I have 3 PCI-GPIB (IEEE 488.2) cards on a machine running Windows 7 (6.1). I see an intermittent issue (that I'm not able to consistently reproduce yet) where GPIB1 and GPIB2 appear to swap (communication with 1 goes to 2 and vice versa - it appears the serial numbers swap in NI MAX so I'm assuming calls to these two get the wrong handles to the card).
I've noticed after a restart of the system, the INI file created (I'm assuming by NI software or driver) sometimes has the serial numbers for GPIB1 and GPIB2 swapped as well (although we produce our own INI before use to setup for our needs and are able to get the correct serial numbers with an ibask call from the gpib-32 library). Our GPIB0 (which we specify as controller-in-charge via the INI) has had no problems. Even with our INI file, the issue has been reported to happen.
The cards always remain in the same physical PCI slot so I'm assuming the PCI bus driver enumerates the devices consistently.
My only guess as to the root cause of the problem is that we are using an older version of NI 488.2 (v 3.1.2) - however I'm unable to prove this. Has anyone seen anything similar or have any insights/suggestions? I'll be happy to provide more information if needed.