Hi,
Suddenly I have started getting Error 28 (Null menu) during Wait for
GPIB RQS in very random way. I have no idea what it means. When it
happens I have to restart LabView or the computer to get GPIB working
again. I use LabView 8.0, GPIB-USB-A and driver 2.2.
From what I've been able to find this is a general LabVIEW error associated with some kind of memory problem. This might explain why your program crashes and you have to restart each time you see it. Could you please post back your VI and how often you see this error? Also, I'd like to know more about what you're doing around this function so we might be able to diagnose the problem a little further. Thanks, I look forward to seeing the VI.
I was wondering if you could provide more information on the occurrence of the error? Also, would it be possible to provide an NI-SPY capture of your VI running?
I did notice that you do not have a wait (ms) present in your while loop. I would suggest putting a 10 ms wait inside the while loop to ensure that LabVIEW is not taking over your processor.