Help require about NI Sound and Vibration Analyzer (assistant)

[ketan dedakia]

Hi, This is Ketan. I am working on Sound and Vibration analyzer, in Windows environment. I came across a hurdle, and I seek help from you in this regard. My application requires me to use a shared variable (on TCPIP network) as a trigger for vibration data logging. I want to know if NI Sound and Vibration analyzer supports the shared variable based data logging / triggering (soft trigger). Thanks in advance.

[Neal M]

Hello Ketan,

I assume you are talking about either our Sound and Vibration Toolkit (SVT) or Sound and Vibration Measurement Suite.  If this is correct, then the software will work with any method of getting your data.  SVT is an analysis tool and does not depend on how you get data as long as you pass it the data type it is expecting.  As long as LabVIEW can handle the shared variable you are using, then you can programatically create your triggering senario using standard methods.  SVT does not in itself have triggering as you describe integrated into it, but I have seen LabVIEW handle all kinds of software triggering.

SVT is used exclusively in LabVIEW, which is why I have been referencing it so much.  We also have Sound and Vibration Assistant which is included with the Sound and Vibration Measurement Suite.  This is a stand alone application for basic acqusitions and analysis.  This application does read shared variables, but this functionality is not nearly as extensive as LabVIEW.  You might be able to use a trigger step in this program to run your analysis.

If your trigger is for the actual acquisition of the data, then we might have some other options depending on the hardware you are using.  If this is the case, please let me know your setup and the software you are using and I will try to help you out.

[Ketan Dedakiya]

Hi Neal, Thanks for reply. Actually I am talking about NI sound and vibration assistant. In my application, I will get the data from TCPIP and if that received data is in perticular range than system has to start the acquisition. In this case how I can use the NI sound and vibration assistant. -- Ketan

[Neal M]

Hello again Ketan,

Sound and Vibration Assistant is basically an add on for LabVIEW SignalExpress.  My original thought was that we could read the shared variable in a loop until it reaches the value we are looking for.  When that loop exits, we then call our DAQmx Acquire.  When I tried this, I saw that one of the features of SignalExpress makes this process not work as I first thought.  SignalExpress can recognize when portions of its program do not rely on others and run them simultaneously.  Because your shared variable and the actual acquisition do not share data in the program, SignalExpress wants to run them in parallel.

The only way I can think of to make the two steps rely on eachother is to somehow output the shared variable (e.g. a proportional voltage) and use an analog trigger for the acquire.  This is an indirect method, but depending on your hardware may be possible.

This is a great example of an opportunity for Product Feedback for the ability to turn this feature off (or control it somehow).  These go to R&D and help drive the direction for development.

Please let me know if you have any questions.

Message Edited by Neal M on 06-11-2008 10:54 AM