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DAQ Output of custom waveform

DAQ Output of custom waveform

DAQ Output of custom waveform

(OP)
Hello,
I apologize if this has been covered but I can not seem to find a solution.

I am fairly new to Labview, and I am having difficultly getting my application to work properly.  

I need to output some cutom waveforms from a DAQ card for some motor testing.  I have been trying to create a vi that loads the waveforms from a 3x100 point tab delimited text file and outputs them on the first three analog out channels.  I have tried this with several of the waveform out and continuous out vi's, but I assume I am making some fundamental mistakes.  Does anyone have any advice or could point me to an example detailing the best approach?

RE: DAQ Output of custom waveform


First, display your array that you read the file into.  Make sure that part works first.  

Next, check your indexing to make sure you are parsing through the data properly.  You did set up a for-loop or a while-loop, right?  I suggest setting a slow clock rate (1/sec?) and displaying the values on the screen for a visual verification.  

As you are driving three outputs make sure the output driver can handle multiple channels.  Don't use multiple instances of a single channel driver or you will probably get some very strange results (including crashing Labview).  

RE: DAQ Output of custom waveform

(OP)
Thanks zappedagain.  I think I am getting close.  After some trial and error this morning, I have successfully read in the data from the text file using the "read from spreadsheet file.vi", "index array.vi", and "build waveform.vi".  The three signals merge into a "waveform graph" and display fine.

I tried running a single waveform through "DAQmx write" and it outputs to a scope fine as well.  Here's the next problem:  I have two DAQ cards with two channels each.  How is the best way to go about syncing 2 outputs from one card with 1 output from another?

RE: DAQ Output of custom waveform

Sorry for the slow reply.  I believe most of the DAQ cards have a 34-pin connector inside the computer case that is used for syncing the boards.  You'll have to check the board manual for more details.  

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