divided by two)
|-
|style="background:#FBBCB7;"|Missing teeth = 0 although there is a gap||m = 0, Pulse/rev = 58||Mean speed nearly correct, but a '''spike of 37 to 65 %''' once per revolution
|-
|style="background:#FBBCB7;"|Pulse/rev kept at the nominal value whatever m||Pulse/rev = 60, m = 3||Correct only if Pulse/rev − m equals P. Otherwise +0.7 to +3.6 %, or worse
|}

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval. With a shorter gap (g = 0.6 tested), no setting gives a correct speed (spikes of 37 to 39 %).
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it (g = 2.05 set to 1 → +1.8 %).
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

NVGate Torsional

2026-10-01T12:48:59Z

Lmagimel: /* Setting Pulse/rev and Missing teeth for a fractional gap */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See [[#Setting Pulse/rev and Missing teeth for a fractional gap|Setting Pulse/rev and Missing teeth for a fractional gap]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

==Annexe : Setting Pulse/rev and Missing teeth ==
With a piano tape, the gap at the junction is never a whole number of teeth: it is, for example, 2.4 teeth, never exactly 2 or 3. NVGate handles such a fractional gap perfectly, '''provided that the two settings are chosen as described below'''. A wrong choice gives no warning message, and the error on the speed can be small enough to go unnoticed.

[[File:Torsional_piano_tape_gap.png|800px|none]]
''Piano tape with P = 58 pulses present per revolution and a gap of g = 2.4 teeth''

=====What the two settings mean=====
{|class="wikitable" style="width:100%;"
!Setting!!Meaning
|-
|'''Pulse / rev''' (N)||Total number of tooth positions on one revolution, '''missing teeth included'''.
|-
|'''Missing teeth''' (m)||Number of missing teeth (the gap).
|-
|'''N − m'''||Number of pulses '''actually present''' on one revolution (P). This is the decisive value: it must match the real number of pulses.
|}

=====Setting rule=====
{|class="wikitable" style="width:100%;"
|style="background:#E8F0FA;"|
# '''Count P''', the number of pulses actually present on one revolution (black stripes of the tape, or pulses between two gaps on a recording).
# '''Measure g''', the gap length in teeth: '''g = (gap interval ÷ normal interval) − 1'''.
# '''Missing teeth = integer part of g'''. If g is within 0.1 of a whole number, use that whole number.
# '''Pulse/rev = P + Missing teeth''' — not the "nominal" number of stripes of the tape.
|}

'''Example''': 58 pulses present and a gap interval 3.4 times the normal interval → g = 2.4 → '''Missing teeth = 2''' and '''Pulse/rev = 58 + 2 = 60'''.

=====How to measure P and g on site=====
# Run the shaft at a roughly constant speed and record the Ext. sync. track for a few revolutions.
# On the recording, read the normal interval between two pulses and the interval across the gap. Compute g = (gap interval ÷ normal interval) − 1. Example: 3.4 ms ÷ 1.0 ms − 1 = 2.4 teeth.
# Count the pulses between two gaps: this is P.
# Check the result: at constant speed the Tors signal must be flat (no spike once per revolution), and its mean value must equal the speed given by another sensor (or by the same input in Tach mode).

=====What happens with a wrong setting=====
The following results were measured with NVGate 18.00.003 on an OR35, with synthetic pulse trains whose pulse instants are exactly known (58 pulses present per revolution, 1200 RPM constant, gap g from 0.6 to 4.0 teeth, 63 cases). Results are identical online (Ext. sync. input) and in post-processing (Signal Op.).

[[File:Torsional_missing_teeth_map.png|900px|none]]
''Error on the mean speed (%) depending on the actual gap g and on the settings. Colour = worst of mean and peak error. Left: Pulse/rev = P + m. Right: Pulse/rev kept at the nominal value 60.''

{|class="wikitable" style="width:100%;"
!Setting!!Example (g = 2.4, P = 58)!!Result
|-
|style="background:#5EF86D;"|'''Missing teeth = integer part of g''', Pulse/rev = P + m||m = 2, Pulse/rev = 60||Correct in all tested cases (g = 1.0 to 4.0): mean error < 0.002 %, peak error < 0.035 %
|-
|Missing teeth rounded up||m = 3, Pulse/rev = 61||Correct only when the decimal part of g is large enough (1.7 → 2, 2.4 → 3 are correct, but 1.3 → 2 gives −57 %)
|-
|style="background:#FBBCB7;"|One tooth less than the integer part||m = 1, Pulse/rev = 59||Speed '''too high by +1.6 to +2.9 %''', with no visible spike — the most misleading error
|-
|style="background:#FBBCB7;"|One or two teeth too many||m = 4, Pulse/rev = 62||Speed too low by −2 % up to '''−68 %''' (speed divided by two)
|-
|style="background:#FBBCB7;"|Missing teeth = 0 although there is a gap||m = 0, Pulse/rev = 58||Mean speed nearly correct, but a '''spike of 37 to 65 %''' once per revolution
|-
|style="background:#FBBCB7;"|Pulse/rev kept at the nominal value whatever m||Pulse/rev = 60, m = 3||Correct only if Pulse/rev − m equals P. Otherwise +0.7 to +3.6 %, or worse
|}

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval. With a shorter gap (g = 0.6 tested), no setting gives a correct speed (spikes of 37 to 39 %).
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it (g = 2.05 set to 1 → +1.8 %).
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

NVGate Torsional

2026-10-01T12:48:27Z

Lmagimel:

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See [[#Setting Pulse/rev and Missing teeth for a fractional gap|Setting Pulse/rev and Missing teeth for a fractional gap]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

===Setting Pulse/rev and Missing teeth for a fractional gap===
With a piano tape, the gap at the junction is never a whole number of teeth: it is, for example, 2.4 teeth, never exactly 2 or 3. NVGate handles such a fractional gap perfectly, '''provided that the two settings are chosen as described below'''. A wrong choice gives no warning message, and the error on the speed can be small enough to go unnoticed.

[[File:Torsional_piano_tape_gap.png|800px|none]]
''Piano tape with P = 58 pulses present per revolution and a gap of g = 2.4 teeth''

=====What the two settings mean=====
{|class="wikitable" style="width:100%;"
!Setting!!Meaning
|-
|'''Pulse / rev''' (N)||Total number of tooth positions on one revolution, '''missing teeth included'''.
|-
|'''Missing teeth''' (m)||Number of missing teeth (the gap).
|-
|'''N − m'''||Number of pulses '''actually present''' on one revolution (P). This is the decisive value: it must match the real number of pulses.
|}

=====Setting rule=====
{|class="wikitable" style="width:100%;"
|style="background:#E8F0FA;"|
# '''Count P''', the number of pulses actually present on one revolution (black stripes of the tape, or pulses between two gaps on a recording).
# '''Measure g''', the gap length in teeth: '''g = (gap interval ÷ normal interval) − 1'''.
# '''Missing teeth = integer part of g'''. If g is within 0.1 of a whole number, use that whole number.
# '''Pulse/rev = P + Missing teeth''' — not the "nominal" number of stripes of the tape.
|}

'''Example''': 58 pulses present and a gap interval 3.4 times the normal interval → g = 2.4 → '''Missing teeth = 2''' and '''Pulse/rev = 58 + 2 = 60'''.

=====How to measure P and g on site=====
# Run the shaft at a roughly constant speed and record the Ext. sync. track for a few revolutions.
# On the recording, read the normal interval between two pulses and the interval across the gap. Compute g = (gap interval ÷ normal interval) − 1. Example: 3.4 ms ÷ 1.0 ms − 1 = 2.4 teeth.
# Count the pulses between two gaps: this is P.
# Check the result: at constant speed the Tors signal must be flat (no spike once per revolution), and its mean value must equal the speed given by another sensor (or by the same input in Tach mode).

=====What happens with a wrong setting=====
The following results were measured with NVGate 18.00.003 on an OR35, with synthetic pulse trains whose pulse instants are exactly known (58 pulses present per revolution, 1200 RPM constant, gap g from 0.6 to 4.0 teeth, 63 cases). Results are identical online (Ext. sync. input) and in post-processing (Signal Op.).

[[File:Torsional_missing_teeth_map.png|900px|none]]
''Error on the mean speed (%) depending on the actual gap g and on the settings. Colour = worst of mean and peak error. Left: Pulse/rev = P + m. Right: Pulse/rev kept at the nominal value 60.''

{|class="wikitable" style="width:100%;"
!Setting!!Example (g = 2.4, P = 58)!!Result
|-
|style="background:#5EF86D;"|'''Missing teeth = integer part of g''', Pulse/rev = P + m||m = 2, Pulse/rev = 60||Correct in all tested cases (g = 1.0 to 4.0): mean error < 0.002 %, peak error < 0.035 %
|-
|Missing teeth rounded up||m = 3, Pulse/rev = 61||Correct only when the decimal part of g is large enough (1.7 → 2, 2.4 → 3 are correct, but 1.3 → 2 gives −57 %)
|-
|style="background:#FBBCB7;"|One tooth less than the integer part||m = 1, Pulse/rev = 59||Speed '''too high by +1.6 to +2.9 %''', with no visible spike — the most misleading error
|-
|style="background:#FBBCB7;"|One or two teeth too many||m = 4, Pulse/rev = 62||Speed too low by −2 % up to '''−68 %''' (speed divided by two)
|-
|style="background:#FBBCB7;"|Missing teeth = 0 although there is a gap||m = 0, Pulse/rev = 58||Mean speed nearly correct, but a '''spike of 37 to 65 %''' once per revolution
|-
|style="background:#FBBCB7;"|Pulse/rev kept at the nominal value whatever m||Pulse/rev = 60, m = 3||Correct only if Pulse/rev − m equals P. Otherwise +0.7 to +3.6 %, or worse
|}

=====Limits=====
* The gap must be at least 1 tooth long, i.e. the gap interval must be longer than twice the normal interval. With a shorter gap (g = 0.6 tested), no setting gives a correct speed (spikes of 37 to 39 %).
* Near a whole number (g = 1.95, 2.0, 2.05), setting that whole number is correct on both sides; setting the lower whole number fails as soon as the gap exceeds it (g = 2.05 set to 1 → +1.8 %).
* In post-processing, when the ''Tach'' option of Signal Op. is used, check that the ''Missing teeth'' value of the created tachometer (''Tachometer > Ext. tach. 1'') is the same as the Tors one.

NVGate Torsional

2026-10-01T12:48:08Z

Lmagimel: /* Setting Pulse/rev and Missing teeth for a fractional gap */

[[category:NVGate]]
[[category:WikiOros]]
OROS propose a comprehensive suite for [https://en.wikipedia.org/wiki/Torsional_vibration torsional measurements] and analyses. It addresses most of the torsional, cyclic and rotational resonances issues.
For both R&D and diagnostics, the latest OROS analyzer feature solutions for '''transmissions, engines '''and''' electric machinery vibration analysis'''.

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics. 

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time. 
'''OROS propose an integrated frequency to RPM converter''' which avoids the above-mentioned inconveniences.

== Frequency to RPM converter (Torsional inputs) ==
This option transforms each external Synch input into a frequency to RPM converter (called IVC, allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.
 

===Specifications===
The IVC (Instantaneous angular Velocity Converter) option features the following main specifications: 

· Number of pulses/rev: 1 to 4096 

· Max pulse frequency: 40 kHz 64 times oversampled, 

· Max angular speed: 

Max RPM = (40 000*64)/pulse per revolution example : 12 800 RPM with 200 Pls/rev 

· Missing teeth management: up to 3 consecutive teeth. 

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator 

===Ext synch Input. Settings===
On the front end, the ext. synch input can be used as a: 
[[File:totion.png|framed|right]]

* '''Mode: '''This setting allows selecting available signal generated by the Ext. synch input to be used by the NVGate analysis components.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%"
|'''Mode'''
|'''Description'''

|-
|Trigger
|The Input generates events only. It can be used as trigger, start and stop of plug-in analyzers and be recorded. Recorded event occurs as 0/1 V signals. Note that the trigger event remains available on any mode.

|-
|[[NVGate_Tachometer#Ext._Tach|Tach]]
|The input generates a tach signal (RPM and revolution phases) in addition to the events.

|-
|[[NVGate_Torsional|Torsional]]
|The input generates the instantaneous velocity measured with the F. to V converter from a pulses train. The torsional signal is considered as a dynamic input. It appears as Tors # in the inputs list (# being the Ext sync number)

|-
|[[NVGate_Torsional|Torsional]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Same as above plus the tach signal is also available. The revolution phase correspond:
* to the missing teeth occurrence if missing teeth is <nowiki>></nowiki> 0
* to the ending of the pulse/rev counting at each revolution (no phase reference) if missing teeth setting is 0

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]]
|The detected pulses on the inputs will be used to synchronize the SOA re-sampling algorithm. The number of pulse/rev is f free and may be different from the SAO resolution.

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Torsional|Tors]]
|Combine the sampling and the Torsional modes. Both angular re-sampling and instantaneous velocity are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|Tach]]
|Combine the sampling and the Tachometer modes. Both angular re-sampling and RPM measurement are provided by the input

|-
|[[NVGate_Torsional#Angular_sampling_for_SOA_analysis|Sampling]] <nowiki>+</nowiki> [[NVGate_Tachometer#Ext._Tach|tach]] <nowiki>+</nowiki> [[NVGate_Torsional|tors]]
|Combine the sampling, the Tachometer and the Torsional modes. Angular re-sampling, Tachometer speed and instantaneous velocity are provided by the input
|}

* '''Pulse / rev''': the number of pulses per revolution. The user can enter an integer value between 1 and 4092. For a non-integer number of pulses per revolution the user must use a virtual tach. 

*[[NVGate_Tachometer#Ext._Tach|other parameters are defined on page tachometer: ext synch .]]

At least the filter which let you integrate or differentiate the RPM speed to get respectively plane angle deviations and angular accelerations for the analyses.

===Fractional missing pulses management===
The missing pulses are a common situation faced while doing torsional measurement. The missing pulse can come as a feature of the encoder (like the common 60:2 encoders). But most of the measurement done on the industry do not offer the comfort of an encoder or gear teeth access.

* '''Missing teeth:''' This setting indicates the number of possible consecutive missing teeth (meaning no pulses). In such case depending on the active mode:
The system interpolates the missing pulses intervals in order to maintain the instantaneous speed at a continuous level during the missing pulses.

[[Image:Release_note_27.jpg|framed|none]]
A very useful solution is the piano (or zebra) tape which is glued on the shaft and read by an optical probe: Easy to install and to use.

But the main problem is to have an entire number of pulses. This is never achievable because the various parameters are difficult to control: Black/white period, diameter of the shaft, thickness of the tape/glue. Well, don<nowiki>'</nowiki>t try, this is not possible.

The solution is to leave a hole which is interpreted as missing pulse. Due to the above variables it will be a fractional number of missing pulse.

OROS torsional function is able to manage such fractional pulses. It offers to achieve torsional measurement on the field in a simple and easy way.

[[Image:Release_note_28.png|framed|none]]

''''' Piano tape junction for fractional missing pulse management'''''

The empty area (missing teeth) length at the piano tape junction must be included between 1 and 3 teeth. The number of missing teeth must be set to the '''integer part''' of the gap length: in this example (gap of 2.x teeth): 2. See [[#Setting Pulse/rev and Missing teeth for a fractional gap|Setting Pulse/rev and Missing teeth for a fractional gap]] below.

Note: the total number of teeth includes the missing teeth. By example, an encoder with '''24 pulse/rev''' and '''1 missing teeth''' must be set as :
[[Image:Torsional_Setup_With_MissTeeth.png|700px|none]] 

[[Image:front_end_22.png|framed|none]]

'''Attention''': The time lap of the first missing pulse must be longer than twice the time lap of the previous pulse interval

'''It is recommended to set the instrumentation in order to limit the number of missing pulse below 3s''': Indeed long interval without pulses will lead to a strong order 1 artefact in the instantaneous speed signal due to interpolation of sample. Remaining below 3s for the missing pulse provide correct measurements.

===Tutorial ===
In on-line mode, the torsional inputs appear as additional channels in the channel connection dialog box. They are identified as ''Tors. x'' from the ''Signal Op.'' resource (not visible in the ASB). These signals can be dispatched exactly as the standard inputs ones :you can connect them to the record, and to any analysis plug-in. 

Both instantaneous velocity channel and pulse train can be recorded at the same time.

====Online mode====
* Plug your tachometer on ext synch channels,
* Activate the Ext-Synch channels and press OK
[[File:tosion1.png|framed|none]]

* Set the ext synch mode as torsional.
[[File:tosion2.png|framed|none]]

* A new input is created : this is the signal of the instantaneous velocity. It can be connected for analysis to any NVGate plug in.
[[File:tosion3.png|framed|none]] 

*The non cyclic behaviour of a shaft can be analysed :
** By the [[NVGate Synchronous Order Analysis|order analysis]] plug-in, providing order profiles
** By the [[NVGate Time Domain Analysis|time domain analysis]] plug-in, for RPM over revolution profiles
** By the [[NVGate FFT|FFT analyser]] plug-in, for displaying the Shaft view to visualize the evolution of speed during one revolution. 
 

*The torsional behaviour of a shaft ([https://en.wikipedia.org/wiki/Torsional_vibration#Crankshaft_torsional_vibration crankshaft], alternator) or a driving belt (service belt) can be excited by its acyclic motion. In such a case the phenomena are analysed order by order using the [[NVGate_Synchronous_Order_Analysis#Average|cross-phase tracking capabilities]] of the [[NVGate Synchronous Order Analysis|SOA Plug-in]]. In that case 2 or more torsional inputs are used on different locations of the shaft, or on each pulley driven by the belt. 

====Post-processing====
For post-analysis purposes, the way to operate depends on the type of recorded signal: 

*If the converted signal (Tors x) have been recorded, the post analysis is exactly like for the usual recorded inputs. 

*if the pulses have been recorded and not the converted signal, a new resource module called ''Signal Operation'' is then available for this conversion. 

*Do a post analysis on the signal:
**Click on connect track. Connect the "Ext synch" tracks to "signal op" by a "drag and drop". Press ok.
[[File:PA_tors.png]] 
**Click again on connect track, a new track "signal op : Tors 1" now appear. It is the converted signal. You can use it in any plug in. press OK.
[[File:PA_tors2.png|framed|none]] 
**The window below appears. On tab tors, you can define the torsional channel settings.
[[File:PA_tors3.png|700px|none]]

==Twist measurements (static and dynamic)==

The twist measurement consists in measuring the angle between the 2 side of a transmission shaft (or belt/chain). The measured angle is directly proportional to the stress and the applied [https://en.wikipedia.org/wiki/Torque torque]. One common application is to choose an appropriate [https://en.wikipedia.org/wiki/Harmonic_damper torsional damper].

The twist can be:

* '''Static''': measure the transmitted torque and power. This is a not a dynamic result and is not to be analysed.
* '''Dynamic ''': measure the oscillating stress and resonances. This is a dynamic signal to be analyzed.

[[File:twist.png|300px]]

Both signals are calculated simultaneously by the virtual input module.

When the torsional signals are setup, simply connect it to the ''Virtual input ''plug-in. 

To calculate the phase between the 2 sides of the twist it is necessary having a tachometer. This tachometer can come from any of the inputs or directly from one of the torsional signals using the ''Torsional <nowiki>+</nowiki> tach.'' mode. Having a missing tooth helps to have better accuracy. 

Then click on the ''Tools/Virtual inputs/dynamic'' button to open the virtual inputs setting. Click on the Twist tab. Select each torsional signal from the ''source 1'' and ''source 2'' lists.

[[Image:Release_note_26.png|700px|none]]

The twist will be displayed in angle or torque. The coefficient is used to convert the read angle in torque. 

The result are available from the add/Remove windows under the virtual input tab.

[[File:torque_display.PNG|300px]]

====Uncorrelated pulse number====
Note that any number of pulses/rev can be used for twist computation and these numbers of pulses/rev can either be different on each side. 

The following table describes the differences between classical twist measurement and the OROS method:

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Classical twist measurement'''
|bgcolor = "#00B0F0"|'''OROS twist'''

|-
|bgcolor = "#FBBCB7"|'''Twist measurement force having the same number of pulse on each side. '''The difference between the 2 signals is requiring the same number of sample/rev.
|bgcolor = "#5EF86D"|'''Twist support different number of pulse/rev signals'''. The OROS twist algorithm is based on phase computation rather than pulse timing comparison. Thanks to this the analysis is independent from the number of pulses/rev.

|-
|bgcolor = "#FBBCB7"|Twist measurement based '''on integration of the angular speed''' (torsional)''' is not stable'''
|bgcolor = "#5EF86D"|'''Twist signal is stable and do not diverge'''. Indeed the OROS Twist algorithm does not use integration techniques

|}

==Angular sampling for SOA analysis==
The major improvement comes as a simple setting… with large effects. Indeed the possibility to sample the measured signal with a distributed angle pulses of a rotating shaft provides accurate results.

This applies mainly on machineries which feature cyclic variation of their rotating speed. Main ones are:

* '''Engines''' (Diesel, Gas, 2/4 strokes)
* Reciprocating '''pumps''' or '''compressors'''
* '''Transmission''' (Torque damper, belt, shaft)
* '''Electric machines''' (generator, alternator, motor)
The angular sampling allows getting the exact angle (or phase) of the events in the machine cycle. The results are event better using the time domain averaging (i.e. angular).

The following example shows the differences between a usual synchronous order analysis and the same one based on angular sampling. The phase differences are clearly visible especially on the ShaftView graphs.

[[Image:Release_note_22.gif|framed|none]]

'''''With and without angular sampling Shaft view on an electric machinery bearing'''''

====Operations====
In order to use the angular sampling function (Optional) it is necessary to have at least:

* A pulses train signal with a known number of pulses/rev
* phase reference (usually a 1 pulse/rev signal)

The sampling signal comes from an ext. synch input. The mode must be set to ''Sampling'' or any of the ''Sampling <nowiki>+</nowiki> xxx''

It is necessary to associate a phase reference (the 0°) to the sampling pulse. It can be any tachometer or the sampling input itself. In this last case the 0° will be the first detected pulse or the missing pulse if there are some.

[[Image:Release_note_23.png|700px|none]]

Then the ''Tachometer'' and the ''Sampling'' are assigned to a SOA plug-in.

[[Image:Release_note_24.png|framed|none]]

The ''Sampling pulse'' setting defines if the angular sampling is activated or not:

* If set to ''None'', the SOA will works on the regular way: Interpolation of the sampling dates from the RPM information).
* If set to a sampling input, the SOA will use it for sampling the channels signals

====Advantages of the OROS solution====
The angular sampling is an old technique, which used to be achieved by replacing the sampling clock by an encoder signal. Even if this procedure provides correct order and angles measurement, it has a lot of defects. The technique provided by ''oros'' corrects these defects.

The following table compares the possible signal alteration and the OROS solution

{|border="1" cellspacing="0" cellpadding="4" width="100%"
|bgcolor = "#00B0F0"|'''Traditional angular sampling'''
|bgcolor = "#00B0F0"|'''OROS angular sampling'''

|-
|bgcolor = "#FBBCB7"|'''Results are not alias free'''. It is not possible to apply anti aliasing as the sampling frequency is not known by the acquisition system.
|bgcolor = "#5EF86D"|'''Alias free results'''. The results are not affected by the alias frequencies thanks to the re-sampling technique. Indeed the analyzer acquires the sample at high freq. (102.4 kS/s) and then re-samples it with a tracking anti-aliasing filter.

|-
|bgcolor = "#FBBCB7"|The '''number of pulses/rev. must be a power of 2'''. Because the digital Fourier transform need a power of 2 samples, if you need to analyze it in order domain (n Revolutions) it is compulsory to deliver n² samples per revolution.
|bgcolor = "#5EF86D"|'''Any number of pulse/rev and any angular resolution are possible'''. The re-sampling technique used by the SOA allows interpolating the correct number of pulse (n²) from any acquire number of pulses

|-
|bgcolor = "#FBBCB7"|'''Missing pulses are not supported'''. Obviously the missing pulses will conduct to missing samples.
|bgcolor = "#5EF86D"|'''Missing pulses are supported'''. The OROS torsional measurement is able to interpolate and create the missing pulses. Then the complete pulse sequence is used by the re-sampling algorithm.

|}

NVGate allows achieving angular sampled analysis avoiding the artefacts introduced by the direct angular sampling.

SRS Tool — Shock Response Spectrum Analyser

2026-09-30T13:40:40Z

Lmagimel: /* Installation */

{{#seo:
|title=SRS Tool: Shock Response Spectrum Analysis for OROS NVGate
|keywords=SRS Tool, Shock Response Spectrum, SRS analysis, MIL-STD-810H, ECSS, NASA-STD, Smallwood filter, vibration analysis, NVGate, OROS software
|description=Professional SRS analysis software for OROS NVGate. Fast shock response spectrum computation, built-in normative limit curves (MIL-STD-810H, ECSS), and automated pass/fail reporting.
}}

'''SRS Tool''' is a professional [https://en.wikipedia.org/wiki/Shock_response_spectrum Shock Response Spectrum] (SRS) analysis application built for structural dynamics engineers working with OROS [[NVGate]] data acquisition systems. It reads shock recordings directly from NVGate measurement folders, computes SRS using the Smallwood (1981) recursive digital filter, and pushes results back into NVGate as live TCP result channels — all from a single application.

[[File:11_main_full.png|center|800px|thumb|'''Figure 1 — SRS Tool main window.''' Time signal with auto-detected shock zone (top right, yellow markers) and log-log SRS plot (bottom right). Three-channel triaxial measurement loaded: channels x, y, z.]]

----

== What makes SRS Tool unique==

SRS Tool is built around the idea that an engineer should go from raw measurement to qualification verdict in under one minute.

{| class="wikitable" style="width:100%; font-size:12px; border-collapse:collapse;"
! style="width:54%; background:#f0f4f8;" | Feature
! style="width:23%; background:#f0f4f8; text-align:center;" | OROS SRS Tool
! style="width:23%; background:#f0f4f8; text-align:center;" | Typical alternatives
|-
| '''30+ normative limit curves built-in''' — MIL-STD-810H, ECSS, NASA-STD, DEF-STAN, ready to use with no setup
| style="background:#e8f5e9; color:#1b5e20; text-align:center; font-weight:bold;" | ✔ Included
| style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ Manual entry only
|-
| '''Multi-channel Pass/Fail with per-channel verdict''' — x, y, z compared simultaneously in one run
| style="background:#e8f5e9; color:#1b5e20; text-align:center; font-weight:bold;" | ✔ Included
| style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ One channel at a time
|-
| '''NVGate TCP result injection''' — log-log display, autoscaled, direct to project
| style="background:#e8f5e9; color:#1b5e20; text-align:center; font-weight:bold;" | ✔ Native
| style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ Not available
|-
| '''Automatic shock zone detection''' — envelope algorithm, runs on load
| style="background:#e8f5e9; color:#1b5e20; text-align:center; font-weight:bold;" | ✔ Automatic
| style="background:#fff8e1; color:#7a5200; text-align:center;" | ~ Manual only
|-
| '''Primary + Residual SRS''' in a single computation pass
| style="background:#e8f5e9; color:#1b5e20; text-align:center; font-weight:bold;" | ✔ One click
| style="background:#fff8e1; color:#7a5200; text-align:center;" | ~ Two separate runs
|-
| '''SRSS + Worst-case Envelope''' — triaxial multi-axis combination
| style="background:#e8f5e9; color:#1b5e20; text-align:center; font-weight:bold;" | ✔ Included
| style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ Rarely available
|-
| '''Interactive dB cursor''' on Pass/Fail chart — frequency, SRS, limit, margin at a glance
| style="background:#e8f5e9; color:#1b5e20; text-align:center; font-weight:bold;" | ✔ Included
| style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ Rarely available
|}

=== Full feature list ===

* '''Signal acquisition:''' reads NVGate signal files directly
* '''Multi-channel:''' up to 10+ simultaneous channels; channel labels read from NVGate recording metadata (e.g. x, y, z)
* '''Smallwood recursive filter:''' vectorised NumPy implementation; all frequencies computed in a single forward pass
* '''Frequency axis:''' 1/3, 1/6, 1/12 or 1/24 octave resolution; user-defined f_min / f_max
* '''SRS types:''' Maximax (absolute maximum), Positive, Negative
* '''Physical quantities:''' Acceleration SRS + derived Pseudo-Velocity SRS + Pseudo-Displacement SRS
* '''Shock zone:''' auto-detection + manual override (drag on plot or type Start/End in seconds)
* '''Residual SRS:''' computes SRS on the signal segment after the shock ends
* '''Multi-axis combination:''' SRSS and/or Worst-case Envelope across all loaded channels
* '''Pass/Fail:''' 30+ built-in normative curves; user CSV; scale factor (dB); multi-channel worst-case
* '''CSV export:''' full table (per-channel SRS, SRSS, limit, per-channel margin, worst margin, status)
* '''PNG export:''' Pass/Fail chart at 150 dpi
* '''NVGate injection:''' injects all SRS curves into NVGate on log-log display, autoscaled
* '''Preprocessing:''' DC offset removal, noise floor suppression
* '''Dark theme:''' optimised for lab-room screen visibility

----

= Quick Start =

<div style="border:1px solid #2e7d32; border-radius:4px; overflow:hidden; margin:14px 0;">
<div style="background:#2e7d32; color:#fff; font-weight:bold; padding:7px 14px; font-size:12px;">⚡ Five steps from measurement folder to qualification verdict</div>
<div style="padding:12px 16px; background:#f9fdf9; font-size:12px; line-height:2.0;">
# '''Main tab''' → '''Select signal folder…''' → navigate to the NVGate Measurement folder
# Channels appear automatically — shock zone is '''auto-detected''' (yellow markers on signal plot)
# Set '''Q = 10''', range '''1–10 000 Hz''', resolution '''1/12 oct''' → click '''Compute SRS'''
# '''Pass / Fail tab''' → limit curve is pre-set to MIL-STD-810H Mid-field → click '''▶ Run Pass / Fail'''
# Read the per-channel verdict, export CSV / PNG, or click '''Inject into NVGate'''
</div>
</div>

----

= Installation =
----
Warning: this is a beta version. Fell free to use it, test it and send your feeback to customer.care@oros.com

[https://partnerzone.digigram.com/s/ENrEdEMctNALAxD SRS V1.3 here ]
Extract and launch the SRS_Tool.exe

( You need to select the '''folder''' of the signal measurement. )

= Main Tab =

[[File:04_left_panel_main.png|right|300px|thumb|'''Figure 2 — Main tab controls.''' From top: NVGate connection indicator, Signal folder, channel checkboxes with Reload, Calculation parameters, Output type selectors, Compute and Inject buttons.]]

== Signal ==

Click '''Select signal folder…''' to open a folder browser (default root: <code>C:\OROS\NVGate data\Projects</code>). Select the '''Measurement folder''' — channels are listed and the signal is plotted immediately.

== Channels ==

One checkbox per recorded channel, showing label, sampling rate, duration and unit:

<pre> ☑ x (25 600 Hz 13.86 s m/s²)
☑ y (25 600 Hz 13.86 s m/s²)
☑ z (25 600 Hz 13.86 s m/s²)</pre>

Channel labels (x, y, z…) come from the <code>Name</code> field set by the operator in NVGate at recording time.
Uncheck a channel to exclude it. '''↺ Reload channels''' re-reads files from disk after a new recording.

== Calculation parameters ==

{| class="wikitable" style="font-size:12px;"
! Parameter !! Description !! Recommended default
|-
| '''Frequency range''' || f_min to f_max of the SRS output || 1 Hz → 10 000 Hz
|-
| '''Q / Damping''' || Q factor or damping ratio ζ (linked: Q = 1/2ζ) || Q = 10 (ζ = 5 %)
|-
| '''Resolution''' || Octave subdivision: 1/3, 1/6, 1/12, 1/24 oct || 1/12 octave
|}

<div style="border-left:4px solid #1565C0; background:#e8f0fb; padding:9px 14px; margin:10px 0; font-size:12px; border-radius:0 3px 3px 0;">
'''Q = 10 (ζ = 5%)''' is the universal standard for aerospace shock SRS — MIL-STD-810H, ECSS-E-ST-10-03C, NASA-STD-7003A all specify this value. f_max is auto-clamped to Nyquist (f_s / 2).
</div>

== Output ==

; Type
: '''Acc''' — Acceleration SRS. Always available.   '''Vel''' — Pseudo-velocity SRS.   '''Disp''' — Pseudo-displacement SRS. (Vel and Disp require an acceleration input.)

; Curve
: '''Maximax''' — max(positive, |negative|). The standard curve required by most norms.   '''Positive''' — max tensile response.   '''Negative''' — max compressive response.

== Signal and SRS plots ==

[[File:05_signal_plot.png|center|760px|thumb|'''Figure 3 — Time signal plot.''' Three channels (x/y/z) overlaid. Yellow dashed lines mark the auto-detected shock zone. Drag horizontally anywhere on the plot to redefine the zone manually.]]

[[File:06_srs_plot.png|center|760px|thumb|'''Figure 4 — SRS log-log plot.''' Channels x (blue), y (orange), z (green). Each curve is the Maximax acceleration SRS over the detected shock zone. Q = 10, 1/12 octave, 1–10 000 Hz.]]

== Injecting results into NVGate ==

Click '''Inject into NVGate''' (or the duplicate button in the Advanced tab) to send all computed curves via the NVDrive TCP protocol as NVD REAL SPECTRUM channels:

* All SRS curves → separate TCP result channels
* X and Y axes: log scale (set automatically)
* Y axis: autoscaled
* All curves displayed in window '''SRS_Results''' of '''Layout1'''

NVGate channel naming convention:
<pre>SRS Acc Shock AbsMax: x
SRS Acc Shock AbsMax: y
SRS Acc Shock AbsMax: z</pre>

----
----

= Advanced Tab =

[[File:09_left_panel_adv.png|right|300px|thumb|'''Figure 5 — Advanced tab.''' Shock zone section (auto-detection parameters + manual Start/End override), Residual SRS option, preprocessing, and multi-axis SRSS / Envelope.]]

== Shock Zone ==

<div style="border-left:4px solid #e65100; background:#fff8f5; padding:9px 14px; margin:10px 0; font-size:12px; border-radius:0 3px 3px 0;">
'''The shock zone is auto-detected every time a signal loads''' — you normally do not need to touch these settings. Use manual override only to fine-tune the boundary.
</div>

=== Auto-detection ===

The detection algorithm:
# Compute a smoothed envelope: rolling mean of |signal| over a 3 ms window
# Trigger threshold = ''Threshold %'' × peak envelope
# Zone = first to last sample above threshold
# Expand by ''Padding ms'' on each side, clamped to signal bounds

{| class="wikitable" style="font-size:12px;"
! Parameter !! Effect !! Default
|-
| '''Threshold (% of peak)''' || Lower → wider zone; higher → core impact only || 5 %
|-
| '''Padding (ms)''' || Symmetric margin added on both sides of detected zone || 20 ms
|}

'''Padding example:''' shock detected at 8.055 s – 9.978 s with 20 ms padding → zone becomes 8.035 s – 9.998 s, ensuring ring-down is fully captured.

=== Manual override ===

Type '''Start''' and '''End''' (seconds, 3-decimal precision) — the yellow markers on the signal plot update immediately.
Dragging on the signal plot synchronises the spinboxes in return.

=== Residual SRS ===

Check '''Also compute residual SRS''' to run a second computation on the signal after the shock zone end. This captures the free-vibration decay required by MIL-STD-810H Method 517 and ECSS-E-ST-10-03C for fragility assessment. Residual curves appear on the SRS plot labelled "(residual)".

== Advanced Preprocessing ==

{| class="wikitable" style="font-size:12px;"
! Option !! Effect !! Typical use
|-
| '''Remove DC offset''' (N ms) || Subtracts the mean of the first N ms from the whole signal || Sensor bias, thermal drift
|-
| '''Noise floor''' (N ms) || Zeroes the first N ms || Pre-trigger noise before impact
|}

== Multi-axis Combination ==

Enabled automatically when ≥ 2 acceleration channels are loaded. Check one or both options before computing:

{| class="wikitable" style="font-size:12px;"
! Option !! Formula !! Display
|-
| '''SRSS''' — Square Root Sum of Squares || √(SRS_x² + SRS_y² + SRS_z²) || White dashed curve, Maximax only
|-
| '''Worst-case Envelope''' || max(SRS_x, SRS_y, SRS_z) at each frequency || Orange dash-dot curve, all types
|}

----

= Pass / Fail Tab =

[[File:07_left_panel_pf.png|right|300px|thumb|'''Figure 6 — Pass/Fail controls.''' Grouped limit curve library (30+ curves), user CSV option, scale factor, channel selector, Run button, and export buttons.]]

The Pass/Fail tab compares computed SRS against any normative or user-defined limit curve.

== Built-in limit curve library ==

<div style="border-left:4px solid #1565C0; background:#e8f0fb; padding:9px 14px; margin:10px 0; font-size:12px; border-radius:0 3px 3px 0;">
'''30+ normative curves are pre-programmed''' — select a standard from the grouped drop-down and run immediately. No other standalone SRS tool provides this library out of the box.
</div>

{| class="wikitable" style="font-size:12px;"
! Standard !! Curves included
|-
| '''MIL-STD-810H — Method 517''' || Near-field (< 0.3 m), '''Mid-field ★''' (0.5–1.5 m), Far-field (> 1.5 m), Gunfire, Tall vehicles
|-
| '''ECSS-E-ST-10-03C''' || Protoflight, Proto+, Acceptance, Qualification, Protoqualification (equipment & system level)
|-
| '''NASA-STD-7003A''' || Payload near/far-field, structure-borne near/far
|-
| '''DEF-STAN 00-35''' || Land vehicle, Ship (deck), Airborne external/internal
|-
| '''MIL-S-901D''' || High-impact shock Grade A / Grade B
|-
| '''IEST-RP-DTE032''' || Light / medium / heavy equipment
|-
| '''RTCA DO-160G''' || Avionics Cat. A / B / C
|}

★ MIL-STD-810H Mid-field is the default — the most common qualification specification.

=== User-defined CSV ===

Select '''← User-defined (CSV)''', load a two-column file (Hz, g). Interpolation is log-log linear between breakpoints. Example:
<pre>10, 5     100, 50     2000, 50     10000, 50</pre>

=== Scale factor (dB) ===

Scales the limit curve before comparison: L_scaled(f) = L_nominal(f) × 10^(dB/20)

{| class="wikitable" style="font-size:12px;"
! dB || Multiplier || Typical use
|-
| +6 || ×2.00 || Conservative / tighter requirement
|-
| +3 || ×1.41 || Standard qualification margin check
|-
| 0 || ×1.00 || Nominal — no change
|-
| −6 || ×0.50 || Relaxed limit
|}

== Pass/Fail results ==

[[File:03_passfail_result.png|center|760px|thumb|'''Figure 7 — Pass/Fail chart.''' Three channels (x/y/z) vs MIL-STD-810H Mid-field limit (red dashed). All channels are well within spec: the margin subplot (bottom) shows 30–60 dB positive margin throughout the full frequency range.]]

=== Top panel — SRS vs Limit ===

Each channel plotted in a distinct colour. Limit curve: red dashed. '''Red fill''' = exceedance (SRS > limit). '''Orange fill''' = caution zone (0 ≤ margin < 3 dB).

=== Bottom panel — Margin (dB) ===

Margin M(f) = 20 × log₁₀( Limit(f) / SRS(f) )

{| class="wikitable" style="font-size:12px;"
! Colour !! Condition !! Meaning
|-
| style="background:#e8f5e9; color:#1b5e20;" | Green || M ≥ 3 dB || Well within specification
|-
| style="background:#fff8e1; color:#7a5200;" | Orange || 0 ≤ M < 3 dB || Caution — low margin
|-
| style="background:#ffebee; color:#b71c1c;" | Red || M < 0 dB || '''FAIL''' — exceedance
|}

=== Interactive cursor ===

Hover anywhere on either panel to see a floating readout snapped to the nearest frequency band, showing frequency, SRS value, limit value, margin in dB, and PASS/FAIL status. The readout border turns green, orange or red accordingly.

=== Verdict text ===

The result box below the chart shows global verdict, per-channel minimum margin, and the 10 worst exceedance frequencies. Example output:

<pre>PASS — Maximax SRS
Limit: MIL-STD-810H Meth.517 — Mid-field (0.5–1.5 m)

Per-channel result:
PASS x min +42.1 dB @ 500 Hz
PASS y min +38.7 dB @ 342 Hz
PASS z min +45.3 dB @ 1000 Hz

Worst margin (all channels): +38.7 dB @ 342.0 Hz
No exceedance detected over the computed frequency range.</pre>

== Export ==

{| class="wikitable" style="font-size:12px;"
! Button !! Output !! Content
|-
| '''Export CSV…''' || .csv || Per-channel SRS · Worst SRS · Limit · Per-channel margin · Worst margin · Status. Header block includes curve name and scale factor for traceability.
|-
| '''Export graph PNG…''' || .png / .pdf || Both panels at 150 dpi.
|}

----

= Calculation Reference =

== Shock Response Spectrum ==

The SRS is the peak response of a bank of Single Degree Of Freedom (SDOF) oscillators, each with a different natural frequency f_n, driven by a common base acceleration x''(t):

<code>z''(t) + 2ζωₙz'(t) + ωₙ²z(t) = −x''(t)</code>

{| class="wikitable" style="font-size:12px;"
! Curve !! Definition !! Standard?
|-
| Positive SRS || maxt[ ωₙ² z(t) ] || Supplementary
|-
| Negative SRS || maxt[ −ωₙ²z(t) ] || Supplementary
|-
| '''Maximax SRS''' || max(Positive, Negative) || '''Required by most norms'''
|}

== Smallwood Recursive Filter ==

The Smallwood (1981) filter avoids step-by-step numerical integration, giving an exact discrete-time equivalent with coefficients computed once per frequency:

{| style="font-size:12px; font-family:monospace; border-collapse:collapse; margin:8px 0;"
|-
| style="padding:2px 10px;" | E = exp(−ζωₙΔt)    K = ωd·Δt    (ωd = ωₙ√(1−ζ²))
|-
| style="padding:2px 10px;" | b₀ = 1 − E·sin(K)/K     b₁ = 2(E·sin(K)/K − E·cos(K))     b₂ = E² − E·sin(K)/K
|-
| style="padding:2px 10px;" | a₁ = 2E·cos(K)     a₂ = −E²
|-
| style="padding:2px 10px; font-weight:bold;" | y[k] = b₀x[k] + b₁x[k−1] + b₂x[k−2] + a₁y[k−1] + a₂y[k−2]
|}

All N natural frequencies are processed in a '''single forward pass''' through the signal using NumPy broadcasting — typically 50–100× faster than a frequency-by-frequency loop.

== Frequency axis ==

Log-spaced at 1/n octave: '''f_k = f_min × 2^(k/n)'''

{| class="wikitable" style="font-size:12px;"
! Resolution !! Bands 1–10 000 Hz
|-
| 1/3 octave || 40
|-
| 1/6 octave || 80
|-
| '''1/12 octave''' (default) || '''160'''
|-
| 1/24 octave || 320
|}

== Q factor and damping ==

<code>Q = 1/(2ζ) ↔ ζ = 1/(2Q)</code>

{| class="wikitable" style="font-size:12px;"
! Q !! ζ !! Use
|-
| '''10''' || '''5 %''' || '''Aerospace standard — MIL-STD-810, ECSS, NASA'''
|-
| 50 || 1 % || Lightly damped structures
|-
| 5 || 10 % || Rubber-mounted, heavily damped
|}

== Primary and Residual SRS ==

{| class="wikitable" style="font-size:12px;"
! Zone !! Signal segment !! Required by
|-
| '''Primary''' || [t_start → t_end] — the shock transient || All norms
|-
| '''Residual''' || [t_end → end] — free vibration decay || MIL-STD-810H §517, ECSS §8.4.3
|}

== Pseudo-velocity and pseudo-displacement ==

{| class="wikitable" style="font-size:12px; font-family:monospace;"
! Quantity !! Formula !! Unit (SA in m/s²)
|-
| Pseudo-velocity || SV(fn) = SA(fn) / (2π·fn) || m/s
|-
| Pseudo-displacement || SD(fn) = SA(fn) / (2π·fn)² || m
|}

== Multi-axis combination ==

{| class="wikitable" style="font-size:12px;"
! Method !! Formula !! Applied to !! Use case
|-
| '''SRSS''' || √(SA_x² + SA_y² + SA_z²) || Maximax only || Euclidean resultant, triaxial sensor
|-
| '''Worst-case Envelope''' || max(SA_x, SA_y, SA_z) at each f || All types || Space programmes (ECSS App. H)
|}

----

= Supported Input Units =

{| class="wikitable" style="font-size:12px; width:100%;"
! Unit !! Physical quantity !! Vel/Disp SRS available
|-
| '''m/s², g''' || Acceleration || style="background:#e8f5e9; color:#1b5e20; text-align:center;" | ✔ Yes
|-
| m/s, mm/s || Velocity || style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ No
|-
| m, mm, µm || Displacement || style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ No
|-
| N, kN || Force || style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ No
|-
| V, mV || Voltage || style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ No
|-
| Pa, N/m² || Pressure || style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ No
|-
| rad/s, RPM || Angular velocity || style="background:#ffebee; color:#b71c1c; text-align:center;" | ✘ No
|}

----

= Glossary =

{| class="wikitable" style="font-size:12px; width:100%;"
! style="width:20%;" | Term !! Definition
|-
| '''SRS''' || Shock Response Spectrum. Peak SDOF response as a function of natural frequency.
|-
| '''Maximax''' || max(Positive, |Negative|). The absolute peak response — required by most norms.
|-
| '''SDOF''' || Single Degree Of Freedom. A mass–spring–damper system with one resonant frequency.
|-
| '''Q factor''' || Quality factor. Q = 1/(2ζ). Q = 10 is the universal aerospace standard.
|-
| '''ζ''' || Damping ratio. Fraction of critical damping. ζ = 5 % ↔ Q = 10.
|-
| '''Primary SRS''' || SRS over the shock transient [t_start, t_end].
|-
| '''Residual SRS''' || SRS on the post-shock free vibration [t_end, end].
|-
| '''SRSS''' || Square Root Sum of Squares: √(SRS_x² + SRS_y² + SRS_z²).
|-
| '''Envelope''' || Point-by-point max across channels at each frequency.
|-
| '''Margin (dB)''' || 20·log₁₀(Limit/SRS). Positive → PASS, negative → FAIL.
|-
| '''Padding''' || Symmetric time margin added around the auto-detected shock zone.
|-
| '''Pyroshock''' || Shock from explosive devices: separation bolts, pyrocutters, pin pullers.
|-
| '''.orm''' || NVGate JSON channel metadata: sampling rate, unit, name.
|-
| '''.ors''' || NVGate binary signal: float32 little-endian samples, SI units.
|-
| '''NVDrive''' || OROS TCP protocol for programmatic communication with NVGate.
|}

----

= Appendix SRS Limit Curves — Normative Reference =

This page documents all predefined SRS limit curves available in the SRS Tool.
Each curve is identified by a '''confidence level''' tag shown next to its name in the interface.

== Confidence level indicators ==

{| class="wikitable" style="width:100%"
! Tag !! Meaning !! What to expect
|-
| style="background:#e8f5e9; color:#1b5e20; font-weight:bold; text-align:center;" | [normative]
| Curve taken '''directly from the published standard''' as an SRS specification.
| Breakpoints are faithful to the document. Use for compliance testing.
|-
| style="background:#fff3e0; color:#e65100; font-weight:bold; text-align:center;" | [approximate]
| Standard defines a '''time-domain waveform''' (half-sine, sawtooth…), '''not''' an SRS.
| The SRS envelope is computed from the pulse shape. For exact results, import the waveform and run compute_srs() on it.
|-
| style="background:#fce4ec; color:#880e4f; font-weight:bold; text-align:center;" | [indicative]
| Levels depend on '''mounting position, equipment mass or mission profile''', or the exact document version was not available.
| Use as a first-pass estimate only. Always verify with the applicable programme document.
|}

All curves use '''Q = 10''' (damping ζ = 5 %) and acceleration units (g).
Between breakpoints, interpolation is '''log-log linear''' (constant dB/octave slope).

== Summary table ==

{| class="wikitable sortable" style="width:100%; font-size:90%;"
! Standard !! Sector !! Tag !! Application !! Peak level !! Freq. range
|-
| NASA GEVS 2500 g || Space || style="background:#e8f5e9; color:#1b5e20;" | normative || Hardware on primary structure || 2 500 g || 20–10 000 Hz
|-
| NASA GEVS 1000 g || Space || style="background:#e8f5e9; color:#1b5e20;" | normative || Hardware on panel or bracket || 1 000 g || 20–10 000 Hz
|-
| NASA GEVS 3750 g (Qual.) || Space || style="background:#e8f5e9; color:#1b5e20;" | normative || Qualification unit (dedicated test article) || 3 750 g || 20–10 000 Hz
|-
| Ariane 5 Equipment Bay || Space || style="background:#fce4ec; color:#880e4f;" | indicative || Satellite equipment bay, component level || 2 000 g || 100–10 000 Hz
|-
| Ariane 6 || Space || style="background:#fce4ec; color:#880e4f;" | indicative || All payload positions, component level || 1 600 g || 100–10 000 Hz
|-
| VEGA-C || Space || style="background:#fce4ec; color:#880e4f;" | indicative || Small satellite missions, component level || 1 200 g || 100–10 000 Hz
|-
| ECSS-E-ST-10-03C Protoqual. || Space || style="background:#fce4ec; color:#880e4f;" | indicative || European space programmes, proto-qualification || 2 000 g || 20–10 000 Hz
|-
| MIL-STD-810H M517 Near-field || Military / Pyro || style="background:#e8f5e9; color:#1b5e20;" | normative || Equipment < 0.5 m from pyrotechnic source || 10 000 g || 100–10 000 Hz
|-
| MIL-STD-810H M517 Mid-field || Military / Pyro || style="background:#e8f5e9; color:#1b5e20;" | normative || Equipment 0.5–1.5 m from pyrotechnic source || 1 000 g || 100–10 000 Hz
|-
| MIL-STD-810H M517 Far-field || Military / Pyro || style="background:#e8f5e9; color:#1b5e20;" | normative || Equipment > 1.5 m from pyrotechnic source || 100 g || 100–10 000 Hz
|-
| MIL-STD-810H M516 Functional 40 g || Military / Mech || style="background:#fff3e0; color:#e65100;" | approximate || Functional shock — must operate before and after || 80 g (2×A) || 5–2 000 Hz
|-
| MIL-STD-810H M516 Crash 40 g || Military / Mech || style="background:#fff3e0; color:#e65100;" | approximate || Crash hazard — must not endanger personnel || 60 g || 5–2 000 Hz
|-
| MIL-STD-810H M516 Bench 15 g || Military / Mech || style="background:#fff3e0; color:#e65100;" | approximate || Bench handling — drops during maintenance || 30 g || 5–2 000 Hz
|-
| MIL-S-901D Grade A || Military / Naval || style="background:#fce4ec; color:#880e4f;" | indicative || US Navy lightweight shipboard equipment (< 136 kg) || 2 000 g || 20–10 000 Hz
|-
| MIL-S-901D Grade B || Military / Naval || style="background:#fce4ec; color:#880e4f;" | indicative || US Navy medium-weight equipment (136–2 268 kg) || 1 000 g || 20–10 000 Hz
|-
| DO-160G Cat. B 6 g || Aviation || style="background:#fff3e0; color:#e65100;" | approximate || Airborne equipment — operational flight shock || 12 g || 5–2 000 Hz
|-
| DO-160G Cat. C 15 g || Aviation || style="background:#fff3e0; color:#e65100;" | approximate || Avionics — bench handling during maintenance || 30 g || 5–2 000 Hz
|-
| DO-160G Cat. D 20 g || Aviation || style="background:#fff3e0; color:#e65100;" | approximate || Airborne equipment — crash / emergency landing || 40 g || 5–2 000 Hz
|-
| DEF STAN 00-35 Cat. M || European Defence || style="background:#fce4ec; color:#880e4f;" | indicative || UK defence — general military ground equipment || 1 000 g || 10–10 000 Hz
|-
| DEF STAN 00-35 Cat. P || European Defence || style="background:#fce4ec; color:#880e4f;" | indicative || UK defence — aircraft store / weapon release || 2 000 g || 100–10 000 Hz
|-
| GAM EG-13 Choc sévère || European Defence (DGA) || style="background:#fce4ec; color:#880e4f;" | indicative || French military — pyrotechnic devices, ejection seats || 2 000 g || 20–10 000 Hz
|-
| GAM EG-13 Choc modéré || European Defence (DGA) || style="background:#fce4ec; color:#880e4f;" | indicative || French military — vehicle impacts, transport drops || 500 g || 10–5 000 Hz
|-
| STANAG 4370 AECTP-201 M417 || NATO || style="background:#fce4ec; color:#880e4f;" | indicative || NATO — pyroshock, severity level 3 || 2 000 g || 100–10 000 Hz
|-
| STANAG 4370 AECTP-201 M403 || NATO || style="background:#fff3e0; color:#e65100;" | approximate || NATO — mechanical shock, severity level 3 || 50 g || 5–2 000 Hz
|-
| IEC 60068-2-27 15 g / 11 ms || Industrial || style="background:#fff3e0; color:#e65100;" | approximate || General industrial / commercial equipment qualification || 30 g || 5–2 000 Hz
|-
| IEC 60068-2-27 50 g / 11 ms || Industrial || style="background:#fff3e0; color:#e65100;" | approximate || Rugged industrial equipment — severe shock || 100 g || 5–2 000 Hz
|-
| IEC 60068-2-27 100 g / 6 ms || Industrial || style="background:#fff3e0; color:#e65100;" | approximate || Harsh shock environments — impacts, sudden accelerations || 200 g || 5–2 000 Hz
|-
| IEC 61373 Cat.1 Class B || Railway || style="background:#fff3e0; color:#e65100;" | approximate || Railway — equipment mounted on vehicle body (interior) || 6 g || 2–2 000 Hz
|-
| IEC 61373 Cat.1 Class A || Railway || style="background:#fff3e0; color:#e65100;" | approximate || Railway — bogie-mounted equipment (running gear) || 15 g || 2–2 000 Hz
|-
| IEC 61373 Cat.2 Under-body || Railway || style="background:#fff3e0; color:#e65100;" | approximate || Railway — under-body / axle-box mounted equipment || 50 g || 2–2 000 Hz
|}

----

== How the SRS Tool uses these curves ==

# Select a curve in the '''Pass/Fail''' tab.
# The tool interpolates the curve at the same frequency resolution as the measured SRS using log-log linear interpolation.
# Margin is computed point-by-point: '''Margin (dB) = 20 × log₁₀(limit / SRS)'''
# The overall result is PASS only if the margin is positive at '''all''' frequencies.

== Adding a custom curve ==

You can import your own limit curve via a two-column CSV file (frequency Hz, level g) using the '''Load CSV''' button in the Pass/Fail tab. The SRS Tool applies the same log-log interpolation as built-in curves.

[[Category:SRS Tool]]
[[Category:Test Standards]]

==Disclaimer==

This tools is deliver free of charge, Support is not automatically provided on this tool.

FFT Spectrum Analyzer Multipurpose

2026-09-30T12:34:11Z

Lmagimel: /* Applications/ Case study */

[[category:WikiOros]]
{{#seo:
|title=Multi-function FFT Spectrum Analyzer for Noise & Vibration | OROS
|keywords=FFT analyzer, vibration analyzer, spectrum analyzer, acoustic analysis, modal analysis, order tracking, octave analyzer, real-time signal processing, NVGate
|description=High-performance portable FFT spectrum analyzer for acoustic and vibration measurement. Supports up to 1000 channels, real-time analysis, and modal testing.
|image=FFT_analyzer_hardware_2.webp
}}

__NOTOC__
[[File:O4_range Gamme O4 + OR10 + OR35 + OR36 + OR38.png|frame|left|FFT analyzers|alt=Analyzer acoustic vibration multichannel]]
The OROS series multi-function FFT analyzer is PC-based, high-performance, high reliability and easy to operate.

We have further increased the arithmetic processing speed and increased the real-time analysis capacity to more than 16 times that of the conventional model (OR20 series). An ethernet LAN cable is used as the interface.

In addition, the number of simultaneous recording channels in the frequency range (40 kHz) has been expanded to a maximum of 1000 channels and the dynamic range has been improved to 140 dB. These improvements allow a user to measure time signals over a wide frequency range simultaneously on multiple channels.

{|class="wikitable" style="width:100%;"
|style="background: #0000A0; text-align:center;"|<big>[https://www.oros.com/demo-request/ Schedule a demo]</big>
|style="background: red; text-align:center;"|<big>[https://www.oros.com/quote-request-form/ Get a quotation]</big>
|style="background: green; text-align:center;"|<big>[[FFT_Spectrum_Analyzer_Multipurpose#Full_technical_support|Contact support]]</big>
|}

<gallery gallery="" mode="packed-hover" align="left">
File:TWanalyzer2.jpg|alt=Vibration measurement up to 1000 channels|Analyzer Cascade mode
File:Situation auto hammer pc.jpg|alt=Hammer test on automotive in anechoic room|Modal FRF measurement
File:Auto anechoic chamber2.webp|alt=Sound intensity measurement in anechoic room|Acoustic Sound intensity
File:Turbo orbit.JPG|alt=Turbomachinery orbit vibration measurement|Vibration on turbomachinery
File:Or34 situation.jpg|alt=NVH measurement on a car|NVH automotive measurement
File:Airfrance.jpg|alt=Acoutic measurement with octave analyzer in a plane|In flight measurement
</gallery>

==Main Features==

* From 2-32 channels
* Synchronous measurements up to 1000ch is possible by combining multiple analyzers (*)
* Compact and lightweight (4ch model 1.5kg, 10ch model 3.0kg)
* Achieves high-speed communication with a PC through an ethernet LAN interface
* Equipped with an output channel as a standard
* Built-in internal battery as a standard
* Record, Fast Fourier Transform analysis, octave analysis, and tracking analysis can be performed simultaneously at high sampling frequencies
* Realtime measurements and post-analysis can be performed with the same software platform ([[NVGate]])
* In addition to sound and vibration, strain and temperature can be measured at the same time using XPODS (**)
* CAN-bus module compatible (***)
* Recording is possible with analyzer in standalone mode or in conjunction with a PC (****)

(*) Synchronous measurements that combine multiple analyzers is possible only for TW OR35 / TW OR36 / TW OR38.

(**) The strain / temperature module(XPOD) can be installed only on TW OR35 / TW OR36 / TW OR38.

(***) CAN-bus module can be installed only on OR10/ TW OR35 / TW OR36 / TW OR38.

(****) Stand-alone measurements are possible only with SSD-equipped models OR10 / TW OR35 / TW OR36 / TW OR38.

==Introducing the hardware==
[[File:hardware.png|right|Spectrum analyzer|alt=OROS instrument analyzer for noise and vibration]]
===Small and lightweight===

OR10-8ch model: 0.8kg

O4: 4ch model: 0.5kg

OR35 TW: 10ch model: 3.0kg

OR36 TW: 16ch model: 5.2kg

OR38 TW: 32ch model: 8.2kg
 
 
 
 
 
 

===Ethernet LAN interface===
[[image:laninterface.PNG|right|FFT analyzer ethernet|alt=Back of FFT analyzer : ethernet connection for PC]]
Achieves high-speed communication with a PC through an ethernet LAN interface
 
 
 
 
 
 

===Built-in battery===
OR10/ OR35/ TW OR36 / TW OR38: Models have a built-in battery.

OR10 can be operated by battery for 4hours

OR35 can be operated by battery for 3 hours.

TW OR36 / TW OR38 can be operated by battery for 2 hours.

04 operate with battery PC.

===External battery===
[[File:external battery.PNG|200px|right|external battery on analyzer|alt=External battery on spetrum analyzer]]

We provide a compact and lightweight external battery that can be installed on all models.

Can be used for up to 8 hours with one external battery.

Can be stored in a "PC integrated carrying case".
 

 

 
 

 

===Synchronous Measurement Of Up To 1000 Channels is Possible by Combining Multiple Analyzers===
(TW OR35 / TW OR36 / TW OR38 only)

High-precision synchronous measurements (0.2 ° @ 20kHz) are possible by simply connecting each analyzer using a general-purpose LAN cable. Function measurements can be taken with the hammer connected to the third unit in the chain and the accelerometers connected to each unit. Tracking analysis can be completed with the accelerometers connected to each unit while using a tachometer connected to the second unit in the chain.

[[File:teamworkanalyzer.png|700px|cascade mode]]

=== Measure From Sound / Vibration and Strain Gauge / Temperature ===
(OR35 / TW OR36 / TW OR38 only)
[[File:Usersmanual_32.jpg|200px|right|Conditioner on analyzer|alt=Temperature and straing conditionner]]
By mounting a [[XPod_Bridge_-_Strain_gauge|strain gauge conditioner]] and [[NVGate_X-Pod:_Temperature_probe_conditioner|thermocouple conditioner]] on the Oros FFT analyzer, it is possible to measure strain and temperature data in addition to sound and vibration data.

Thermocouple amplifier: Supports types J, K, T, N, E (with temperature compensation)
 
 
 
 

===CAN-bus Module Available ===
[[File:Can_Bus.jpg|150px|right|Can bus measurement|alt=Can bus to add on OROS instrument]]
(OR10/ TW OR35 / TW OR36 / TW OR38 only)

By using the [[NVGate_Can_BUS|CAN-bus module]], tracking analysis can be performed using information such as the engine speed flowing from the CAN-bus. By using this function, tracking analysis can be performed without using a tachometer.
 
 

===Recording is possible without the use of a PC by using the FFT analyzer in stand alone mode ===
(OR35 / TW OR36 / TW OR38 only)

[[File:d_rec.PNG|150px|right|Data acquisition recorder|alt=Vibration time signal Measurement without PC]]
The FFT analyzer is equipped with a [[NVGate_D-Rec|record-only button]]. Simply select a predefined measurement setup and press the record button to record onto the FFT analyzer alone without the use of a PC.

 
 
 
 

In addition, the back of the Fast Fourier Transform Spectrum Analyzer Multipurpose is equipped with an audio terminal and power supply. It is possible to record audio data while also measuring the time signal. The analyzer also can supply power to required sensors, such as proximity probes, tachometers and DC sensors.

[[File:FFT_analyzer.jpg|600px|Back of the hardware|alt=all the plug available on the backside of instrment]]
 
 
 

==Software Introduction==

*Easy-to-use interface
*Real-time measurement / post-analysis can be performed with the same software platform (NVGate)
*One-click report creation function

===Start the Measurement Quickly and Easily===

You can start measuring immediately by using the quick function provided in the OROS FFT analyzer mult function. This is completed by defining the number of input channels in the channel field and the measurement/analysis content in the show results area.

The Oros series FFT spectrum analyzer multifunction uses an interface similar to the ribbon interface used by Microsoft Office. All menus are accessible via the ribbon interface, making it easy to change measurement settings.

[[File:home3.PNG|800px|software ribbon|alt=NVgate ribbon technology]]

===One-click Setting Function===
With the Oros series multi-purpose FFT analyzer, you can display related measurement condition settings by double-clicking on the measurement screen. For example, if you double-click on the FFT analysis screen, the dialog for setting the measurement conditions for FFT analysis will be displayed on the screen as shown below.

[[File:FFT_analyzer_spectrum.png|500px|FFT spectrum|alt=Parameters easy to change]]

===Control Panel===
In addition, the OROS FFT spectrum analyzer is equipped with a control panel function that allows users to save frequently used measurement settings for quick access. By using this function, all settings can be changed on the [[NVGate_Control_Panel|control panel]]. For example, the following is the setting screen for a hammer test. By saving the input settings, threshold settings, and FFT analysis settings to the control panel as shown below, it is possible to make all the necessary settings quickly by only using the control panel.

===Various filters can be applied to recorded signals & FFT analysis results===
Four types of filters: Low-pass filter, high-pass filter, band-bus filter, and band-stop filter, can be applied to the results of recorded signal and FFT analysis. By using a [[NVGate_Filter_Builder|filter]], it is possible to remove abnormal noise components from the recorded signal and perform processing such as reproducing the extracted abnormal noise components.

[[File:filter_fft.png|600px|Filter analyzer]]

===Extract arbitrary order components from the color spectrum graph in real time===

Any order component can be extracted in real time from the color spectrum graph.

[[File:extraction.jpg|Synchronous order analysis extraction|alt=order extraction on vibration software]]

Easy-to-read Layout

The area for arranging windows is called a layout.
The OROS multi function FFT analyzer can create up to 16 layouts per project. You can easily arrange your windows by using the layout function. And your windows will open the same way each time.

It is possible to display up to 32 screens in one layout.

Up to 512 windows (= 16 x 32) can be displayed.

<big>'''Layout utilization example:'''</big>

'''Layout 1''': Record waveform, FFT analysis result, order ratio analysis result displayed

[[File:Fft_extraction_data.jpg|Order extraction|alt=Recorder and FFT together]]

'''Layout 2''': Display 3D frequency analysis results and 3D order ratio analysis results

[[File:waterfall_extract_order.jpg|3d display order spectrum |alt=NVGate software on line measurement]]

'''Layout 3''': Display 3D '''octave analyzer''' analysis results

[[File:octave waterfall.jpg|Octave acoustic measurement 3d display|alt=Acoustic measurement with octave]]

===Easy operation <Graph layout selection button>===

You can easily arrange windows just by selecting the grid menu.

[[File:gridwindows_PNG.PNG|NVGate icon|alt=Grid icon]]

Batch copy of measurement data with one menu. Numerical data can be transferred to Excel all at once.

[[File:excel_report.jpg|400px|FFT spectrum Report function|alt=export your data]]

Data measured at different times can be overwritten by dragging which allows for easily comparing measurement data.

[[File:drag_drop_report.jpg|Software NVGate]]

===One-click report creation function===

Simply click the report button located on the ribbon interface to create a [[NVGate_Report|report]] file containing the current measurement results.

[[File:allwindows_.PNG|NVGate report|alt=report all windows]]

• The content of the report is customizable. Customize it to the format that best suits your needs.

[[File:report-customize.jpg|500px|customize FFT analyzer software report|alt=Post analysis vibration software]]

===Measurement data search function===
[[File:pc cloud.PNG|right|Data stored|alt=cloud vibration data]]
Various information (meta-data) can be added when saving measurement data.
You then can search for measurement data and projects based on the added information.

Filter:
* Project name
* Measurement date and time
* Measurement conditions
* Measurement target
* Measurement site
* User
[[File:filter_project.PNG|550px|meta data on noise and vibration software NVGate|alt=Acoustic and vibration search function]]

===Fail judgment function as standard===
The [https://youtu.be/kx2HbcvfG_w pass / fail feature] of NVGate can be performed automatically after setting the desired bounds.

In the example below, a dialog is displayed when the product fails, but it is also possible to output a contact signal instead of the dialog.

[[File:fail_test.JPG|Pass/fail test on resonnance frequency impact hammer test|alt=Failed pass test on resonnance frequency test]]

===Automate post-analysis processing===

The same processing can be continuously performed for record files measured multiple times. By using this function, it is possible to automate the generation of reports, and it is possible to generate the same number of post-analysis results and EXCEL-based reports as record files with one click. Processing that used to take more than a week can now be done in a few hours.

[[File:BPP2.jpg|Post processing acoustic measurement batch |alt=Offline measurement]]

==specification==
===Main specifications===

{| class=wikitable style="width:100%;" style="text-align:center;"
! style="width:16%|
! style="width:21%|O4
! style="width:21%|OR35
! style="width:21%|OR36
! style="width:21%|OR38
|-
!colspan=6 style="text-align:center;" | Dynamical Input channel
|-
! Number of analysis channels
| 2, 4
| 6, 10 (Select Analysis or tachometer on 2 channels)
| 4, 8, 12, 16
| 8, 16, 24, 32
|-
! Terminal shape
| colspan=5| BNC
|-
!Input coupling and sensor support
|colspan=5| Compatible with AC, DC / ICP (sensor with built-in amplifier) and TEDS
|-
!Cutoff frequency
|colspan=5| - 3dB at AC cutoff frequency 0.35Hz
|-
! Input voltage range
|colspan=5| +/- 100mV to +/- 40V (auto range function)
|-
! Maximum voltage
|colspan=5| 60V
|-
!Anti-Aliasing filter
|colspan=5| 400dB / OCT
|-
!Input impedance
|colspan=5| 1MΩ <100pF
|-
!A / D converter
|colspan=5| 24-bit
|-
!Dynamic range
|colspan=5| >140dB
|-
!Channels-to-channels phase accuracy
|colspan=5| ± 0.02 ° (10V, 20kHz range)
|-
!Input filter
|colspan=5| Acoustic A, C, Z, low pass, high pass, band pass, integrator, differentiator, time axis integration function
|-
!Sampling frequency of the signal
|colspan=5|Select from 13 ranges between 102.4kHz and 2.048kHz.
|-
!colspan=6| Tachometer channel (Ext synch channels)
|-
!Number of input channels
|colspan=2|2 channels
|colspan=2|2 channels (up to 6 channels as an option)
|-
!Sampling frequency
|colspan=5|6.4MHz (counter method)
|-
!Voltage range
|colspan=4|+/- 300mV 40V
|-
!colspan=6| DC input
|-
!number of input channels
|colspan=1|none
|colspan=3|Analysis channel can be switched and used
|-
!Voltage range
|colspan=1|none
|colspan=3|22 bits, ± 40V, offset DC 100μV or less
|-
!Sampling frequency
|colspan=1|none
|colspan=3|15Hz or 12.5Hz
|-
!colspan=6|Calibration function
|-
!Calibration method
|colspan=5| Automatic sensitivity calculation by numerical input or reference signal (for position and standard vibration oscillatory meter)
|-
!How to use at the time of measurement
|colspan=5|Select by registered sensor name such as model name and machine number
|-
!colspan=6|Trigger function
|-
!Trigger type
|colspan=5|Edge, period, △ RPM, △ level, manual, multi (A or B, A and B, A after B)
|-
!Trigger delay
|colspan=5|Pre- and post-trigger functions
|-
!Trigger signal
|colspan=5|Select from any input channel
|-
!colspan=6|Record function
|-
!Sampling frequency
|colspan=5|13 ranges from 102.4kHz to 2.048kHz possible to select 2 types of range together
|-
!A / D converter resolution
|colspan=5| 24-bit or 16-bit
|-
!Hard drive size
|PC hard drive
|colspan=1|64 GB SSD
|colspan=2|128 GB removable SSD hard drive (256GB or 512 GB optional)
|-
!colspan=6|FFT analysis performance
|-
!Analysis frequency range
|colspan=1|0.8Hz-100kHz
|colspan=4|0.8Hz-40kHz
|-
!FFT block size
|colspan=5|256, 512, 1024, 2048, 4096, 8192, 1638
|-
!Number of analysis lines
|colspan=5|101, 201, 401, 801, 1601, 3201, 6401
|-
!Zoom analysis
|colspan=5|2 to 128 times (all channels at the same time)
|-
!Overlap setting
|colspan=5|0-99.99%
|-
!Window function
|colspan=5|Flat Top, Hanning, Humming, Kaiser Vessel, Rectangular, Force / Response
|-
!Average mode
|colspan=5|Time, frequency, fdsa / linear, exponential, peak hold
|-
!colspan=6|Analysis / display function
|-
!Time series
|colspan=5|Real-time waveform, record waveform, DC, Max, Min, RMS
|-
!FFT analysis
|colspan=5|Linear power spectrum, average spectrum, PSD, cross spectrum,
transfer function (H1, H2), copying function
|-
!Display color
|colspan=5|Display color: Arbitrary specification of trace, cursor, background, and grid display colors

|-
|-
!colspan=6|Options:
|-

!colspan=6|Time domain analysis (ORNV-TDA)
|-
!Analysis items
|colspan=5|Monitor display for arbitrary time (msec to day), effective value for arbitrary section, Min, Max, Peak,
Peak / Peak, RMS, DC, crest factor, Skew, Kurtosis
|-
!colspan=6| 1/n octave analysis (ORNV-OCT)
|-
!method
|colspan=5|Digital filter operation on time domain
|-
!Analysis band
|colspan=5|1/1, 1/3, 1/12, 1/24 octave (IEC1260: 1995 Class 1, ANSI S1.11-1986)
|-
!Analysis frequency
|colspan=5|Simultaneous analysis of all channels at 20kHz is possible (DSP option may be required)
|-
!Average
|colspan=5|Fast, Slow, lmpulse, LEQ, constantBT, linear repeat,exponential
|-

!colspan=6| Multi-sound level meter [ORNV-OVA]
|-
!Operation method
|colspan=6|Time series signal digital operation
|-
!Acoustic weighting
|colspan=6|Linear, A, C
|-
!Measurement
|colspan=6|Leq, Fast, Slow, lmpulse, average, Peak, Max, Min
|-
!Average
|colspan=6|Fast, Slow, lmpulse, LEQ, constantBT, linear repeat,exponential
|-

!colspan=6| Synchronous Order tracking analysis [ORNV-ORD]
|-
!Analysis function
|colspan=5| Instantaneous and average spectrum,phase, order profile and overall.
|-
!Maximum rotation speed
|colspan=5|1,200,000 RPM
|-
!Max analysis ordersetting
|colspan=5|6.25, 12.5, 25, 50, 100, 200, 400
|-
!Number of analysis lines
|colspan=5|25-800
|-
!Analysis bandwidth
|colspan=5|resampling method and fixed sampling method
|-
!display
|colspan=5|Simultaneous display of 3D display and tracking order, simultaneous display of time signal
|-

!colspan=6| Rotational torsion analysis [ORNV-IVC]
|-
!Operation method
|colspan=5| Digital Frequency Voltage converter
|-
!Number of analysis channels
|colspan=2|2ch
|colspan=3|2ch (up to 6ch as an option)
|-

|-
!colspan=6| Rotation diagnosis function [ORNV-FFTDiag]
|-
!Analysis items
|colspan=5| Envelope analysis, cepstrum, self-cross function, MAX, MIN, peak detection from block data, simulated tach,
|-

!colspan=6| Output Channel
|-
!Number of output channels
|colspan=1| 1ch (lemo conector, include)
|colspan=1| 2ch
|colspan=2| 2ch (up to 6ch as an option)
|-
!Output waveform
|colspan=1|Sinus, step sinus, sweep sinus, chirp, multi-sinus, random (pink and white), DC voltage, record signal
|colspan=3|Sinus, step sinus, sweep sinus, chirp, multi-sinus, random (pink and white), DC voltage, record signal
|-
!Digital / Analogic converter
|colspan=1|24 bits
|colspan=3|24 bits

|-
!Output voltage
|colspan=1|+/- 10V
|colspan=3|+/- 10V

|-
!Output Impedance
|colspan=1|50 Ω
|colspan=3|50 Ω
|-
!Frequency range
|colspan=1|~ 100kHz
|colspan=3|~ 40kHz
|-
!Sweep mode
|colspan=1|Sweep and step, analyze, trigger and sync, linear and log
|colspan=3|Sweep and step, analyze, trigger and sync, linear and log

|-
!Synchronization with the analysis
|colspan=1|Synchronization and free run
|colspan=3|Synchronization and free run
|-
!Output protection
|colspan=1|Stabilization with time specification and forced stop button
|colspan=3|Stabilization with time specification and forced stop button
|-
|-
!colspan=6|Data
|-
!Image and print
|colspan=5|Image, printing for Windows and user template creation function for Word and Excel
|-
!File
|colspan=5| TXT, UFF, MATLAB, WAV (OROS and Audio) SDF, binary, ATFX (optional)
|-
!Data entry
|colspan=5|WAV, TXT, UFF and OR20 series AE2
|-
|-
!colspan=6|Dimensions / weight
|-
!Dimensions (width x height x depth mm)
|35 x 110 x 185
|56 × 246 × 222
|102 x 260 x 311
|102 x 364 x 311
|-
!Weight
| 0.5kg
| 2.8kg
| 5.2 kg
| 8.2 kg
|-
!colspan=6|Power supply
|-
!AC
|colspan=5|AC 100V-240V
|-
!DC
| USB 3.0 type C 5V
| 10V-28V, 20VA
| 10V-28V, 60VA
| 10V-28V, 100VA
|-
!DC battery internal operating time (built-in)
| NA : using PC battery
| 3h
| 2h
| 2h
|-
!Recommended operating temperature range
|colspan=1| 0 ℃ ～ 40 ℃
|colspan=3| 0 ℃ ～ 50 ℃
|-
!cooling fan
|colspan=1|Fan less
|colspan=3|Automatic control by built-in temperature sensor, forced stop possible (however, forced ON when the temperature rises above 50 ° C)
|} 

===PC requirement===

{| class=wikitable style="width:100%;" style="text-align:center;"
|-
!Connections
|Type: '''Ethernet''', Connector: '''RJ45''' 

|-
!Operating systems
|Windows 7 / '''Windows 10''' / '''Windows 11'''

|-
!Recommended
|'''CPU : Quad core processor''' (Desktop : Intel Core i3 or Ryzen 3, Laptop : Intel Core i5 or Ryzen 5) 
'''RAM : 6 GB''' 
'''Storage : SSD''', 1 GB free <nowiki>+</nowiki> storage for signals
|}

 

==Function==

<li style="display: inline-table;">
{| class="wikitable"
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Overall_Acoustic_-_Sound_Level_meter|Sound Level Meter]]
|-
| [[File:REF-MAN_VOL1_Analyzer_Settings_Browser_wiki_partA_13.png]] [[NVGate_Waterfall|Waterfall analysis (three-dimensional display)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 10.png]] [[NVGate_Recorder|Signal record and post analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_FFT|Resonance frequency by impact hammer]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[ORBIGate|Vibration on rotordynamics (orbit,...)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Modal|Modal Analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Sound_Power|Sound Power]]
|} </li>

<li style="display: inline-table;">

{| class="wikitable"
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_FFT|Frequency analysis, spectrum analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Octave_Analyzer|Noise / acoustic analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 10.png]] [[NVGate_D-Rec|Time series analysis (data logger)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Synchronous_Order_Analysis|Vibration of rotating machines]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Ribbons:_Automation|Customization (ex: automatic measurement)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Sound_Quality_Lite|Sound Quality]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Monitoring_Solution|Monitoring]]
|} </li>

===Catalog download===
[[File:download_brochure.jpg|left|250px|noise and vibration catalog download]]
 
 
 
 
 

[https://www.oros.com/wp-content/uploads/2020/08/m002-103-10_oros_range_brochure.pdf Download]
 
 
 
 
 
 
 
 
 
 
 
 

===Applications/ Case study===

'''Main application and commonly used functions:'''

FFT analyzers are used in research and development, quality control, inspection, service departments, etc.

'''Improvements in vehicle quietness, ride quality, comfort, maneuverability, etc.'''

[[File:car_NVH.PNG|right|Automotive noise and vibration]]

* [https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
* [https://www.oros.com/solutions/acoustics/1-n-octave-analysis/ 1 / N octave analysis]
* [https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]
* [https://www.oros.com/solutions/structural-dynamics/modal-analysis/ Experimental mode analysis]

'''Responding to quality problems caused by vibration and noise of vehicles and rotating equipment'''

[[File:rotating.PNG|right|rotating machine vibration]]

*[https://www.oros.com/solutions/acoustics/sound-level-meter/ Overall measurement]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/rotating-analysis/turbomachinery-vibration-and-rotordynamics/ Turbomachinery Analysis]
*[https://www.oros.com/solutions/rotating-analysis/order-tracking-analysis/ Rotation order ratio / RPM tracking analysis]
*[https://www.oros.com/solutions/rotating-analysis/torsion-twist/ Rotational torsional vibration analysis]
*[https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]

'''Environmental problems caused by noise from construction machinery, office machines, home appliances, etc.'''

[[File:machinery.PNG|right|Acoustic and vibration application]]
*[https://www.oros.com/solutions/acoustics/sound-level-meter/ Overall measurement]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/acoustics/1-n-octave-analysis/ 1/N octave analysis]

'''Problems with processing accuracy due to minute vibrations in microscopes, machine tools, semiconductor manufacturing equipment, etc'''.

[[File:accuracy.PNG|right| Accuracy measurement]]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]
*[https://www.oros.com/solutions/structural-dynamics/modal-analysis/ Experimental modal analysis]

'''A collection of application examples using the OROS FFT analyzer OROS series'''

Introducing solution examples that can be provided by various functions unique to OROS FFT analyzers.

*'''Vibration measurement of cutting machine'''

[[File:cutting tools machine.jpg|150px|left|Vibration measurement of cutting machine]]

Introducing what approach can be taken using the OROS FFT Analyzer to identify mechanical resonance problems due to changes in cutting conditions.
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need register)]
 
 
 
 

*'''Monitoring of wind power generation equipment and abnormality diagnosis'''

[[File:eolienne.PNG|left|Monitoring vibration]]

Measuring vibration noise generated from rotating machines (gearboxes, generators, etc.) in wind power generation equipment is indispensable for equipment maintenance and longevity. In addition to the real-time analysis capability of rotating machinery, which is the strength of the OROS FFT analyzer, remote control / monitoring and stand-alone functions can be used to more efficiently diagnose equipment for wind power generation equipment.
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need to register)]
 
 

*'''Diesel engine camshaft rotational twist measurement'''

In the prototype of a small diesel engine, there is a problem that the rotational torsional vibration of the timing belt and the camshaft resonates, causing a large vibration. By measuring rotational fluctuations and rotational twists with high accuracy using the six tachometer channels mounted on the OROS FFT analyzer, it is clarified which rotational order is dominant for vibration. 
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need register)]
 

*'''Much more Application note on [https://my.oros.com/ my.oros.com]'''

<gallery gallery="" mode="packed-hover" align="left">
File:End of line turbine test.jpg|alt=Gear box measurement with accelerometers|Allen Gears: gear box rotating vibration
File:Mecalac sound power.jpg|alt=Octave and sound level meter with microphone|Mecalac: Sound power acoustic measurement
File:In-porsche.JPG|alt=Automotive octave waterfall analyzer with order extraction|Porsche: acoustic sound quality measurement
File:Sound power2.jpg|alt=Acoustic room with microphone |Bosch: Sound power acoustic measurement on anechoic chamber
File:Vibration on block press.jpg|alt=Shock test measurement|IFF Weimar: Vibration on block press
File:Blade vibration.jpg|alt=Spectrum analyzer on the field|Blade vibration
File:Elevator shaft vibration.jpg|alt=accelerometer and microphone analysis|Sicor: Elevator motor vibration
File:DBVib 01.JPG|alt=Orbit shaft center line and fluid film bearing vibration|dBVib: On site measurement on turbomachinery
File:Equilibrage 005.jpg|alt=Acceleromters on each side of the plan|BSCA: Vibration balancing test
File:Washingmachine.jpg|alt=Bump test geometry with modal software|Washing machine FRF resonance frequency test
File:Master at work.jpg|alt=team watching overall value of accelerometer|Vibration measurement
File:Windturbine.jpg|alt=Motor of wind turbine analysis|GDF SUEZ: Windturbine monitoring measurement
File:3 OR38.JPG|alt=multichannel analyzer portable |3 analyzers working together
File:Turbine.JPG|alt=hydro vibration measurement|Alstom: Measurement on turbine
</gallery>

'''Some references:'''

[[File:reference.PNG|800px|Analyzer reference|alt=airplane automotive energy measurement]]

===Full technical support===

* '''Hotline dedicated'''

[[File:Custcare team2 web-1.jpg|right|150px|support FFT analyzer|alt=expert on noise and vibration]]
Responsiveness is the key to offer the best level of services. OROS relies on a powerful network of subsidiaries, offices, resellers, maintenance centers and qualified partners. They are the first steps of efficiency.

Tel: +33.4.76.90.52.40 
Email: [http://customer.care@oros.com customer.care@oros.com]

[https://www.oros.com/find-us/ Your local distributor] 
 

* '''User training course'''
OROS proposes training specially dedicated to customers every year for free (depending on countries). This is an opportunity to take advantage of your analyzer system capabilities, to get premium information on OROS range evolution, to discuss with your peers, and for OROS, to listen to your product enhancement desires.
 
[[File:user_day.jpg|Acoustic and vibration training|alt=Korean vibration camp]]
 
 

* '''Worldwide presence and accredited maintenance center'''

With a worldwide coverage of distributor network and maintenance center (China, Europe, India, Japan, Saudi Arabia, South Korea, USA), OROS is in close proximity to its customers, reducing maintenance downtime.
 
[[File:map_world_distributor.JPG|Spectrum analyzer worldwide seller|alt=maintenance center]] 
[https://www.oros.com/find-us/ Find Your local distributor]
[[File:repair.jpg|200px|right|repair hardware analyzer|alt=calibration repair metrologic instrument]]
 
 
Technicians are certiﬁed on a regular basis by OROS specialists, enabling them to repair, calibrate and upgrade all OROS systems.

*'''Premium contract'''

1, 2 or 4 years renewable [https://www.oros.com/services/contracts/ contracts] to extend your warranty.

* Access to the latest software version.
* Full coverage on your instrument (calibration and maintenance)
* Guaranteed turn around time (4 days) for hardware repairs and calibration
* Privileged access to extended services at a preferential rate: urgent loan within 1 day.

===Video content ===

We have released videos such as product introductions and demonstrations.

[https://www.youtube.com/user/OROSanalyzers/videos Click here for the youtube video content page]
 

{|class="wikitable" style="width:100%;"
|style="background: #0000A0; text-align:center;"|<big>[https://www.oros.com/demo-request/ Schedule a demo]</big>
|style="background: red; text-align:center;"|<big>[https://www.oros.com/quote-request-form/ Get a quotation]</big>
|style="background: green; text-align:center;"|<big>[[FFT_Spectrum_Analyzer_Multipurpose#Full_technical_support|Contact support]]</big>
|}

FFT Spectrum Analyzer Multipurpose

2026-09-30T12:33:36Z

Lmagimel: /* Applications/ Case study */

[[category:WikiOros]]
{{#seo:
|title=Multi-function FFT Spectrum Analyzer for Noise & Vibration | OROS
|keywords=FFT analyzer, vibration analyzer, spectrum analyzer, acoustic analysis, modal analysis, order tracking, octave analyzer, real-time signal processing, NVGate
|description=High-performance portable FFT spectrum analyzer for acoustic and vibration measurement. Supports up to 1000 channels, real-time analysis, and modal testing.
|image=FFT_analyzer_hardware_2.webp
}}

__NOTOC__
[[File:O4_range Gamme O4 + OR10 + OR35 + OR36 + OR38.png|frame|left|FFT analyzers|alt=Analyzer acoustic vibration multichannel]]
The OROS series multi-function FFT analyzer is PC-based, high-performance, high reliability and easy to operate.

We have further increased the arithmetic processing speed and increased the real-time analysis capacity to more than 16 times that of the conventional model (OR20 series). An ethernet LAN cable is used as the interface.

In addition, the number of simultaneous recording channels in the frequency range (40 kHz) has been expanded to a maximum of 1000 channels and the dynamic range has been improved to 140 dB. These improvements allow a user to measure time signals over a wide frequency range simultaneously on multiple channels.

{|class="wikitable" style="width:100%;"
|style="background: #0000A0; text-align:center;"|<big>[https://www.oros.com/demo-request/ Schedule a demo]</big>
|style="background: red; text-align:center;"|<big>[https://www.oros.com/quote-request-form/ Get a quotation]</big>
|style="background: green; text-align:center;"|<big>[[FFT_Spectrum_Analyzer_Multipurpose#Full_technical_support|Contact support]]</big>
|}

<gallery gallery="" mode="packed-hover" align="left">
File:TWanalyzer2.jpg|alt=Vibration measurement up to 1000 channels|Analyzer Cascade mode
File:Situation auto hammer pc.jpg|alt=Hammer test on automotive in anechoic room|Modal FRF measurement
File:Auto anechoic chamber2.webp|alt=Sound intensity measurement in anechoic room|Acoustic Sound intensity
File:Turbo orbit.JPG|alt=Turbomachinery orbit vibration measurement|Vibration on turbomachinery
File:Or34 situation.jpg|alt=NVH measurement on a car|NVH automotive measurement
File:Airfrance.jpg|alt=Acoutic measurement with octave analyzer in a plane|In flight measurement
</gallery>

==Main Features==

* From 2-32 channels
* Synchronous measurements up to 1000ch is possible by combining multiple analyzers (*)
* Compact and lightweight (4ch model 1.5kg, 10ch model 3.0kg)
* Achieves high-speed communication with a PC through an ethernet LAN interface
* Equipped with an output channel as a standard
* Built-in internal battery as a standard
* Record, Fast Fourier Transform analysis, octave analysis, and tracking analysis can be performed simultaneously at high sampling frequencies
* Realtime measurements and post-analysis can be performed with the same software platform ([[NVGate]])
* In addition to sound and vibration, strain and temperature can be measured at the same time using XPODS (**)
* CAN-bus module compatible (***)
* Recording is possible with analyzer in standalone mode or in conjunction with a PC (****)

(*) Synchronous measurements that combine multiple analyzers is possible only for TW OR35 / TW OR36 / TW OR38.

(**) The strain / temperature module(XPOD) can be installed only on TW OR35 / TW OR36 / TW OR38.

(***) CAN-bus module can be installed only on OR10/ TW OR35 / TW OR36 / TW OR38.

(****) Stand-alone measurements are possible only with SSD-equipped models OR10 / TW OR35 / TW OR36 / TW OR38.

==Introducing the hardware==
[[File:hardware.png|right|Spectrum analyzer|alt=OROS instrument analyzer for noise and vibration]]
===Small and lightweight===

OR10-8ch model: 0.8kg

O4: 4ch model: 0.5kg

OR35 TW: 10ch model: 3.0kg

OR36 TW: 16ch model: 5.2kg

OR38 TW: 32ch model: 8.2kg
 
 
 
 
 
 

===Ethernet LAN interface===
[[image:laninterface.PNG|right|FFT analyzer ethernet|alt=Back of FFT analyzer : ethernet connection for PC]]
Achieves high-speed communication with a PC through an ethernet LAN interface
 
 
 
 
 
 

===Built-in battery===
OR10/ OR35/ TW OR36 / TW OR38: Models have a built-in battery.

OR10 can be operated by battery for 4hours

OR35 can be operated by battery for 3 hours.

TW OR36 / TW OR38 can be operated by battery for 2 hours.

04 operate with battery PC.

===External battery===
[[File:external battery.PNG|200px|right|external battery on analyzer|alt=External battery on spetrum analyzer]]

We provide a compact and lightweight external battery that can be installed on all models.

Can be used for up to 8 hours with one external battery.

Can be stored in a "PC integrated carrying case".
 

 

 
 

 

===Synchronous Measurement Of Up To 1000 Channels is Possible by Combining Multiple Analyzers===
(TW OR35 / TW OR36 / TW OR38 only)

High-precision synchronous measurements (0.2 ° @ 20kHz) are possible by simply connecting each analyzer using a general-purpose LAN cable. Function measurements can be taken with the hammer connected to the third unit in the chain and the accelerometers connected to each unit. Tracking analysis can be completed with the accelerometers connected to each unit while using a tachometer connected to the second unit in the chain.

[[File:teamworkanalyzer.png|700px|cascade mode]]

=== Measure From Sound / Vibration and Strain Gauge / Temperature ===
(OR35 / TW OR36 / TW OR38 only)
[[File:Usersmanual_32.jpg|200px|right|Conditioner on analyzer|alt=Temperature and straing conditionner]]
By mounting a [[XPod_Bridge_-_Strain_gauge|strain gauge conditioner]] and [[NVGate_X-Pod:_Temperature_probe_conditioner|thermocouple conditioner]] on the Oros FFT analyzer, it is possible to measure strain and temperature data in addition to sound and vibration data.

Thermocouple amplifier: Supports types J, K, T, N, E (with temperature compensation)
 
 
 
 

===CAN-bus Module Available ===
[[File:Can_Bus.jpg|150px|right|Can bus measurement|alt=Can bus to add on OROS instrument]]
(OR10/ TW OR35 / TW OR36 / TW OR38 only)

By using the [[NVGate_Can_BUS|CAN-bus module]], tracking analysis can be performed using information such as the engine speed flowing from the CAN-bus. By using this function, tracking analysis can be performed without using a tachometer.
 
 

===Recording is possible without the use of a PC by using the FFT analyzer in stand alone mode ===
(OR35 / TW OR36 / TW OR38 only)

[[File:d_rec.PNG|150px|right|Data acquisition recorder|alt=Vibration time signal Measurement without PC]]
The FFT analyzer is equipped with a [[NVGate_D-Rec|record-only button]]. Simply select a predefined measurement setup and press the record button to record onto the FFT analyzer alone without the use of a PC.

 
 
 
 

In addition, the back of the Fast Fourier Transform Spectrum Analyzer Multipurpose is equipped with an audio terminal and power supply. It is possible to record audio data while also measuring the time signal. The analyzer also can supply power to required sensors, such as proximity probes, tachometers and DC sensors.

[[File:FFT_analyzer.jpg|600px|Back of the hardware|alt=all the plug available on the backside of instrment]]
 
 
 

==Software Introduction==

*Easy-to-use interface
*Real-time measurement / post-analysis can be performed with the same software platform (NVGate)
*One-click report creation function

===Start the Measurement Quickly and Easily===

You can start measuring immediately by using the quick function provided in the OROS FFT analyzer mult function. This is completed by defining the number of input channels in the channel field and the measurement/analysis content in the show results area.

The Oros series FFT spectrum analyzer multifunction uses an interface similar to the ribbon interface used by Microsoft Office. All menus are accessible via the ribbon interface, making it easy to change measurement settings.

[[File:home3.PNG|800px|software ribbon|alt=NVgate ribbon technology]]

===One-click Setting Function===
With the Oros series multi-purpose FFT analyzer, you can display related measurement condition settings by double-clicking on the measurement screen. For example, if you double-click on the FFT analysis screen, the dialog for setting the measurement conditions for FFT analysis will be displayed on the screen as shown below.

[[File:FFT_analyzer_spectrum.png|500px|FFT spectrum|alt=Parameters easy to change]]

===Control Panel===
In addition, the OROS FFT spectrum analyzer is equipped with a control panel function that allows users to save frequently used measurement settings for quick access. By using this function, all settings can be changed on the [[NVGate_Control_Panel|control panel]]. For example, the following is the setting screen for a hammer test. By saving the input settings, threshold settings, and FFT analysis settings to the control panel as shown below, it is possible to make all the necessary settings quickly by only using the control panel.

===Various filters can be applied to recorded signals & FFT analysis results===
Four types of filters: Low-pass filter, high-pass filter, band-bus filter, and band-stop filter, can be applied to the results of recorded signal and FFT analysis. By using a [[NVGate_Filter_Builder|filter]], it is possible to remove abnormal noise components from the recorded signal and perform processing such as reproducing the extracted abnormal noise components.

[[File:filter_fft.png|600px|Filter analyzer]]

===Extract arbitrary order components from the color spectrum graph in real time===

Any order component can be extracted in real time from the color spectrum graph.

[[File:extraction.jpg|Synchronous order analysis extraction|alt=order extraction on vibration software]]

Easy-to-read Layout

The area for arranging windows is called a layout.
The OROS multi function FFT analyzer can create up to 16 layouts per project. You can easily arrange your windows by using the layout function. And your windows will open the same way each time.

It is possible to display up to 32 screens in one layout.

Up to 512 windows (= 16 x 32) can be displayed.

<big>'''Layout utilization example:'''</big>

'''Layout 1''': Record waveform, FFT analysis result, order ratio analysis result displayed

[[File:Fft_extraction_data.jpg|Order extraction|alt=Recorder and FFT together]]

'''Layout 2''': Display 3D frequency analysis results and 3D order ratio analysis results

[[File:waterfall_extract_order.jpg|3d display order spectrum |alt=NVGate software on line measurement]]

'''Layout 3''': Display 3D '''octave analyzer''' analysis results

[[File:octave waterfall.jpg|Octave acoustic measurement 3d display|alt=Acoustic measurement with octave]]

===Easy operation <Graph layout selection button>===

You can easily arrange windows just by selecting the grid menu.

[[File:gridwindows_PNG.PNG|NVGate icon|alt=Grid icon]]

Batch copy of measurement data with one menu. Numerical data can be transferred to Excel all at once.

[[File:excel_report.jpg|400px|FFT spectrum Report function|alt=export your data]]

Data measured at different times can be overwritten by dragging which allows for easily comparing measurement data.

[[File:drag_drop_report.jpg|Software NVGate]]

===One-click report creation function===

Simply click the report button located on the ribbon interface to create a [[NVGate_Report|report]] file containing the current measurement results.

[[File:allwindows_.PNG|NVGate report|alt=report all windows]]

• The content of the report is customizable. Customize it to the format that best suits your needs.

[[File:report-customize.jpg|500px|customize FFT analyzer software report|alt=Post analysis vibration software]]

===Measurement data search function===
[[File:pc cloud.PNG|right|Data stored|alt=cloud vibration data]]
Various information (meta-data) can be added when saving measurement data.
You then can search for measurement data and projects based on the added information.

Filter:
* Project name
* Measurement date and time
* Measurement conditions
* Measurement target
* Measurement site
* User
[[File:filter_project.PNG|550px|meta data on noise and vibration software NVGate|alt=Acoustic and vibration search function]]

===Fail judgment function as standard===
The [https://youtu.be/kx2HbcvfG_w pass / fail feature] of NVGate can be performed automatically after setting the desired bounds.

In the example below, a dialog is displayed when the product fails, but it is also possible to output a contact signal instead of the dialog.

[[File:fail_test.JPG|Pass/fail test on resonnance frequency impact hammer test|alt=Failed pass test on resonnance frequency test]]

===Automate post-analysis processing===

The same processing can be continuously performed for record files measured multiple times. By using this function, it is possible to automate the generation of reports, and it is possible to generate the same number of post-analysis results and EXCEL-based reports as record files with one click. Processing that used to take more than a week can now be done in a few hours.

[[File:BPP2.jpg|Post processing acoustic measurement batch |alt=Offline measurement]]

==specification==
===Main specifications===

{| class=wikitable style="width:100%;" style="text-align:center;"
! style="width:16%|
! style="width:21%|O4
! style="width:21%|OR35
! style="width:21%|OR36
! style="width:21%|OR38
|-
!colspan=6 style="text-align:center;" | Dynamical Input channel
|-
! Number of analysis channels
| 2, 4
| 6, 10 (Select Analysis or tachometer on 2 channels)
| 4, 8, 12, 16
| 8, 16, 24, 32
|-
! Terminal shape
| colspan=5| BNC
|-
!Input coupling and sensor support
|colspan=5| Compatible with AC, DC / ICP (sensor with built-in amplifier) and TEDS
|-
!Cutoff frequency
|colspan=5| - 3dB at AC cutoff frequency 0.35Hz
|-
! Input voltage range
|colspan=5| +/- 100mV to +/- 40V (auto range function)
|-
! Maximum voltage
|colspan=5| 60V
|-
!Anti-Aliasing filter
|colspan=5| 400dB / OCT
|-
!Input impedance
|colspan=5| 1MΩ <100pF
|-
!A / D converter
|colspan=5| 24-bit
|-
!Dynamic range
|colspan=5| >140dB
|-
!Channels-to-channels phase accuracy
|colspan=5| ± 0.02 ° (10V, 20kHz range)
|-
!Input filter
|colspan=5| Acoustic A, C, Z, low pass, high pass, band pass, integrator, differentiator, time axis integration function
|-
!Sampling frequency of the signal
|colspan=5|Select from 13 ranges between 102.4kHz and 2.048kHz.
|-
!colspan=6| Tachometer channel (Ext synch channels)
|-
!Number of input channels
|colspan=2|2 channels
|colspan=2|2 channels (up to 6 channels as an option)
|-
!Sampling frequency
|colspan=5|6.4MHz (counter method)
|-
!Voltage range
|colspan=4|+/- 300mV 40V
|-
!colspan=6| DC input
|-
!number of input channels
|colspan=1|none
|colspan=3|Analysis channel can be switched and used
|-
!Voltage range
|colspan=1|none
|colspan=3|22 bits, ± 40V, offset DC 100μV or less
|-
!Sampling frequency
|colspan=1|none
|colspan=3|15Hz or 12.5Hz
|-
!colspan=6|Calibration function
|-
!Calibration method
|colspan=5| Automatic sensitivity calculation by numerical input or reference signal (for position and standard vibration oscillatory meter)
|-
!How to use at the time of measurement
|colspan=5|Select by registered sensor name such as model name and machine number
|-
!colspan=6|Trigger function
|-
!Trigger type
|colspan=5|Edge, period, △ RPM, △ level, manual, multi (A or B, A and B, A after B)
|-
!Trigger delay
|colspan=5|Pre- and post-trigger functions
|-
!Trigger signal
|colspan=5|Select from any input channel
|-
!colspan=6|Record function
|-
!Sampling frequency
|colspan=5|13 ranges from 102.4kHz to 2.048kHz possible to select 2 types of range together
|-
!A / D converter resolution
|colspan=5| 24-bit or 16-bit
|-
!Hard drive size
|PC hard drive
|colspan=1|64 GB SSD
|colspan=2|128 GB removable SSD hard drive (256GB or 512 GB optional)
|-
!colspan=6|FFT analysis performance
|-
!Analysis frequency range
|colspan=1|0.8Hz-100kHz
|colspan=4|0.8Hz-40kHz
|-
!FFT block size
|colspan=5|256, 512, 1024, 2048, 4096, 8192, 1638
|-
!Number of analysis lines
|colspan=5|101, 201, 401, 801, 1601, 3201, 6401
|-
!Zoom analysis
|colspan=5|2 to 128 times (all channels at the same time)
|-
!Overlap setting
|colspan=5|0-99.99%
|-
!Window function
|colspan=5|Flat Top, Hanning, Humming, Kaiser Vessel, Rectangular, Force / Response
|-
!Average mode
|colspan=5|Time, frequency, fdsa / linear, exponential, peak hold
|-
!colspan=6|Analysis / display function
|-
!Time series
|colspan=5|Real-time waveform, record waveform, DC, Max, Min, RMS
|-
!FFT analysis
|colspan=5|Linear power spectrum, average spectrum, PSD, cross spectrum,
transfer function (H1, H2), copying function
|-
!Display color
|colspan=5|Display color: Arbitrary specification of trace, cursor, background, and grid display colors

|-
|-
!colspan=6|Options:
|-

!colspan=6|Time domain analysis (ORNV-TDA)
|-
!Analysis items
|colspan=5|Monitor display for arbitrary time (msec to day), effective value for arbitrary section, Min, Max, Peak,
Peak / Peak, RMS, DC, crest factor, Skew, Kurtosis
|-
!colspan=6| 1/n octave analysis (ORNV-OCT)
|-
!method
|colspan=5|Digital filter operation on time domain
|-
!Analysis band
|colspan=5|1/1, 1/3, 1/12, 1/24 octave (IEC1260: 1995 Class 1, ANSI S1.11-1986)
|-
!Analysis frequency
|colspan=5|Simultaneous analysis of all channels at 20kHz is possible (DSP option may be required)
|-
!Average
|colspan=5|Fast, Slow, lmpulse, LEQ, constantBT, linear repeat,exponential
|-

!colspan=6| Multi-sound level meter [ORNV-OVA]
|-
!Operation method
|colspan=6|Time series signal digital operation
|-
!Acoustic weighting
|colspan=6|Linear, A, C
|-
!Measurement
|colspan=6|Leq, Fast, Slow, lmpulse, average, Peak, Max, Min
|-
!Average
|colspan=6|Fast, Slow, lmpulse, LEQ, constantBT, linear repeat,exponential
|-

!colspan=6| Synchronous Order tracking analysis [ORNV-ORD]
|-
!Analysis function
|colspan=5| Instantaneous and average spectrum,phase, order profile and overall.
|-
!Maximum rotation speed
|colspan=5|1,200,000 RPM
|-
!Max analysis ordersetting
|colspan=5|6.25, 12.5, 25, 50, 100, 200, 400
|-
!Number of analysis lines
|colspan=5|25-800
|-
!Analysis bandwidth
|colspan=5|resampling method and fixed sampling method
|-
!display
|colspan=5|Simultaneous display of 3D display and tracking order, simultaneous display of time signal
|-

!colspan=6| Rotational torsion analysis [ORNV-IVC]
|-
!Operation method
|colspan=5| Digital Frequency Voltage converter
|-
!Number of analysis channels
|colspan=2|2ch
|colspan=3|2ch (up to 6ch as an option)
|-

|-
!colspan=6| Rotation diagnosis function [ORNV-FFTDiag]
|-
!Analysis items
|colspan=5| Envelope analysis, cepstrum, self-cross function, MAX, MIN, peak detection from block data, simulated tach,
|-

!colspan=6| Output Channel
|-
!Number of output channels
|colspan=1| 1ch (lemo conector, include)
|colspan=1| 2ch
|colspan=2| 2ch (up to 6ch as an option)
|-
!Output waveform
|colspan=1|Sinus, step sinus, sweep sinus, chirp, multi-sinus, random (pink and white), DC voltage, record signal
|colspan=3|Sinus, step sinus, sweep sinus, chirp, multi-sinus, random (pink and white), DC voltage, record signal
|-
!Digital / Analogic converter
|colspan=1|24 bits
|colspan=3|24 bits

|-
!Output voltage
|colspan=1|+/- 10V
|colspan=3|+/- 10V

|-
!Output Impedance
|colspan=1|50 Ω
|colspan=3|50 Ω
|-
!Frequency range
|colspan=1|~ 100kHz
|colspan=3|~ 40kHz
|-
!Sweep mode
|colspan=1|Sweep and step, analyze, trigger and sync, linear and log
|colspan=3|Sweep and step, analyze, trigger and sync, linear and log

|-
!Synchronization with the analysis
|colspan=1|Synchronization and free run
|colspan=3|Synchronization and free run
|-
!Output protection
|colspan=1|Stabilization with time specification and forced stop button
|colspan=3|Stabilization with time specification and forced stop button
|-
|-
!colspan=6|Data
|-
!Image and print
|colspan=5|Image, printing for Windows and user template creation function for Word and Excel
|-
!File
|colspan=5| TXT, UFF, MATLAB, WAV (OROS and Audio) SDF, binary, ATFX (optional)
|-
!Data entry
|colspan=5|WAV, TXT, UFF and OR20 series AE2
|-
|-
!colspan=6|Dimensions / weight
|-
!Dimensions (width x height x depth mm)
|35 x 110 x 185
|56 × 246 × 222
|102 x 260 x 311
|102 x 364 x 311
|-
!Weight
| 0.5kg
| 2.8kg
| 5.2 kg
| 8.2 kg
|-
!colspan=6|Power supply
|-
!AC
|colspan=5|AC 100V-240V
|-
!DC
| USB 3.0 type C 5V
| 10V-28V, 20VA
| 10V-28V, 60VA
| 10V-28V, 100VA
|-
!DC battery internal operating time (built-in)
| NA : using PC battery
| 3h
| 2h
| 2h
|-
!Recommended operating temperature range
|colspan=1| 0 ℃ ～ 40 ℃
|colspan=3| 0 ℃ ～ 50 ℃
|-
!cooling fan
|colspan=1|Fan less
|colspan=3|Automatic control by built-in temperature sensor, forced stop possible (however, forced ON when the temperature rises above 50 ° C)
|} 

===PC requirement===

{| class=wikitable style="width:100%;" style="text-align:center;"
|-
!Connections
|Type: '''Ethernet''', Connector: '''RJ45''' 

|-
!Operating systems
|Windows 7 / '''Windows 10''' / '''Windows 11'''

|-
!Recommended
|'''CPU : Quad core processor''' (Desktop : Intel Core i3 or Ryzen 3, Laptop : Intel Core i5 or Ryzen 5) 
'''RAM : 6 GB''' 
'''Storage : SSD''', 1 GB free <nowiki>+</nowiki> storage for signals
|}

 

==Function==

<li style="display: inline-table;">
{| class="wikitable"
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Overall_Acoustic_-_Sound_Level_meter|Sound Level Meter]]
|-
| [[File:REF-MAN_VOL1_Analyzer_Settings_Browser_wiki_partA_13.png]] [[NVGate_Waterfall|Waterfall analysis (three-dimensional display)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 10.png]] [[NVGate_Recorder|Signal record and post analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_FFT|Resonance frequency by impact hammer]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[ORBIGate|Vibration on rotordynamics (orbit,...)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Modal|Modal Analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Sound_Power|Sound Power]]
|} </li>

<li style="display: inline-table;">

{| class="wikitable"
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_FFT|Frequency analysis, spectrum analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Octave_Analyzer|Noise / acoustic analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 10.png]] [[NVGate_D-Rec|Time series analysis (data logger)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Synchronous_Order_Analysis|Vibration of rotating machines]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Ribbons:_Automation|Customization (ex: automatic measurement)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Sound_Quality_Lite|Sound Quality]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Monitoring_Solution|Monitoring]]
|} </li>

===Catalog download===
[[File:download_brochure.jpg|left|250px|noise and vibration catalog download]]
 
 
 
 
 

[https://www.oros.com/wp-content/uploads/2020/08/m002-103-10_oros_range_brochure.pdf Download]
 
 
 
 
 
 
 
 
 
 
 
 

===Applications/ Case study===

'''Main application and commonly used functions:'''

FFT analyzers are used in research and development, quality control, inspection, service departments, etc.

'''Improvements in vehicle quietness, ride quality, comfort, maneuverability, etc.'''

[[File:car_NVH.PNG|right|Automotive noise and vibration]]

* [https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
* [https://www.oros.com/solutions/acoustics/1-n-octave-analysis/ 1 / N octave analysis]
* [https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]
* [https://www.oros.com/solutions/structural-dynamics/modal-analysis/ Experimental mode analysis]

'''Responding to quality problems caused by vibration and noise of vehicles and rotating equipment'''

[[File:rotating.PNG|right|rotating machine vibration]]

*[https://www.oros.com/solutions/acoustics/sound-level-meter/ Overall measurement]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/rotating-analysis/turbomachinery-vibration-and-rotordynamics/ Turbomachinery Analysis]
*[https://www.oros.com/solutions/rotating-analysis/order-tracking-analysis/ Rotation order ratio / RPM tracking analysis]
*[https://www.oros.com/solutions/rotating-analysis/torsion-twist/ Rotational torsional vibration analysis]
*[https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]

'''Environmental problems caused by noise from construction machinery, office machines, home appliances, etc.'''

[[File:machinery.PNG|right|Acoustic and vibration application]]
*[https://www.oros.com/solutions/acoustics/sound-level-meter/ Overall measurement]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/acoustics/1-n-octave-analysis/ 1/N octave analysis]

'''Problems with processing accuracy due to minute vibrations in microscopes, machine tools, semiconductor manufacturing equipment, etc'''.

[[File:accuracy.PNG|right| Accuracy measurement]]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]
*[https://www.oros.com/solutions/structural-dynamics/modal-analysis/ Experimental modal analysis]

'''A collection of application examples using the OROS FFT analyzer OROS series'''

Introducing solution examples that can be provided by various functions unique to OROS FFT analyzers.

*'''Vibration measurement of cutting machine'''

[[File:cutting tools machine.jpg|150px|left|Vibration measurement of cutting machine]]

Introducing what approach can be taken using the OROS FFT Analyzer to identify mechanical resonance problems due to changes in cutting conditions.
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need register)]
 
 
 
 

*'''Monitoring of wind power generation equipment and abnormality diagnosis'''

[[File:eolienne.PNG|left|Monitoring vibration]]

Measuring vibration noise generated from rotating machines (gearboxes, generators, etc.) in wind power generation equipment is indispensable for equipment maintenance and longevity. In addition to the real-time analysis capability of rotating machinery, which is the strength of the OROS FFT analyzer, remote control / monitoring and stand-alone functions can be used to more efficiently diagnose equipment for wind power generation equipment.
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need to register)]
 
 

*'''Diesel engine camshaft rotational twist measurement'''

In the prototype of a small diesel engine, there is a problem that the rotational torsional vibration of the timing belt and the camshaft resonates, causing a large vibration. By measuring rotational fluctuations and rotational twists with high accuracy using the six tachometer channels mounted on the OROS FFT analyzer, it is clarified which rotational order is dominant for vibration. 
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need register)]
 

*'''Much more Application note on [https://my.oros.com/ my.oros.com]'''

<gallery gallery="" mode="packed-hover" align="left">
File:End of line turbine test.jpg|alt=Gear box measurement with accelerometers|Allen Gears: gear box rotating vibration
File:In flight helicopter vibration measurement.PNG|alt=motor vibration order extraction|Conrad: On helicopter vibration measurement
File:Mecalac sound power.jpg|alt=Octave and sound level meter with microphone|Mecalac: Sound power acoustic measurement
File:In-porsche.JPG|alt=Automotive octave waterfall analyzer with order extraction|Porsche: acoustic sound quality measurement
File:Sound power2.jpg|alt=Acoustic room with microphone |Bosch: Sound power acoustic measurement on anechoic chamber
File:Vibration on block press.jpg|alt=Shock test measurement|IFF Weimar: Vibration on block press
File:Blade vibration.jpg|alt=Spectrum analyzer on the field|Blade vibration
File:Elevator shaft vibration.jpg|alt=accelerometer and microphone analysis|Sicor: Elevator motor vibration
File:DBVib 01.JPG|alt=Orbit shaft center line and fluid film bearing vibration|dBVib: On site measurement on turbomachinery
File:Equilibrage 005.jpg|alt=Acceleromters on each side of the plan|BSCA: Vibration balancing test
File:Washingmachine.jpg|alt=Bump test geometry with modal software|Washing machine FRF resonance frequency test
File:Master at work.jpg|alt=team watching overall value of accelerometer|Vibration measurement
File:Windturbine.jpg|alt=Motor of wind turbine analysis|GDF SUEZ: Windturbine monitoring measurement
File:3 OR38.JPG|alt=multichannel analyzer portable |3 analyzers working together
File:Turbine.JPG|alt=hydro vibration measurement|Alstom: Measurement on turbine
</gallery>

'''Some references:'''

[[File:reference.PNG|800px|Analyzer reference|alt=airplane automotive energy measurement]]

===Full technical support===

* '''Hotline dedicated'''

[[File:Custcare team2 web-1.jpg|right|150px|support FFT analyzer|alt=expert on noise and vibration]]
Responsiveness is the key to offer the best level of services. OROS relies on a powerful network of subsidiaries, offices, resellers, maintenance centers and qualified partners. They are the first steps of efficiency.

Tel: +33.4.76.90.52.40 
Email: [http://customer.care@oros.com customer.care@oros.com]

[https://www.oros.com/find-us/ Your local distributor] 
 

* '''User training course'''
OROS proposes training specially dedicated to customers every year for free (depending on countries). This is an opportunity to take advantage of your analyzer system capabilities, to get premium information on OROS range evolution, to discuss with your peers, and for OROS, to listen to your product enhancement desires.
 
[[File:user_day.jpg|Acoustic and vibration training|alt=Korean vibration camp]]
 
 

* '''Worldwide presence and accredited maintenance center'''

With a worldwide coverage of distributor network and maintenance center (China, Europe, India, Japan, Saudi Arabia, South Korea, USA), OROS is in close proximity to its customers, reducing maintenance downtime.
 
[[File:map_world_distributor.JPG|Spectrum analyzer worldwide seller|alt=maintenance center]] 
[https://www.oros.com/find-us/ Find Your local distributor]
[[File:repair.jpg|200px|right|repair hardware analyzer|alt=calibration repair metrologic instrument]]
 
 
Technicians are certiﬁed on a regular basis by OROS specialists, enabling them to repair, calibrate and upgrade all OROS systems.

*'''Premium contract'''

1, 2 or 4 years renewable [https://www.oros.com/services/contracts/ contracts] to extend your warranty.

* Access to the latest software version.
* Full coverage on your instrument (calibration and maintenance)
* Guaranteed turn around time (4 days) for hardware repairs and calibration
* Privileged access to extended services at a preferential rate: urgent loan within 1 day.

===Video content ===

We have released videos such as product introductions and demonstrations.

[https://www.youtube.com/user/OROSanalyzers/videos Click here for the youtube video content page]
 

{|class="wikitable" style="width:100%;"
|style="background: #0000A0; text-align:center;"|<big>[https://www.oros.com/demo-request/ Schedule a demo]</big>
|style="background: red; text-align:center;"|<big>[https://www.oros.com/quote-request-form/ Get a quotation]</big>
|style="background: green; text-align:center;"|<big>[[FFT_Spectrum_Analyzer_Multipurpose#Full_technical_support|Contact support]]</big>
|}

FFT Spectrum Analyzer Multipurpose

2026-09-30T12:32:08Z

Lmagimel: /* Control Panel */

[[category:WikiOros]]
{{#seo:
|title=Multi-function FFT Spectrum Analyzer for Noise & Vibration | OROS
|keywords=FFT analyzer, vibration analyzer, spectrum analyzer, acoustic analysis, modal analysis, order tracking, octave analyzer, real-time signal processing, NVGate
|description=High-performance portable FFT spectrum analyzer for acoustic and vibration measurement. Supports up to 1000 channels, real-time analysis, and modal testing.
|image=FFT_analyzer_hardware_2.webp
}}

__NOTOC__
[[File:O4_range Gamme O4 + OR10 + OR35 + OR36 + OR38.png|frame|left|FFT analyzers|alt=Analyzer acoustic vibration multichannel]]
The OROS series multi-function FFT analyzer is PC-based, high-performance, high reliability and easy to operate.

We have further increased the arithmetic processing speed and increased the real-time analysis capacity to more than 16 times that of the conventional model (OR20 series). An ethernet LAN cable is used as the interface.

In addition, the number of simultaneous recording channels in the frequency range (40 kHz) has been expanded to a maximum of 1000 channels and the dynamic range has been improved to 140 dB. These improvements allow a user to measure time signals over a wide frequency range simultaneously on multiple channels.

{|class="wikitable" style="width:100%;"
|style="background: #0000A0; text-align:center;"|<big>[https://www.oros.com/demo-request/ Schedule a demo]</big>
|style="background: red; text-align:center;"|<big>[https://www.oros.com/quote-request-form/ Get a quotation]</big>
|style="background: green; text-align:center;"|<big>[[FFT_Spectrum_Analyzer_Multipurpose#Full_technical_support|Contact support]]</big>
|}

<gallery gallery="" mode="packed-hover" align="left">
File:TWanalyzer2.jpg|alt=Vibration measurement up to 1000 channels|Analyzer Cascade mode
File:Situation auto hammer pc.jpg|alt=Hammer test on automotive in anechoic room|Modal FRF measurement
File:Auto anechoic chamber2.webp|alt=Sound intensity measurement in anechoic room|Acoustic Sound intensity
File:Turbo orbit.JPG|alt=Turbomachinery orbit vibration measurement|Vibration on turbomachinery
File:Or34 situation.jpg|alt=NVH measurement on a car|NVH automotive measurement
File:Airfrance.jpg|alt=Acoutic measurement with octave analyzer in a plane|In flight measurement
</gallery>

==Main Features==

* From 2-32 channels
* Synchronous measurements up to 1000ch is possible by combining multiple analyzers (*)
* Compact and lightweight (4ch model 1.5kg, 10ch model 3.0kg)
* Achieves high-speed communication with a PC through an ethernet LAN interface
* Equipped with an output channel as a standard
* Built-in internal battery as a standard
* Record, Fast Fourier Transform analysis, octave analysis, and tracking analysis can be performed simultaneously at high sampling frequencies
* Realtime measurements and post-analysis can be performed with the same software platform ([[NVGate]])
* In addition to sound and vibration, strain and temperature can be measured at the same time using XPODS (**)
* CAN-bus module compatible (***)
* Recording is possible with analyzer in standalone mode or in conjunction with a PC (****)

(*) Synchronous measurements that combine multiple analyzers is possible only for TW OR35 / TW OR36 / TW OR38.

(**) The strain / temperature module(XPOD) can be installed only on TW OR35 / TW OR36 / TW OR38.

(***) CAN-bus module can be installed only on OR10/ TW OR35 / TW OR36 / TW OR38.

(****) Stand-alone measurements are possible only with SSD-equipped models OR10 / TW OR35 / TW OR36 / TW OR38.

==Introducing the hardware==
[[File:hardware.png|right|Spectrum analyzer|alt=OROS instrument analyzer for noise and vibration]]
===Small and lightweight===

OR10-8ch model: 0.8kg

O4: 4ch model: 0.5kg

OR35 TW: 10ch model: 3.0kg

OR36 TW: 16ch model: 5.2kg

OR38 TW: 32ch model: 8.2kg
 
 
 
 
 
 

===Ethernet LAN interface===
[[image:laninterface.PNG|right|FFT analyzer ethernet|alt=Back of FFT analyzer : ethernet connection for PC]]
Achieves high-speed communication with a PC through an ethernet LAN interface
 
 
 
 
 
 

===Built-in battery===
OR10/ OR35/ TW OR36 / TW OR38: Models have a built-in battery.

OR10 can be operated by battery for 4hours

OR35 can be operated by battery for 3 hours.

TW OR36 / TW OR38 can be operated by battery for 2 hours.

04 operate with battery PC.

===External battery===
[[File:external battery.PNG|200px|right|external battery on analyzer|alt=External battery on spetrum analyzer]]

We provide a compact and lightweight external battery that can be installed on all models.

Can be used for up to 8 hours with one external battery.

Can be stored in a "PC integrated carrying case".
 

 

 
 

 

===Synchronous Measurement Of Up To 1000 Channels is Possible by Combining Multiple Analyzers===
(TW OR35 / TW OR36 / TW OR38 only)

High-precision synchronous measurements (0.2 ° @ 20kHz) are possible by simply connecting each analyzer using a general-purpose LAN cable. Function measurements can be taken with the hammer connected to the third unit in the chain and the accelerometers connected to each unit. Tracking analysis can be completed with the accelerometers connected to each unit while using a tachometer connected to the second unit in the chain.

[[File:teamworkanalyzer.png|700px|cascade mode]]

=== Measure From Sound / Vibration and Strain Gauge / Temperature ===
(OR35 / TW OR36 / TW OR38 only)
[[File:Usersmanual_32.jpg|200px|right|Conditioner on analyzer|alt=Temperature and straing conditionner]]
By mounting a [[XPod_Bridge_-_Strain_gauge|strain gauge conditioner]] and [[NVGate_X-Pod:_Temperature_probe_conditioner|thermocouple conditioner]] on the Oros FFT analyzer, it is possible to measure strain and temperature data in addition to sound and vibration data.

Thermocouple amplifier: Supports types J, K, T, N, E (with temperature compensation)
 
 
 
 

===CAN-bus Module Available ===
[[File:Can_Bus.jpg|150px|right|Can bus measurement|alt=Can bus to add on OROS instrument]]
(OR10/ TW OR35 / TW OR36 / TW OR38 only)

By using the [[NVGate_Can_BUS|CAN-bus module]], tracking analysis can be performed using information such as the engine speed flowing from the CAN-bus. By using this function, tracking analysis can be performed without using a tachometer.
 
 

===Recording is possible without the use of a PC by using the FFT analyzer in stand alone mode ===
(OR35 / TW OR36 / TW OR38 only)

[[File:d_rec.PNG|150px|right|Data acquisition recorder|alt=Vibration time signal Measurement without PC]]
The FFT analyzer is equipped with a [[NVGate_D-Rec|record-only button]]. Simply select a predefined measurement setup and press the record button to record onto the FFT analyzer alone without the use of a PC.

 
 
 
 

In addition, the back of the Fast Fourier Transform Spectrum Analyzer Multipurpose is equipped with an audio terminal and power supply. It is possible to record audio data while also measuring the time signal. The analyzer also can supply power to required sensors, such as proximity probes, tachometers and DC sensors.

[[File:FFT_analyzer.jpg|600px|Back of the hardware|alt=all the plug available on the backside of instrment]]
 
 
 

==Software Introduction==

*Easy-to-use interface
*Real-time measurement / post-analysis can be performed with the same software platform (NVGate)
*One-click report creation function

===Start the Measurement Quickly and Easily===

You can start measuring immediately by using the quick function provided in the OROS FFT analyzer mult function. This is completed by defining the number of input channels in the channel field and the measurement/analysis content in the show results area.

The Oros series FFT spectrum analyzer multifunction uses an interface similar to the ribbon interface used by Microsoft Office. All menus are accessible via the ribbon interface, making it easy to change measurement settings.

[[File:home3.PNG|800px|software ribbon|alt=NVgate ribbon technology]]

===One-click Setting Function===
With the Oros series multi-purpose FFT analyzer, you can display related measurement condition settings by double-clicking on the measurement screen. For example, if you double-click on the FFT analysis screen, the dialog for setting the measurement conditions for FFT analysis will be displayed on the screen as shown below.

[[File:FFT_analyzer_spectrum.png|500px|FFT spectrum|alt=Parameters easy to change]]

===Control Panel===
In addition, the OROS FFT spectrum analyzer is equipped with a control panel function that allows users to save frequently used measurement settings for quick access. By using this function, all settings can be changed on the [[NVGate_Control_Panel|control panel]]. For example, the following is the setting screen for a hammer test. By saving the input settings, threshold settings, and FFT analysis settings to the control panel as shown below, it is possible to make all the necessary settings quickly by only using the control panel.

===Various filters can be applied to recorded signals & FFT analysis results===
Four types of filters: Low-pass filter, high-pass filter, band-bus filter, and band-stop filter, can be applied to the results of recorded signal and FFT analysis. By using a [[NVGate_Filter_Builder|filter]], it is possible to remove abnormal noise components from the recorded signal and perform processing such as reproducing the extracted abnormal noise components.

[[File:filter_fft.png|600px|Filter analyzer]]

===Extract arbitrary order components from the color spectrum graph in real time===

Any order component can be extracted in real time from the color spectrum graph.

[[File:extraction.jpg|Synchronous order analysis extraction|alt=order extraction on vibration software]]

Easy-to-read Layout

The area for arranging windows is called a layout.
The OROS multi function FFT analyzer can create up to 16 layouts per project. You can easily arrange your windows by using the layout function. And your windows will open the same way each time.

It is possible to display up to 32 screens in one layout.

Up to 512 windows (= 16 x 32) can be displayed.

<big>'''Layout utilization example:'''</big>

'''Layout 1''': Record waveform, FFT analysis result, order ratio analysis result displayed

[[File:Fft_extraction_data.jpg|Order extraction|alt=Recorder and FFT together]]

'''Layout 2''': Display 3D frequency analysis results and 3D order ratio analysis results

[[File:waterfall_extract_order.jpg|3d display order spectrum |alt=NVGate software on line measurement]]

'''Layout 3''': Display 3D '''octave analyzer''' analysis results

[[File:octave waterfall.jpg|Octave acoustic measurement 3d display|alt=Acoustic measurement with octave]]

===Easy operation <Graph layout selection button>===

You can easily arrange windows just by selecting the grid menu.

[[File:gridwindows_PNG.PNG|NVGate icon|alt=Grid icon]]

Batch copy of measurement data with one menu. Numerical data can be transferred to Excel all at once.

[[File:excel_report.jpg|400px|FFT spectrum Report function|alt=export your data]]

Data measured at different times can be overwritten by dragging which allows for easily comparing measurement data.

[[File:drag_drop_report.jpg|Software NVGate]]

===One-click report creation function===

Simply click the report button located on the ribbon interface to create a [[NVGate_Report|report]] file containing the current measurement results.

[[File:allwindows_.PNG|NVGate report|alt=report all windows]]

• The content of the report is customizable. Customize it to the format that best suits your needs.

[[File:report-customize.jpg|500px|customize FFT analyzer software report|alt=Post analysis vibration software]]

===Measurement data search function===
[[File:pc cloud.PNG|right|Data stored|alt=cloud vibration data]]
Various information (meta-data) can be added when saving measurement data.
You then can search for measurement data and projects based on the added information.

Filter:
* Project name
* Measurement date and time
* Measurement conditions
* Measurement target
* Measurement site
* User
[[File:filter_project.PNG|550px|meta data on noise and vibration software NVGate|alt=Acoustic and vibration search function]]

===Fail judgment function as standard===
The [https://youtu.be/kx2HbcvfG_w pass / fail feature] of NVGate can be performed automatically after setting the desired bounds.

In the example below, a dialog is displayed when the product fails, but it is also possible to output a contact signal instead of the dialog.

[[File:fail_test.JPG|Pass/fail test on resonnance frequency impact hammer test|alt=Failed pass test on resonnance frequency test]]

===Automate post-analysis processing===

The same processing can be continuously performed for record files measured multiple times. By using this function, it is possible to automate the generation of reports, and it is possible to generate the same number of post-analysis results and EXCEL-based reports as record files with one click. Processing that used to take more than a week can now be done in a few hours.

[[File:BPP2.jpg|Post processing acoustic measurement batch |alt=Offline measurement]]

==specification==
===Main specifications===

{| class=wikitable style="width:100%;" style="text-align:center;"
! style="width:16%|
! style="width:21%|O4
! style="width:21%|OR35
! style="width:21%|OR36
! style="width:21%|OR38
|-
!colspan=6 style="text-align:center;" | Dynamical Input channel
|-
! Number of analysis channels
| 2, 4
| 6, 10 (Select Analysis or tachometer on 2 channels)
| 4, 8, 12, 16
| 8, 16, 24, 32
|-
! Terminal shape
| colspan=5| BNC
|-
!Input coupling and sensor support
|colspan=5| Compatible with AC, DC / ICP (sensor with built-in amplifier) and TEDS
|-
!Cutoff frequency
|colspan=5| - 3dB at AC cutoff frequency 0.35Hz
|-
! Input voltage range
|colspan=5| +/- 100mV to +/- 40V (auto range function)
|-
! Maximum voltage
|colspan=5| 60V
|-
!Anti-Aliasing filter
|colspan=5| 400dB / OCT
|-
!Input impedance
|colspan=5| 1MΩ <100pF
|-
!A / D converter
|colspan=5| 24-bit
|-
!Dynamic range
|colspan=5| >140dB
|-
!Channels-to-channels phase accuracy
|colspan=5| ± 0.02 ° (10V, 20kHz range)
|-
!Input filter
|colspan=5| Acoustic A, C, Z, low pass, high pass, band pass, integrator, differentiator, time axis integration function
|-
!Sampling frequency of the signal
|colspan=5|Select from 13 ranges between 102.4kHz and 2.048kHz.
|-
!colspan=6| Tachometer channel (Ext synch channels)
|-
!Number of input channels
|colspan=2|2 channels
|colspan=2|2 channels (up to 6 channels as an option)
|-
!Sampling frequency
|colspan=5|6.4MHz (counter method)
|-
!Voltage range
|colspan=4|+/- 300mV 40V
|-
!colspan=6| DC input
|-
!number of input channels
|colspan=1|none
|colspan=3|Analysis channel can be switched and used
|-
!Voltage range
|colspan=1|none
|colspan=3|22 bits, ± 40V, offset DC 100μV or less
|-
!Sampling frequency
|colspan=1|none
|colspan=3|15Hz or 12.5Hz
|-
!colspan=6|Calibration function
|-
!Calibration method
|colspan=5| Automatic sensitivity calculation by numerical input or reference signal (for position and standard vibration oscillatory meter)
|-
!How to use at the time of measurement
|colspan=5|Select by registered sensor name such as model name and machine number
|-
!colspan=6|Trigger function
|-
!Trigger type
|colspan=5|Edge, period, △ RPM, △ level, manual, multi (A or B, A and B, A after B)
|-
!Trigger delay
|colspan=5|Pre- and post-trigger functions
|-
!Trigger signal
|colspan=5|Select from any input channel
|-
!colspan=6|Record function
|-
!Sampling frequency
|colspan=5|13 ranges from 102.4kHz to 2.048kHz possible to select 2 types of range together
|-
!A / D converter resolution
|colspan=5| 24-bit or 16-bit
|-
!Hard drive size
|PC hard drive
|colspan=1|64 GB SSD
|colspan=2|128 GB removable SSD hard drive (256GB or 512 GB optional)
|-
!colspan=6|FFT analysis performance
|-
!Analysis frequency range
|colspan=1|0.8Hz-100kHz
|colspan=4|0.8Hz-40kHz
|-
!FFT block size
|colspan=5|256, 512, 1024, 2048, 4096, 8192, 1638
|-
!Number of analysis lines
|colspan=5|101, 201, 401, 801, 1601, 3201, 6401
|-
!Zoom analysis
|colspan=5|2 to 128 times (all channels at the same time)
|-
!Overlap setting
|colspan=5|0-99.99%
|-
!Window function
|colspan=5|Flat Top, Hanning, Humming, Kaiser Vessel, Rectangular, Force / Response
|-
!Average mode
|colspan=5|Time, frequency, fdsa / linear, exponential, peak hold
|-
!colspan=6|Analysis / display function
|-
!Time series
|colspan=5|Real-time waveform, record waveform, DC, Max, Min, RMS
|-
!FFT analysis
|colspan=5|Linear power spectrum, average spectrum, PSD, cross spectrum,
transfer function (H1, H2), copying function
|-
!Display color
|colspan=5|Display color: Arbitrary specification of trace, cursor, background, and grid display colors

|-
|-
!colspan=6|Options:
|-

!colspan=6|Time domain analysis (ORNV-TDA)
|-
!Analysis items
|colspan=5|Monitor display for arbitrary time (msec to day), effective value for arbitrary section, Min, Max, Peak,
Peak / Peak, RMS, DC, crest factor, Skew, Kurtosis
|-
!colspan=6| 1/n octave analysis (ORNV-OCT)
|-
!method
|colspan=5|Digital filter operation on time domain
|-
!Analysis band
|colspan=5|1/1, 1/3, 1/12, 1/24 octave (IEC1260: 1995 Class 1, ANSI S1.11-1986)
|-
!Analysis frequency
|colspan=5|Simultaneous analysis of all channels at 20kHz is possible (DSP option may be required)
|-
!Average
|colspan=5|Fast, Slow, lmpulse, LEQ, constantBT, linear repeat,exponential
|-

!colspan=6| Multi-sound level meter [ORNV-OVA]
|-
!Operation method
|colspan=6|Time series signal digital operation
|-
!Acoustic weighting
|colspan=6|Linear, A, C
|-
!Measurement
|colspan=6|Leq, Fast, Slow, lmpulse, average, Peak, Max, Min
|-
!Average
|colspan=6|Fast, Slow, lmpulse, LEQ, constantBT, linear repeat,exponential
|-

!colspan=6| Synchronous Order tracking analysis [ORNV-ORD]
|-
!Analysis function
|colspan=5| Instantaneous and average spectrum,phase, order profile and overall.
|-
!Maximum rotation speed
|colspan=5|1,200,000 RPM
|-
!Max analysis ordersetting
|colspan=5|6.25, 12.5, 25, 50, 100, 200, 400
|-
!Number of analysis lines
|colspan=5|25-800
|-
!Analysis bandwidth
|colspan=5|resampling method and fixed sampling method
|-
!display
|colspan=5|Simultaneous display of 3D display and tracking order, simultaneous display of time signal
|-

!colspan=6| Rotational torsion analysis [ORNV-IVC]
|-
!Operation method
|colspan=5| Digital Frequency Voltage converter
|-
!Number of analysis channels
|colspan=2|2ch
|colspan=3|2ch (up to 6ch as an option)
|-

|-
!colspan=6| Rotation diagnosis function [ORNV-FFTDiag]
|-
!Analysis items
|colspan=5| Envelope analysis, cepstrum, self-cross function, MAX, MIN, peak detection from block data, simulated tach,
|-

!colspan=6| Output Channel
|-
!Number of output channels
|colspan=1| 1ch (lemo conector, include)
|colspan=1| 2ch
|colspan=2| 2ch (up to 6ch as an option)
|-
!Output waveform
|colspan=1|Sinus, step sinus, sweep sinus, chirp, multi-sinus, random (pink and white), DC voltage, record signal
|colspan=3|Sinus, step sinus, sweep sinus, chirp, multi-sinus, random (pink and white), DC voltage, record signal
|-
!Digital / Analogic converter
|colspan=1|24 bits
|colspan=3|24 bits

|-
!Output voltage
|colspan=1|+/- 10V
|colspan=3|+/- 10V

|-
!Output Impedance
|colspan=1|50 Ω
|colspan=3|50 Ω
|-
!Frequency range
|colspan=1|~ 100kHz
|colspan=3|~ 40kHz
|-
!Sweep mode
|colspan=1|Sweep and step, analyze, trigger and sync, linear and log
|colspan=3|Sweep and step, analyze, trigger and sync, linear and log

|-
!Synchronization with the analysis
|colspan=1|Synchronization and free run
|colspan=3|Synchronization and free run
|-
!Output protection
|colspan=1|Stabilization with time specification and forced stop button
|colspan=3|Stabilization with time specification and forced stop button
|-
|-
!colspan=6|Data
|-
!Image and print
|colspan=5|Image, printing for Windows and user template creation function for Word and Excel
|-
!File
|colspan=5| TXT, UFF, MATLAB, WAV (OROS and Audio) SDF, binary, ATFX (optional)
|-
!Data entry
|colspan=5|WAV, TXT, UFF and OR20 series AE2
|-
|-
!colspan=6|Dimensions / weight
|-
!Dimensions (width x height x depth mm)
|35 x 110 x 185
|56 × 246 × 222
|102 x 260 x 311
|102 x 364 x 311
|-
!Weight
| 0.5kg
| 2.8kg
| 5.2 kg
| 8.2 kg
|-
!colspan=6|Power supply
|-
!AC
|colspan=5|AC 100V-240V
|-
!DC
| USB 3.0 type C 5V
| 10V-28V, 20VA
| 10V-28V, 60VA
| 10V-28V, 100VA
|-
!DC battery internal operating time (built-in)
| NA : using PC battery
| 3h
| 2h
| 2h
|-
!Recommended operating temperature range
|colspan=1| 0 ℃ ～ 40 ℃
|colspan=3| 0 ℃ ～ 50 ℃
|-
!cooling fan
|colspan=1|Fan less
|colspan=3|Automatic control by built-in temperature sensor, forced stop possible (however, forced ON when the temperature rises above 50 ° C)
|} 

===PC requirement===

{| class=wikitable style="width:100%;" style="text-align:center;"
|-
!Connections
|Type: '''Ethernet''', Connector: '''RJ45''' 

|-
!Operating systems
|Windows 7 / '''Windows 10''' / '''Windows 11'''

|-
!Recommended
|'''CPU : Quad core processor''' (Desktop : Intel Core i3 or Ryzen 3, Laptop : Intel Core i5 or Ryzen 5) 
'''RAM : 6 GB''' 
'''Storage : SSD''', 1 GB free <nowiki>+</nowiki> storage for signals
|}

 

==Function==

<li style="display: inline-table;">
{| class="wikitable"
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Overall_Acoustic_-_Sound_Level_meter|Sound Level Meter]]
|-
| [[File:REF-MAN_VOL1_Analyzer_Settings_Browser_wiki_partA_13.png]] [[NVGate_Waterfall|Waterfall analysis (three-dimensional display)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 10.png]] [[NVGate_Recorder|Signal record and post analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_FFT|Resonance frequency by impact hammer]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[ORBIGate|Vibration on rotordynamics (orbit,...)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Modal|Modal Analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Sound_Power|Sound Power]]
|} </li>

<li style="display: inline-table;">

{| class="wikitable"
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_FFT|Frequency analysis, spectrum analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Octave_Analyzer|Noise / acoustic analysis]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 10.png]] [[NVGate_D-Rec|Time series analysis (data logger)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Synchronous_Order_Analysis|Vibration of rotating machines]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[NVGate_Ribbons:_Automation|Customization (ex: automatic measurement)]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Sound_Quality_Lite|Sound Quality]]
|-
| [[File:REF-MAN VOL1 Analyzer Settings Browser wiki partA 12.png]] [[Monitoring_Solution|Monitoring]]
|} </li>

===Catalog download===
[[File:download_brochure.jpg|left|250px|noise and vibration catalog download]]
 
 
 
 
 

[https://www.oros.com/wp-content/uploads/2020/08/m002-103-10_oros_range_brochure.pdf Download]
 
 
 
 
 
 
 
 
 
 
 
 

===Applications/ Case study===

'''Main application and commonly used functions:'''

FFT analyzers are used in research and development, quality control, inspection, service departments, etc.

'''Improvements in vehicle quietness, ride quality, comfort, maneuverability, etc.'''

[[File:car_NVH.PNG|right|Automotive noise and vibration]]

* [https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
* [https://www.oros.com/solutions/acoustics/1-n-octave-analysis/ 1 / N octave analysis]
* [https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]
* [https://www.oros.com/solutions/structural-dynamics/modal-analysis/ Experimental mode analysis]

'''Responding to quality problems caused by vibration and noise of vehicles and rotating equipment'''

[[File:rotating.PNG|right|rotating machine vibration]]

*[https://www.oros.com/solutions/acoustics/sound-level-meter/ Overall measurement]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/rotating-analysis/turbomachinery-vibration-and-rotordynamics/ Turbomachinery Analysis]
*[https://www.oros.com/solutions/rotating-analysis/order-tracking-analysis/ Rotation order ratio / RPM tracking analysis]
*[https://www.oros.com/solutions/rotating-analysis/torsion-twist/ Rotational torsional vibration analysis]
*[https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]

'''Environmental problems caused by noise from construction machinery, office machines, home appliances, etc.'''

[[File:machinery.PNG|right|Acoustic and vibration application]]
*[https://www.oros.com/solutions/acoustics/sound-level-meter/ Overall measurement]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/acoustics/1-n-octave-analysis/ 1/N octave analysis]

'''Problems with processing accuracy due to minute vibrations in microscopes, machine tools, semiconductor manufacturing equipment, etc'''.

[[File:accuracy.PNG|right| Accuracy measurement]]
*[https://www.oros.com/solutions/data-acquisition-and-signal-processing/narrow-band-spectral-analysis/ Frequency analysis]
*[https://www.oros.com/solutions/structural-dynamics/frequency-response-function-frf-acquisitions/ Resonance frequency measurement by vibration]
*[https://www.oros.com/solutions/structural-dynamics/modal-analysis/ Experimental modal analysis]

'''A collection of application examples using the OROS FFT analyzer OROS series'''

Introducing solution examples that can be provided by various functions unique to OROS FFT analyzers.

*'''Vibration measurement of cutting machine'''

[[File:cutting tools machine.jpg|150px|left|Vibration measurement of cutting machine]]

Introducing what approach can be taken using the OROS FFT Analyzer to identify mechanical resonance problems due to changes in cutting conditions.
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need register)]
 
 
 
 

*'''Monitoring of wind power generation equipment and abnormality diagnosis'''

[[File:eolienne.PNG|left|Monitoring vibration]]

Measuring vibration noise generated from rotating machines (gearboxes, generators, etc.) in wind power generation equipment is indispensable for equipment maintenance and longevity. In addition to the real-time analysis capability of rotating machinery, which is the strength of the OROS FFT analyzer, remote control / monitoring and stand-alone functions can be used to more efficiently diagnose equipment for wind power generation equipment.
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need to register)]
 
 

*'''Diesel engine camshaft rotational twist measurement'''
[[File:danielson torsional.PNG|left|Diesel engine camshaft rotational twist]]

In the prototype of a small diesel engine, there is a problem that the rotational torsional vibration of the timing belt and the camshaft resonates, causing a large vibration. By measuring rotational fluctuations and rotational twists with high accuracy using the six tachometer channels mounted on the OROS FFT analyzer, it is clarified which rotational order is dominant for vibration. 
 
[https://my.oros.com/categories/application-notes/ Download on my.oros.com (need register)]
 

*'''Much more Application note on [https://my.oros.com/ my.oros.com]'''

<gallery gallery="" mode="packed-hover" align="left">
File:End of line turbine test.jpg|alt=Gear box measurement with accelerometers|Allen Gears: gear box rotating vibration
File:In flight helicopter vibration measurement.PNG|alt=motor vibration order extraction|Conrad: On helicopter vibration measurement
File:Mecalac sound power.jpg|alt=Octave and sound level meter with microphone|Mecalac: Sound power acoustic measurement
File:In-porsche.JPG|alt=Automotive octave waterfall analyzer with order extraction|Porsche: acoustic sound quality measurement
File:Sound power2.jpg|alt=Acoustic room with microphone |Bosch: Sound power acoustic measurement on anechoic chamber
File:Vibration on block press.jpg|alt=Shock test measurement|IFF Weimar: Vibration on block press
File:Blade vibration.jpg|alt=Spectrum analyzer on the field|Blade vibration
File:Elevator shaft vibration.jpg|alt=accelerometer and microphone analysis|Sicor: Elevator motor vibration
File:DBVib 01.JPG|alt=Orbit shaft center line and fluid film bearing vibration|dBVib: On site measurement on turbomachinery
File:Equilibrage 005.jpg|alt=Acceleromters on each side of the plan|BSCA: Vibration balancing test
File:Washingmachine.jpg|alt=Bump test geometry with modal software|Washing machine FRF resonance frequency test
File:Master at work.jpg|alt=team watching overall value of accelerometer|Vibration measurement
File:Windturbine.jpg|alt=Motor of wind turbine analysis|GDF SUEZ: Windturbine monitoring measurement
File:3 OR38.JPG|alt=multichannel analyzer portable |3 analyzers working together
File:Turbine.JPG|alt=hydro vibration measurement|Alstom: Measurement on turbine
</gallery>

'''Some references:'''

[[File:reference.PNG|800px|Analyzer reference|alt=airplane automotive energy measurement]]

===Full technical support===

* '''Hotline dedicated'''

[[File:Custcare team2 web-1.jpg|right|150px|support FFT analyzer|alt=expert on noise and vibration]]
Responsiveness is the key to offer the best level of services. OROS relies on a powerful network of subsidiaries, offices, resellers, maintenance centers and qualified partners. They are the first steps of efficiency.

Tel: +33.4.76.90.52.40 
Email: [http://customer.care@oros.com customer.care@oros.com]

[https://www.oros.com/find-us/ Your local distributor] 
 

* '''User training course'''
OROS proposes training specially dedicated to customers every year for free (depending on countries). This is an opportunity to take advantage of your analyzer system capabilities, to get premium information on OROS range evolution, to discuss with your peers, and for OROS, to listen to your product enhancement desires.
 
[[File:user_day.jpg|Acoustic and vibration training|alt=Korean vibration camp]]
 
 

* '''Worldwide presence and accredited maintenance center'''

With a worldwide coverage of distributor network and maintenance center (China, Europe, India, Japan, Saudi Arabia, South Korea, USA), OROS is in close proximity to its customers, reducing maintenance downtime.
 
[[File:map_world_distributor.JPG|Spectrum analyzer worldwide seller|alt=maintenance center]] 
[https://www.oros.com/find-us/ Find Your local distributor]
[[File:repair.jpg|200px|right|repair hardware analyzer|alt=calibration repair metrologic instrument]]
 
 
Technicians are certiﬁed on a regular basis by OROS specialists, enabling them to repair, calibrate and upgrade all OROS systems.

*'''Premium contract'''

1, 2 or 4 years renewable [https://www.oros.com/services/contracts/ contracts] to extend your warranty.

* Access to the latest software version.
* Full coverage on your instrument (calibration and maintenance)
* Guaranteed turn around time (4 days) for hardware repairs and calibration
* Privileged access to extended services at a preferential rate: urgent loan within 1 day.

===Video content ===

We have released videos such as product introductions and demonstrations.

[https://www.youtube.com/user/OROSanalyzers/videos Click here for the youtube video content page]
 

{|class="wikitable" style="width:100%;"
|style="background: #0000A0; text-align:center;"|<big>[https://www.oros.com/demo-request/ Schedule a demo]</big>
|style="background: red; text-align:center;"|<big>[https://www.oros.com/quote-request-form/ Get a quotation]</big>
|style="background: green; text-align:center;"|<big>[[FFT_Spectrum_Analyzer_Multipurpose#Full_technical_support|Contact support]]</big>
|}

THD Sweep Measurement

2026-09-30T12:26:56Z

Lmagimel: /* Change log */

== THD SWEEP MEASUREMENT - USER GUIDE ==
''Master the art of measuring Total Harmonic Distortion with style''

[[File:sweep.png|400px]]

__TOC__

{| style="width:100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 20px 0; text-align: center;"
|-
| style="font-size: 2.5em; font-weight: bold;" | 🎵 THD SWEEP MEASUREMENT
|-
| style="font-size: 1.2em; opacity: 0.95;" | Professional Acoustic Testing Made Simple
|}

---

== Install ==

Download THD measurement :

[https://partnerzone.digigram.com/s/i7ZCnB8jzgxY6W8 THD sweep measurement V1.2] september 2026
=== Change log ===

V1.2

- The THD in percent (DC1) is now displayed with **NVGate's standard "%" unit**. No more "spare" in place of the unit.

- The **NVGate model "THD computation"** is corrected: it opens directly in "%".

=== Install model===

Put the model folder : "THD computation" on model database of NVgate.
(By default : C:\OROS\NVGate data\Workbook Library\User\ )

=== Requirement ===

NVGate V17 or upper.

Option : DC simulated on NVGate front end.

== ⚡ QUICK START - 30 SECONDS ==

{| style="width: 100%; border-collapse: collapse; margin: 20px 0;"
|-
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 10%;" | STEP
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 90%;" | ACTION
|-
| style="padding: 15px; background: #fafbff;" | 1️⃣ Launch
| style="padding: 15px; background: #fafbff;" | Launch NVgate in connected mode and load the THD computation model Double-click <code>THD_Sweep_Measurement.exe</code>
|-
| style="padding: 15px; background: white;" | 2️⃣ Connect
| style="padding: 15px; background: white;" | Put the sweep sine signal on channel 4️⃣ ; put the response on channel 1️⃣
|-
| style="padding: 15px; background: #fafbff;" | 3️⃣ Start
| style="padding: 15px; background: #fafbff;" | Start the THD_Sweep_Measurement.exe and Click green <code>▶ START</code> button
|-
| style="padding: 15px; background: white;" | 4️⃣ Monitor
| style="padding: 15px; background: white;" | Watch 4 metrics update live , THD and frequency will also be injected on NVGate channels DC simulated.
|-
| style="padding: 15px; background: #fafbff;" | 5️⃣ Stop
| style="padding: 15px; background: #fafbff;" | Click red <code>■ STOP</code> button
|}

<div style="background: #e8f5e9; border-left: 5px solid #4caf50; padding: 20px; margin: 20px 0; border-radius: 5px;">
✅ '''That's it!''' Your first THD measurement is complete. You're now a certified acoustic engineer. (Not really, but it feels good.)
</div>

---

=== 📊 Four Metric Cards ===

The heart of the interface. These four numbers tell the whole story:

{| style="width: 100%; margin: 20px 0; border-collapse: collapse;"
|-
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📈 THD (dB)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📊 THD (%)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📡 Frequency
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | ⚡ Fundamental
|-
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (log scale)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (%)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Current sweep point
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Signal strength
|-
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | +5.42 dB
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 58.294 %
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 1234.56 Hz
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 5.0e-01 V
|}

== 🎯 UNDERSTANDING YOUR RESULTS ==

=== THD (%) - The Easy Number ===

<div style="background: linear-gradient(135deg, #c8e6c9, #a5d6a7); padding: 25px; border-radius: 10px; margin: 20px 0; color: #1b5e20;">

'''What is it?''' Percentage of unwanted harmonics in your signal.

Think of it this way:
* THD 5% = 95% pure signal, 5% noise
* THD 20% = 80% pure signal, 20% noise

'''The Quality Scale:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2; font-weight: bold;" | 🌟 1% - 5%
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2;" | Excellent - Professional grade equipment
|-
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9; font-weight: bold;" | ✅ 5% - 15%
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9;" | Good - Solid speaker performance
|-
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d; font-weight: bold;" | ⚠️ 15% - 30%
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d;" | Acceptable - Consumer level equipment
|-
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2; font-weight: bold;" | ❌ > 30%
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2;" | Poor - Time for an upgrade 🛠️
|}

</div>

=== THD (dB) - The Technical Number ===

<div style="background: linear-gradient(135deg, #bbdefb, #90caf9); padding: 25px; border-radius: 10px; margin: 20px 0; color: #0d47a1;">

Same measurement as THD (%) but in decibels (logarithmic scale).

'''Quick Conversion Chart:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD %
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD dB
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | Quality
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 1%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -40 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 🌟 Perfect
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 3%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -30 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Great
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 10%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -20 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Good
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 30%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -10 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ⚠️ Poor
|}

</div>

---

== ⚙️ CONFIGURATION ==

=== When Do I Need to Change This? ===

<div style="background: #e3f2fd; border-left: 5px solid #2196f3; padding: 20px; margin: 20px 0; border-radius: 5px;">

'''Honest answer: Almost never.'''

The default settings work for 95% of users. Only change if your NVGate project has:
* Different window names
* Different marker numbers
* Different DC input addresses

If you're not sure → Don't change anything. It works.

</div>

The NVgate Model generate a sweep sine on the output, feel free to modify the settings if you need. We recommand to not put a sweep speed more than 0.05dec/s (or less) in logarithme for accurate results

=== How to Access Configuration ===

Click on '''▶ Configuration''' (section expands)

=== Important Settings ===

{| style="width: 100%; border-collapse: collapse; margin: 15px 0;"
|-
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 30%;" | Setting
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 25%;" | Default
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 45%;" | When to Change
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Window (sweep)
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | Window2
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Your sweep FFT has different name
|-
| style="padding: 12px; border: 1px solid #ddd;" | Window (response)
| style="padding: 12px; border: 1px solid #ddd; font-family: monospace;" | Window1
| style="padding: 12px; border: 1px solid #ddd;" | Your response FFT has different name
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Number of harmonics
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | 9
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" |
|}

=== How to Apply Changes ===

# Modify field value
# Click '''Apply Configuration'''
# Log displays "Configuration applied" ✓
# Done!

---

== ❓ FREQUENTLY ASKED QUESTIONS ==

=== Q: I Have only one channels. Can i take the max marker on windows 1 ?===

'''A:''' Yes, on this configuration, put windows 1 for window (sweep) and select the good number for the marker.

=== Q: Is THD 5% good? ===

'''A:''' For a speaker? Excellent! You can be proud of that equipment. 🎉

=== Q: Why does THD change with frequency? ===

'''A:''' Because speakers aren't perfect at all frequencies. Some frequencies cause more distortion than others. That's physics being weird.

=== Q: Can I use this on any speaker? ===

'''A:''' Yes! Desktop speakers, studio monitors, subwoofers, car speakers - if it's connected to NVGate, we can measure it.

=== Q: How many times should I measure? ===

'''A:''' Once for curiosity. Three times for reliability. Ten times if you're publishing a paper.

=== Q: Can I export the results? ===

'''A:''' Yes! Copy text from the log console and paste into Excel, Word, or wherever you need it.

=== Q: What if my project has different settings? ===

'''A:''' Use the Configuration panel to adjust. It's literally made for this.

=== Q: Does this work over WiFi? ===

'''A:''' No. It only works locally (same computer or local network). WiFi would add too much latency.

---

===disclaimer===

1) This program is delivered free of charge for NVGate V12. Support is not automatically provided on this tool.

2) For any other requests, please contact your local distributor or the [mailto:customer.care@oros.com OROS Customer Care department.]

---

{| style="width: 100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 30px 0; text-align: center;"
|-
| style="font-size: 1.5em; font-weight: bold;" | You're Ready!
|-
| style="font-size: 1.1em; margin-top: 10px; opacity: 0.95;" | Go measure some THD and make your speakers proud 🎵
|}

== Technical appendix THD Formulas ==

=== THD Percentage (DC1) ===

'''Formula:'''

<code>THD(%) = (√(H2² + H3² + ... + H9²) / H1) × 100</code>

Where:
* H1 = Fundamental amplitude (1st harmonic)
* H2, H3, ..., H9 = Harmonic amplitudes (2nd to 9th)
* √ = Square root

'''Example:'''
* H1 (fundamental) = 1.0 V
* H2 = 0.02 V
* H3 = 0.01 V
* H4 = 0.01 V
* (all others = 0)

Calculation:
* Harmonics RMS = √(0.02² + 0.01² + 0.01²) = √0.0006 = 0.0245 V
* THD% = (0.0245 / 1.0) × 100 = '''2.45%'''

---

=== THD in Decibels (DC2) ===

'''Formula:'''

<code>THD(dB) = 20 × log₁₀(√(H2² + H3² + ... + H9²) / H1)</code>

Or from THD%:

<code>THD(dB) = 20 × log₁₀(THD% / 100)</code>

Where:
* log₁₀ = Base-10 logarithm
* All H values same as above

'''Example from above:'''
* Ratio = 0.0245 / 1.0 = 0.0245
* log₁₀(0.0245) = -1.611
* THD(dB) = 20 × (-1.611) = '''−32.2 dB'''

Or: THD(dB) = 20 × log₁₀(2.45 / 100) = 20 × (−1.611) = '''−32.2 dB'''

---

=== Quick Conversion Table ===

{| class="wikitable"
|-
! THD Percentage !! THD in dB !! Quality Rating
|-
| 0.5% || −46 dB || Excellent (pro audio)
|-
| 1% || −40 dB || Very Good
|-
| 3% || −30 dB || Good
|-
| 5% || −26 dB || Acceptable
|-
| 10% || −20 dB || Fair
|-
| 30% || −10 dB || Poor
|-
| 100% || 0 dB || Unusable
|}

---

=== Three DC Outputs ===

{| class="wikitable"
|-
! Output Channel !! Measurement !! Formula !! Typical Range
|-
| DC1 || THD % || (Harmonics RMS / H1) × 100 || 0 to 100%
|-
| DC2 || THD dB || 20 × log₁₀(ratio) || −200 to 0 dB
|-
| DC3 || Frequency || Sweep frequency at current point || 0 to 40 kHz
|}

---

=== Coherence Between DC1 and DC2 ===

The two THD channels always maintain mathematical coherence. Given DC1 value (THD%), you can always calculate DC2:

<code>DC2(dB) = 20 × log₁₀(DC1(%) / 100)</code>

'''Example:'''
* If DC1 displays 5.5%
* Then DC2 = 20 × log₁₀(0.055) = 20 × (−1.26) = '''−25.2 dB'''

This relationship is guaranteed by the software mathematics.

---

=== Why Two Formats (% and dB)? ===

'''THD %:'''
* Easier to understand for non-technical users
* Direct representation: "5% distortion"
* Useful for product specifications

'''THD dB:'''
* Logarithmic scale: easier to see small differences
* Standard in audio/RF engineering
* Used in all standards and specifications
* Better for comparing measurements at different levels

Both represent the same information, just in different scales.

---
==Disclaimer==

This tools is deliver free of charge, Support is not automatically provided on this tool.

THD Sweep Measurement

2026-09-30T12:26:49Z

Lmagimel: /* Change log */

== THD SWEEP MEASUREMENT - USER GUIDE ==
''Master the art of measuring Total Harmonic Distortion with style''

[[File:sweep.png|400px]]

__TOC__

{| style="width:100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 20px 0; text-align: center;"
|-
| style="font-size: 2.5em; font-weight: bold;" | 🎵 THD SWEEP MEASUREMENT
|-
| style="font-size: 1.2em; opacity: 0.95;" | Professional Acoustic Testing Made Simple
|}

---

== Install ==

Download THD measurement :

[https://partnerzone.digigram.com/s/i7ZCnB8jzgxY6W8 THD sweep measurement V1.2] september 2026
=== Change log ===

V1.2
- The THD in percent (DC1) is now displayed with **NVGate's standard "%" unit**. No more "spare" in place of the unit.

- The **NVGate model "THD computation"** is corrected: it opens directly in "%".

=== Install model===

Put the model folder : "THD computation" on model database of NVgate.
(By default : C:\OROS\NVGate data\Workbook Library\User\ )

=== Requirement ===

NVGate V17 or upper.

Option : DC simulated on NVGate front end.

== ⚡ QUICK START - 30 SECONDS ==

{| style="width: 100%; border-collapse: collapse; margin: 20px 0;"
|-
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 10%;" | STEP
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 90%;" | ACTION
|-
| style="padding: 15px; background: #fafbff;" | 1️⃣ Launch
| style="padding: 15px; background: #fafbff;" | Launch NVgate in connected mode and load the THD computation model Double-click <code>THD_Sweep_Measurement.exe</code>
|-
| style="padding: 15px; background: white;" | 2️⃣ Connect
| style="padding: 15px; background: white;" | Put the sweep sine signal on channel 4️⃣ ; put the response on channel 1️⃣
|-
| style="padding: 15px; background: #fafbff;" | 3️⃣ Start
| style="padding: 15px; background: #fafbff;" | Start the THD_Sweep_Measurement.exe and Click green <code>▶ START</code> button
|-
| style="padding: 15px; background: white;" | 4️⃣ Monitor
| style="padding: 15px; background: white;" | Watch 4 metrics update live , THD and frequency will also be injected on NVGate channels DC simulated.
|-
| style="padding: 15px; background: #fafbff;" | 5️⃣ Stop
| style="padding: 15px; background: #fafbff;" | Click red <code>■ STOP</code> button
|}

<div style="background: #e8f5e9; border-left: 5px solid #4caf50; padding: 20px; margin: 20px 0; border-radius: 5px;">
✅ '''That's it!''' Your first THD measurement is complete. You're now a certified acoustic engineer. (Not really, but it feels good.)
</div>

---

=== 📊 Four Metric Cards ===

The heart of the interface. These four numbers tell the whole story:

{| style="width: 100%; margin: 20px 0; border-collapse: collapse;"
|-
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📈 THD (dB)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📊 THD (%)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📡 Frequency
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | ⚡ Fundamental
|-
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (log scale)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (%)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Current sweep point
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Signal strength
|-
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | +5.42 dB
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 58.294 %
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 1234.56 Hz
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 5.0e-01 V
|}

== 🎯 UNDERSTANDING YOUR RESULTS ==

=== THD (%) - The Easy Number ===

<div style="background: linear-gradient(135deg, #c8e6c9, #a5d6a7); padding: 25px; border-radius: 10px; margin: 20px 0; color: #1b5e20;">

'''What is it?''' Percentage of unwanted harmonics in your signal.

Think of it this way:
* THD 5% = 95% pure signal, 5% noise
* THD 20% = 80% pure signal, 20% noise

'''The Quality Scale:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2; font-weight: bold;" | 🌟 1% - 5%
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2;" | Excellent - Professional grade equipment
|-
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9; font-weight: bold;" | ✅ 5% - 15%
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9;" | Good - Solid speaker performance
|-
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d; font-weight: bold;" | ⚠️ 15% - 30%
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d;" | Acceptable - Consumer level equipment
|-
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2; font-weight: bold;" | ❌ > 30%
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2;" | Poor - Time for an upgrade 🛠️
|}

</div>

=== THD (dB) - The Technical Number ===

<div style="background: linear-gradient(135deg, #bbdefb, #90caf9); padding: 25px; border-radius: 10px; margin: 20px 0; color: #0d47a1;">

Same measurement as THD (%) but in decibels (logarithmic scale).

'''Quick Conversion Chart:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD %
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD dB
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | Quality
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 1%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -40 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 🌟 Perfect
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 3%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -30 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Great
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 10%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -20 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Good
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 30%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -10 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ⚠️ Poor
|}

</div>

---

== ⚙️ CONFIGURATION ==

=== When Do I Need to Change This? ===

<div style="background: #e3f2fd; border-left: 5px solid #2196f3; padding: 20px; margin: 20px 0; border-radius: 5px;">

'''Honest answer: Almost never.'''

The default settings work for 95% of users. Only change if your NVGate project has:
* Different window names
* Different marker numbers
* Different DC input addresses

If you're not sure → Don't change anything. It works.

</div>

The NVgate Model generate a sweep sine on the output, feel free to modify the settings if you need. We recommand to not put a sweep speed more than 0.05dec/s (or less) in logarithme for accurate results

=== How to Access Configuration ===

Click on '''▶ Configuration''' (section expands)

=== Important Settings ===

{| style="width: 100%; border-collapse: collapse; margin: 15px 0;"
|-
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 30%;" | Setting
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 25%;" | Default
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 45%;" | When to Change
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Window (sweep)
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | Window2
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Your sweep FFT has different name
|-
| style="padding: 12px; border: 1px solid #ddd;" | Window (response)
| style="padding: 12px; border: 1px solid #ddd; font-family: monospace;" | Window1
| style="padding: 12px; border: 1px solid #ddd;" | Your response FFT has different name
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Number of harmonics
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | 9
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" |
|}

=== How to Apply Changes ===

# Modify field value
# Click '''Apply Configuration'''
# Log displays "Configuration applied" ✓
# Done!

---

== ❓ FREQUENTLY ASKED QUESTIONS ==

=== Q: I Have only one channels. Can i take the max marker on windows 1 ?===

'''A:''' Yes, on this configuration, put windows 1 for window (sweep) and select the good number for the marker.

=== Q: Is THD 5% good? ===

'''A:''' For a speaker? Excellent! You can be proud of that equipment. 🎉

=== Q: Why does THD change with frequency? ===

'''A:''' Because speakers aren't perfect at all frequencies. Some frequencies cause more distortion than others. That's physics being weird.

=== Q: Can I use this on any speaker? ===

'''A:''' Yes! Desktop speakers, studio monitors, subwoofers, car speakers - if it's connected to NVGate, we can measure it.

=== Q: How many times should I measure? ===

'''A:''' Once for curiosity. Three times for reliability. Ten times if you're publishing a paper.

=== Q: Can I export the results? ===

'''A:''' Yes! Copy text from the log console and paste into Excel, Word, or wherever you need it.

=== Q: What if my project has different settings? ===

'''A:''' Use the Configuration panel to adjust. It's literally made for this.

=== Q: Does this work over WiFi? ===

'''A:''' No. It only works locally (same computer or local network). WiFi would add too much latency.

---

===disclaimer===

1) This program is delivered free of charge for NVGate V12. Support is not automatically provided on this tool.

2) For any other requests, please contact your local distributor or the [mailto:customer.care@oros.com OROS Customer Care department.]

---

{| style="width: 100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 30px 0; text-align: center;"
|-
| style="font-size: 1.5em; font-weight: bold;" | You're Ready!
|-
| style="font-size: 1.1em; margin-top: 10px; opacity: 0.95;" | Go measure some THD and make your speakers proud 🎵
|}

== Technical appendix THD Formulas ==

=== THD Percentage (DC1) ===

'''Formula:'''

<code>THD(%) = (√(H2² + H3² + ... + H9²) / H1) × 100</code>

Where:
* H1 = Fundamental amplitude (1st harmonic)
* H2, H3, ..., H9 = Harmonic amplitudes (2nd to 9th)
* √ = Square root

'''Example:'''
* H1 (fundamental) = 1.0 V
* H2 = 0.02 V
* H3 = 0.01 V
* H4 = 0.01 V
* (all others = 0)

Calculation:
* Harmonics RMS = √(0.02² + 0.01² + 0.01²) = √0.0006 = 0.0245 V
* THD% = (0.0245 / 1.0) × 100 = '''2.45%'''

---

=== THD in Decibels (DC2) ===

'''Formula:'''

<code>THD(dB) = 20 × log₁₀(√(H2² + H3² + ... + H9²) / H1)</code>

Or from THD%:

<code>THD(dB) = 20 × log₁₀(THD% / 100)</code>

Where:
* log₁₀ = Base-10 logarithm
* All H values same as above

'''Example from above:'''
* Ratio = 0.0245 / 1.0 = 0.0245
* log₁₀(0.0245) = -1.611
* THD(dB) = 20 × (-1.611) = '''−32.2 dB'''

Or: THD(dB) = 20 × log₁₀(2.45 / 100) = 20 × (−1.611) = '''−32.2 dB'''

---

=== Quick Conversion Table ===

{| class="wikitable"
|-
! THD Percentage !! THD in dB !! Quality Rating
|-
| 0.5% || −46 dB || Excellent (pro audio)
|-
| 1% || −40 dB || Very Good
|-
| 3% || −30 dB || Good
|-
| 5% || −26 dB || Acceptable
|-
| 10% || −20 dB || Fair
|-
| 30% || −10 dB || Poor
|-
| 100% || 0 dB || Unusable
|}

---

=== Three DC Outputs ===

{| class="wikitable"
|-
! Output Channel !! Measurement !! Formula !! Typical Range
|-
| DC1 || THD % || (Harmonics RMS / H1) × 100 || 0 to 100%
|-
| DC2 || THD dB || 20 × log₁₀(ratio) || −200 to 0 dB
|-
| DC3 || Frequency || Sweep frequency at current point || 0 to 40 kHz
|}

---

=== Coherence Between DC1 and DC2 ===

The two THD channels always maintain mathematical coherence. Given DC1 value (THD%), you can always calculate DC2:

<code>DC2(dB) = 20 × log₁₀(DC1(%) / 100)</code>

'''Example:'''
* If DC1 displays 5.5%
* Then DC2 = 20 × log₁₀(0.055) = 20 × (−1.26) = '''−25.2 dB'''

This relationship is guaranteed by the software mathematics.

---

=== Why Two Formats (% and dB)? ===

'''THD %:'''
* Easier to understand for non-technical users
* Direct representation: "5% distortion"
* Useful for product specifications

'''THD dB:'''
* Logarithmic scale: easier to see small differences
* Standard in audio/RF engineering
* Used in all standards and specifications
* Better for comparing measurements at different levels

Both represent the same information, just in different scales.

---
==Disclaimer==

This tools is deliver free of charge, Support is not automatically provided on this tool.

THD Sweep Measurement

2026-09-30T12:26:40Z

Lmagimel: /* Change log */

== THD SWEEP MEASUREMENT - USER GUIDE ==
''Master the art of measuring Total Harmonic Distortion with style''

[[File:sweep.png|400px]]

__TOC__

{| style="width:100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 20px 0; text-align: center;"
|-
| style="font-size: 2.5em; font-weight: bold;" | 🎵 THD SWEEP MEASUREMENT
|-
| style="font-size: 1.2em; opacity: 0.95;" | Professional Acoustic Testing Made Simple
|}

---

== Install ==

Download THD measurement :

[https://partnerzone.digigram.com/s/i7ZCnB8jzgxY6W8 THD sweep measurement V1.2] september 2026
=== Change log ===

V1.2
- The THD in percent (DC1) is now displayed with **NVGate's standard "%" unit**. No more "spare" in place of the unit.
- The **NVGate model "THD computation"** is corrected: it opens directly in "%".

=== Install model===

Put the model folder : "THD computation" on model database of NVgate.
(By default : C:\OROS\NVGate data\Workbook Library\User\ )

=== Requirement ===

NVGate V17 or upper.

Option : DC simulated on NVGate front end.

== ⚡ QUICK START - 30 SECONDS ==

{| style="width: 100%; border-collapse: collapse; margin: 20px 0;"
|-
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 10%;" | STEP
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 90%;" | ACTION
|-
| style="padding: 15px; background: #fafbff;" | 1️⃣ Launch
| style="padding: 15px; background: #fafbff;" | Launch NVgate in connected mode and load the THD computation model Double-click <code>THD_Sweep_Measurement.exe</code>
|-
| style="padding: 15px; background: white;" | 2️⃣ Connect
| style="padding: 15px; background: white;" | Put the sweep sine signal on channel 4️⃣ ; put the response on channel 1️⃣
|-
| style="padding: 15px; background: #fafbff;" | 3️⃣ Start
| style="padding: 15px; background: #fafbff;" | Start the THD_Sweep_Measurement.exe and Click green <code>▶ START</code> button
|-
| style="padding: 15px; background: white;" | 4️⃣ Monitor
| style="padding: 15px; background: white;" | Watch 4 metrics update live , THD and frequency will also be injected on NVGate channels DC simulated.
|-
| style="padding: 15px; background: #fafbff;" | 5️⃣ Stop
| style="padding: 15px; background: #fafbff;" | Click red <code>■ STOP</code> button
|}

<div style="background: #e8f5e9; border-left: 5px solid #4caf50; padding: 20px; margin: 20px 0; border-radius: 5px;">
✅ '''That's it!''' Your first THD measurement is complete. You're now a certified acoustic engineer. (Not really, but it feels good.)
</div>

---

=== 📊 Four Metric Cards ===

The heart of the interface. These four numbers tell the whole story:

{| style="width: 100%; margin: 20px 0; border-collapse: collapse;"
|-
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📈 THD (dB)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📊 THD (%)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📡 Frequency
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | ⚡ Fundamental
|-
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (log scale)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (%)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Current sweep point
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Signal strength
|-
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | +5.42 dB
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 58.294 %
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 1234.56 Hz
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 5.0e-01 V
|}

== 🎯 UNDERSTANDING YOUR RESULTS ==

=== THD (%) - The Easy Number ===

<div style="background: linear-gradient(135deg, #c8e6c9, #a5d6a7); padding: 25px; border-radius: 10px; margin: 20px 0; color: #1b5e20;">

'''What is it?''' Percentage of unwanted harmonics in your signal.

Think of it this way:
* THD 5% = 95% pure signal, 5% noise
* THD 20% = 80% pure signal, 20% noise

'''The Quality Scale:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2; font-weight: bold;" | 🌟 1% - 5%
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2;" | Excellent - Professional grade equipment
|-
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9; font-weight: bold;" | ✅ 5% - 15%
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9;" | Good - Solid speaker performance
|-
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d; font-weight: bold;" | ⚠️ 15% - 30%
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d;" | Acceptable - Consumer level equipment
|-
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2; font-weight: bold;" | ❌ > 30%
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2;" | Poor - Time for an upgrade 🛠️
|}

</div>

=== THD (dB) - The Technical Number ===

<div style="background: linear-gradient(135deg, #bbdefb, #90caf9); padding: 25px; border-radius: 10px; margin: 20px 0; color: #0d47a1;">

Same measurement as THD (%) but in decibels (logarithmic scale).

'''Quick Conversion Chart:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD %
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD dB
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | Quality
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 1%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -40 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 🌟 Perfect
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 3%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -30 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Great
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 10%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -20 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Good
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 30%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -10 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ⚠️ Poor
|}

</div>

---

== ⚙️ CONFIGURATION ==

=== When Do I Need to Change This? ===

<div style="background: #e3f2fd; border-left: 5px solid #2196f3; padding: 20px; margin: 20px 0; border-radius: 5px;">

'''Honest answer: Almost never.'''

The default settings work for 95% of users. Only change if your NVGate project has:
* Different window names
* Different marker numbers
* Different DC input addresses

If you're not sure → Don't change anything. It works.

</div>

The NVgate Model generate a sweep sine on the output, feel free to modify the settings if you need. We recommand to not put a sweep speed more than 0.05dec/s (or less) in logarithme for accurate results

=== How to Access Configuration ===

Click on '''▶ Configuration''' (section expands)

=== Important Settings ===

{| style="width: 100%; border-collapse: collapse; margin: 15px 0;"
|-
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 30%;" | Setting
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 25%;" | Default
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 45%;" | When to Change
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Window (sweep)
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | Window2
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Your sweep FFT has different name
|-
| style="padding: 12px; border: 1px solid #ddd;" | Window (response)
| style="padding: 12px; border: 1px solid #ddd; font-family: monospace;" | Window1
| style="padding: 12px; border: 1px solid #ddd;" | Your response FFT has different name
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Number of harmonics
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | 9
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" |
|}

=== How to Apply Changes ===

# Modify field value
# Click '''Apply Configuration'''
# Log displays "Configuration applied" ✓
# Done!

---

== ❓ FREQUENTLY ASKED QUESTIONS ==

=== Q: I Have only one channels. Can i take the max marker on windows 1 ?===

'''A:''' Yes, on this configuration, put windows 1 for window (sweep) and select the good number for the marker.

=== Q: Is THD 5% good? ===

'''A:''' For a speaker? Excellent! You can be proud of that equipment. 🎉

=== Q: Why does THD change with frequency? ===

'''A:''' Because speakers aren't perfect at all frequencies. Some frequencies cause more distortion than others. That's physics being weird.

=== Q: Can I use this on any speaker? ===

'''A:''' Yes! Desktop speakers, studio monitors, subwoofers, car speakers - if it's connected to NVGate, we can measure it.

=== Q: How many times should I measure? ===

'''A:''' Once for curiosity. Three times for reliability. Ten times if you're publishing a paper.

=== Q: Can I export the results? ===

'''A:''' Yes! Copy text from the log console and paste into Excel, Word, or wherever you need it.

=== Q: What if my project has different settings? ===

'''A:''' Use the Configuration panel to adjust. It's literally made for this.

=== Q: Does this work over WiFi? ===

'''A:''' No. It only works locally (same computer or local network). WiFi would add too much latency.

---

===disclaimer===

1) This program is delivered free of charge for NVGate V12. Support is not automatically provided on this tool.

2) For any other requests, please contact your local distributor or the [mailto:customer.care@oros.com OROS Customer Care department.]

---

{| style="width: 100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 30px 0; text-align: center;"
|-
| style="font-size: 1.5em; font-weight: bold;" | You're Ready!
|-
| style="font-size: 1.1em; margin-top: 10px; opacity: 0.95;" | Go measure some THD and make your speakers proud 🎵
|}

== Technical appendix THD Formulas ==

=== THD Percentage (DC1) ===

'''Formula:'''

<code>THD(%) = (√(H2² + H3² + ... + H9²) / H1) × 100</code>

Where:
* H1 = Fundamental amplitude (1st harmonic)
* H2, H3, ..., H9 = Harmonic amplitudes (2nd to 9th)
* √ = Square root

'''Example:'''
* H1 (fundamental) = 1.0 V
* H2 = 0.02 V
* H3 = 0.01 V
* H4 = 0.01 V
* (all others = 0)

Calculation:
* Harmonics RMS = √(0.02² + 0.01² + 0.01²) = √0.0006 = 0.0245 V
* THD% = (0.0245 / 1.0) × 100 = '''2.45%'''

---

=== THD in Decibels (DC2) ===

'''Formula:'''

<code>THD(dB) = 20 × log₁₀(√(H2² + H3² + ... + H9²) / H1)</code>

Or from THD%:

<code>THD(dB) = 20 × log₁₀(THD% / 100)</code>

Where:
* log₁₀ = Base-10 logarithm
* All H values same as above

'''Example from above:'''
* Ratio = 0.0245 / 1.0 = 0.0245
* log₁₀(0.0245) = -1.611
* THD(dB) = 20 × (-1.611) = '''−32.2 dB'''

Or: THD(dB) = 20 × log₁₀(2.45 / 100) = 20 × (−1.611) = '''−32.2 dB'''

---

=== Quick Conversion Table ===

{| class="wikitable"
|-
! THD Percentage !! THD in dB !! Quality Rating
|-
| 0.5% || −46 dB || Excellent (pro audio)
|-
| 1% || −40 dB || Very Good
|-
| 3% || −30 dB || Good
|-
| 5% || −26 dB || Acceptable
|-
| 10% || −20 dB || Fair
|-
| 30% || −10 dB || Poor
|-
| 100% || 0 dB || Unusable
|}

---

=== Three DC Outputs ===

{| class="wikitable"
|-
! Output Channel !! Measurement !! Formula !! Typical Range
|-
| DC1 || THD % || (Harmonics RMS / H1) × 100 || 0 to 100%
|-
| DC2 || THD dB || 20 × log₁₀(ratio) || −200 to 0 dB
|-
| DC3 || Frequency || Sweep frequency at current point || 0 to 40 kHz
|}

---

=== Coherence Between DC1 and DC2 ===

The two THD channels always maintain mathematical coherence. Given DC1 value (THD%), you can always calculate DC2:

<code>DC2(dB) = 20 × log₁₀(DC1(%) / 100)</code>

'''Example:'''
* If DC1 displays 5.5%
* Then DC2 = 20 × log₁₀(0.055) = 20 × (−1.26) = '''−25.2 dB'''

This relationship is guaranteed by the software mathematics.

---

=== Why Two Formats (% and dB)? ===

'''THD %:'''
* Easier to understand for non-technical users
* Direct representation: "5% distortion"
* Useful for product specifications

'''THD dB:'''
* Logarithmic scale: easier to see small differences
* Standard in audio/RF engineering
* Used in all standards and specifications
* Better for comparing measurements at different levels

Both represent the same information, just in different scales.

---
==Disclaimer==

This tools is deliver free of charge, Support is not automatically provided on this tool.

THD Sweep Measurement

2026-09-30T12:26:11Z

Lmagimel: /* Install */

== THD SWEEP MEASUREMENT - USER GUIDE ==
''Master the art of measuring Total Harmonic Distortion with style''

[[File:sweep.png|400px]]

__TOC__

{| style="width:100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 20px 0; text-align: center;"
|-
| style="font-size: 2.5em; font-weight: bold;" | 🎵 THD SWEEP MEASUREMENT
|-
| style="font-size: 1.2em; opacity: 0.95;" | Professional Acoustic Testing Made Simple
|}

---

== Install ==

Download THD measurement :

[https://partnerzone.digigram.com/s/i7ZCnB8jzgxY6W8 THD sweep measurement V1.2] september 2026
=== Change log ===

V1.2
- The THD in percent (DC1) is now displayed with **NVGate's standard "%" unit**, with
**3 decimals** (for example "58.294 %"). No more "spare" in place of the unit.
- The **NVGate model "THD computation"** is corrected: it opens directly in "%".

=== Install model===

Put the model folder : "THD computation" on model database of NVgate.
(By default : C:\OROS\NVGate data\Workbook Library\User\ )

=== Requirement ===

NVGate V17 or upper.

Option : DC simulated on NVGate front end.

== ⚡ QUICK START - 30 SECONDS ==

{| style="width: 100%; border-collapse: collapse; margin: 20px 0;"
|-
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 10%;" | STEP
| style="background: #f0f4ff; padding: 20px; border-left: 5px solid #667eea; font-weight: bold; width: 90%;" | ACTION
|-
| style="padding: 15px; background: #fafbff;" | 1️⃣ Launch
| style="padding: 15px; background: #fafbff;" | Launch NVgate in connected mode and load the THD computation model Double-click <code>THD_Sweep_Measurement.exe</code>
|-
| style="padding: 15px; background: white;" | 2️⃣ Connect
| style="padding: 15px; background: white;" | Put the sweep sine signal on channel 4️⃣ ; put the response on channel 1️⃣
|-
| style="padding: 15px; background: #fafbff;" | 3️⃣ Start
| style="padding: 15px; background: #fafbff;" | Start the THD_Sweep_Measurement.exe and Click green <code>▶ START</code> button
|-
| style="padding: 15px; background: white;" | 4️⃣ Monitor
| style="padding: 15px; background: white;" | Watch 4 metrics update live , THD and frequency will also be injected on NVGate channels DC simulated.
|-
| style="padding: 15px; background: #fafbff;" | 5️⃣ Stop
| style="padding: 15px; background: #fafbff;" | Click red <code>■ STOP</code> button
|}

<div style="background: #e8f5e9; border-left: 5px solid #4caf50; padding: 20px; margin: 20px 0; border-radius: 5px;">
✅ '''That's it!''' Your first THD measurement is complete. You're now a certified acoustic engineer. (Not really, but it feels good.)
</div>

---

=== 📊 Four Metric Cards ===

The heart of the interface. These four numbers tell the whole story:

{| style="width: 100%; margin: 20px 0; border-collapse: collapse;"
|-
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📈 THD (dB)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📊 THD (%)
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | 📡 Frequency
| style="background: linear-gradient(135deg, #667eea, #764ba2); color: white; padding: 25px; text-align: center; font-weight: bold; width: 25%; border: none;" | ⚡ Fundamental
|-
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (log scale)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Harmonic distortion (%)
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Current sweep point
| style="background: #f5f5f5; padding: 20px; text-align: center; border: 1px solid #ddd;" | Signal strength
|-
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | +5.42 dB
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 58.294 %
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 1234.56 Hz
| style="background: white; padding: 20px; text-align: center; border: 1px solid #ddd; font-family: monospace; font-weight: bold; color: #667eea;" | 5.0e-01 V
|}

== 🎯 UNDERSTANDING YOUR RESULTS ==

=== THD (%) - The Easy Number ===

<div style="background: linear-gradient(135deg, #c8e6c9, #a5d6a7); padding: 25px; border-radius: 10px; margin: 20px 0; color: #1b5e20;">

'''What is it?''' Percentage of unwanted harmonics in your signal.

Think of it this way:
* THD 5% = 95% pure signal, 5% noise
* THD 20% = 80% pure signal, 20% noise

'''The Quality Scale:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2; font-weight: bold;" | 🌟 1% - 5%
| style="padding: 12px; background: #fff3e0; border: 1px solid #ffe0b2;" | Excellent - Professional grade equipment
|-
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9; font-weight: bold;" | ✅ 5% - 15%
| style="padding: 12px; background: #e8f5e9; border: 1px solid #c8e6c9;" | Good - Solid speaker performance
|-
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d; font-weight: bold;" | ⚠️ 15% - 30%
| style="padding: 12px; background: #fff9c4; border: 1px solid #fff59d;" | Acceptable - Consumer level equipment
|-
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2; font-weight: bold;" | ❌ > 30%
| style="padding: 12px; background: #ffebee; border: 1px solid #ffcdd2;" | Poor - Time for an upgrade 🛠️
|}

</div>

=== THD (dB) - The Technical Number ===

<div style="background: linear-gradient(135deg, #bbdefb, #90caf9); padding: 25px; border-radius: 10px; margin: 20px 0; color: #0d47a1;">

Same measurement as THD (%) but in decibels (logarithmic scale).

'''Quick Conversion Chart:'''

{| style="width: 100%; background: white; border-collapse: collapse; margin-top: 15px;"
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD %
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | THD dB
| style="padding: 12px; background: #f5f5f5; border: 1px solid #e0e0e0; font-weight: bold; text-align: center;" | Quality
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 1%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -40 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 🌟 Perfect
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 3%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -30 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Great
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 10%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -20 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ✅ Good
|-
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | 30%
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center; font-family: monospace;" | -10 dB
| style="padding: 12px; border: 1px solid #e0e0e0; text-align: center;" | ⚠️ Poor
|}

</div>

---

== ⚙️ CONFIGURATION ==

=== When Do I Need to Change This? ===

<div style="background: #e3f2fd; border-left: 5px solid #2196f3; padding: 20px; margin: 20px 0; border-radius: 5px;">

'''Honest answer: Almost never.'''

The default settings work for 95% of users. Only change if your NVGate project has:
* Different window names
* Different marker numbers
* Different DC input addresses

If you're not sure → Don't change anything. It works.

</div>

The NVgate Model generate a sweep sine on the output, feel free to modify the settings if you need. We recommand to not put a sweep speed more than 0.05dec/s (or less) in logarithme for accurate results

=== How to Access Configuration ===

Click on '''▶ Configuration''' (section expands)

=== Important Settings ===

{| style="width: 100%; border-collapse: collapse; margin: 15px 0;"
|-
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 30%;" | Setting
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 25%;" | Default
| style="background: #667eea; color: white; padding: 12px; font-weight: bold; width: 45%;" | When to Change
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Window (sweep)
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | Window2
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Your sweep FFT has different name
|-
| style="padding: 12px; border: 1px solid #ddd;" | Window (response)
| style="padding: 12px; border: 1px solid #ddd; font-family: monospace;" | Window1
| style="padding: 12px; border: 1px solid #ddd;" | Your response FFT has different name
|-
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" | Number of harmonics
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd; font-family: monospace;" | 9
| style="padding: 12px; background: #f5f5f5; border: 1px solid #ddd;" |
|}

=== How to Apply Changes ===

# Modify field value
# Click '''Apply Configuration'''
# Log displays "Configuration applied" ✓
# Done!

---

== ❓ FREQUENTLY ASKED QUESTIONS ==

=== Q: I Have only one channels. Can i take the max marker on windows 1 ?===

'''A:''' Yes, on this configuration, put windows 1 for window (sweep) and select the good number for the marker.

=== Q: Is THD 5% good? ===

'''A:''' For a speaker? Excellent! You can be proud of that equipment. 🎉

=== Q: Why does THD change with frequency? ===

'''A:''' Because speakers aren't perfect at all frequencies. Some frequencies cause more distortion than others. That's physics being weird.

=== Q: Can I use this on any speaker? ===

'''A:''' Yes! Desktop speakers, studio monitors, subwoofers, car speakers - if it's connected to NVGate, we can measure it.

=== Q: How many times should I measure? ===

'''A:''' Once for curiosity. Three times for reliability. Ten times if you're publishing a paper.

=== Q: Can I export the results? ===

'''A:''' Yes! Copy text from the log console and paste into Excel, Word, or wherever you need it.

=== Q: What if my project has different settings? ===

'''A:''' Use the Configuration panel to adjust. It's literally made for this.

=== Q: Does this work over WiFi? ===

'''A:''' No. It only works locally (same computer or local network). WiFi would add too much latency.

---

===disclaimer===

1) This program is delivered free of charge for NVGate V12. Support is not automatically provided on this tool.

2) For any other requests, please contact your local distributor or the [mailto:customer.care@oros.com OROS Customer Care department.]

---

{| style="width: 100%; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px; border-radius: 10px; margin: 30px 0; text-align: center;"
|-
| style="font-size: 1.5em; font-weight: bold;" | You're Ready!
|-
| style="font-size: 1.1em; margin-top: 10px; opacity: 0.95;" | Go measure some THD and make your speakers proud 🎵
|}

== Technical appendix THD Formulas ==

=== THD Percentage (DC1) ===

'''Formula:'''

<code>THD(%) = (√(H2² + H3² + ... + H9²) / H1) × 100</code>

Where:
* H1 = Fundamental amplitude (1st harmonic)
* H2, H3, ..., H9 = Harmonic amplitudes (2nd to 9th)
* √ = Square root

'''Example:'''
* H1 (fundamental) = 1.0 V
* H2 = 0.02 V
* H3 = 0.01 V
* H4 = 0.01 V
* (all others = 0)

Calculation:
* Harmonics RMS = √(0.02² + 0.01² + 0.01²) = √0.0006 = 0.0245 V
* THD% = (0.0245 / 1.0) × 100 = '''2.45%'''

---

=== THD in Decibels (DC2) ===

'''Formula:'''

<code>THD(dB) = 20 × log₁₀(√(H2² + H3² + ... + H9²) / H1)</code>

Or from THD%:

<code>THD(dB) = 20 × log₁₀(THD% / 100)</code>

Where:
* log₁₀ = Base-10 logarithm
* All H values same as above

'''Example from above:'''
* Ratio = 0.0245 / 1.0 = 0.0245
* log₁₀(0.0245) = -1.611
* THD(dB) = 20 × (-1.611) = '''−32.2 dB'''

Or: THD(dB) = 20 × log₁₀(2.45 / 100) = 20 × (−1.611) = '''−32.2 dB'''

---

=== Quick Conversion Table ===

{| class="wikitable"
|-
! THD Percentage !! THD in dB !! Quality Rating
|-
| 0.5% || −46 dB || Excellent (pro audio)
|-
| 1% || −40 dB || Very Good
|-
| 3% || −30 dB || Good
|-
| 5% || −26 dB || Acceptable
|-
| 10% || −20 dB || Fair
|-
| 30% || −10 dB || Poor
|-
| 100% || 0 dB || Unusable
|}

---

=== Three DC Outputs ===

{| class="wikitable"
|-
! Output Channel !! Measurement !! Formula !! Typical Range
|-
| DC1 || THD % || (Harmonics RMS / H1) × 100 || 0 to 100%
|-
| DC2 || THD dB || 20 × log₁₀(ratio) || −200 to 0 dB
|-
| DC3 || Frequency || Sweep frequency at current point || 0 to 40 kHz
|}

---

=== Coherence Between DC1 and DC2 ===

The two THD channels always maintain mathematical coherence. Given DC1 value (THD%), you can always calculate DC2:

<code>DC2(dB) = 20 × log₁₀(DC1(%) / 100)</code>

'''Example:'''
* If DC1 displays 5.5%
* Then DC2 = 20 × log₁₀(0.055) = 20 × (−1.26) = '''−25.2 dB'''

This relationship is guaranteed by the software mathematics.

---

=== Why Two Formats (% and dB)? ===

'''THD %:'''
* Easier to understand for non-technical users
* Direct representation: "5% distortion"
* Useful for product specifications

'''THD dB:'''
* Logarithmic scale: easier to see small differences
* Standard in audio/RF engineering
* Used in all standards and specifications
* Better for comparing measurements at different levels

Both represent the same information, just in different scales.

---
==Disclaimer==

This tools is deliver free of charge, Support is not automatically provided on this tool.

OROS Hardware reboot analyzer together

2026-09-23T06:55:03Z

Lmagimel: /* Download */

OLD page not valid anymore.

This add on in beta version will reboot several analyzer together.

==Download==

no version available !

==Process==
*Putty must be installed, at least v0.76 (https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html)
*Set analyzers IP list into list_ip.txt file, one per line
*You can change delay between reboot into reboot_hard.bat, tempo variable
*Then run reboot_hard.bat script

==FAQ==
If the analyzer is off and you want to start it, you need a [[Monitoring_Solution#Autonomy_kit_installation_.28optional.29|reboot box]].
Ask OROS if you need it.

OROS Hardware reboot analyzer together

2026-09-23T06:54:50Z

Lmagimel:

OLD page not valid anymore.

This add on in beta version will reboot several analyzer together.

==Download==

==Process==
*Putty must be installed, at least v0.76 (https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html)
*Set analyzers IP list into list_ip.txt file, one per line
*You can change delay between reboot into reboot_hard.bat, tempo variable
*Then run reboot_hard.bat script

==FAQ==
If the analyzer is off and you want to start it, you need a [[Monitoring_Solution#Autonomy_kit_installation_.28optional.29|reboot box]].
Ask OROS if you need it.

OROS Hardware reboot analyzer together

2026-09-23T06:54:39Z

Lmagimel:

OLD page not valid anymore
This add on in beta version will reboot several analyzer together.

==Download==

==Process==
*Putty must be installed, at least v0.76 (https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html)
*Set analyzers IP list into list_ip.txt file, one per line
*You can change delay between reboot into reboot_hard.bat, tempo variable
*Then run reboot_hard.bat script

==FAQ==
If the analyzer is off and you want to start it, you need a [[Monitoring_Solution#Autonomy_kit_installation_.28optional.29|reboot box]].
Ask OROS if you need it.

NVGate Output Signals

2026-09-11T09:02:26Z

Lmagimel: /* Listening track */

[[category:NVGate]]
[[category:WikiOros]]
This module generates multiple signals such as fixed sinus, random noises, and swept sinus. You can have up to 6 outputs channels with OROS analyzers.

==Connect==

<Youtube>https://youtu.be/cXtX7NVTtmg?t=17</Youtube>

[[Image:Reports_Tools_Ribbons_344.png|250px|none]]
On the tab [[NVGate_Ribbons:_Acquisition_Tab|acquisition]], Output can generate a signal on the front-end outputs (generators)

The left button (''signals'') allows selecting the signal type from the list and connecting it to the available outputs (1 to 6) .The other buttons open the signal settings and manage the generators activity.

*[[Image:Reports_Tools_Ribbons_345.png|Reports_Tools_Ribbons_345.png]] ''Signals:'' Shows the list of available signals and let the users connect it to the outputs. You can easily connect signal with a "drag and drop" on the windows below.
[[File:out3.png]]

==Settings==
===Output general settings===
[[Image:Reports_Tools_Ribbons_351.png]] Outputs settings: Manages the generated signal settling, (Mute, transition time). It is also available on ASB front end.
[[File:out4.png|framed|right]]
Used to control general output behavior. i.e. the signal generated on Out 1 &2 and Aux. Out 1 to 4.

* '''Transition time''': The value of this setting is the time it takes for the output to go from 0 to activated level and the time it takes for the output to go from the activated level to 0 when deactivated. This transition time is applied only if the ''Output x/transition control ''value is "On"

[[Image:front_end_23.png|framed|none]]

* '''Mute ''''''all''': On / Off: When "On", all the outputs are set to zero. The value of this setting is automatically set is "On" when the ''Emergency Stop ''setting from the same sub-module is pushed.
'''Emergency ''''''Stop''': Automatically mutes all the outputs when pushed. Use the ''Mute all ''setting from the same sub-module to make the outputs work again.

===Output channel settings===
Available on ASB/ front end/Output. 
[[image:out5.png|framed|right]]
* '''Label''': the name of this Output (by default Output n, with 1 <nowiki><</nowiki>= n <nowiki><</nowiki>= 2). The label of each output is used in the result name and in all connection tools.
* '''Source''': the input signal of the output (NONE by default). The input signal can be any dynamic input of the Front-end (in the On-line mode) or any signal generated by the output signals resource (in the On-line mode) or any track of the Player (recorded from inputs).
* '''Applied ''''''filter''': the filter applied to this output. The list of filters applicable to the outputs is defined in the Filter module, by choosing Apply to = All.
* '''Clipping''': the amplitude limitation of the output signal (from 1 mV to 10 V).
* '''Gain''': This setting can be displayed in dB. It is the gain applied to the output signal.
* '''Impedance''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="77%" align="center"
|'''Impedance'''
|'''Description'''

|-
|GND
|The output is connected to the ground.

|-
|50 Ohms
|The output impedance is equal to 50 Ohms.

|-
|600 Ohms<ref>Only available for OR38 & OR36. For phone lines connections use.</ref>
|The output impedance is equal to 600 Ohms.

|} 

* '''Synchronization''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="92%" align="center"
|'''Synchronization'''
|'''Description'''

|-
|Free run
|The output delivers a signal as soon as there is a source connected.

|-
|Linked to run
|The output is activated only after the first run action.

|} 

* '''Transition control''': On / Off. If the value of this setting is "On" the ''Output settings/transition time'' is applied when this output is activated or disabled.

==Signal available==
===Sine===
* [[Image:Reports_Tools_Ribbons_346.png]] ''Sine:'' Opens the pure sine properties dialog for adjustment.

Used to generate and configure up to 6 fixed sinus. A sinusoidal signal is generated with the frequency specified in the sine '''Frequency''' field. The frequency corresponds to one of the analysis bands. This type of signal is used for measuring the amount of distortion in a system for example. The amplitude of the signal can be changed using the '''Level''' settings.
[[Image:Resources_output_02.png|framed|none]]

* '''Frequency''': sine frequency.

'''Tips: put 0Hz for DC Volatge generation.'''

* '''Peak level''': the peak level
* '''RMS level''': sine RMS level. This setting can be displayed in dB.

'''Note:''' Amplitude and frequency modifications are applied immediately without any transition.

[[Image:Resources_output_03.png|framed|none]]

===Multi-sine===
[[Image:Reports_Tools_Ribbons_347.png]]: Multi-sine: Opens the ''Multi-sine'' properties dialog for adjustment.

Multisine is computed by adding sine signals whose frequencies are power of two sub-modules of sampling frequency. This means that multisine output block includes all discrete sine waves of FFT spectrum of corresponding block size and resolution. Multisine has the advantage of showing no leakage effect in FFT as all sine waves are exact periods of the trigger block for FFT computation. The most appropriate FFT weighting window to be used is “uniform” window. Multisine generators work on a sample block basis, it means signal blocks are repeated identically over time.

Used to generate and configure up to 2 multi-sines. The multi-sine is computed by adding sine signals whose frequencies are power of two sub-modules of sampling frequency. So with the FFT analyzer, each sine signal can be exactly at an analysis frequency line and there is no leakage due to analysis window. Due to its specific structure, using a rectangular analysis window for FFT analysis on a multi-sine excitation is recommended.

The phase between sine signals can be controlled in order to get a low crest factor or randomized, but with a higher crest factor.

Multi-sine is periodic with a period equal to the opposite of its frequency resolution.

[[Image:Resources_output_04.png|framed|none]]

* '''Lower frequency''': the lower frequency of the multi-sine frequency range. Its minimum value is the resolution.
* '''Upper frequency''': the upper frequency of the multi-sine frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': multi-sine RMS level. This setting can be displayed in dB.
* '''Resolution''': the resolution of the multi-sine. Its minimum value is SF / 16384, where SF is the sampling frequency. Its maximum value is SF / 256.
* '''Phase''': Computational mode of the original sinusoid phases.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''Phase'''
|'''Description'''

|-
|Random 
|The original phase of each sinusoid is selected randomly after each multi sine deactivation/activation. First activation: 
[[Image:Resources_output_05.png|framed|none]]
 After reactivation: 
[[Image:Resources_output_06.png|framed|none]]
Phase relationship between sine waves is selected at selection of setting and will not change unless “random” setting is changed back and forward. After “random” is selected phase relationship is defined (randomly for the first block) and repeated identically for each signal block of N lines. Phase relationship for all multisine generators will be different as random setting activation is made at different moment in time and applied for different generator objects. Two blocks of multisine random phase of the same generator are 100% correlated.
Two mulitsine random phase generators are not correlated.
 

|-
|Fixed 
|Each sinusoid has the same original phase even after multi sine deactivation/activation. 
[[Image:Resources_output_07.png|framed|none]]
Multisine phase relation if fixed and will be the same each time setting “fixed” is selected.
Phase relationship is the same for all multisine generators meaning that signal blocks will be the identical between any multisine generators of the same setting. Multisine fixed phase generators are 100% correlated.
 

|} 

'''Burst setting''' in Multisine generators will shorten the time during which the output signal is active despite the signal block being of the same length.
All bandwidth frequencies are present in each burst but may not be complete cycles as block period is truncated. Two bursts being identical (respectively fixed or random phase) they are 100% correlated. Two random bursts from two separate generators will not be correlated signals.

===Random noise===
[[Image:Reports_Tools_Ribbons_350.png]]Random Noise: Opens the ''Random noise'' properties dialog for adjustment. Adapted for non linear responses measurement. 

Used to generate and configure up to 2 white or pink random noise types.

Signal block is recalculated each time. All frequencies of generator bandwidth are taken into account with a resolution of Fs/16384 (Fs being front end sampling frequency), this resolution is independent from FFT resolution. Consequently signal content of each FFT trigger block is not the same meaning that signals between two trigger blocks are not correlated. Similarly random noise signal between two separate generators are also not correlated.

[[Image:Resources_output_08.png|framed|none]]

Random noise is generated using algorithms that guarantee no short or long-term periodicity.

* '''Lower frequency''': the lower frequency of the Random noise frequency range. Its minimum value is equal to SF / (2.56 * 6400), where SF is the sampling frequency and 6400 <nowiki>+</nowiki> 1 is the resolution.
* '''Upper frequency''': the upper frequency of the Random noise frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': the Random noise RMS level. This setting can be displayed in dB.
* '''Period''': The period selected for the Random noise. It used to define a Random Block. Its maximum value is 100s.
* '''Burst''': This setting lets the user specify the percentage of non-null signal in a random block.

'''Exemple''' with: burst: 60% - period: 100ms :

[[Image:Resources_output_09.png|framed|none]]

* '''Type''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="92%" align="center"
|'''Type'''
|'''Description'''

|-
|[https://en.wikipedia.org/wiki/White_noise White]
|White noise has the same distribution of power for all frequencies, so there is the same amount of power between 0 and 500 Hz, 500 and 1,000 Hz or 20,000 and 20,500 Hz.

|-
|[https://en.wikipedia.org/wiki/Pink_noise Pink]
|Pink noise has the same distribution of power for each octave, so the power between 0.5 Hz and 1 Hz is the same as between 5,000 Hz and 10,000 Hz. Since power is proportional to amplitude squared, the energy per Hz will decline at higher frequencies at the rate of -10dB/decade.

|} 

===Chirp===
Chirp means continuous short term variable frequency (1 analysis block), 1 amplitude. Adapted for damping measurement and FFT analysis. 

[[Image:Reports_Tools_Ribbons_349.png]] Chirp: Opens the ''Chirp'' properties dialog for adjustment. 

Used to generate and configure up to 6 chirps. A sine signal, of which the frequency varies from '''Lower Frequency''' to '''Upper Frequency''', is generated in the delay corresponding to the size of a generator block.

[[Image:Resources_output_10.png|framed|none]]

* '''Lower frequency''': the lower frequency of the Random noise frequency range. Its minimum value is equal to SF / (2.56 * 6400), where SF is the sampling frequency and 6400 <nowiki>+</nowiki> 1 is the resolution.
* '''Upper frequency''': the upper frequency of the chirp frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': the chirp RMS level. This setting can be displayed in dB.
* '''Size''': This setting specifies the number of samples required for the generator to go from the lower frequency to the upper one.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="31%" align="center"
|align = "center"|'''Block size'''
|align = "center"|'''FFT lines number'''

|-
|256
|101

|-
|512
|201

|-
|1024
|401

|-
|2048
|801

|-
|4096
|1601

|-
|8192
|3201

|-
|16384
|6401

|} 

* '''Burst''': This setting lets the user specify the percentage of non-null signal greater than the size of a generator block. For instance, for a burst value of 25% and a block size of 1024, the generator delivers blocks of 256 samples of chirp separated by blocks of 768 null samples.

{|cellspacing="0" cellpadding = "10" style="border-style:solid; border-color:black; border-width:1px;"
|Size = 256 
Burst = 70 
|}

[[Image:Resources_output_11.png|framed|none]]

===Advanced sine===
[[Image:Reports_Tools_Ribbons_348.png]] Swept-sine: Opens the ''Swept-sine'' properties dialog for adjustment.

Used to generate and configure up to 6 advanced sines, allowing the user to generate a swept sine, a pure tone, or to sweep step-by-step.

[[Image:Resources_output_12.png|framed|none]]

* '''Gain''': Each advanced sine has a gain setting with a 0dB reference that is the value of the ''Advanced sine settings/ Peak level setting''
* '''Phase offset''': All the advanced sine have the same phase reference. This setting is used to set a phase offset between them.
====Advanced sine settings====
This sub-module contains the settings related to the main advanced sine generator, including the advanced sine mode setting, stabilization time, amplitude variation...

* '''Mode''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Mode'''
|'''Description'''

|-
|Sweep: 
[[Image:Resources_output_13.png|framed|none]]

|The advanced sine performs a continuous sweep of the frequencies between Start Frequency and Stop Frequency 

|-
|Step: 
[[Image:Resources_output_14.png|framed|none]]

|The advanced sine performs a sweep of the frequencies between Start Frequency and Stop Frequency, it stops at each step, waits during stabilization time, and waits for the new step event before going on.

|-
|Pure tone: 
[[Image:Resources_output_15.png|framed|none]]

|The advanced sine generates a pure sine with the frequency of the ''Advanced sine settings/ Target Frequency ''value

|} 

* '''Synchronization''': "linked to run" or "Free run". The Advanced sine generator will not be stopped by a stop event, if the setting is on <nowiki>’</nowiki>Free run<nowiki>’</nowiki>. The default value is <nowiki>’</nowiki>Linked to run<nowiki>’</nowiki>.

If you change the amplitude or the frequency of the generated signal, there will be a stabilization time, and you will have to generate an event when the signal is stabilized.

In these 3 modes, each time the generator stops on a frequency;

1. At the beginning (amplitude increase until the first frequency),

2. At a new step (at the end of stabilization time), or in <nowiki>’</nowiki>pure tone<nowiki>’</nowiki> or <nowiki>’</nowiki>swept sine<nowiki>’</nowiki> pause mode when it reaches the target frequency; the generator sends a stabilized event, after being stabilized (amplitude and frequency).

3. In <nowiki>’</nowiki>Free run<nowiki>’</nowiki>, if the generator is already stabilized at the run event, then a stabilized event is generated at this moment.

If the output is on <nowiki>’</nowiki>Advanced sine<nowiki>’</nowiki> source, the setting of <nowiki>’</nowiki>Synchronization<nowiki>’</nowiki> of the advanced sine will recopied to the <nowiki>’</nowiki>synchronization<nowiki>’</nowiki> of the output (which one become fixed).

:''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Synchronization
|Fixed to <nowiki>’</nowiki>Linked to run<nowiki>’</nowiki>
|Visible
|Visible

|} 

* '''Pause''': On / Off. When Pause is active, the frequency sweeping is halted when there is only one frequency generated. This frequency is now called "Target frequency". You can modify this frequency value to another target so the frequency will sweep to the new target.

[[Image:Resources_output_16.png|framed|none]]

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Pause
|visible
|hidden
|hidden

|} 

* '''Peak level''': the advanced sine peak level (between 0 and 10 V).
* '''Start frequency''': The start frequency of the sweep.

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Start frequency
|visible
|visible
|hidden

|} 

* '''Stop frequency''': The stop frequency of the sweep.

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Stop frequency
|visible
|visible
|hidden

|} 

* '''Target frequency''': The value of this setting is the frequency currently generated when the value of the'' Pause ''setting is "On" or if the'' Mode ''is set to "Pure Tone"

''Hidden/fixed: ''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
| '''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Target frequency
|visible if Pause = On
|visible if Pause = On
|visible

|} 

* '''Sweep variation''': Two different types of sweep are available: a linear sweeping or a logarithmic sweep:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="74%" align="center"
|'''Sweep variation'''
|'''Description'''

|-
|Lin
|The Sweep speed is constant.

|-
|Log
|The Sweep speed increases exponentially when the frequency increase is linear.

|} 

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep variation
|visible
|fixed to Lin
|hidden

|} 

* '''Sweep speed''': It is expressed in Hz/s in a linear sweep variation, and in dec/s in a logarithmic sweep variation. The unit of the logarithmic sweep speed can be changed to oct/min in the user preferences/physical quantity (select "Sweep speed (logarithmic)" in the physical quantity list).
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep speed
|visible
|hidden
|hidden

|} 

* '''Sweep type''':

[[Image:Resources_output_17.png|framed|none]]

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Sweep type'''
|'''Description'''

|-
|One shot
|The advanced sine sweeps the frequencies from Start Frequency to Stop Frequency and stops.

|-
|One cycle
|The advanced sine sweeps the frequencies from Start Frequency to Stop Frequency, then back to Start Frequency and stops.

|-
|Continuous
|The advanced sine sweeps the frequencies between Start Frequency to Stop Frequency without stopping.

|} 

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|visible
|visible
|hidden

|} 

* '''Stabilization time''': Sweep mode: Selects wait time for the advanced sine at the start frequency and at the right level before starting the sweep. Step mode: Selects wait time for the advanced sine at each step before waiting for the new step event.
* '''Amplitude ''''''variation''': Maximum length of time for the advanced sine to reach a new level.
* '''Phase speed''': Speed of phase variation when setting a new value for ''Advanced sine x/ Phase offset setting''
* '''Step''': Frequency gap between two steps
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|visible
|visible
|hidden

|} 

* '''New step''': The event that triggers the sweep of the advanced sine to the next step
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|hidden
|visible
|hidden

|} 

===Synchro===
This special output signal is used to synchronize raw data recorded on multiple OR3X units (even OR2X). This synch signal must be connected on ext. synch trigger input of each recording unit (see below)


[[Image:Resources_output_18.png|framed|none]]

* '''Active''': On/Off Set the synch signal available in sources list, no signal is generated on outputs at this stage
* '''Generator Mode''': Controls synch signal behavior.
* '''On''': start the synch clock generation (0 / <nowiki>+</nowiki>2 V square @ 50 Hz)
* '''Off''': stop the synch clock generation followed by a -2V step during 1 sec.

Track assembly procedure.

1. Activate the synch signal

2. Select ''Front-end / Output 1 / source = Synchro''

3. Set'' Front-end / ext synch / coupling = DC ''on each recording unit

4. Set'' Front-end / ext synch / threshold = 1 V ''on each recording unit

5. Set'' Recorder/trigger/start = ext synch ''on each recording unit

6. Add ext. sync track to the recorder on each unit

7. Set same recording duration on each unit

8. Run each unit

9. Set'' generator mode = on ''to start record


[[Image:Resources_output_19.png|framed|none]]

10. Download all recorded files on one PC

11. Launch <nowiki>’</nowiki>Track Assembler<nowiki>’</nowiki>

[[Image:Resources_output_20.png|framed|none]]

The concatenation synopsis is shown on the following scheme:


[[Image:Resources_output_21.png|framed|none]]



More information on the Track Assembler in <nowiki>’</nowiki>Operation on multiples Hardware<nowiki>’</nowiki>.

==Listening track==
There are 3 ways to listen track:
====Input: listen during measurement====
Back to the roots of vibration analysis: Everybody knows that our ears and brain is the best instrument to feel and interpret vibration signals. This is also why we take so much care in removing these NVH signals from our machines, vehicles and appliances. The audio playback of vibration (or any other) signal allows the user to "listen in" on what your OROS analyzer is "hearing".

Connect input feature allows a user to play input channels on an output. This allows the user to listen during measurement with an headphone on the output. 

[[Image:input_on_output.png|400px]]
 

====Monitor channels : Hot Swap ====

NVgate uses the monitor hot swap capability to allow changing the replicated signal during acquisition/recording.

The NVGate synopsis is as follows:

[[Image:Release_note_20.png|700px|none]]

To activate it, simply connect one of the monitor ''Channels'' to the desired output from the ''Acquisition/Outputs/Signal'' dialog.

[[Image:Release_note_21.png|framed|none]]

Then you can add any front-end input to the monitor channel. The selected input signal will replicate (play) on the output. You can swap from one input to another at any time including during the run and signal recording.

NB: Remember to switch the output impedance to 600 Ω for better listening quality.

====Play-Back on PC speaker====
If you need to listen a signal already recorded, do not use an output channel. We advice to use the playback on PC speaker defined here:
From any of the previous configurations, the recorded signal can be listened to on PC speakers.
[[File:Player_playback.png|none]]

Click on [[Image:Player_connection_wizard_06.png]] in the active window. The button stops the play back at any time. A mobile cursor (blue) localizes the played back signal part in the signal window.

==Create and play ANY signal==

You can play a signal already recorded with an OROS analyzer, or any signal imported into NVgate.
You can put the signal in the player (even in connected mode) allowing the signal to be played on an ouptut channel.

====Example : playing a triangle signal on analyzer output ====

• Generate a triangular signal with an application ([https://fr.mathworks.com/?requestedDomain= Matlab],…) or an online site (example: http://onlinetonegenerator.com/); 

• Save this signal in .wav; 

• In NVGate, import this signal (File / Import / Files / OR2X Signal (* .wav, .mat, .UFF...); 

• Load this signal in the player (right click then "load in player"); 

• In the options proposed in output, select the channel coming from the player:
[[File:player_out.png|framed|none]]
•If you want to play this signal repeatedly, you must change the "Repeat mode" parameter in "Analyzer Setting Browser":
[[File:player_out2.png|framed|none]]

NVGate Output Signals

2026-09-11T09:01:57Z

Lmagimel: /* Input: listen during measurement */

[[category:NVGate]]
[[category:WikiOros]]
This module generates multiple signals such as fixed sinus, random noises, and swept sinus. You can have up to 6 outputs channels with OROS analyzers.

==Connect==

<Youtube>https://youtu.be/cXtX7NVTtmg?t=17</Youtube>

[[Image:Reports_Tools_Ribbons_344.png|250px|none]]
On the tab [[NVGate_Ribbons:_Acquisition_Tab|acquisition]], Output can generate a signal on the front-end outputs (generators)

The left button (''signals'') allows selecting the signal type from the list and connecting it to the available outputs (1 to 6) .The other buttons open the signal settings and manage the generators activity.

*[[Image:Reports_Tools_Ribbons_345.png|Reports_Tools_Ribbons_345.png]] ''Signals:'' Shows the list of available signals and let the users connect it to the outputs. You can easily connect signal with a "drag and drop" on the windows below.
[[File:out3.png]]

==Settings==
===Output general settings===
[[Image:Reports_Tools_Ribbons_351.png]] Outputs settings: Manages the generated signal settling, (Mute, transition time). It is also available on ASB front end.
[[File:out4.png|framed|right]]
Used to control general output behavior. i.e. the signal generated on Out 1 &2 and Aux. Out 1 to 4.

* '''Transition time''': The value of this setting is the time it takes for the output to go from 0 to activated level and the time it takes for the output to go from the activated level to 0 when deactivated. This transition time is applied only if the ''Output x/transition control ''value is "On"

[[Image:front_end_23.png|framed|none]]

* '''Mute ''''''all''': On / Off: When "On", all the outputs are set to zero. The value of this setting is automatically set is "On" when the ''Emergency Stop ''setting from the same sub-module is pushed.
'''Emergency ''''''Stop''': Automatically mutes all the outputs when pushed. Use the ''Mute all ''setting from the same sub-module to make the outputs work again.

===Output channel settings===
Available on ASB/ front end/Output. 
[[image:out5.png|framed|right]]
* '''Label''': the name of this Output (by default Output n, with 1 <nowiki><</nowiki>= n <nowiki><</nowiki>= 2). The label of each output is used in the result name and in all connection tools.
* '''Source''': the input signal of the output (NONE by default). The input signal can be any dynamic input of the Front-end (in the On-line mode) or any signal generated by the output signals resource (in the On-line mode) or any track of the Player (recorded from inputs).
* '''Applied ''''''filter''': the filter applied to this output. The list of filters applicable to the outputs is defined in the Filter module, by choosing Apply to = All.
* '''Clipping''': the amplitude limitation of the output signal (from 1 mV to 10 V).
* '''Gain''': This setting can be displayed in dB. It is the gain applied to the output signal.
* '''Impedance''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="77%" align="center"
|'''Impedance'''
|'''Description'''

|-
|GND
|The output is connected to the ground.

|-
|50 Ohms
|The output impedance is equal to 50 Ohms.

|-
|600 Ohms<ref>Only available for OR38 & OR36. For phone lines connections use.</ref>
|The output impedance is equal to 600 Ohms.

|} 

* '''Synchronization''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="92%" align="center"
|'''Synchronization'''
|'''Description'''

|-
|Free run
|The output delivers a signal as soon as there is a source connected.

|-
|Linked to run
|The output is activated only after the first run action.

|} 

* '''Transition control''': On / Off. If the value of this setting is "On" the ''Output settings/transition time'' is applied when this output is activated or disabled.

==Signal available==
===Sine===
* [[Image:Reports_Tools_Ribbons_346.png]] ''Sine:'' Opens the pure sine properties dialog for adjustment.

Used to generate and configure up to 6 fixed sinus. A sinusoidal signal is generated with the frequency specified in the sine '''Frequency''' field. The frequency corresponds to one of the analysis bands. This type of signal is used for measuring the amount of distortion in a system for example. The amplitude of the signal can be changed using the '''Level''' settings.
[[Image:Resources_output_02.png|framed|none]]

* '''Frequency''': sine frequency.

'''Tips: put 0Hz for DC Volatge generation.'''

* '''Peak level''': the peak level
* '''RMS level''': sine RMS level. This setting can be displayed in dB.

'''Note:''' Amplitude and frequency modifications are applied immediately without any transition.

[[Image:Resources_output_03.png|framed|none]]

===Multi-sine===
[[Image:Reports_Tools_Ribbons_347.png]]: Multi-sine: Opens the ''Multi-sine'' properties dialog for adjustment.

Multisine is computed by adding sine signals whose frequencies are power of two sub-modules of sampling frequency. This means that multisine output block includes all discrete sine waves of FFT spectrum of corresponding block size and resolution. Multisine has the advantage of showing no leakage effect in FFT as all sine waves are exact periods of the trigger block for FFT computation. The most appropriate FFT weighting window to be used is “uniform” window. Multisine generators work on a sample block basis, it means signal blocks are repeated identically over time.

Used to generate and configure up to 2 multi-sines. The multi-sine is computed by adding sine signals whose frequencies are power of two sub-modules of sampling frequency. So with the FFT analyzer, each sine signal can be exactly at an analysis frequency line and there is no leakage due to analysis window. Due to its specific structure, using a rectangular analysis window for FFT analysis on a multi-sine excitation is recommended.

The phase between sine signals can be controlled in order to get a low crest factor or randomized, but with a higher crest factor.

Multi-sine is periodic with a period equal to the opposite of its frequency resolution.

[[Image:Resources_output_04.png|framed|none]]

* '''Lower frequency''': the lower frequency of the multi-sine frequency range. Its minimum value is the resolution.
* '''Upper frequency''': the upper frequency of the multi-sine frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': multi-sine RMS level. This setting can be displayed in dB.
* '''Resolution''': the resolution of the multi-sine. Its minimum value is SF / 16384, where SF is the sampling frequency. Its maximum value is SF / 256.
* '''Phase''': Computational mode of the original sinusoid phases.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''Phase'''
|'''Description'''

|-
|Random 
|The original phase of each sinusoid is selected randomly after each multi sine deactivation/activation. First activation: 
[[Image:Resources_output_05.png|framed|none]]
 After reactivation: 
[[Image:Resources_output_06.png|framed|none]]
Phase relationship between sine waves is selected at selection of setting and will not change unless “random” setting is changed back and forward. After “random” is selected phase relationship is defined (randomly for the first block) and repeated identically for each signal block of N lines. Phase relationship for all multisine generators will be different as random setting activation is made at different moment in time and applied for different generator objects. Two blocks of multisine random phase of the same generator are 100% correlated.
Two mulitsine random phase generators are not correlated.
 

|-
|Fixed 
|Each sinusoid has the same original phase even after multi sine deactivation/activation. 
[[Image:Resources_output_07.png|framed|none]]
Multisine phase relation if fixed and will be the same each time setting “fixed” is selected.
Phase relationship is the same for all multisine generators meaning that signal blocks will be the identical between any multisine generators of the same setting. Multisine fixed phase generators are 100% correlated.
 

|} 

'''Burst setting''' in Multisine generators will shorten the time during which the output signal is active despite the signal block being of the same length.
All bandwidth frequencies are present in each burst but may not be complete cycles as block period is truncated. Two bursts being identical (respectively fixed or random phase) they are 100% correlated. Two random bursts from two separate generators will not be correlated signals.

===Random noise===
[[Image:Reports_Tools_Ribbons_350.png]]Random Noise: Opens the ''Random noise'' properties dialog for adjustment. Adapted for non linear responses measurement. 

Used to generate and configure up to 2 white or pink random noise types.

Signal block is recalculated each time. All frequencies of generator bandwidth are taken into account with a resolution of Fs/16384 (Fs being front end sampling frequency), this resolution is independent from FFT resolution. Consequently signal content of each FFT trigger block is not the same meaning that signals between two trigger blocks are not correlated. Similarly random noise signal between two separate generators are also not correlated.

[[Image:Resources_output_08.png|framed|none]]

Random noise is generated using algorithms that guarantee no short or long-term periodicity.

* '''Lower frequency''': the lower frequency of the Random noise frequency range. Its minimum value is equal to SF / (2.56 * 6400), where SF is the sampling frequency and 6400 <nowiki>+</nowiki> 1 is the resolution.
* '''Upper frequency''': the upper frequency of the Random noise frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': the Random noise RMS level. This setting can be displayed in dB.
* '''Period''': The period selected for the Random noise. It used to define a Random Block. Its maximum value is 100s.
* '''Burst''': This setting lets the user specify the percentage of non-null signal in a random block.

'''Exemple''' with: burst: 60% - period: 100ms :

[[Image:Resources_output_09.png|framed|none]]

* '''Type''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="92%" align="center"
|'''Type'''
|'''Description'''

|-
|[https://en.wikipedia.org/wiki/White_noise White]
|White noise has the same distribution of power for all frequencies, so there is the same amount of power between 0 and 500 Hz, 500 and 1,000 Hz or 20,000 and 20,500 Hz.

|-
|[https://en.wikipedia.org/wiki/Pink_noise Pink]
|Pink noise has the same distribution of power for each octave, so the power between 0.5 Hz and 1 Hz is the same as between 5,000 Hz and 10,000 Hz. Since power is proportional to amplitude squared, the energy per Hz will decline at higher frequencies at the rate of -10dB/decade.

|} 

===Chirp===
Chirp means continuous short term variable frequency (1 analysis block), 1 amplitude. Adapted for damping measurement and FFT analysis. 

[[Image:Reports_Tools_Ribbons_349.png]] Chirp: Opens the ''Chirp'' properties dialog for adjustment. 

Used to generate and configure up to 6 chirps. A sine signal, of which the frequency varies from '''Lower Frequency''' to '''Upper Frequency''', is generated in the delay corresponding to the size of a generator block.

[[Image:Resources_output_10.png|framed|none]]

* '''Lower frequency''': the lower frequency of the Random noise frequency range. Its minimum value is equal to SF / (2.56 * 6400), where SF is the sampling frequency and 6400 <nowiki>+</nowiki> 1 is the resolution.
* '''Upper frequency''': the upper frequency of the chirp frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': the chirp RMS level. This setting can be displayed in dB.
* '''Size''': This setting specifies the number of samples required for the generator to go from the lower frequency to the upper one.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="31%" align="center"
|align = "center"|'''Block size'''
|align = "center"|'''FFT lines number'''

|-
|256
|101

|-
|512
|201

|-
|1024
|401

|-
|2048
|801

|-
|4096
|1601

|-
|8192
|3201

|-
|16384
|6401

|} 

* '''Burst''': This setting lets the user specify the percentage of non-null signal greater than the size of a generator block. For instance, for a burst value of 25% and a block size of 1024, the generator delivers blocks of 256 samples of chirp separated by blocks of 768 null samples.

{|cellspacing="0" cellpadding = "10" style="border-style:solid; border-color:black; border-width:1px;"
|Size = 256 
Burst = 70 
|}

[[Image:Resources_output_11.png|framed|none]]

===Advanced sine===
[[Image:Reports_Tools_Ribbons_348.png]] Swept-sine: Opens the ''Swept-sine'' properties dialog for adjustment.

Used to generate and configure up to 6 advanced sines, allowing the user to generate a swept sine, a pure tone, or to sweep step-by-step.

[[Image:Resources_output_12.png|framed|none]]

* '''Gain''': Each advanced sine has a gain setting with a 0dB reference that is the value of the ''Advanced sine settings/ Peak level setting''
* '''Phase offset''': All the advanced sine have the same phase reference. This setting is used to set a phase offset between them.
====Advanced sine settings====
This sub-module contains the settings related to the main advanced sine generator, including the advanced sine mode setting, stabilization time, amplitude variation...

* '''Mode''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Mode'''
|'''Description'''

|-
|Sweep: 
[[Image:Resources_output_13.png|framed|none]]

|The advanced sine performs a continuous sweep of the frequencies between Start Frequency and Stop Frequency 

|-
|Step: 
[[Image:Resources_output_14.png|framed|none]]

|The advanced sine performs a sweep of the frequencies between Start Frequency and Stop Frequency, it stops at each step, waits during stabilization time, and waits for the new step event before going on.

|-
|Pure tone: 
[[Image:Resources_output_15.png|framed|none]]

|The advanced sine generates a pure sine with the frequency of the ''Advanced sine settings/ Target Frequency ''value

|} 

* '''Synchronization''': "linked to run" or "Free run". The Advanced sine generator will not be stopped by a stop event, if the setting is on <nowiki>’</nowiki>Free run<nowiki>’</nowiki>. The default value is <nowiki>’</nowiki>Linked to run<nowiki>’</nowiki>.

If you change the amplitude or the frequency of the generated signal, there will be a stabilization time, and you will have to generate an event when the signal is stabilized.

In these 3 modes, each time the generator stops on a frequency;

1. At the beginning (amplitude increase until the first frequency),

2. At a new step (at the end of stabilization time), or in <nowiki>’</nowiki>pure tone<nowiki>’</nowiki> or <nowiki>’</nowiki>swept sine<nowiki>’</nowiki> pause mode when it reaches the target frequency; the generator sends a stabilized event, after being stabilized (amplitude and frequency).

3. In <nowiki>’</nowiki>Free run<nowiki>’</nowiki>, if the generator is already stabilized at the run event, then a stabilized event is generated at this moment.

If the output is on <nowiki>’</nowiki>Advanced sine<nowiki>’</nowiki> source, the setting of <nowiki>’</nowiki>Synchronization<nowiki>’</nowiki> of the advanced sine will recopied to the <nowiki>’</nowiki>synchronization<nowiki>’</nowiki> of the output (which one become fixed).

:''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Synchronization
|Fixed to <nowiki>’</nowiki>Linked to run<nowiki>’</nowiki>
|Visible
|Visible

|} 

* '''Pause''': On / Off. When Pause is active, the frequency sweeping is halted when there is only one frequency generated. This frequency is now called "Target frequency". You can modify this frequency value to another target so the frequency will sweep to the new target.

[[Image:Resources_output_16.png|framed|none]]

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Pause
|visible
|hidden
|hidden

|} 

* '''Peak level''': the advanced sine peak level (between 0 and 10 V).
* '''Start frequency''': The start frequency of the sweep.

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Start frequency
|visible
|visible
|hidden

|} 

* '''Stop frequency''': The stop frequency of the sweep.

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Stop frequency
|visible
|visible
|hidden

|} 

* '''Target frequency''': The value of this setting is the frequency currently generated when the value of the'' Pause ''setting is "On" or if the'' Mode ''is set to "Pure Tone"

''Hidden/fixed: ''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
| '''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Target frequency
|visible if Pause = On
|visible if Pause = On
|visible

|} 

* '''Sweep variation''': Two different types of sweep are available: a linear sweeping or a logarithmic sweep:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="74%" align="center"
|'''Sweep variation'''
|'''Description'''

|-
|Lin
|The Sweep speed is constant.

|-
|Log
|The Sweep speed increases exponentially when the frequency increase is linear.

|} 

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep variation
|visible
|fixed to Lin
|hidden

|} 

* '''Sweep speed''': It is expressed in Hz/s in a linear sweep variation, and in dec/s in a logarithmic sweep variation. The unit of the logarithmic sweep speed can be changed to oct/min in the user preferences/physical quantity (select "Sweep speed (logarithmic)" in the physical quantity list).
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep speed
|visible
|hidden
|hidden

|} 

* '''Sweep type''':

[[Image:Resources_output_17.png|framed|none]]

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Sweep type'''
|'''Description'''

|-
|One shot
|The advanced sine sweeps the frequencies from Start Frequency to Stop Frequency and stops.

|-
|One cycle
|The advanced sine sweeps the frequencies from Start Frequency to Stop Frequency, then back to Start Frequency and stops.

|-
|Continuous
|The advanced sine sweeps the frequencies between Start Frequency to Stop Frequency without stopping.

|} 

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|visible
|visible
|hidden

|} 

* '''Stabilization time''': Sweep mode: Selects wait time for the advanced sine at the start frequency and at the right level before starting the sweep. Step mode: Selects wait time for the advanced sine at each step before waiting for the new step event.
* '''Amplitude ''''''variation''': Maximum length of time for the advanced sine to reach a new level.
* '''Phase speed''': Speed of phase variation when setting a new value for ''Advanced sine x/ Phase offset setting''
* '''Step''': Frequency gap between two steps
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|visible
|visible
|hidden

|} 

* '''New step''': The event that triggers the sweep of the advanced sine to the next step
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|hidden
|visible
|hidden

|} 

===Synchro===
This special output signal is used to synchronize raw data recorded on multiple OR3X units (even OR2X). This synch signal must be connected on ext. synch trigger input of each recording unit (see below)


[[Image:Resources_output_18.png|framed|none]]

* '''Active''': On/Off Set the synch signal available in sources list, no signal is generated on outputs at this stage
* '''Generator Mode''': Controls synch signal behavior.
* '''On''': start the synch clock generation (0 / <nowiki>+</nowiki>2 V square @ 50 Hz)
* '''Off''': stop the synch clock generation followed by a -2V step during 1 sec.

Track assembly procedure.

1. Activate the synch signal

2. Select ''Front-end / Output 1 / source = Synchro''

3. Set'' Front-end / ext synch / coupling = DC ''on each recording unit

4. Set'' Front-end / ext synch / threshold = 1 V ''on each recording unit

5. Set'' Recorder/trigger/start = ext synch ''on each recording unit

6. Add ext. sync track to the recorder on each unit

7. Set same recording duration on each unit

8. Run each unit

9. Set'' generator mode = on ''to start record


[[Image:Resources_output_19.png|framed|none]]

10. Download all recorded files on one PC

11. Launch <nowiki>’</nowiki>Track Assembler<nowiki>’</nowiki>

[[Image:Resources_output_20.png|framed|none]]

The concatenation synopsis is shown on the following scheme:


[[Image:Resources_output_21.png|framed|none]]



More information on the Track Assembler in <nowiki>’</nowiki>Operation on multiples Hardware<nowiki>’</nowiki>.

==Listening track==
There are 3 ways to listen track:
====Input: listen during measurement====
Back to the roots of vibration analysis: Everybody knows that our ears and brain is the best instrument to feel and interpret vibration signals. This is also why we take so much care in removing these NVH signals from our machines, vehicles and appliances. The audio playback of vibration (or any other) signal allows the user to "listen in" on what your OROS analyzer is "hearing".

Connect input feature allows a user to play input channels on an output. This allows the user to listen during measurement with an headphone on the output.
[[File:input_on_output.png|400px]]
 

====Monitor channels : Hot Swap ====

NVgate uses the monitor hot swap capability to allow changing the replicated signal during acquisition/recording.

The NVGate synopsis is as follows:

[[Image:Release_note_20.png|700px|none]]

To activate it, simply connect one of the monitor ''Channels'' to the desired output from the ''Acquisition/Outputs/Signal'' dialog.

[[Image:Release_note_21.png|framed|none]]

Then you can add any front-end input to the monitor channel. The selected input signal will replicate (play) on the output. You can swap from one input to another at any time including during the run and signal recording.

NB: Remember to switch the output impedance to 600 Ω for better listening quality.

====Play-Back on PC speaker====
If you need to listen a signal already recorded, do not use an output channel. We advice to use the playback on PC speaker defined here:
From any of the previous configurations, the recorded signal can be listened to on PC speakers.
[[File:Player_playback.png|none]]

Click on [[Image:Player_connection_wizard_06.png]] in the active window. The button stops the play back at any time. A mobile cursor (blue) localizes the played back signal part in the signal window.

==Create and play ANY signal==

You can play a signal already recorded with an OROS analyzer, or any signal imported into NVgate.
You can put the signal in the player (even in connected mode) allowing the signal to be played on an ouptut channel.

====Example : playing a triangle signal on analyzer output ====

• Generate a triangular signal with an application ([https://fr.mathworks.com/?requestedDomain= Matlab],…) or an online site (example: http://onlinetonegenerator.com/); 

• Save this signal in .wav; 

• In NVGate, import this signal (File / Import / Files / OR2X Signal (* .wav, .mat, .UFF...); 

• Load this signal in the player (right click then "load in player"); 

• In the options proposed in output, select the channel coming from the player:
[[File:player_out.png|framed|none]]
•If you want to play this signal repeatedly, you must change the "Repeat mode" parameter in "Analyzer Setting Browser":
[[File:player_out2.png|framed|none]]

NVGate Output Signals

2026-09-11T09:01:49Z

Lmagimel: /* Input: listen during measurement */

[[category:NVGate]]
[[category:WikiOros]]
This module generates multiple signals such as fixed sinus, random noises, and swept sinus. You can have up to 6 outputs channels with OROS analyzers.

==Connect==

<Youtube>https://youtu.be/cXtX7NVTtmg?t=17</Youtube>

[[Image:Reports_Tools_Ribbons_344.png|250px|none]]
On the tab [[NVGate_Ribbons:_Acquisition_Tab|acquisition]], Output can generate a signal on the front-end outputs (generators)

The left button (''signals'') allows selecting the signal type from the list and connecting it to the available outputs (1 to 6) .The other buttons open the signal settings and manage the generators activity.

*[[Image:Reports_Tools_Ribbons_345.png|Reports_Tools_Ribbons_345.png]] ''Signals:'' Shows the list of available signals and let the users connect it to the outputs. You can easily connect signal with a "drag and drop" on the windows below.
[[File:out3.png]]

==Settings==
===Output general settings===
[[Image:Reports_Tools_Ribbons_351.png]] Outputs settings: Manages the generated signal settling, (Mute, transition time). It is also available on ASB front end.
[[File:out4.png|framed|right]]
Used to control general output behavior. i.e. the signal generated on Out 1 &2 and Aux. Out 1 to 4.

* '''Transition time''': The value of this setting is the time it takes for the output to go from 0 to activated level and the time it takes for the output to go from the activated level to 0 when deactivated. This transition time is applied only if the ''Output x/transition control ''value is "On"

[[Image:front_end_23.png|framed|none]]

* '''Mute ''''''all''': On / Off: When "On", all the outputs are set to zero. The value of this setting is automatically set is "On" when the ''Emergency Stop ''setting from the same sub-module is pushed.
'''Emergency ''''''Stop''': Automatically mutes all the outputs when pushed. Use the ''Mute all ''setting from the same sub-module to make the outputs work again.

===Output channel settings===
Available on ASB/ front end/Output. 
[[image:out5.png|framed|right]]
* '''Label''': the name of this Output (by default Output n, with 1 <nowiki><</nowiki>= n <nowiki><</nowiki>= 2). The label of each output is used in the result name and in all connection tools.
* '''Source''': the input signal of the output (NONE by default). The input signal can be any dynamic input of the Front-end (in the On-line mode) or any signal generated by the output signals resource (in the On-line mode) or any track of the Player (recorded from inputs).
* '''Applied ''''''filter''': the filter applied to this output. The list of filters applicable to the outputs is defined in the Filter module, by choosing Apply to = All.
* '''Clipping''': the amplitude limitation of the output signal (from 1 mV to 10 V).
* '''Gain''': This setting can be displayed in dB. It is the gain applied to the output signal.
* '''Impedance''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="77%" align="center"
|'''Impedance'''
|'''Description'''

|-
|GND
|The output is connected to the ground.

|-
|50 Ohms
|The output impedance is equal to 50 Ohms.

|-
|600 Ohms<ref>Only available for OR38 & OR36. For phone lines connections use.</ref>
|The output impedance is equal to 600 Ohms.

|} 

* '''Synchronization''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="92%" align="center"
|'''Synchronization'''
|'''Description'''

|-
|Free run
|The output delivers a signal as soon as there is a source connected.

|-
|Linked to run
|The output is activated only after the first run action.

|} 

* '''Transition control''': On / Off. If the value of this setting is "On" the ''Output settings/transition time'' is applied when this output is activated or disabled.

==Signal available==
===Sine===
* [[Image:Reports_Tools_Ribbons_346.png]] ''Sine:'' Opens the pure sine properties dialog for adjustment.

Used to generate and configure up to 6 fixed sinus. A sinusoidal signal is generated with the frequency specified in the sine '''Frequency''' field. The frequency corresponds to one of the analysis bands. This type of signal is used for measuring the amount of distortion in a system for example. The amplitude of the signal can be changed using the '''Level''' settings.
[[Image:Resources_output_02.png|framed|none]]

* '''Frequency''': sine frequency.

'''Tips: put 0Hz for DC Volatge generation.'''

* '''Peak level''': the peak level
* '''RMS level''': sine RMS level. This setting can be displayed in dB.

'''Note:''' Amplitude and frequency modifications are applied immediately without any transition.

[[Image:Resources_output_03.png|framed|none]]

===Multi-sine===
[[Image:Reports_Tools_Ribbons_347.png]]: Multi-sine: Opens the ''Multi-sine'' properties dialog for adjustment.

Multisine is computed by adding sine signals whose frequencies are power of two sub-modules of sampling frequency. This means that multisine output block includes all discrete sine waves of FFT spectrum of corresponding block size and resolution. Multisine has the advantage of showing no leakage effect in FFT as all sine waves are exact periods of the trigger block for FFT computation. The most appropriate FFT weighting window to be used is “uniform” window. Multisine generators work on a sample block basis, it means signal blocks are repeated identically over time.

Used to generate and configure up to 2 multi-sines. The multi-sine is computed by adding sine signals whose frequencies are power of two sub-modules of sampling frequency. So with the FFT analyzer, each sine signal can be exactly at an analysis frequency line and there is no leakage due to analysis window. Due to its specific structure, using a rectangular analysis window for FFT analysis on a multi-sine excitation is recommended.

The phase between sine signals can be controlled in order to get a low crest factor or randomized, but with a higher crest factor.

Multi-sine is periodic with a period equal to the opposite of its frequency resolution.

[[Image:Resources_output_04.png|framed|none]]

* '''Lower frequency''': the lower frequency of the multi-sine frequency range. Its minimum value is the resolution.
* '''Upper frequency''': the upper frequency of the multi-sine frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': multi-sine RMS level. This setting can be displayed in dB.
* '''Resolution''': the resolution of the multi-sine. Its minimum value is SF / 16384, where SF is the sampling frequency. Its maximum value is SF / 256.
* '''Phase''': Computational mode of the original sinusoid phases.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="100%" align="center"
|'''Phase'''
|'''Description'''

|-
|Random 
|The original phase of each sinusoid is selected randomly after each multi sine deactivation/activation. First activation: 
[[Image:Resources_output_05.png|framed|none]]
 After reactivation: 
[[Image:Resources_output_06.png|framed|none]]
Phase relationship between sine waves is selected at selection of setting and will not change unless “random” setting is changed back and forward. After “random” is selected phase relationship is defined (randomly for the first block) and repeated identically for each signal block of N lines. Phase relationship for all multisine generators will be different as random setting activation is made at different moment in time and applied for different generator objects. Two blocks of multisine random phase of the same generator are 100% correlated.
Two mulitsine random phase generators are not correlated.
 

|-
|Fixed 
|Each sinusoid has the same original phase even after multi sine deactivation/activation. 
[[Image:Resources_output_07.png|framed|none]]
Multisine phase relation if fixed and will be the same each time setting “fixed” is selected.
Phase relationship is the same for all multisine generators meaning that signal blocks will be the identical between any multisine generators of the same setting. Multisine fixed phase generators are 100% correlated.
 

|} 

'''Burst setting''' in Multisine generators will shorten the time during which the output signal is active despite the signal block being of the same length.
All bandwidth frequencies are present in each burst but may not be complete cycles as block period is truncated. Two bursts being identical (respectively fixed or random phase) they are 100% correlated. Two random bursts from two separate generators will not be correlated signals.

===Random noise===
[[Image:Reports_Tools_Ribbons_350.png]]Random Noise: Opens the ''Random noise'' properties dialog for adjustment. Adapted for non linear responses measurement. 

Used to generate and configure up to 2 white or pink random noise types.

Signal block is recalculated each time. All frequencies of generator bandwidth are taken into account with a resolution of Fs/16384 (Fs being front end sampling frequency), this resolution is independent from FFT resolution. Consequently signal content of each FFT trigger block is not the same meaning that signals between two trigger blocks are not correlated. Similarly random noise signal between two separate generators are also not correlated.

[[Image:Resources_output_08.png|framed|none]]

Random noise is generated using algorithms that guarantee no short or long-term periodicity.

* '''Lower frequency''': the lower frequency of the Random noise frequency range. Its minimum value is equal to SF / (2.56 * 6400), where SF is the sampling frequency and 6400 <nowiki>+</nowiki> 1 is the resolution.
* '''Upper frequency''': the upper frequency of the Random noise frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': the Random noise RMS level. This setting can be displayed in dB.
* '''Period''': The period selected for the Random noise. It used to define a Random Block. Its maximum value is 100s.
* '''Burst''': This setting lets the user specify the percentage of non-null signal in a random block.

'''Exemple''' with: burst: 60% - period: 100ms :

[[Image:Resources_output_09.png|framed|none]]

* '''Type''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="92%" align="center"
|'''Type'''
|'''Description'''

|-
|[https://en.wikipedia.org/wiki/White_noise White]
|White noise has the same distribution of power for all frequencies, so there is the same amount of power between 0 and 500 Hz, 500 and 1,000 Hz or 20,000 and 20,500 Hz.

|-
|[https://en.wikipedia.org/wiki/Pink_noise Pink]
|Pink noise has the same distribution of power for each octave, so the power between 0.5 Hz and 1 Hz is the same as between 5,000 Hz and 10,000 Hz. Since power is proportional to amplitude squared, the energy per Hz will decline at higher frequencies at the rate of -10dB/decade.

|} 

===Chirp===
Chirp means continuous short term variable frequency (1 analysis block), 1 amplitude. Adapted for damping measurement and FFT analysis. 

[[Image:Reports_Tools_Ribbons_349.png]] Chirp: Opens the ''Chirp'' properties dialog for adjustment. 

Used to generate and configure up to 6 chirps. A sine signal, of which the frequency varies from '''Lower Frequency''' to '''Upper Frequency''', is generated in the delay corresponding to the size of a generator block.

[[Image:Resources_output_10.png|framed|none]]

* '''Lower frequency''': the lower frequency of the Random noise frequency range. Its minimum value is equal to SF / (2.56 * 6400), where SF is the sampling frequency and 6400 <nowiki>+</nowiki> 1 is the resolution.
* '''Upper frequency''': the upper frequency of the chirp frequency range. Its maximum value is SF / 2.56, where SF is the sampling frequency.
* '''RMS level''': the chirp RMS level. This setting can be displayed in dB.
* '''Size''': This setting specifies the number of samples required for the generator to go from the lower frequency to the upper one.

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="31%" align="center"
|align = "center"|'''Block size'''
|align = "center"|'''FFT lines number'''

|-
|256
|101

|-
|512
|201

|-
|1024
|401

|-
|2048
|801

|-
|4096
|1601

|-
|8192
|3201

|-
|16384
|6401

|} 

* '''Burst''': This setting lets the user specify the percentage of non-null signal greater than the size of a generator block. For instance, for a burst value of 25% and a block size of 1024, the generator delivers blocks of 256 samples of chirp separated by blocks of 768 null samples.

{|cellspacing="0" cellpadding = "10" style="border-style:solid; border-color:black; border-width:1px;"
|Size = 256 
Burst = 70 
|}

[[Image:Resources_output_11.png|framed|none]]

===Advanced sine===
[[Image:Reports_Tools_Ribbons_348.png]] Swept-sine: Opens the ''Swept-sine'' properties dialog for adjustment.

Used to generate and configure up to 6 advanced sines, allowing the user to generate a swept sine, a pure tone, or to sweep step-by-step.

[[Image:Resources_output_12.png|framed|none]]

* '''Gain''': Each advanced sine has a gain setting with a 0dB reference that is the value of the ''Advanced sine settings/ Peak level setting''
* '''Phase offset''': All the advanced sine have the same phase reference. This setting is used to set a phase offset between them.
====Advanced sine settings====
This sub-module contains the settings related to the main advanced sine generator, including the advanced sine mode setting, stabilization time, amplitude variation...

* '''Mode''':

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="91%" align="center"
|'''Mode'''
|'''Description'''

|-
|Sweep: 
[[Image:Resources_output_13.png|framed|none]]

|The advanced sine performs a continuous sweep of the frequencies between Start Frequency and Stop Frequency 

|-
|Step: 
[[Image:Resources_output_14.png|framed|none]]

|The advanced sine performs a sweep of the frequencies between Start Frequency and Stop Frequency, it stops at each step, waits during stabilization time, and waits for the new step event before going on.

|-
|Pure tone: 
[[Image:Resources_output_15.png|framed|none]]

|The advanced sine generates a pure sine with the frequency of the ''Advanced sine settings/ Target Frequency ''value

|} 

* '''Synchronization''': "linked to run" or "Free run". The Advanced sine generator will not be stopped by a stop event, if the setting is on <nowiki>’</nowiki>Free run<nowiki>’</nowiki>. The default value is <nowiki>’</nowiki>Linked to run<nowiki>’</nowiki>.

If you change the amplitude or the frequency of the generated signal, there will be a stabilization time, and you will have to generate an event when the signal is stabilized.

In these 3 modes, each time the generator stops on a frequency;

1. At the beginning (amplitude increase until the first frequency),

2. At a new step (at the end of stabilization time), or in <nowiki>’</nowiki>pure tone<nowiki>’</nowiki> or <nowiki>’</nowiki>swept sine<nowiki>’</nowiki> pause mode when it reaches the target frequency; the generator sends a stabilized event, after being stabilized (amplitude and frequency).

3. In <nowiki>’</nowiki>Free run<nowiki>’</nowiki>, if the generator is already stabilized at the run event, then a stabilized event is generated at this moment.

If the output is on <nowiki>’</nowiki>Advanced sine<nowiki>’</nowiki> source, the setting of <nowiki>’</nowiki>Synchronization<nowiki>’</nowiki> of the advanced sine will recopied to the <nowiki>’</nowiki>synchronization<nowiki>’</nowiki> of the output (which one become fixed).

:''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Synchronization
|Fixed to <nowiki>’</nowiki>Linked to run<nowiki>’</nowiki>
|Visible
|Visible

|} 

* '''Pause''': On / Off. When Pause is active, the frequency sweeping is halted when there is only one frequency generated. This frequency is now called "Target frequency". You can modify this frequency value to another target so the frequency will sweep to the new target.

[[Image:Resources_output_16.png|framed|none]]

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Pause
|visible
|hidden
|hidden

|} 

* '''Peak level''': the advanced sine peak level (between 0 and 10 V).
* '''Start frequency''': The start frequency of the sweep.

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Start frequency
|visible
|visible
|hidden

|} 

* '''Stop frequency''': The stop frequency of the sweep.

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="70%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Stop frequency
|visible
|visible
|hidden

|} 

* '''Target frequency''': The value of this setting is the frequency currently generated when the value of the'' Pause ''setting is "On" or if the'' Mode ''is set to "Pure Tone"

''Hidden/fixed: ''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
| '''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Target frequency
|visible if Pause = On
|visible if Pause = On
|visible

|} 

* '''Sweep variation''': Two different types of sweep are available: a linear sweeping or a logarithmic sweep:

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="74%" align="center"
|'''Sweep variation'''
|'''Description'''

|-
|Lin
|The Sweep speed is constant.

|-
|Log
|The Sweep speed increases exponentially when the frequency increase is linear.

|} 

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep variation
|visible
|fixed to Lin
|hidden

|} 

* '''Sweep speed''': It is expressed in Hz/s in a linear sweep variation, and in dec/s in a logarithmic sweep variation. The unit of the logarithmic sweep speed can be changed to oct/min in the user preferences/physical quantity (select "Sweep speed (logarithmic)" in the physical quantity list).
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep speed
|visible
|hidden
|hidden

|} 

* '''Sweep type''':

[[Image:Resources_output_17.png|framed|none]]

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Sweep type'''
|'''Description'''

|-
|One shot
|The advanced sine sweeps the frequencies from Start Frequency to Stop Frequency and stops.

|-
|One cycle
|The advanced sine sweeps the frequencies from Start Frequency to Stop Frequency, then back to Start Frequency and stops.

|-
|Continuous
|The advanced sine sweeps the frequencies between Start Frequency to Stop Frequency without stopping.

|} 

''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|visible
|visible
|hidden

|} 

* '''Stabilization time''': Sweep mode: Selects wait time for the advanced sine at the start frequency and at the right level before starting the sweep. Step mode: Selects wait time for the advanced sine at each step before waiting for the new step event.
* '''Amplitude ''''''variation''': Maximum length of time for the advanced sine to reach a new level.
* '''Phase speed''': Speed of phase variation when setting a new value for ''Advanced sine x/ Phase offset setting''
* '''Step''': Frequency gap between two steps
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|visible
|visible
|hidden

|} 

* '''New step''': The event that triggers the sweep of the advanced sine to the next step
''Hidden/fixed:''

{|class="wikitable" style="background:white" border="2" cellspacing="0" cellpadding="4" width="73%" align="center"
|'''Mode'''
|'''Sweep'''
|'''Step'''
|'''Pure tone'''

|-
|Sweep type
|hidden
|visible
|hidden

|} 

===Synchro===
This special output signal is used to synchronize raw data recorded on multiple OR3X units (even OR2X). This synch signal must be connected on ext. synch trigger input of each recording unit (see below)


[[Image:Resources_output_18.png|framed|none]]

* '''Active''': On/Off Set the synch signal available in sources list, no signal is generated on outputs at this stage
* '''Generator Mode''': Controls synch signal behavior.
* '''On''': start the synch clock generation (0 / <nowiki>+</nowiki>2 V square @ 50 Hz)
* '''Off''': stop the synch clock generation followed by a -2V step during 1 sec.

Track assembly procedure.

1. Activate the synch signal

2. Select ''Front-end / Output 1 / source = Synchro''

3. Set'' Front-end / ext synch / coupling = DC ''on each recording unit

4. Set'' Front-end / ext synch / threshold = 1 V ''on each recording unit

5. Set'' Recorder/trigger/start = ext synch ''on each recording unit

6. Add ext. sync track to the recorder on each unit

7. Set same recording duration on each unit

8. Run each unit

9. Set'' generator mode = on ''to start record


[[Image:Resources_output_19.png|framed|none]]

10. Download all recorded files on one PC

11. Launch <nowiki>’</nowiki>Track Assembler<nowiki>’</nowiki>

[[Image:Resources_output_20.png|framed|none]]

The concatenation synopsis is shown on the following scheme:


[[Image:Resources_output_21.png|framed|none]]



More information on the Track Assembler in <nowiki>’</nowiki>Operation on multiples Hardware<nowiki>’</nowiki>.

==Listening track==
There are 3 ways to listen track:
====Input: listen during measurement====
Back to the roots of vibration analysis: Everybody knows that our ears and brain is the best instrument to feel and interpret vibration signals. This is also why we take so much care in removing these NVH signals from our machines, vehicles and appliances. The audio playback of vibration (or any other) signal allows the user to "listen in" on what your OROS analyzer is "hearing".

Connect input feature allows a user to play input channels on an output. This allows the user to listen during measurement with an headphone on the output.
[[File:input_on_output.png|400px]]

====Monitor channels : Hot Swap ====

NVgate uses the monitor hot swap capability to allow changing the replicated signal during acquisition/recording.

The NVGate synopsis is as follows:

[[Image:Release_note_20.png|700px|none]]

To activate it, simply connect one of the monitor ''Channels'' to the desired output from the ''Acquisition/Outputs/Signal'' dialog.

[[Image:Release_note_21.png|framed|none]]

Then you can add any front-end input to the monitor channel. The selected input signal will replicate (play) on the output. You can swap from one input to another at any time including during the run and signal recording.

NB: Remember to switch the output impedance to 600 Ω for better listening quality.

====Play-Back on PC speaker====
If you need to listen a signal already recorded, do not use an output channel. We advice to use the playback on PC speaker defined here:
From any of the previous configurations, the recorded signal can be listened to on PC speakers.
[[File:Player_playback.png|none]]

Click on [[Image:Player_connection_wizard_06.png]] in the active window. The button stops the play back at any time. A mobile cursor (blue) localizes the played back signal part in the signal window.

==Create and play ANY signal==

You can play a signal already recorded with an OROS analyzer, or any signal imported into NVgate.
You can put the signal in the player (even in connected mode) allowing the signal to be played on an ouptut channel.

====Example : playing a triangle signal on analyzer output ====

• Generate a triangular signal with an application ([https://fr.mathworks.com/?requestedDomain= Matlab],…) or an online site (example: http://onlinetonegenerator.com/); 

• Save this signal in .wav; 

• In NVGate, import this signal (File / Import / Files / OR2X Signal (* .wav, .mat, .UFF...); 

• Load this signal in the player (right click then "load in player"); 

• In the options proposed in output, select the channel coming from the player:
[[File:player_out.png|framed|none]]
•If you want to play this signal repeatedly, you must change the "Repeat mode" parameter in "Analyzer Setting Browser":
[[File:player_out2.png|framed|none]]

File:Input on output.png

2026-09-11T09:01:43Z

Lmagimel: File uploaded with MsUpload

File uploaded with MsUpload

NVGate Tools: AutoReport

2026-08-21T14:24:50Z

Lmagimel: /* Download */

[[category:WikiOros]]
Start NVGate directly with a model and a Microsoft report directly set. This is useful for operators in production environments.

===Download===
[https://partnerzone.digigram.com/s/HfF2XcaA7kwyGA7 Auto report V2 version august 2026] 

''Compatible with NVGate V12.00 or upper.''

===Presentation ===

This program will automatically: 

1) Launch NVGate in connected mode 

2) Create a copy of a word or excel document and open it 

3) Open an NVGate Project 

4) Load an NVGate Model 

5) Select the opened document in the report Tab 

The Refresh.exe, Refreshandprint.exe and RefreshAndSave.exe can be used in a Macro to automatically update and save the report.

===Configuration===

1) Configure the initialization file (.ini) with notepad.

[[File:Auto_rep.png]]

Tips: To connect with an OR10, type “or10=True” and use the following IP: 192.168.150.28. 

To connect with an OR3X analyzer, the “DHCP server” option of the analyzer must be disabled. 

For both OR3X and OR10, your computer must have a fixed IP address. 

2) Put the NVGate_AutoReport.exe next to the .ini and launch it. You may create a shortcut to this application on the desktop of your computer.

===Bonus:===

You can put Refresh.exe, RefreshAndSave.exe, and Refreshandprint.exe in C:\OROS\NVGate data\Links.

Refresh will refresh the word/excel document.
RefreshAndSave will save the report as “Current Name + Version_N”
Refresh and print will refresh and print the word excel document.

Tips: Select .pdf creator as a default Windows OS printer.

Hardware Specification OR3X TW

2026-08-18T08:43:40Z

Lmagimel: /* Expander modules (XPod) */

[[category: specification]]
[[category:WikiOros]]
==General description==
The following specifications concern OR352, OR363 & OR383 Teamwork instruments. These systems consist of OR3x hardware containing optional inputs and processing modules, a PC with an Ethernet interface, and NVGate® software with optional plug-in analyzers.

===Modules===
The following tables detail the complete capacity of OR352, OR363, & OR383 hardware system. Optional or standard modules may fill the described slots.

====OR35====

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "4"|'''Front-end slots'''
|Dynamic and/or parametric analog inputs
|2 slots of 4 universal inputs (BNC)

|-
|Dynamic analog outputs
|1 slot of 2 outputs (BNC)

|-
|Externals sync
|1 slot of 2 trigger/tachometer inputs (BNC)

|-
|Dynamic Inputs (<nowiki>+</nowiki>2)
|1 slot of 2 dynamic inputs shared with Externals sync BNCs

|-
|'''Auxiliary slots'''
|colspan = "2"|1 slot for: TEDS

|-
|rowspan = "4"|'''Processor slots'''
|PC, Disk, Bus interfaces
|1 slot

|-
|Clock synchronization
|1 slot

|-
|Trigger / tachometer / monitoring
|1 slot of 1 ForceDSP

|-
|Real-time Processing power
|2 slots of 1 ForceDSP

|-
|rowspan = "3"|'''Miscellaneous '''
|Internal hard drive
|64 GB internal SSD

|-
|High speed serial ports
|1 port for CAN Bus probe

|-
|Remote control (power control, NVTerm)
|1 RS232 cable connection (RJ11)

|}

====OR36====

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "4"|'''Front-end slots'''
|Dynamic and/or parametric analog inputs
|4 slots of 4 universal inputs (BNC)

|-
|Dynamic analog outputs
|1 slot of 2 outputs (BNC)

|-
|Externals sync
|1 slot of 2 trigger/tachometer inputs (BNC)

|-
|Auxiliary
|2 slots of 2 inputs/outputs for optional outputs, Ext. sync or DC (parametric) inputs (BNC)

|-
|'''Auxiliary slots'''
|colspan = "2"|1 slot for: TEDS

|-
|rowspan = "4"|'''Processor slots'''
|PC, Disk, Bus interfaces
|1 slot

|-
|Clock synchronization
|1 slot

|-
|Trigger / tachometer / monitoring
|1 slot of 1 ForceDSP

|-
|Real-time Processing power
|4 slots of 1 ForceDSP

|-
|rowspan = "3"|'''Miscellaneous '''
|Internal hard drive
|128 to 256 GB removable SSD with USB 3.0 port

|-
|High speed serial ports
|2 ports for CAN Bus probe

|-
|Remote control (power control, NVTerm)
|1 RS232 cable connection (RJ11)

|}

====OR38====

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "4"|'''Front-end slots'''
|Dynamic and/or parametric analog inputs
|4 slots of 8 universal inputs (BNC)

|-
|Dynamic analog outputs
|1 slot of 2 outputs (BNC)

|-
|Externals sync
|1 slot of 2 trigger/tachometer inputs (BNC)

|-
|Auxiliary
|2 slots of 2 inputs/outputs for optional outputs or Ext. sync or DC (parametric) inputs (BNC)

|-
|'''Auxiliary slots'''
|colspan = "2"|1 slot for: TEDS

|-
|rowspan = "4"|'''Processor slots''' 
|PC, Disk, Bus interfaces
|1 slot

|-
|Clock synchronization
|1 slot

|-
|Trigger / tachometer / monitoring
|1 slot of 1 ForceDSP

|-
|Real-time Processing power
|8 slots of 1 ForceDSP

|-
|rowspan = "3"|'''Miscellaneous '''
|Internal Hard drive
|128 to 256 GB removable SSD with USB 3.0 port

|-
|High speed serial ports
|2 ports for CAN Bus probe

|-
|Remote control (power control, NVTerm)
|1 RS232 cable connection (RJ11)

|}

----

===Basic hardware configuration===
Hardware unit contains at least the following modules. All the other modules are optional.

====OR35====

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Font end'''
|4 universal analog inputs, 2 analog outputs, 2 trigger/tachometer inputs <nowiki>+</nowiki> 2 analog dynamic inputs

|-
|rowspan = "4"|'''Processors'''
|1 interface board (Ethernet, CAN, Disk, USB)

|-
|1 Clock synchronization module

|-
|1 master ForceDSP module for Trigger / tachometer / monitoring.

|-
|1 ForceDSP computation module

|-
|'''Disk'''
|64 GB internal SSD

|}

====OR36====

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Font end'''
|4 universal analog inputs, 2 analog outputs, 2 trigger/tachometer inputs

|-
|rowspan = "4"|'''Processors'''
|1 interface board (Ethernet, CAN, Disk, USB)

|-
|1 Clock synchronization module

|-
|1 master ForceDSP module for Trigger / tachometer / monitoring.

|-
|1 ForceDSP computation module

|-
|'''Disk'''
|128 GB removable SSD with USB 3.0 port

|}

====OR38====

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Front-end'''
|8 universal analog inputs, 2 analog outputs, 2 trigger/tachometer inputs

|-
|rowspan = "4"|'''Processors'''
|1 interface board (Ethernet, CAN ,Disk, USB)

|-
|1 Clock synchronization module

|-
|1 master ForceDSP module for Trigger / tachometer / monitoring.

|-
|1 ForceDSP computation module

|-
|'''Disk'''
|128 GB removable SSD with USB 3.0 port

|}

==Connections==
===Network===
OR352, OR363 & OR383 can operate over multiple network configurations.

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|align = "center" bgcolor = "#D9D9D9"|'''Connection to PC'''
|bgcolor = "#D9D9D9"|'''Ethernet 1 Gb/s''' / <nowiki>></nowiki> 100 m / Cat 5E

|-
|align = "center"|'''Security'''
|Support '''SSH tunneling connections'''

|-
|align = "center" bgcolor = "#D9D9D9"|'''IP management'''
|bgcolor = "#D9D9D9"|TCP/IP / The instrument can be '''DHCP server''' (non-authoritative)

|-
|align = "center"|'''Supported Networks'''
|'''WAN''' (Internet) / '''LAN''' (Company) / '''Wi-Fi''' (wireless)

|}

----

===Cascade===
OR352, OR363 & OR383 can be cascaded flexibly.

[[Image:Hardware_spec_02.png|700px]]

'''Specifications'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|align = "center" bgcolor = "#D9D9D9"|'''Configuration'''
|bgcolor = "#D9D9D9"|'''Switchless daisy-chain''' / '''30<nowiki>+</nowiki> '''cascaded analyzers / '''Mixed''' analyzer<nowiki>'</nowiki>s type

|-
|align = "center"|'''Connections'''
|NVGate: Ethernet '''1Gb/s''' / Clock sync & Reference distribution : Ethernet '''100 Mb/s'''

|-
|align = "center" bgcolor = "#D9D9D9"|'''Cables'''
|bgcolor = "#D9D9D9"|'''<nowiki>></nowiki> 100 m''' per connection / Variable lengths / Cat 5E

|-
|align = "center"|'''Master/Slave'''
|Undifferentiated analyzers<nowiki>'</nowiki> type

|-
|align = "center"|'''Accuracy'''
|'''Phase : <nowiki>></nowiki> ±0.2° '''@ 20 kHz / '''<nowiki>></nowiki> 8 ns '''@ 51.2 kS/s / '''Amplitude: <nowiki>></nowiki> ±0.02 dB'''

|-
|align = "center"|'''Synch. protocol'''
|'''IEEE 1588.2''' Precision Time Protocol / '''SyncE''' (synchronous Ethernet) - No phase shift

|-
|align = "center"|'''IP management'''
|'''Automatic IP''' check and resolution at NVGate start / '''DHCP server''' (non-authoritative)

|}

==Case==
===Mechanicals===
'''OR35'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Weight'''
|colspan = "2"|'''3 kg '''(6.6 lb)

|-
|rowspan = "2"|
'''Dimensions'''
|Case (w.h.d)
|'''303 mm''' '''x 52 mm x 236 mm '''(11 15/16" in x 2 1/16" in x 9 9/32" in)

|-
|Overall (w.h.d)
|'''310 mm x''' '''58 mm x 245 mm '''(12 7/32" in x 2 9/32" in x 9 21/32" in)

|}

'''OR36'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Weight'''
|colspan = "2"|'''5.6 kg to 6.1 kg''' (12.3 lb to 13.4 lb)

|-
|rowspan = "2"|
'''Dimensions'''
|Case (w.h.d)
|'''102 mm x 260 mm x 311 mm''' (4 1/32" in x 1 1/4" in x 12 25/32" in)

|-
|Overall (w.h.d)
|'''114 mm x 280 mm x 325 mm''' (4 1/2" in x 11 1/32" in x 12 25/32" in)

|}

'''OR38'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Weight'''
|colspan = "2"|'''7.9 kg to 8.8 kg''' (17.4 lb to 19.4 lb)

|-
|rowspan = "2"|
'''Dimensions'''
|Case (w.h.d)
|'''102 mm x 380 mm x 311 mm''' (4 1/32" in x 15" in x 12 25/32" in)

|-
|Overall (w.h.d)
|'''114 mm x 400 mm x 325 mm''' (4 1/2" in x 15 3/4" in x 12 25/32" in)

|}

----

===Power supply===
'''OR35'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Power'''
|colspan = "2"|'''<nowiki><</nowiki> 30 VA '''

|-
|rowspan = "2"|
'''External AC Power supply'''
|Voltage
|'''100 to 240 VAC / '''1.7 A max

|-
|Frequency
|'''50/60 Hz'''

|-
|rowspan = "2"|'''DCin'''
|Range
|
'''10 V to 28 V'''

|-
|Overload protection
|Absolute maximum''' <nowiki><</nowiki> 40 V '''/''' '''<nowiki>></nowiki> 31 V poles are disconnected

|-
|rowspan = "5"|'''Battery'''
|Type
|Built-in''' 89 Wh Li-ion '''8 modules

|-
|Autonomy
|'''3 h '''

|-
|safety
|Certified under''' UN38.3 '''and''' IEC 62133 '''regulations

|-
|Charge time
|'''3 h '''(typical)

|-
|bgcolor = "#D9D9D9"|Charge conditions
|bgcolor = "#D9D9D9"|DC power supply <nowiki>></nowiki> 12 V

|}

'''OR36'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Power'''
|colspan = "2"|'''<nowiki><</nowiki> 60 VA '''

|-
|rowspan = "2"|
'''External AC Power supply'''
|Voltage
|'''100 to 240 VAC / '''1.7 A max

|-
|Frequency
|'''50/60 Hz'''

|-
|rowspan = "2"|'''DCin'''
|Range
|

''' DC power voltage > 17 V will discard the battery to 28 V'''

|-
|Overload protection
|'''31 V''' (over this voltage DC poles are short-circuited)

|-
|rowspan = "4"|'''Battery'''
|Type
|'''NiMh''' 11 modules (no memory effect)

|-
|Autonomy
|'''2 h '''

|-
|Charge time
|'''2 h''' '''30 min''' (typical)

|-
|bgcolor = "#D9D9D9"|Charge conditions
|bgcolor = "#D9D9D9"|DC power supply <nowiki>></nowiki> 18 V

|}

'''OR38'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Power'''
|colspan = "2"|'''<nowiki><</nowiki> 100 VA'''

|-
|rowspan = "2"|
'''External AC Power supply'''
|Voltage
|'''100 to 240 VAC / '''2.0 A max

|-
|Frequency
|'''50/60 Hz'''

|-
|rowspan = "2"|'''DCin'''
|Range
|
'''DC power voltage > 22 V will discard the battery to 28 V'''

|-
|Overload protection
|'''31 V''' (over this voltage DC poles are short-circuited)

|-
|rowspan = "4"|'''Battery'''
|Type
|'''NiMh''' 17 modules (no memory effect)

|-
|Autonomy
|'''2 h'''

|-
|Charge time
|'''3 h''' (typical)

|-
|Charge conditions
|DC power supply <nowiki>></nowiki> 24 V

|}

==Environmental / Compliance with standards==

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|'''CE\CB\FCC'''
| colspan = "2"|Indicates compliance with EMC Directive '''89/336/EEC''', '''2014/30/EU''' and Low Voltage Directive '''73/23/EEC''','''2014/35/EU'''

|-
|rowspan = "3"|'''Safety'''
|bgcolor = "#D9D9D9"| '''IEC 61010-1'''
|bgcolor = "#D9D9D9"| Safety requirements for electrical equipment for measurement, control and laboratory use.

|-
|'''IEC 61010-2-30'''
|Particular requirements for testing and measuring circuits.

|-
|bgcolor = "#D9D9D9"|'''Over-voltage Cat.'''
|bgcolor = "#D9D9D9"|'''II '''(Local level mains, appliance, and portable equipment)

|-
|rowspan = "5"|'''EMC Emission'''
|'''IEC 61000-6-3'''
|Emission standard for residential, commercial and light-industrial environments.

|-
|bgcolor = "#D9D9D9"|'''IEC 61000-6-4'''
|bgcolor = "#D9D9D9"|Emission standard for industrial environments.

|-
|'''IEC 61326-1'''
|Electrical equipment for measurement control and laboratory use EMC requirements.

|-
|bgcolor = "#D9D9D9"|'''CISPR 11 '''
|bgcolor = "#D9D9D9"|Radio disturbance characteristics of industrial and scientific equipment.: Class B limit. 

|-
|'''FCC Rules'''
|Complies with the limits for a Class B digital device.

|-
|rowspan = "4"|'''EMC Immunity'''
|bgcolor = "#D9D9D9"|'''IEC 61000-6-1''' 
|bgcolor = "#D9D9D9"|Immunity standard for residential, commercial and light-industrial environments.

|-
|'''IEC 61000-6-2'''
|Immunity standard for industrial environments

|-
|bgcolor = "#D9D9D9"|'''IEC 61326-1'''
|bgcolor = "#D9D9D9"|Electrical equipment for measurement control and laboratory use EMC requirements.

|-
|'''EN 50082-2'''
|Generic immunity standard: Industrial environment.

|-
|'''EMF'''
|bgcolor = "#D9D9D9"|'''Recommendations 199/519/CE EN 62311'''
|bgcolor = "#D9D9D9"|Evaluation of person exposure to electromagnetic fields 

|-
|rowspan = "2"|'''Materials'''
|'''ROHS'''
|'''2011/65/EU and 2015/863'''

|-
|bgcolor = "#D9D9D9"|'''WEEE'''
|bgcolor = "#D9D9D9"|'''2012/19/EU'''
|}

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|-
|rowspan = "4"|'''Temperature'''
|OR35, OR36 Operating
|'''-20°C Requires a warmup (power on + run NVGAte) which last 1 min per 1 Celsius degree below zero. to 50°C''' (-4°F to 122°F)

|-
|bgcolor = "#D9D9D9"|OR38 Operating
|bgcolor = "#D9D9D9"|'''-20°C'''4''' to 45°C''' (-4°F to 113°F)

|-
|Storage
|'''-20°C to 65°C''' (-4°F to 149°F)

|-
|bgcolor = "#D9D9D9"|Absolute maximum ratingii
|bgcolor = "#D9D9D9"|'''-35°C to 70°C''' (-31°F to 158°F)

|-
|'''Humidity'''
|colspan = "2"|Max''' 80 % RH''' at 40°C non condensing

|-
|rowspan = "4"|'''Shocks'''
|bgcolor = "#D9D9D9" colspan = "2"|Complies with '''IEC 68-2-27'''

|-
|Operating
|'''100 m/s² '''(11 ms, ½ sine) and '''700 m/s²''' (3 ms, ½ sine)

|-
|bgcolor = "#D9D9D9"|Storage
|bgcolor = "#D9D9D9"|'''200 m/s² ('''11 ms, ½ sine) and '''1 000 m/s²''' (3 ms, ½ sine)

|-
|Absolute maximum ratingii
|'''1 000 m/s²''' (3 ms, ½ sine)

|-
|rowspan = "4"|'''Vibrations'''
|bgcolor = "#D9D9D9" colspan = "2"|Complies with '''IEC 68-2-6'''

|-
|Operating
|'''10 m/s², 5-500 Hz, 5mm'''

|-
|bgcolor = "#D9D9D9"|Storage
|bgcolor = "#D9D9D9"|'''25 m/s², 5-500 Hz, 5mm'''

|-
|Absolute maximum ratingii
|'''30 m/s², 5-500 Hz, 5mm'''

|-
|rowspan = "2"|'''Enclosure'''
|bgcolor = "#D9D9D9"|OR35
|bgcolor = "#D9D9D9"|'''IP 40'''

|-
|OR36, OR38
|'''IP 42'''

|}

===Radio frequencies sensibility===

{|border="2" cellspacing="0" cellpadding="4" width="100%"
| 
|align = "center"|Input measured with 50 Ω terminator

|-
|Radiated RF: 80-1000 MHz, 80% AM 1 kHz, 10 V/m
|align = "center"|<nowiki><</nowiki> 20 µV

|-
|Conducted RF: 0.15-80 MHz, 80% AM 1 kHz, 10 V
|align = "center"|<nowiki><</nowiki> 100 µV

|-
|Magnetic field: 30 A/m, 50 Hz
|align = "center"|<nowiki><</nowiki> 2 µV

|}

===OR36 & OR38 Removable Disk===

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "5"|'''Performances'''
|Type
|'''1.8" - SSD - 128 GB '''or''' 256 GB - MLC''' '''NAND '''Flash Memory

|-
|Shock
|'''15 000 m/s² '''- 0.5 ms''' '''½ sine

|-
|Vibrations
|'''50 m/s'''² - 10 to 2 kHz

|-
|Throughput
|'''32 inputs <nowiki>+</nowiki> 6 aux. '''@20 kHz BW – '''10h 40min''' gap free

|-
|MTBF
|'''2 x 10''''''6 ''''''hours'''

|-
|rowspan = "2"|
'''Case'''
|Case (w.h.d)
|'''83 mm x 20 mm x 97 mm''' (3.24 in x 0.78 in x 3.79 in)

|-
|weight
|'''0.200 kg '''(0.55 lb)

|-
|rowspan = "2"|'''Connection'''
|Into the analyzer
|'''SATA '''-''' 1.5 Gb/s '''sustained read/write

|-
|To the PC
|'''USB 3.0''' - '''200 Mb/s''' sustained read

|-
|rowspan = "2"|'''Power supply'''
|On PC
|'''USB '''powered

|-
|On analyzer
|'''Internal '''power supply

|}

==Front-end==
Each front end slot of the OR35 (4 BNC <nowiki>+</nowiki> 2 BNC), OR36 (4 BNC) and the OR38 (8 BNC) can be occupied by one of the following inputs type:

* Universal inputs
* Dynamic inputs
* Parametric inputs
===Universal inputs===

The universal inputs gather both dynamics and parametric input in the same board and connector. The universal inputs are necessary to support the XPod signal conditioners. The type of use of the universal inputs is selectable by software (NVGate) during the analyzer operations.

The universal inputs fulfill all the performances, precision and operability of each specific input type.

===Dynamic inputs===

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "4"|
'''Sampling'''
|Sampling frequencies (Additional decimators allow analysis bandwidth down to 0.8 Hz)
|'''102.4 kHz, 65.536 kHz, 51.2 kHz, 37.768 kHz, 25.6 kHz, 16.384 kHz, 12.8 kHz, 8.192 kHz, 6.4 kHz, 5.12 kHz, 4.096 kHz, 3.2 kHz, 2.048 kHz'''

|-
|Converters
|One '''24 bit ''''''sigma-delta ADC''' for each input

|-
|Frequency relative precision
|'''0.5 10''''''-4''' (typical 1 10 –5)

|-
|Synchronization
|All inputs synchronized on the same sampling clock

|-
|rowspan = "5"|
'''Anti-aliasing filter'''
|Type
|Over-sampled digital filters

|-
|Slope
|''' <nowiki>></nowiki> 400 dB/octave'''

|-
|Pass band ripple
|'''<nowiki><</nowiki> ± 0.005 dB'''

|-
|Rejection of parasites bands
|'''<nowiki>></nowiki> 100 dB ('''@ frequency <nowiki>></nowiki> 0.57 x FS)

|-
|Effective bandwidth
|'''0.45 x FS''' (ex: 23.4 kHz @ 51.2 kS/s)

|-
|rowspan = "3"|
'''Range (peak)'''
|With amplifier (included)
|'''±100 mV, ±300 mV, ±1 V'''

|-
|Direct
|'''±10 V '''

|-
|With attenuator (included)
|'''±40 V '''

|-
|rowspan = "3"|
'''Absolute accuracy'''
|Resolution
|'''24 bits''' (144 dB)

|-
|All input ranges at 1 kHz
|'''±0.05 dB '''(typical ±0.015 dB)

|-
|Temperature variability
|'''<nowiki><</nowiki> 0.002 dB / 10 °C'''

|-
|rowspan = "3"|
'''DC offset'''
|±100 mV, ±300 mV and ±1V ranges
|'''<nowiki><</nowiki> '''± '''100 µV'''

|-
|±10 V range
|'''<nowiki><</nowiki> '''± '''1 mV'''

|-
|±40 V range
|'''<nowiki><</nowiki> '''± '''2 mV'''

|-
|rowspan = "9"| '''Frequency flatness and phase response''' ''(Includes channel to channel match with different ranges'')'''
|colspan = "2"|''Inside one front-end''

|-
|±10 V range, DC to 20 kHz
|'''<nowiki><</nowiki> ±0.02 dB / <nowiki><</nowiki> ±0.02 °'''

|-
|±10 V range, 20 kHz to 40 kHz
|'''<nowiki><</nowiki> ±0.05 dB / <nowiki><</nowiki> ±0.05 °'''

|-
|±0.1 V, ±0.3 V , ±1 V ranges, DC - 20 kHz
|'''<nowiki><</nowiki> ±0.02 dB / <nowiki><</nowiki> ±0.1 °'''

|-
|±0.1 V, ±0.3 V, ±1 V ranges, 20 kHz - 40 kHz
|'''<nowiki><</nowiki> ±0.1 dB / <nowiki><</nowiki> ±0.5 °'''

|-
|±40 V range, DC - 20 kHz
|'''<nowiki><</nowiki> ±0.1 dB / <nowiki><</nowiki> ±0.4°'''

|-
|±40 V range, 20 kHz - 40 kHz
|'''<nowiki><</nowiki> ±0.1 dB / <nowiki><</nowiki> ±0.8 °'''

|-
|colspan = "2"|''Mixed front-ends''

|-
|±10 V range, DC to 20 kHz
|'''<nowiki><</nowiki> ±0.02 dB / <nowiki><</nowiki> ±0.2 °'''

|-
|rowspan = "4"|
'''Cross-talk'''
|''Between N (N is odd) and N<nowiki>+</nowiki>1 inputs:''
| 

|-
|colspan = "2"|@ 1 kHz:''' <nowiki><</nowiki> -120 dB, ''' @ 20 kHz: '''<nowiki><</nowiki> -96 dB, ''' @ 40 kHz: '''<nowiki><</nowiki> -90 dB'''

|-
|colspan = "2"|''Between any inputs excluding: N (N is odd) and N<nowiki>+</nowiki>1 inputs:''

|-
|colspan = "2"|@ 1 kHz: '''<nowiki><</nowiki> -140 dB, ''' @ 20 kHz:''' <nowiki><</nowiki> -114 dB,''' @ 40 kHz: '''<nowiki><</nowiki> -108 dB '''

|-
|rowspan = "3"|
'''Signal to noise ratio'''
|colspan = "2"|''With 50 Ω terminators:''

|-
|colspan = "2"|±10 V range, 40 kHz bandwidth: '''<nowiki>></nowiki> 100 dB''', spurious lines '''<nowiki><</nowiki> -115 dB''' of full scale

|-
|colspan = "2"|±10 V range, 20 kHz bandwidth: '''<nowiki>></nowiki> 104 dB''', spurious lines '''<nowiki><</nowiki> -125 dB''' of full scale

|-
|rowspan = "5"|
'''Input noise'''
|''With 50 Ω terminators:''
| 

|-
|Thermal input noise
|'''20nV/<math>\sqrt{Hz}</math>'''

|-
|±100 mV and ±300 mV ranges
|20 kHz BW '''<nowiki><</nowiki> 3.5 µV '''rms, 40 kHz BW: '''<nowiki><</nowiki> 5 µV '''rms

|-
|±1 V range
|20 kHz BW '''<nowiki><</nowiki> 5.4 µV '''rms, 40 kHz BW: '''<nowiki><</nowiki> 8.5 µV '''rms

|-
|±10 V range
|20 kHz BW '''<nowiki><</nowiki> 44 µV '''rms, 40 kHz BW: '''<nowiki><</nowiki> 70 µV '''rms

|}

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Impedance'''
| 
|'''1 MΩ ±1 %, <nowiki><</nowiki> 100 pF'''

|-
|'''Protection'''
|Overvoltage
|'''±60 V peak without damage - On any input'''ii

|-
|'''Dynamic'''
|Spectral domain
|''' 140 dB 25601 lines / 30 sec. averaging'''

|-
|rowspan = "5"|
'''Coupling'''
|AC
|'''-3dB Cut-off frequency 0.35 Hz ±10% (first order analog filter)''' [[NVGate_filter_formula_appendix#AC_filter|See curve]]

|-
|
'''DC '''
| 

|-
|ICP
|'''2 mA '''or''' 4 mA''' power supply with AC coupling (±10%)

|-
|ICP <nowiki>+</nowiki> TEDS
|ICP <nowiki>+</nowiki> reverse current on TEDS reading operations

|-
|GND
|Shortcut to ground - '''Automatic current limitation''' to 50 mA

|-
|rowspan = "2"|'''Floating'''
|Coupling
|'''AC '''or''' DC / '''All ranges''' / '''overall voltage''' <nowiki><</nowiki> ±40 V'''

|-
|Common'' ''mode voltage (all ranges)
|Max: '''±12 V'''

|-
|rowspan = "2"|
'''TEDS'''
|
'''Standards'''
|
'''IEEE 1451.4 2001 revision 1'''

|-
|Supported templates
|Accelerometer/Force meter ('''25''') Microphones ('''27''', '''28''' and '''29''')

|}

===Parametric (DC) inputs===

The following parametric inputs can be added to the standard OR363 or OR383 hardware configuration as follows:

* On the '''auxiliary slots''' by set of 2 inputs (max 4) ''DC inputs on auxiliary slots features 16 bit dedicated converters''
* On the '''OR36''' as replacement of 4 dynamics inputs (max 12)
* On the '''OR38 '''as replacement of 8 dynamics inputs (max 24)

The following specifications apply to the universal inputs.

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "2"|
'''Sampling'''
|Bandwidth / Sampling
|'''-3 dB @ 3.5 Hz''' Independent from dynamic sampling clock

|-
|Converters
|One '''24 bit sigma-delta ADC''' for each input

|-
|rowspan = "2"|'''Range (peak)'''
|Direct
|'''±10 V'''

|-
|With attenuator (included)
|'''±40 V'''

|-
|rowspan = "2"|'''Frequencies rejection'''
|Notch filters frequencies
|'''50 Hz '''& '''60 Hz''' @ '''±1% '''

|-
|Rejection
|'''<nowiki>></nowiki> 120 dB'''

|-
|rowspan = "3"|
'''Amplitude'''
|Effective resolution
|'''22 bits '''(out of noise)

|-
|Linearity
|Typ. '''0.0003 % '''of input range peak

|-
|Gain drift
|'''20 ppm '''of input range peak'''/°C '''typ.

|-
|rowspan = "2"|
'''Offset'''
|Offset
|±10 V range: <nowiki><</nowiki> ±'''1 mV '''/ ±40 V range: <nowiki><</nowiki> ±'''2 mV'''

|-
|Offset drift
|±10 V range:''' <nowiki><</nowiki> 40 µV/°C''' / ±40 V range:''' <nowiki><</nowiki> 160 µV/°C'''

|-
|
'''Impedance'''
| 
|'''1 MΩ, 5 nF '''typ.

|-
|
'''Protection'''
|On any inputii
|'''±60 V''' peak

|-
|rowspan = "3"| '''Input Noise'''
|colspan = "2"|''With 50 Ω terminators, excepted ''±40 V range'':''

|-
|Input noise
|'''<nowiki><</nowiki> 4 µV '''rms in 0.1 to 2 Hz BW – Typ '''2 µV rms'''

|-
|Max. Deviation
|'''<nowiki><</nowiki> 6 µV '''peak

|}

'''Dynamic outputs'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "2"|'''Sampling'''
|Converters
|One '''24 bit DAC''' for each output

|-
|Synchronization
|Same sampling clock as the dynamic inputs

|-
|rowspan = "4"|
'''Range'''
|Direct
|±'''10 V peak'''

|-
|With attenuator (included)
|±'''1 V peak'''

|-
|Clipping
|'''User selectable''' in the output range

|-
|Digital gain
|From''' 10''''''-5''' to '''10''''''3'''

|-
|rowspan = "3"|'''Absolute accuracy'''
|Resolution
|'''24 bits''' (144 dB)

|-
|All output ranges at 1 kHz
|±'''0.05 dB'''

|-
|Temperature variability
|'''<nowiki><</nowiki> 0.1 dB / 10 °C'''

|-
|rowspan = "4"|'''Frequency response'''
|colspan = "2"|''Variation relative to 0 dB @ 1kHz''

|-
|All ranges, at 10 kHz
|<nowiki><</nowiki> ±'''0.05 dB'''

|-
|All ranges, at 20 kHz
|<nowiki><</nowiki> ±'''0.15 dB'''

|-
|All ranges, at 40 kHz
|<nowiki><</nowiki> ±'''0.8 dB'''

|}

'''Dynamic outputs (continued)'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "4"|'''Noise floor level'''
|10 V range, 20 kHz bandwidth
|-'''110 dB''' of full scale, spurious lines '''<nowiki><</nowiki> -125 dB''' of full scale

|-
|10 V range, 40 kHz bandwidth
|-'''105 dB''' of full scale, spurious lines '''<nowiki><</nowiki> -125 dB''' of full scale

|-
|1 V range, 20 kHz bandwidth
|-'''99 dB''' of full scale, spurious lines '''<nowiki><</nowiki> -110 dB''' of full scale

|-
|1 V range, 40 kHz bandwidth
|-'''94 dB''' of full scale, spurious lines '''<nowiki><</nowiki> -110 dB''' of full scale

|-
|
'''Impedance'''
|User selectable
|'''50''' Ω, '''600''' Ω or '''Grounded'''

|-
|
'''Current'''
|Max 
|'''±10 mA'''

|-
|
'''Protection'''
|Sum of injected <nowiki>+</nowiki> generated voltages
|±'''15 V peak, '''On any outputii Permanent short circuit supported

|-
|rowspan = "2"|
'''Total harmonic distortion '''
|THD @ 1 kHz
|'''<nowiki><</nowiki> 0.002% '''or''' -94dB '''at 20 kHz BW

|-
|THD @ 5 kHz
|'''<nowiki><</nowiki> 0.005% '''or ''' -86dB '''at 20 kHz BW

|-
|
'''Cross-talk'''
|Output 0 dBV to 50 Ω terminated input
|
'''Lower than measurable noise '''

|}

'''External sync'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "2"|
'''Sampling'''
|Frequencies
|'''64 times over-sampling''' of the current input sampling (up to '''6.4 MHz''')

|-
|Converters
|High speed voltage comparator and time counter

|-
|'''Ranges (peak)'''
| 
|±'''300 mV''', ±'''1 V''', ±'''3 V''', ±'''10 V''', ±'''40 V '''

|-
|'''Resolution'''
|Amplitude accuracy
|±'''1%''' of '''range'''

|-
|rowspan = "4"|'''Setting'''
|Hysteresis
|'''1%''' (of input range) to input range

|-
|Hold off
|'''0 s''' to '''500 s'''

|-
|Slope
|'''Rise''' or '''fall'''

|-
|Hardwired pre-divider
|'''1''' to '''255'''

|-
|'''Accuracy'''
|'''Time resolution'''
|'''<nowiki>></nowiki> 160 ns '''(0.06° at 1 kHz and 1.2° at 20 kHz)

|-
|'''Pulse rate'''
|Max
|'''375 kpulse/s '''

|-
|rowspan = "2"|'''Coupling'''
|'''AC'''
|'''-3dB Cut-off frequency 0.35 Hz ±10% (first order analog filter)'''

|-
|
'''DC'''
| 

|-
|'''Impedance'''
| 
|'''1 M'''Ω, <nowiki><</nowiki> 100 pF

|-
|'''Protection'''
|on any external syncii
|±'''60 V peak''' without damage

|}

===Expander modules (XPod)===
With the universal inputs the OR352, OR363 and OR383 can receive signal conditioning modules called XPod. Different Xpod types are available.

'''Wheatstone bridge XPod'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|'''Connectors'''
|Type
|'''Sub-D9 – Female'''

|-
|rowspan = "6"|'''Bridges'''
|Mounting
|'''Full''', '''Half''' and '''quarter'''

|-
|½ bridge completion resistors
|2 * '''10 kΩ''' - 0.1% - 10 ppm

|-
|¼ bridge completion resistors
|120 '''Ω''' or 350 '''Ω''' - 0.1% - 25 ppm

|-
|Excitation voltages
|'''0 to 10 V '''

|-
|Excitation currents
|0 to 4 V:''' <nowiki><</nowiki> 30 mA - '''4 V to 10 V: <nowiki><</nowiki> '''12 mA '''

|-
|Sensing
|'''Negative '''and '''positive''' probes

|-
|rowspan = "3"|'''Amplifiers'''
|Type
|Differential - DC capable

|-
|Gains
|'''10 '''or''' 100'''

|-
|Error
|'''<nowiki><</nowiki> 0.01 dB'''

|-
|rowspan = "4"|'''Inputs'''
|Ranges
|±'''100 mV - '''±'''1 V'''

|-
|Common mode voltage
|'''±7''' V without limiting differential input

|-
|Impedance
|'''1 MΩ'''

|-
|Noise floor levels (100 Hz to 20 kHz)
|Gain 100: '''2 µVrms''' - Gain 10: '''4 µVrms'''

|-
|rowspan = "2"|'''DC offset'''
|Temperature drift
|'''1 µV/°C'''

|-
|Compensation resolution
|'''3 % '''of present offset

|-
|'''Protection'''
|Overvoltage
|Device on: max '''±30 V''' - device off: max '''±15 V'''

|}

'''Temperature XPod'''

The temperature XPod operates on the universal or parametric inputs. The XPod support thermocouple and RTDS conditioning, cold point compensation and linearization. Amplified signal are injected in the analyzer on the ±10 V range.

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "3"|Connectors
|Type
|Mini Thermocouple/RTD type

|-
|Pins
|'''3 polarized pin''' - spring-loaded - compatible with 2 point plugs

|-
|Material
|Glass filled thermoplastic - White body

|-
|rowspan = "7"|Thermocouples
|'''Type J'''
|<nowiki>-</nowiki>'''210 °C to <nowiki>+</nowiki>1 100 °C''' - Yellow LED

|-
|'''Type K'''
|'''-200 °C to <nowiki>+</nowiki>1 300 °C''' - Green LED

|-
|'''Type T'''
|'''-200 °C to <nowiki>+</nowiki>390 °C''' - Brown LED

|-
|'''Type N Add 0.1°C to absolute temperature error'''
|'''-200 °C to <nowiki>+</nowiki>1 200 °C''' - Pink LED

|-
|'''Type E'''
|'''-200 °C to <nowiki>+</nowiki>800 °C -''' Purple LED

|-
|Cold compensation
|Integrated - 2 sensors - user on/off

|-
|Absolute temperature error
|<nowiki>></nowiki> -150 °C : ±'''0.9°C '''/ <nowiki><</nowiki> -150 °C : ±('''0.4°C '''<nowiki>+</nowiki>''' 0.1% '''of MT<ref>) MT is Measured Temperature</ref>)

|-
|rowspan = "5"|RTDS
|PT 100
|<nowiki>-</nowiki>'''190 °C to <nowiki>+</nowiki>880 °C''''''*''' – Blue LED

|-
|PT 1000
|'''-190 °C to <nowiki>+</nowiki>880 °C''''''*''' - Grey LED

|-
|Absolute temperature error
|±('''0.4°C '''<nowiki>+</nowiki>''' 0.3% '''of MT9)

|-
|Wires
|3 wires connections

|-
|Current
|PT100: '''500 µA''' '''to 4 mA''' - PT1000: '''500 µA''' to '''1 mA'''

|}

<nowiki>*</nowiki>Calibrated up to <nowiki>+</nowiki>800 °C

===CAN BUS probe===
The CAN bus probe is connected to the OR352, OR363 and OR383 via the high speed serial ports. It offers a passive CAN bus listener with the following specifications.

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "2"|
'''Type'''
|Standards
|'''CAN 2.0A''' & '''CAN 2.0B''' / Compliant with '''J1939 protocol'''

|-
|Speed
|'''125 kb/s '''to''' 500 kb/s'''

|-
|rowspan = "2"|'''Probe'''
|Probe
|'''High Z / Analyzer '''or''' bus '''powered

|-
|Connectors
|CAN :''' Sub-D 15 / '''Analyzer:''' High speed serial''' '''port''' (1,5 m)

|-
|'''Capacity'''
|Channels
|'''100 channels''' @ '''10 Hz''' refresh rate / '''Synchronous''' with analyzer inputs

|}

==Digital computation==

===Force DSPs modules===

'''ForceDSP on OR3XTW'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "3"|
'''Type'''
|Sample size
|'''32 bit floating'''

|-
|Computation words
|'''32/40 bit'''

|-
|Internal memory
|'''16 MSample'''

|-
|'''Power'''
|
'''Computation capability'''
|'''[[NVGate_DSP_computation_SPU#Force_DSP|see here]]'''

|-
|'''Input sharing'''
|Inputs per DSP
|'''8 max'''

|}

'''Number of DSPs/unit'''

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|
'''Minimum'''
|'''1''' Computation DSP module

|-
|'''OR35 Max.'''
|'''2''' Computation DSP modules

|-
|'''OR36 Max.'''
|'''4''' Computation DSP modules

|-
|'''OR38 Max.'''
|'''8''' Computation DSP modules

|}

===Special DSPs modules===
The following DSPs are always integrated in OR35, OR36 & OR38 hardware.

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "3"|
'''Master DSP module'''
|Monitor computations
|'''FFT 401 lines '''(max 4 Channels)

|-
|Time domain detectors
|'''DC, Max, Min, RMS, Kurtosis''' (on the monitor Channels)

|-
|Special
|Auxiliary inputs, Events, Tachs, Torsion, Generators

|}

===Normal DSP (OR34)===
This specification are about normal DSP. For force DSP on OR3TW. This information can not be accurate.
The following table details the calculation needs (SPUs) for each analysis plug-in of NVGate software.

{|border="2" cellspacing="0" cellpadding="4" width="100%"
|rowspan = "5"|'''Narrow band analysis (FFT)'''
|Real-time FFT analysis with;

|-
|'''401 lines '''(for 801, 1601,3201, 6401 lines, multiply requested SPU respectively by 1.25, 1.5, 2, 3)

|-
|'''20 kHz''' bandwidth (Requested SPU are proportional to bandwidth)

|-
|'''0%''' overlap

|-
|1 channel processing requires '''1 SPU'''

|-
|rowspan = "4"|'''Synchronous order analysis'''
|Real-time order spectrum analysis (re-sampled time signal) with:

|-
|Any duration of visualization, any averaging

|-
|'''20 kHz''' bandwidth (Requested SPU are proportional to bandwidth)

|-
|1 channel processing requires '''3 SPUs'''

|-
|rowspan = "4"|'''Time Domain analysis'''
|Real-time time domain monitor and statistical analysis with:

|-
|Simultaneous time view and statistical extraction.''' '''Any duration of visualization, any averaging

|-
|'''20 kHz''' bandwidth (Requested SPU are proportional to bandwidth)

|-
|1 channel processing requires '''3 SPU'''

|-
|rowspan = "4"|'''1/n Octave'''
|Real-time filter based 1/n octave analysis with:

|-
|'''1/3rd''' octave (for 1/12th and 1/24th octave multiply requested SPU respectively by 2 and 4)

|-
|'''20 kHz''' bandwidth (Requested SPU are proportional to bandwidth)

|-
|1 channel processing requires '''3 SPUs'''

|-
|rowspan = "3"|'''Recorder'''
|Gap free recording with:

|-
|'''51.2 kHz''' sampling rate gap free recording

|-
|1 channel processing requires: '''0.66 SPU'''

|}

===Signal Processing Units===

SPU (Signal Processing Units): the previous table gives the characteristics of each analysis mode and the associated SPU consumption. For multi-analysis purpose, add the corresponding SPUs of each mode used simultaneously and increase the sum by 10%. "Real-time" means that the analysis speed is faster than the input rate and does not miss any sample.

==Notes==
The previous specifications describe all the guaranteed capacities and performances of the instrument and are applicable to an OR352-10, OR363-16 or OR383-32 hardware powered for more than 15 minutes at a stabilized room temperature of 23°C ±5°C and calibrated since less than one year.

The adapted control software NVGate is described separately.

-------------------------------------------------------------------------------

i Prepared for future use: the related specifications or options are in development.

ii Exceeding absolute maximum ratings damages the system and voids guarantee.

Specifications not binding; OROS reserves its right to change these specifications without notice.

----

Campbell Diagram Tool

2026-07-24T11:42:29Z

Lmagimel: /* Getting Started */

The '''Campbell Diagram Tool''' is a standalone Windows application for rotating machinery noise and vibration (NVH) analysis. It builds a frequency × RPM color map (Campbell diagram) from OROS NVGate data — either from raw time-domain signals or from pre-computed waterfall results — and overlays order lines and resonance markers to identify critical speeds.

[[File:campbel2.png|600px]]

[[category:WikiOros]]
{{#seo:
|title=Campbell Diagram Tool — OROS NVGate | Rotating Machinery Vibration Analysis
|keywords=Campbell diagram, order tracking, rotating machinery, NVH, waterfall, RPM, resonance, vibration analysis, NVGate, OROS
|description=Campbell diagram software for rotating machinery vibration analysis. Visualize frequency vs. RPM with order lines and resonance markers, from NVGate raw signals or pre-computed waterfalls.
|image=Campbell_diagram_screenshot.png
}}

__TOC__

----

== What is a Campbell Diagram? ==

A Campbell diagram plots '''vibration amplitude''' as a function of both '''frequency''' (Y-axis) and '''rotation speed''' (X-axis, in RPM). The color intensity represents the amplitude level (in dB or linear units).

Two families of features are visible at a glance:

{|class="wikitable" style="width:100%;"
|-
!Feature!!Appearance on the plot!!Physical meaning
|-
|'''Order lines'''||Diagonal straight lines rising from lower-left to upper-right||Harmonic excitations that rotate with the shaft (1X = imbalance, 2X = misalignment, nX = gear mesh, blade pass…)
|-
|'''Structural resonances'''||Horizontal bright bands at fixed frequency||Natural frequencies of the structure, independent of rotation speed
|-
|'''Critical speeds'''||Intersection of an order line and a resonance band||Operating speed where a harmonic excitation drives a structural mode → high vibration risk
|}

Understanding the difference with a classic waterfall:

* A '''waterfall''' shows spectra stacked over time or speed
* A '''Campbell diagram''' adds the diagonal order lines that immediately reveal which peaks are rotation-driven and which are structural resonances.

----

== Getting Started ==
=== Download ===

This is a beta version free of charge. Feel free to test it and report to us what you think of this to customer.care@oros.com

Download [https://partnerzone.digigram.com/s/m7mmTpYnC7j3gdc Campbell Diagram V1.1] july 2026

Valid with NVGate V18 or upper

=== Launching the application ===

Double-click '''Campbell_Diagram.exe'''. No installation is required; all dependencies are bundled.

The application opens on the '''Data''' tab showing your NVGate project tree.

=== Setting the database path ===

By default the tool looks for NVGate projects in <code>C:\OROS\NVGate data\Projects</code>. To change it:

# Click the '''<code>…</code>''' button next to the path field at the top of the Data tab.
# Browse to your NVGate database folder.
# The project tree refreshes automatically.

----

== Data Tab ==

=== Project tree ===

Projects are listed alphabetically in a collapsible tree. Click the arrow ▶ next to a project name to expand it and see its measurements.

Each measurement shows an icon indicating what data is available:

{|class="wikitable"
|-
!Icon!!Meaning
|-
|<code>▶</code>||Raw time-domain signals (.ors/.orm)
|-
|<code>◈</code>||Pre-computed waterfall (Result.res)
|-
|<code>▶◈</code>||Both available
|}

Click a measurement to select it. The right panel shows the available channels and a summary.

=== Choosing the data source ===

Two modes are available via radio buttons:

==== Raw signals (.ors/.orm) ====

This is the '''metrologically rigorous''' method. The tool reads raw vibration samples and a tacho signal, then computes one independent FFT per RPM bin (no speed-smearing).

Required settings:

{|class="wikitable" style="width:100%;"
|-
!Setting!!Description!!Recommended
|-
|'''Vibration channel'''||The acceleration, velocity or displacement channel to analyse||The main vibration sensor
|-
|'''Tacho channel'''||The tachometer pulse channel||Any channel named "Tacho", "Ref", "RPM"… (auto-detected if possible)
|-
|'''PPR'''||Pulses per revolution of the tacho encoder||1 for a single-pulse encoder
|-
|'''FFT lines'''||Frequency resolution: 400 to 6400 lines||1600 lines (good balance)
|-
|'''RPM bin size'''||Width of each RPM slice||50 RPM (reduce for finer RPM resolution)
|-
|'''RPM min/max'''||Limit the analysis to a speed range||Leave at 0/120 000 for full range
|}

Optional tacho settings (advanced):

{|class="wikitable" style="width:100%;"
|-
!Setting!!Default!!Notes
|-
|Threshold||Auto (signal midpoint)||Override for noisy tacho signals
|-
|Hysteresis||5 %||Schmitt-trigger band — increase if false triggers occur
|-
|Edge||Rising||Use Falling if your encoder pulses are inverted
|}

==== NVGate waterfall (.res) ====

Loads a pre-computed waterfall directly from the <code>Result.res</code> file produced by NVGate. This is '''faster''' but uses the STFT windows already computed by NVGate (speed-smearing may affect amplitude accuracy at high sweep rates and high orders).

Required settings:

{|class="wikitable" style="width:100%;"
|-
!Setting!!Description
|-
|'''Waterfall channel'''||Select the vibration channel from the .res file
|-
|'''RPM reference'''||The tacho reference used to build the RPM axis (auto-selected to Tacho by priority)
|}

=== Computing the diagram ===

Click '''⚙ Compute Campbell Diagram''' (or '''Load Waterfall from Result.res''' in .res mode).

A progress bar appears at the bottom right. The computation runs in a background thread — the interface stays responsive.

When complete, the tool switches automatically to the '''Campbell Map''' tab.

----

== Campbell Map Tab ==

The Campbell Map tab displays the diagram and all display controls in a scrollable right panel.

Use the '''← Back to Data / Compute''' button at the top of the right panel to return without losing your current diagram.

=== Display Options ===

{|class="wikitable" style="width:100%;"
|-
!Option!!Description!!Tips
|-
|'''Colormap'''||Color palette for the amplitude intensity||<code>jet</code> (classic), <code>hot</code>, <code>plasma</code>, <code>turbo</code>
|-
|'''Scale'''||dB (logarithmic) or Linear||dB strongly recommended — compresses the dynamic range
|-
|'''dB min / dB max'''||Color axis limits||Narrow the range (e.g. −40 to 0 dB) to increase contrast on weak features
|-
|'''Freq min / Freq max'''||Frequency range displayed||Auto-set to the data's full band on first load; preserved on recompute
|-
|'''Peak threshold'''||Show Campbell dots within N dB of the loudest peak||−40 dB shows strong peaks; −80 dB shows more (noisier)
|-
|'''Marker size'''||Maximum circle size for the loudest peaks (pt²)||400 pt² default (Onosokki DS-3000 style)
|-
|'''Circle lower / upper'''||Linear amplitude limits for dot sizing||Leave blank for automatic scaling
|-
|'''Spectrogram background'''||Show the color-map waterfall behind the Campbell dots||Useful to see the full amplitude field
|-
|'''Apply Display'''||Redraw with current settings||Colormap changes apply immediately; other settings need Apply
|}

=== Order Lines ===

Check or uncheck orders to overlay the corresponding harmonic lines on the diagram. Each order <code>nX</code> corresponds to the line <code>f = n × RPM / 60</code>.

Available orders: 0.5X, 1X, 1.5X, 2X, 2.5X, 3X, 4X, 5X, 6X, 7X, 8X, 9X, 10X, 12X, 15X, 20X.

=== Auto Marker (beta) ===

Click '''⚡ Detect Orders & Resonances''' to automatically:

# '''Select active order lines''' — the tool samples the amplitude along each order's frequency track across all RPM slices and checks the orders that carry the most energy (above 15 % of the strongest order).
# '''Add resonance marker candidates''' — the tool averages the amplitude over all RPM slices to get a mean spectrum, then picks the top 5 peaks. A sub-bin parabolic interpolation gives accurate frequency estimates. Existing auto-markers are replaced each time.

Review the result and delete false positives with the '''− Remove''' button.

=== Resonance Markers ===

Resonance markers draw a horizontal dashed line at a fixed frequency — useful to visualise where a structural mode intersects the order lines (critical speed).

* '''+ Add''' — opens a dialog to enter the frequency (Hz) and a label. The label appears on the plot with a coloured background.
* '''− Remove''' — select a row in the table then click Remove.
* '''Right-click on the plot''' — opens a context menu pre-filled with the cursor frequency for fast placement.

Markers persist across display changes (Apply Display, zoom, color change) but are cleared when a new diagram is computed.

=== Cursor ===

Move the mouse over the plot to see the current RPM, frequency, and amplitude in the status bar at the bottom of the window.

=== Export ===

{|class="wikitable"
|-
!Button!!Output
|-
|'''PNG'''||High-resolution (200 dpi) image of the current diagram, including order lines and markers
|-
|'''CSV'''||Full amplitude matrix: rows = RPM bins, columns = frequency bins
|}

----

== Interpretation Guide ==

=== Reading the diagram ===

# Look for '''diagonal bright streaks''' aligned with order lines → strong harmonic excitations from the rotor.
# Look for '''horizontal bright bands''' → structural resonances of the machine or test bench.
# The '''intersections''' (where a diagonal crosses a horizontal band) are the '''critical speeds''' — operating RPMs to avoid for extended periods.

=== Adjusting the display for clarity ===

* If the diagram looks flat (all one colour), narrow the '''dB range''' (e.g. set dB min to −30 instead of −60).
* If weak features are invisible, widen the dB range or switch to '''Linear scale'''.
* Enable '''Spectrogram background''' to see the full spectral energy distribution.
* Reduce '''Peak threshold''' (less negative) to show only the strongest peaks; increase it (more negative) to reveal faint features.

==Disclaimer==

this tools is deliver free of charge, Support is not automatically provided on this tool.

== See Also ==

* [[NVGate_SOA_and_CBT_techniques|NVGate SOA and CBT techniques]]
* [[NVGate_Tachometer|NVGate Tachometer — centred averaging]]
* [[FFT_Spectrum_Analyzer_Multipurpose|OROS Multi-function FFT Spectrum Analyzer]]

----
''Campbell Diagram Tool — OROS NVGate · Last updated {{CURRENTYEAR}}''