EPM2000 hanging with PCI-GPIB card but not USB or PCI-GPIB+ card

[Steve_Block]

I recently upgraded a Labview program from 8.5 to 2009 and am having trouble with the VISA drivers. Using a USB to GPIB adapter or a PCI-GPIB+ card, the software works fine, however, when I use a PCI-GPIB card, the software hangs on a visa read command. This problem is similar to a previous post that I placed on the forum, except this time nothing is trying the access the instrument at the same time and the problem is card specific. Would anyone have insight into what the root cause of the problem might be.

[macncheese]

Hello Steve,

Make sure that you are using the correct driver version, take a look at the NI-VISA driver versions compatibility here and the NI-488.2 driver versions compatibility here.

[Steve_Block]

I'm using valid drivers.

[macncheese]

Can you communicate with the device using MAX? Have you tried to do a Self Test Using MAX or send commands to the device?

Also, sometimes could be because of different timing delays.

[Steve_Block]

Yes. All of that works so part of the problem must be how the software is using the instrument. Unfortionately the software is already released so I don't have any flexibility to make any changes to it.

[macncheese]

Hi Steve,

So you are not able to modify the block diagram?

Sometimes replacing the VISA VI’s by the exact same ones helps to fix upgrading problems.  

[Steve_Block]

Everything is precompiled so code changes are not an option. What could be the cause about why a PCI-GPIB hangs and a PCI-GPIB+ card does not?

[macncheese]

Those two are very similar so I don't see why one works and the other not.

Did you try to use the NI IO Trace to see what is going on?

[Michael_Munroe]

Look at the properties of the two cards in MAX.  There may be a difference in the parameters causing the problem.  Otherwise, slow down some of the timing parameters to see if one board cannot keep up with the default settings.