NI cDAQ 9172 with 3 USB 9233 for collecting impact hammer data

[StuMtu]

Hello,

      I am collecting data on a NI cDAQ 9172 with 3 USB 9233 cRIO. The software I am using is Sound and Vibration assistant. I have setup the necessary parameters and trigger. The impact hammer is connected on the USB 9233 module one and the rest of the channels on the first module and remaining two modules are accelerometer channels. Would I have a problem triggering the rest of the channels on module 2 and 3?

I have attached my project file for you to have a look at. Thank you very much for your help.

[Corby_B]

Hello StuMtu,

Thanks for your post! It looks like a great setup. You should not have a problem using another software Trigger step to trigger the other channels. I can only be software though. So just add another trigger step but specify the input to be only specific channels. There is an option to define a "sub group" of triggered channels so you can select the remaining acc channels. Let us know if this helps and good luck with your applications!

Cheers!

Corby_B

http://www.ni.com/support 

[StuMtu]

I did not completely understand what has to be done here. How do I set up a software trigger again after I have setup already a trigger in the steps? I am using a NI cDAQ 9172 with 3 NI USB 9233 modules and Signal Express 3.0. I have currently set up the 12 channels to acquire data and I have used the hammer channel to trigger the remaining accelaration channels. Will selecting only the hammer channel only trigger to collect data from the first USB 9233? Do the remaining 9233s have to be triggered separately?

My project is attached to the earlier posts. Could you demonstrate on tht? or send me an example.

Thank you.

[preston_johnson]

The data acquisition part of the project should have just one step.  All the channels should be in the daq step of the project.  In this way they are all sampled simultaneously and all channels will be triggered and sampled at the same time.  This looks like you have this in your project. 

I would consider using the cDAQ chassis as the holder of the 9233 which you have.  In your project you have all the 9233's in the cDAQ chassis - this is also good. 

Since your DAQ step has all the channels, the trigger applies to all the channels in the DAQ step.   consider putting a time series plot on your view so that you can see all the data after the trigger.  In other words drag the triggered data from the trigger step out onto a graph. 

You can also review  the the example which ships with the assistant for impact test.  Pull down the help menu,  select open example,  select sound and vibration assistant, and then select the SVA_Impact Test example project. 

[StuMtu]

Thank you very much Preston and Corby. The problem has been resolved. A new issue I am facing is device buffer overflow.I am using NI cDAQ 9172 with 3 USB 9233 devices and Sound and Vibration assistant 6.0 (signal express 3.0) to collect impact hammer data. Everytime I am trying to collect data I am getting the following error ---  "Logging was stopped because an error occurred with a Step in the Project. If this error is because of a device buffer overflow, you can improve performance by turning off display updates using the "Operate >>Update Signal Views While Running" menu item. You can also change the way signals are logged by changing the Logging Options in the Tools>>Options dialog.
Turning off "Prepare log data for viewing" will greatly improve performance."

I tried switiching off the update signals and prepare log data for viewing but it did not seem to work. Also, I tried changing the sampling rate and number of samples. Could you please help me out with this error.
Thank you very much for your help.