Basic Timeout Newbie Question

[DoomPirate]

Hi, I have written a subVI which sends a command(gpib write) to a physical instrument. Ocassionally it will become stuck at the gpib write VI. I would like to program this subVI such that the failure of this subVI will not result in the failure of the entire program. I have tried different "timeout ms" values, it doesn't seem to help my problem. Is it possible to abort the operation of this VI and return a default value when it becomes stuck like this for X many seconds? Any help would be appreaciated.

[jack47]

If you get a timeout doesn't that create and error message?  You can wire the error to a case structure or error handler to process it instead of getting the default pop-up.

[DoomPirate]

Thanks for the replym I guess I am using the word "timeout" when I don't know what it means. When I inspect the problem with highlight execution, I notice the program remains stuck at the "gpib write". No errors are generated, no outputs are produced, and I get no error messages. This leads me to believe that the "gpib write" never finishes executing.    I would like my higherlevel program to continue operating instead of staying stuck at this place. 

[DoomPirate]

[Harold_Timmis]

here is an example for 10scounter.vi

hope it helps

[DoomPirate]

Thanks for the reply,In my case, (Labview 8.5) there are occassionally times when the program fails to finish execution of the GPIB write VI. So regardless of how long or short I "wait" the while loop will not proceed. This is why I want to kick myself out of the while loop after 10 seconds. 

Message Edited by DoomPirate on 06-30-2009 12:33 PM

[jack47]

Sorry I can't be of more help, I have never had a command fail to timeout.  Your example writes the same data 10 times.  The delay you have gives the GPIB only 50ms + 50ms timeout.  It's possible that you are calling the function again before it has reached timeout.  I would increase the time between 'writes'  and see if the performance improves.

[DoomPirate]

Because the program never finishes executing the GPIB read(I just realized I've been having trouble with read not write) command, the while loop never iterates past the first cycle.

[jack47]

Is the read imediately after the write?  You can try putting a delay between the two.

[DoomPirate]

No :'( In my scenario, I am only reading from the device. Never writing. The first read iteration never completes whenever I have the GPIB cable disconnected from the device. I want to have error handling but the program hangs at this one spot.    I have posted the code here for download