A problem about GPIB with Agilent 34401A

[CHC]

When I trying to work with Agilent 34401A multimeter (GPIB connection), HP34401A Getting Started.vi gives always the message: "Error 1073807369 occurred at Old VISA Open in HP34401A Initialize.vi->HP34401A Getting Started.vi. Possible reasons :VISA:(Hex 0xBFFF0000)Unknown system error(miscellaneous error)"
In MAX the GPIB card and 34401A operate well.
The address string I input is "GPIB0::20::INSTR" and I am sure the address is correct.
I don't know where the problem is.
My OS is XP SP1,LV 6.1,NI-VISA 2.6 .

Thank for any help
Best regards

CHChen

[ian_fung]

I do not very sure what went wrong but does the HP34401A Getting Strated.vi requires "GPIB0::20::INSTR" address string? (didn't the address/ port number will do?)

If you only need to take measurement, you might wanna try using VISA instead of the instr. drivers

I have attached a simple (you may need to modify it) example for your reference. Hope this will help.

ian.f.k

[Albert.Geven]

From where did you download the driver? From agilent or NI?
It is easy to replace the Old visa open by the new one although the new one is buried deep down below. You can then wire a visa session to the visa open and in the visa resource select the correct instrument already. (so the string should be replaced by a visa session control)

[Dennis_Knutson]

Besides Ian and Albert's comments, I would like to mention that you are apparently not using the driver that comes with LabVIEW 6.1. The shipping driver is an IVI example and does not use Old VISA open function. I would try the new version and see if the error still occurs or use the old one with the Old VISA Open function replaced and make sure that MAX does not have the meter defined as an installed IVI instrument.

[CHC]

Thank to all your attention to my problem.
I forgot the library of 34401A has been built in LV 6.1 and I download the newest one from NI.
I will try these methods.

Best Regards.

CHChen