Analyzing RC Circuit

[jeffdillon]

We have a graduate school homework assignment where we need to generate a AC waveout (DACOUT), then measure the response and phase shift of an RC circuit (DACIN)

Since this is a homework assignment, I'm just looking for general advice. I am using a NI 6024E Card.

I am able to generate the output waveform OK. But then I need to measure the rc waveforms on either side of the RC circuit. How can I measure phase shift, since both signals would need to have a common time reference?

I tried just generating a single cycle waveform, and tried capturing the result using triggered acquistion. But my board doesn't support hardware analog triggering, only software triggers.

Any suggestions?

thx

Jeff

[Steve_M.]

Hi Jeff,

What you basically need to do here is simultaneous analog input/output. I would recommend doing this by having the analog input and output share the same clock. This can be done by using the route signal vi to connect the analog input scan clock and the analog output update clock through either PFI5 or PFI7 depending on which clock you want to use as the master. This is outlined in the link below:

http://zone.ni.com/devzone/explprog.nsf/webmain/913E26CCF1019BBB862566EB007BB202?opendocument

After you have the simultaneous analog I/O portion of your code running, you should be able to use the cross power spectrum vi to input your two time domain signals and take a look at the phase difference between them. Good luck.

-Steve