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From: REash on 8 Dec 2006 13:10
napview, I just said that's how my program is right now.  The VISA Opens to VISA Closes is about a 1:1 ratio....
And what do you mean by "...disable index of those wires..."??
Did you read what Dennis just said, too??
From: napview on 8 Dec 2006 15:10
I have not looked at those init VIs yet but the error is repeatable but it does not mean where it stopped is the real problem regarding to Visa issues. The GPIB buffer must be overflowed with repeating open and close visa improperly. To troubleshoot it, if you have time, try to copy at least two loops (start from outer or inner) from the diagram into a new vi and run it a few hundred times (no long time delay in between). Then increase to 3 loops based on the same program and repeat it. This way will take some time (a few hours most) but it sure will point to the real problem.
Troubleshooting with only one loop without a visa close is not exactly what you have in the program. This error ONLY occurs in more 1 loop structure either with the same instrument or not.
 


visaloop.vi:
http://forums.ni.com/attachments/ni/170/219459/1/visaloop.vi
From: napview on 8 Dec 2006 16:40
The number of loops does matter because the visa open creates a different reference everytime. Then one loop has only one reference but two would make it different regarding to the way the GPIB port works. One thing I did not tell you was when the error happened, put a probe on the reference out of the first error in the visa chain, you should see something like "GPIB0::6::INSTR:x" or "(x)" where x is an integer, 6 is the GPIB address. This number to me indicated that the visa resourse is not closed properly and it would increase the index of the that resource until it ran out of buffer memory or the like. This was seen only at more than one loop structure.
The bottom line is there is not a good explanation of why this error happens but that is what the failing pattern seen so far from older to the latest version of labview.
From: Dennis Knutson on 8 Dec 2006 18:10
You are confusing. You just said that every time a VISA Open is called, it creates a new reference. Of course you get a different reference for a different instrument but that is not what the problem is. He was repeatedly opening a reference to the same instrument and not calling a VISA Close on that reference. Go back and read the entire thread. If the problem is fixed, it would seem that the issue is with the single reference and nothing at all with the the other references because he made no changes at all there. That's why the problem is so weird to me.
And what buffer are you talking about? A memory buffer?
From: REash on 8 Dec 2006 18:40
napview, you are very confusing to me as well.  I'm thinking
exactly the same thing as Dennis about those last few posts of yours.

Dennis, I am at home now so I can't get an image of the block diagram
to you, but it is very large.  It takes up WELL over 2 19" screens
set at a decent resolution.  I will try to get an image on Monday with SnagIt.
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