Try running NI-Spy and configure it to log all VISA transactions before durring and after the crash. It just may shed some light on what you are seeing.
Does it crash if your widget is not turned on?
Ben mentioned that there were some crash issues related to COM ports in LV 7.1, perhaps you can help with something really strange I have run into. My application, written in LV 7.1 and compiled via Application Builder to an .exe., uses the serial port with standard commands, and runs just fine at many sites and on many different computers from PIII's to Core Duo's, 2000 to Vista. The users will either connect directly to the desktop COM1 or use a USB-serial adapter, and both work fine. At one particular location, two PC's both exhibited the same symptom - after seemingly random periods ranging from minutes to hours, the program crashes with a generic Windows error rather than any particular LV error message. The crash is clearly related to the serial port since a) it only occurs when communicating via the serial port and not when doing other things (e.g. ethernet communications, calculations, graphing, etc.), and b) the serial port is no longer available, so just restarting the software doesn't work, it complains that the port is not accessible and requires a full reboot. A completely fresh PC at that location works fine. Recently I heard of this occuring at another site that, as far as I know, did not experience the problem in the past. I believe all three crashing computers are PIV's running XP.
It seems that there is a software incompatibility somewhere, but none of the other packages on the offending computers seem to do anything with the serial port, and in any case are not running. Any ideas on what might be causing this, or how to track it down?
Wyatt technology Corp.
It would be helpful if you could obtain a screenshot and/or error log file from when Windows crashes. Have you tried updating your VISA driver? There may have been a fix in the latest version, and this is a good starting point. Are the two PC's that exhibit the crash the same configuration or different?
Should have checked this before asking - no, I cannot just overwrite the NiViAsrl.dll, the executable does not work with it properly.
Alright, I've figured out how to use the new VISA version at the client site - have them install the NI-VISA Run Time Engine, in case anyone is interested. Will try this out and see if it fixes the problems.
For general edification - my problems of general protection fault crashes occurred almost exclusively on PCs configured with a particular corporate IT image, and became worse with a Quad core computer. Eventually I was able to get a hold of the offending PC and, based on other threads in the forum, found that I could eliminate these crashes by replacing almost all the timed loops with While loops.
My advice - avoid timed loops unless they are absolutely necessary.