gpib not working

[kmo]

I know this question has been posted million times but I couldnt find something I wanted to know.

I am using gpib to connect to the instruments. It worked very well untill yesterday. Suddenly none of of my VI could talk to instruments!

Does anyone know what could be problem? This is quite abstract question so I would be looking for any possible answers !!

Could any of the following have caused problem?

1 : the instruments (Ansitru and Keithley piccometer) were on for the overnight run! everything working properly. Could overnight running and heating of the instrument be a problem ?

2: I stopped the running VI few times. Could that have blocked GPIB bus or something? if it has, is there any way to clear the gpib bus?

do let me know. 

[daijoubu]

Can you communicate with the instruments using Measurement and Automation Explorer (MAX)?
Does rebooting your PC fix the problem?

[kmo]

no i coudnt communicate through automation and measurement. i checked it but there was no gpib device detected there ! All the gpib devices should be displayed there right?

do let me know. more ideas the better !!

restarting the computer didnt help either. did that more than ones 🙂

Message Edited by kmo on 02-07-2006 04:41 PM

Message Edited by kmo on 02-07-2006 04:43 PM

[Dennis_Knutson]

If the GPIB device is not detected, the driver could have been corrupted or the card damaged somehow. You could try re-installing the driver. I would also try moving the card to a different slot or to a different pc and see if the problem follows the board.

[daijoubu]

When you say "i checked it but there was no gpib device detected there" does that mean there was no GPIB card listed or just no instruments listed?

If there is a GPIB card listed, select the card and press Scan For Instruments.  Does it find any?  If not, turn off all your instruments.  Run the NI-488.2 Troubleshooting Wizard (right click on the card and select the troubleshooting wizard).  If it passes, power on one instrument and scan for instruments again.  Continue this until all instruments are powered up and working or you find the faulty device.

If there is no GPIB card listed, are you using an NI-GPIB card?  All NI-GPIB cards should be listed in MAX.  If it's not listed, the card may be defective. 

[kmo]

No, we are not using NI gpib card, I guess thats why its not detecting the card and ofcourse no instruments.

Is there any other way to find the problem ?

[daijoubu]

Did the card manufacturer supply you with any diagnostic utilities? 

The basic steps we want to accomplish are still the same, I just don't know the tools.
1) Self test the card.
2) Verify that we can communicate to each instrument.
3) Verify that there are no conflicts between the instruments. I know it worked yesterday, but some clumsy co-worker could have performed a factory reset on one and created an address conflict.  An AC source I have sometimes locks the bus up if sent a *IDN?...

Most manufacturers will give you a self test program.  You will need to check your manual for this.  They will also give you some form of simple terminal program.  For NI it's the Interactive Control (ibic) application or MAX.