measure pulse width of signals generated by DAQ

[apaulsen]

Eventually, I would like to:

    Start a counter pulse width measurement and analog out at the same instant.

    Stop the pulse width measurement with an external digital signal.

My current plan is to use a digital out on the DAQ to go to a digital input and the counter start input.  The digital input will be a start trigger for the analog output.  This works, except for the counter.

While trying to implement this, I tried a simpler test of just generating a digital pulse with the DAQ and wiring that to the counter inputs.  That doesn't work, even though it looks fine on an oscilloscope.  Then, without changing the software at all, I connect a function generator to my  counter inputs, and it measures pulse widths flawlessly.

I'm actually implementing this with a Python wrapper around the DAQmx C API, but I recreated it in LabVIEW, and it behaves the same.  VI attached.  I have the latest DAQmx drivers.

[ColeTrain]

apaulsen,

Just a friendly heads up, but this is more of a DAQ post and you will generally get more replies to these types of questions by posting in the proper forum.

That being said, try taking a look at the Example Finder and look under the DAQmx examples at synchronization/multifunction as this would be a good place to start working on what you're trying to wind up doing down the road. 

[jpkotta]

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ColeTrain wrote:

apaulsen,

Just a friendly heads up, but this is more of a DAQ post and you will generally get more replies to these types of questions by posting in the proper forum.

That being said, try taking a look at the Example Finder and look under the DAQmx examples at synchronization/multifunction as this would be a good place to start working on what you're trying to wind up doing down the road. 

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I am actually the OP.  apaulson is my coworker, and he was logged in to the forums on the workstation from which I posted.

I realized that it ended up in the LabVIEW forum, so I reposted on the DAQ forum: http://forums.ni.com/ni/board/message?board.id=40&thread.id=7185.  I understand why there is a search-to-post policy, but it's rather unintuitive and clunky, and I got confused.  IMHO, ubuntuforums.com does this the right way and automatically searches before you submit your post.

Anyway, I figured it out.  See the other post for solution.