Labview Access Violation

[Marlon Persaud]

Hello everyone,

I have developed a VB GUI which controls the Test Stand API and runs sequence files made up of LabView code modules. Thanks for the help so far everyone! I seem to have progressed from 'newbie' to 'rookie'.

However........ I am having another problem now! Whenever I run my sequence (either from the VB Panel or directly from Test Stand) the second run almost always comes up with a LabView access violation (0x00005) and kills LabView.

This only ever occurs on 'Single Pass'. On 'Test UUTs' the problem doesnt occur. I may just create my own Model by copying Test UUTs and making it do what I need it to. But can anyone think of a reason for this?

Thanks
Marlon

[RayFarmer]

Hi,

As a suggestion:

Try running one of the demo sequences such Computer Motherboard Test Sequence.seq either in your GUI or the seq editor or both. That will eliminate any corruption problems. Make sure you are using default Process Models etc.

If every thing works with the demo seq, then its something in your sequence. Maybe a driver making an illegal call.

Regards
Ray Farmer

[Ryan Ramcharan]

Hello Marlon,

You may want to try stepping into your code to see where the Access Violation is being thrown. Maybe by using the Single Pass entry point you are corrupting memory that is not harmed when using the TestUUTs entry point. This problem may be due to a driver that you may be calling from the LabVIEW VI. I would try the debugging approach to narrow the problem. Modifying the process model, may not help the situation, you need to find out which VI is causing the Access Violation.

[Marlon Persaud]

Hey I found the problem! I wasnt closing the VISA handles to my instruments when terminating a sequence. I had my close VISA handles VI in the Main sequence. Upon moving it to the cleanup steps my problem was solved.

Thanks for the help guys
Marlon