error in Hp34401a example.vi

[hkie]

When I use HP34401A Example.vi to measure resistance, at the same time I have other instruments connected to the same GPIB card on a PC, but not run any other program, just turned their power on. I got "Error-1073807339 occurred at Visa Wait on Event in Visa Wait on Event Async.vi -> Wait for RQS.vi -> Hp34401a Read Meas.vi -> Hp34401A Example.vi". I found if I switch off other instruments, then HP34401A Example.vi can run properly. I was told it could be an error in HP34401a example.vi. As I'm a new LabView user, just use this available program as a sub-program for my application. If anybody could tell me how to fix this error, I'll appreciate it very much.

[Dennis_Knutson]

Since the only time you have a problem is when other instruments are on the bus, I think you have a problem with one of the other instruments. Make sure that all of the addresses are unique. Try turning on the other instruments one at a time. You could also use NI-Spy in Max so whats going on over the bus. Good luck.

[hkie]

Dear Dennis,
Thanks very much for your response. I'm sure all instruments have an unique address. Also I have a small program, which is just sending "*ind?" to every instrument on the bus and reading IDs back to PC. It works well with all instruments power on. But HP34401A Getting Started.vi, which has nothing to do with other instruments on the bus, will not work, unless only Agilent 34401A multimeter on the bus.

I tried NI-Spy, not able to understand. The program seems stopped at"viWaitOnEvent [0x00990028,0x3fff200B,0[0x0],0x3FFF20... 0xBFFF0015" and kept repeating it many times, then shown the error I mensioned befor.

Any advice? Thanks.

[Dennis_Knutson]

I still think there's something wrong with one of the other instruments or maybe one of the cables. Use NI-Spy before sending the command to the 34401 and check the status of the I/F management lines (SRQ, etc.). The controller is not seeing the RQS the 34401 is generating. I've had the exact same problem in the past and it's always been one of the other instruments causing the problem. Have you tried turning off the other instruments one at a time?

[hkie]

I tried to use just one instrument at a time by turning off other instruments. Each instrument is ok. This mean every instrument and its cable is ok. I also tried turning on all instruments one by one, then run seperate program for each instrument, or run one program involving all instruments. I found other instruments can work properly, except Agilent 34401A. The only thing I can think about is the problem in HP34401A Getting Started.vi. As I'm not able to figure out where is the problem in this program, I really don't know how to fix it.

Used NI-spy got the follow result:
Description: viWaitOnEvent[0x00994D34,0x3FF200B,0[0x0]0,0x00000000]
Status:0xBFFF0015.

Please advise. Thank you.

[Randy Solomonson]

Hello-

Be sure that the instruments are all at different primary addresses (PAD). This may be the cause. Be sure that all cables are less than 4m.

Randy Solomonson
Application Engineer
National Instruments