alternating between NI GPIB-USB-HS and Agilent 82357A USB-GPIB controllers

[Mike....]

Hello,

I am into new territory here.  I need to write my application so that it will work with EITHER the NI GPIB USB HS or the Agilent 82357A interfaces.  It seems that my end users will have one or the other.

I think I have figured out this much.  In order to use the Agilent USB-GPIB controller, I have to use VISA calls, and not GPIB write and GPIB read calls.  Is this correct?

I have also installed both VISA applications on my computer, with the Agilent VISA being installed in side by side mode.

I am able to use the NI hardware with VISA calls to control my insturment.  Then I switch to the Agilent USB-GPIB controller, and it does not show up in NI-max, and I can not get anywhere.

Then I go back to my NI GPIB controller, and when I plug it in, it acts like this is new found hardware, and wants to install new driver software.  So I let it.  But says that the GPIB-32.dll file is damaged or missing.  So I uninstall NI-488.2 software, and re-install it, as that is the instruction provided to resolve this problem.  Then I plug in the NI GPIB USB controller, and everything works. 

But alas, when I try to go back to the Agilent controller, I end up with the same problem.  I can not get the Agilent controller to work, and after trying, I end up with damated GPIB-32.dll.

Any ideas.  I have already enabled the NI-VISA passport for tulip.

And I may not have mentioned, but I am using LabVIEW for all of this.

What I really want to do is be able to use either USB-GPIB controller, which ever one I have available on a given day.  Is it possible to switch back and forth between these two USB-GPIB controllers?

Thanks in advance for any help.

Mike

[JasonSmith]

You do not need to install Agilent VISA in order to use your Agilent GPIB adapter with NI-VISA.  The followign KnowledgeBase explains how to configure NI-VISA to see your Agilent adapter using the Tulip passport:

KnowledgeBase 20KG1C7Z: Can I Use Both National Instrument and Agilent Controllers in the Same Syste...

The later versions of the Agilent I/O Libraries replace one of the NI-488.2 DLLs, creating the conflict you described in your post.  Remove the Agilent I/O Libraries and Aglient VISA, and you will be able to communicate with both controllers through NI-VISA following the instructions in the above KB.

Jason S.
Applications Engineer
National Instruments

[Mike....]

Jason,

Thank you for the response, but that does not resolve the problem. 

This is what I did:

1.  I un-installed the Agilent VISA.

2.  I also un-installed the NI VISA.

3.  I installed the NI VISA.

4.  I plugged in my NI USB-GPIB adaptor, and it worked both with GPIB 488.2 calls and the VISA calls.

5.  I installed the Agilent VISA as the secondary VISA, following the knowledgebase instructions.  (I did NOT have to restart after installing the Agilent VISA.)

6.  I never unplugged my NI USB-GPIB adaptor, and it still worked with both GPIB 488.2 calls and VISA calls.

7.  I then unplugged my NI USB-GPIB adaptor, and then plugged it.

            This caused a new hardware found

[Mike....]

Jason,

Thank you for the response, but that does not resolve the problem. 

This is what I did:

1.  I un-installed the Agilent VISA.

2.  I also un-installed the NI VISA.

3.  I installed the NI VISA.

4.  I plugged in my NI USB-GPIB adaptor, and it worked both with GPIB 488.2 calls and the VISA calls.

4a.  I can unplug the NI USB-GPIB adaptor, and then plug it back it, and it works as expected.  I do not get the "new hardware found" message.

4b.  I have the NI USB-GPIB adaptor plugged in before moving on to step 5.

5.  I installed the Agilent VISA as the secondary VISA, following the knowledgebase instructions.  (I did NOT have to restart after installing the Agilent VISA.)

6.  I never unplugged my NI USB-GPIB adaptor, and it still worked with both GPIB 488.2 calls and VISA calls.

7.  I then unplugged my NI USB-GPIB adaptor, and then plugged it.

            This caused a new hardware found dialog box, which re-installed the driver.

            The re-installation of the driver caused the NI GPIB-32.dll damaged message.

            Now the NI USB-GPIB adaptor no longer works.

The only way to repair this is to un-install the Agilent VISA, un-install the NI VISA, and then re-install the NI-VISA.

So following the knowledgebase instructions does not work. 

As far as trying to use the Agilent USB-GPIB adaptor with the NI VISA, the Agilent USB-GPIB adaptor is not seen without the Agilent VISA installed.  To me it looks like there is no point in enabling the VISA passport for tulip if the Agilent VISA is not installed.

Any further ideas?

Mike

[JasonSmith]

Which version of the Agilent IO Libraries are you installing?  Version 14.1 is incompatible with NI-488.2, in which case you will need to install a prior version of the Agilent I/O Libraries.

The following KnowledgeBase describes this problem in more detail:

http://digital.ni.com/public.nsf/websearch/CC53752D661A912B862570B60080C019?OpenDocument

Jason S.
Applications Engineer
National Instruments

[Mike....]

Jason,

I was using Agilent IO version 14.1.  I will try to go back one version to 14.0. 

Thank you,

Mike