Trigger integrals

[bbentelin]

If I have a waveform with 50% pretrigger data, and 50% posttrigger data, is there a way to take two separate integrals, one for each section?  I want to calculate the background noise for our experiment.  Currently I'm trying to fetch the measurements from two different waveforms, one with 100% pretrigger data and one with 0%.  But the pretrigger data doesn't match up with the signal data so the noise calculation is incorrect.

I'm using a PXI-1000B.

Thanks

Here's the old vi that I'm trying to modify:

Message Edited by bbentelin on 05-14-2010 03:47 PM

[David_L · Accepted solution]

Have you tried taking the original signal with pre and post trigger data and simply split the array in half?  It will take a couple of functions to do this, but it's a pretty straightforward task.  For Example:

 

[bbentelin]

Thank you so much, I'll try that out immediately.

[bbentelin]

Yes that worked perfectly.  Do you know which vi I should use to replace the niScope Fetch Measurement I had before?  I need the integral of the waveforms.

Thanks again.

[David_L]

I'm not sure if you would replace the Fetch Measurement VI, because that is what gets the actual data from the Hardware.  However once you have the data, you could probably just extract the data array and then use the integral x(t).VI to do the integration.

[bbentelin]

How do I get the data for both waveforms? Do I need to do a similar splicing procedure to the results of the fetch measurement vi?

[bbentelin]

Over at the far right of the block diagram is my attempt at doing the integral for the post trigger data.  The integral indicator isn't responding.  Do I have the wrong things wired into the integral x(t) function?

Thanks

[bbentelin]

I figured it all out.

Thank you so much for your time and help.

[David_L]

Haha glad you figured it out, I was somewhat confused by your previous post.  Glad to help!