Agilent 82357a

[LVs2005]

Hello,

 I have an Agilent 82357a usb to GPIB adapter.  I have successfully been able to install the adapter on my computer and use Agilents VISA Assistant to view and configure my test instruments.  I have also installed Measurement & Automation 3.0.2 and successfully added the NiVisaTulip.dll passport.  My question is can I use the 82357a without using VISA.  I know it sounds odd, but I would like to be able to send GPIB commands directly to my device without going through VISA.  At the moment I have Agilent IO Library M.01.01.04 installed.  I would like the Agilent adapter to appear as a GPIB controller, not a VISA Resource.

Windows 2000 SP4
Labview 7.1
Agilent 82357a
Agilent IO Library M.01.01.04
Measurement & Automation 3.0.2


Thanks

[Dennis_Knutson]

If Agilent supplied a low level GPIB driver that you can access via the Call Library Function Node or LabVIEW VIs that are a wrapper to it, then it should work. Of course, you cannot use the built-n LabVIEW GPIB functions because they are only for NI GPIB boards. You also won't be able to use any instrument drivers from NI (or Agilent for that matter) since they're written for either VISA or NI's GPIB functions. Why don't you want to use VISA? It seems to me that it's an awful amount of work for little if any gain. The VISA overhead is small, especially considering how slow the actual GPIB bus communication is.

[LVs2005]

Thank you for the reply, but I want to make sure I'm getting this correct.  Are you saying that I have to use an NI controller to work with LabView GPIB if I don't want to use VISA?

The Agilent controller was purchased because it specifically says that is 488.2 LabView compatible. 

I've installed Agilent IO library 14.1 which is supposed to work with NI-488.2.  It replaces the gpib-32.dll in system32.  The IO library has a polling system that is supposed to monitor and detect requests to the dll.  Unfortunately, MAX does not recognize 488.2 as being installed at all once the Agilent library is installed.

I have upgraded to NI-488.2 version 2.42 since the last message. 

I need to use GPIB without VISA because the current test lab is not configured to use VISA and we need the portable environment to be close to the current test lab.

Thanks.  Any help is greatly appreciated.

[Dennis_Knutson]

I don't think you understand what the difference between 488.2 and VISA is. 488.2 defines the communication (hardware and software) between an instrument and a controller. Many GPIB controllers, including Agilent's and NI's are 488.2 compliant. VISA is a software layer that sits above 488.2. It abstracts the details of specific hardware. VISA is a single API that can be used to communicate with GPIB, VXI, USB, serial, PXI, and Ethernet. VISA is the portable environment. A program using VISA commands will work with either an Agilent or NI 488 board. There should be no "configuration" required outside of installing the VISA software.

[LVs2005]

Hello,

I just wanted to post an update on using the Agilent 82357a with LabView for IEEE 488.  First let me say, this has been an interesting month to say the least.  Yes, I do understand the difference between VISA and IEEE 488.  I understand that VISA is an abstraction layer used to communicate with a multitude of devices without needing to worry about the low-level driver support.  Originally I stated that I wanted to use an Agilent controller without going through VISA and that is exactly what I meant.  I have learned that is possible and quite simple, but should be more clearly stated as not using VISA from within LabView.  I understand that most users will want to go through and abstraction layer such as VISA for instrumentation communication, but I guess I have a special case.  I needed direct IEEE 488 access to the controller.

I'm going to reiterate that this is a special case and most users won't need this type of configuration.
With the latest IO Libraries from Agilent, it is possible to use the built in LabView functions for GPIB such as gpib read and gpib write with an Agilent controller.  I'm now able to use the VI's that I'm writing with both National Instruments GPIB controllers and Agilent GPIB controllers with no modification.  I needed this ability because our university labs use NI controllers, but our student organization went with all Agilent controllers and measurement devices.  The Agilent controller was purchased for a portable Test Engineering lab.  For the configuration to match the real lab, we needed to be able to communicate with the instruments without VISA.

The reason I needed to use 488.2 without VISA is because it was a requirement in project specifications.  A lot of headache would have been solved by using VISA, but it wasn't allowed.

At first, both National Instruments support and Agilent support told me this was not possible.  Then a few weeks later I was contacted by Agilent, letting me know their latest library has this functionality.  For direct 488 access, NI-MAX doesn't even need to be installed because MAX will never see the 82357a as a GPIB controller.  Only as a VISA device.  After installing library 14.1, there is an option under Tools >> options >>Agilent 488 options: Use the Agilent 488 library where possible.

http://www.home.agilent.com/cgi-bin/pub/agilent/editorial/cp_MiscEditorial.jsp?NAV_ID=-536897828.536894874.02&NAV_FROM_REF=-536897828.536894874.00&LANGUAGE_CODE=eng&CONTENT_KEY=671781&ID=671781&COUNTRY_CODE=US

Once this is checked, the Agilent 488 library can be used which is the low level driver needed to communication with the GPIB controller.  I have found it is not perfect, and I'll e-mail Agilent about the problems that I have found with it, but it allows me to communicate with the instrumentation easily.

Thank you for the quick responses.

LVs2005