Hi,
I would greatly appreciate any help with this issue and I will provide any extra information I have missed.
Hardware setup: There is a computer (XP Professional SP 3) with a PCI-GPIB board (driver 3.1.0.49152) installed. This computer has been used for years with three GPIB instruments connected. Cable lengths are short and cables are in good condition.
Problem onset: With no warning, GPIB communication via a LV program dropped out completely today. No changes were made to the computer's software, but two of the instruments had been disconnected to run a newer LV program that only talks to one instrument. The two unused instruments were disconnected in such a way as to leave only a direct link between the PC and the sole GPIB device with no dangling cables or attached and inactive devices. After the new software was run a few times successfully, the GPIB cables were connected to all three instruments. The old software was run with the three instruments once successfully, and GPIB communication failed when it was run a second time.
Steps taken so far: I have restarted the computer, power cycled the instruments, and limited my troubleshooting to get one GPIB insturment connected directly to the computer. I am using NI MAX (5.5.0f0) and whereas both NI MAX and Windows Device Manager can see the PCI-GPIB board, no instruments are shown when I select "Scan For Instruments".
I have also run the NI-488.2 Troubleshooting Utility several times, testing Software and GPIB0, and they always pass.
I should note that there is something I have not been able to find an explanation for: As soon as I select "Scan for Instruments" the message "There was an error performing the instrument scan" appears in the Connected Instruments pane. The message appears instantly, which might suggest an issue with the board configuration. Given this, I turned to ibic.exe and began following this document:
http://www.ni.com/support/gpib/max/ibic.htm
It suggests some initial troubleshooting steps, which I followed. I know for a fact that the GPIB address of the sole device connected to the PCI-GPIB board is 2. This is after a fresh restart and power cycling the device. Note the ECIC error.
At this point I am at a loss, since:
- This exact same setup worked earlier today,
- No software has been added/removed/updated after the original 3-device and 1-device setups ran multiple times successfully, through computer restarts, etc.
- The only configuration change was disconnecting some GPIB devices via the cable, but the problem persists even through restarts, power cycles and reconnecting the cables in the same configuration.
Apart from resolving my issue, I am looking for help with the following:
- What does "There was an error performing the instrument scan" mean in this context?
- From my reading and limited understanding, the error message suggests that my GPIB 0 board is not in CIC status for the above command. Is this a likely scenario, or could this error simply be a consequence of something different?
- I would appreciate an hints on connecting and disconnecting GPIB devices. Is there a preferred order of turning devices/PC on, power cycling things while connected/disconnected, and do cabling changes require a restart?
Thank you in advance.
Paul