interface 4284a using gpib

[6Nlaboratory]

I have a problem linking our HP4284a LCR meter with Labview. I have corrected all the paths, except for this error:

it says it needs

C:\Program Files\National Instruments\LabView 7.0\instr.lib\hp428xa\hp428xau.llb\HP428XA Utility Default Instrument Setup

but is reading

C:\Program Files\National Instruments\LabView 7.0\instr.lib\hp428a\hp428xa\hp428xau.llb\HP428XA Utility Default Instrument Setup

The problem is that this last path mentioned is needed to avoid some other errors. I need to be able to override the original path (the second one) to allow this proper path to be followed. Any suggestions?

Thanks.

[Dennis_Knutson]

All that you have to do is open HP428XA VI Tree and point it to the function in hp428xau.llb. Then close the VI and when prompted, select Save SubVIs. the next time you open something like the getting started VI, the path will okay. The VI isn't really expecting to find the subVI in the main llb. It's just that the path to the other llb is different from when NI created it and you just have to point to it.

[6Nlaboratory]

I opened the HP428XA VI Tree, but I have no idea how to "point" it to the function in hp428xau.llb. My knowledge of this is extremely limited. Thanks for your help.

[Dennis_Knutson]

It should ask you to find the subVI. This is a windows file dialog. You just have to browse to the hp428xau.llb file, double-click it, select the VI, and click ok.

[6Nlaboratory]

Hi again, I think we solved the original problem (Thanks!), but now we are having difficulty with "HP428A Initialize2.vi". It says the property node has one more invalid properties or uninitialized properties.

Thanks.

[Dennis_Knutson]

Where are you seeing this message? The only property node I see in HP428XA Initialize is a timeout and that looks okay. Is there some error code generated (and what is it) or are you not able to run the VI? Do you have the VISA resource name set to match what MAX (Measurement & Automation Explorer) found? Do you actually have NI-VISA installed? This can be checked in MAX.

[6Nlaboratory]

We have now made sure that we have NI-Visa and MAX, which reads the GPIB and identifies the 4284a.  I still get the following errors, which I have included screenshots of below.  I appreciate any further help.

[Dennis_Knutson]

When and where did you download the driver from? Mine has the timeout value correctly wired to the 1000 constant and it doesn't have the "Old" VISA Open. Here's the two files I have or you can re-download the driver from NI.

[6Nlaboratory]

What VISA do you have open then? I just downloaded the latest version of ni-Visa yesterday, however the visa in that code had been the previously. How does that area of the bad block diagram look for you? Is there another way we can change it? We took the files you sent, but they didn't seem to do anything, as the same error message still popped up. Thanks for your time.

[Dennis_Knutson]

You must have a very, very old version of NI-VISA on your pc. You should download the latest version of VISA (3.4 I think). It seems like LabVIEW is converting the driver to use an obsolete version of VISA and you'll have problems with that. Your VI should look like this picture.

Message Edited by Dennis Knutson on 06-07-2006 09:51 AM