Discussion:
nesting generated waveforms, multiple initiate calls?
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billmileski
2007-05-20 00:40:07 UTC
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Hi,
 
 
I am generating a digital pattern with a PXI-6542 that uses scripting to generate one pattern followed by 500+ repeats of another pattern.   I used a software start trigger to begin the generation.  But now I need to tell the 6542 to do this whole pattern some number of times, i.e. 2 to 20.  Scripting won't support this additional nesting.  I tried using a for loop: In the for loop "send software start trigger" is followed by a while loop that checks for generation complete before the next iteration.  This resulted in only one triggering of the generation.  I got it working by putting the HSDIO Initiate VI inside of the for loop, but that doesn't seem right (additional delay? hiccupping in the timebase?).  Is it a bad idea to do it this way and is another solution obvious to anyone out there?  Do I need to send advance triggers after the first start trigger?

I also have two marker events generated near the start of the first pattern that I need to retain (they are exported to start a high speed digitizer, which will also need to trigger as many times as the generation).
 
Thank you for any help,
 
Bill M
 
billmileski
2007-05-21 17:40:10 UTC
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Juan,
Yep, just tried doing what you suggested. I get an HSDIO error that says to unroll one of the repeat/end repeats, as the device allowed number of levels of nesting is 1.
Thanks anyway!  It is a pain, this limitation. My workaround is to explicitly duplicate my statements in the script, and only start trigger once (no multiple initiate calls).
Bill
billmileski
2007-05-21 19:40:09 UTC
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Thanks Juan,
I may give this a shot.  Right now I'm having trouble using TClk with a 6542 gen session, a 6542 acq session, and a 5122 session.
 
Bill

billmileski
2007-05-21 17:40:10 UTC
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Juan,
Thanks for the reply.  I am almost positive I tried this as first thing long ago, and got an error saying the device (PXI-6542) does not support two levels of repeat nesting. Will try again and verify.  But I'm pretty sure that's why I originally put my start trigger in a loop.
Bill
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