Trouble getting LabVIEW 8.2.1 to take measurements from an HP3457A DMM when using a GPIB-USB-HS interface

[UCD_EE]

Hello,

Im using LabVIEW 8.2.1 and trying to take measurements from an HP3457A DMM. I'm using a GPIB-USB-HS adapter. I wrote a VI in 8.2.1, but used a GPIB-PCMCIA card. That worked fine but my new computer does not have a PCMCIA slot. MACS detects the HP3457A, but no matter what I try, my VI keeps giving me an error message as soon as the VISA OPEN subVI tries to access the HP3457A. Any thoughts?

-Chris

[Albert.Geven]

What kind of error do you get?

And be careful with the connector, the GPIB part is slightly thicker than a normal gpib connector and does not fit always.

Try with a cable inbetween.

[Eric_K]

Hey Chris,

There shouldn't be any difference in the way that the PCMCIA GPIB device and the GPIB-USB-HS works. I was wondering if you could post a screenshot of the MAX configuration and how the resource is shown for the HP3457A DMM and then what you are placing at the VISA resource in your LabVIEW program. Usually if you're getting an error at the VISA open there are either problems physically communicating with the instrument (cable could have come loose or the instrument could have been powered down), the VISA resource could already be open due to an alternate program using it (Test Panels), or the VISA resource being used is incorrect.

Thanks

Eric K
Applications Engineering

National Instruments

[UCD_EE]

Thanks for responding :). I have attached a screenshot of the MACS screen. When I used the PCMCIA card, MACS was unable to get a response to a *IDN? query but the overall program worked and I was able to take measurements. I used the Interactive Control feature of MACS and was able to get a response to a ID? query (a command I found in the HP3457A manual). The response to the query was "HP3457A" and a timeout error.

-Chris

[Dennis_Knutson]

That screen in MAX (sorry, it's not MACS) is expected since your instrument does not support the *IDN? command. It's unclear to me whether you got the data read and the timeout in MAX with the PCMCIA card or whether you got the data read and timeout error with VISA. If you simply select 'Communicate with Instrument', you are not using VISA at all. What was the VISA error you got when you attempted to run your old program? Are you using the driver or is this code that you wrote?

Message Edited by Dennis Knutson on 06-30-2009 09:49 PM