Weird GPIB Configuration Problem

[Harmonicwave]

I am hopeful that you GPIB gurus can help me. 

I am new to GPIB.  I am trying to interface a Tektronix 2710 Spectrum Analyzer to a National Instruments GPIB-232CT-A.

***Please see the attached Word file to see Software set up and Win32 Interactive Control information.***

My computer is a 333 MHz Windows 98se PII and I have the GPIB-232CT-A interconnected to the COM2 port at 9600 baud with a 9 pin RS-232 null modem cable and am using a new NI 2.1 meter X2 GPIB interconnect cable between the TEK/2710 and the GPIB-232CT-A.  I am using the most recent NI.488.2 GPIB drivers (2.7) available for the GPIB-232CT-A.  NI's diagnostics programs respond with the interface working.

The GPIB interface on my Tektronix 2710 Spectrum Analyzer doesn't give many options.  I have it configured for Status: "Online," Address: "1", Power On SRQ: "OFF," EOI/LF Mode: "EOI", and Talk Only Mode: "OFF."  When I run the 2710's internal GPIB diagnostics program, it responds with "Success."

One would think that with these settings, it would work.  But it doesn't.

Do I have a bad GPIB board or controller?

If you have any ideas on how to test the interface and get it working, I would very much appreciate your help.  

Brian

[Robert M]

Hi Brian,

From the looks of it, you have everything set up and configured correctly.  I'm not sure why you would want to set the address of your instrument to '0', the same as the controller.

Have you ever been able to communicate with the device? 

What exactly does "NDAC" indicate? 

Are you sure that you have the address configured properly on the device as well?  I wouldn't recommend address '0', but have you tried anything above '1'?

It may be worth your while to upgrade to a PCI-GPIB card so you would have all of the troubleshooting resources of Measurement and Automation Explorer available to you.  You also would not have to worry about writing the low-level commands to the instrument.

Hope this helps,

[Harmonicwave]

Hi Robert,

This is the first time that I have tried to use this controller.  It is also the first time that I have tried to interface with my spectrum analyzer.  Unfortunately, at the moment, I don't have any other GPIB controllers or and other GPIB devices. 

At least to me, it is beginning to look like I have a hardware problem.

I wanted to use the GPIB-232CT-A so I could use a laptop in the field.

NDAC seems to indicate that the device is on line.  I had originally configured the analyzer on GPIB address 1.  I switched it to GPIB address 0 just to see what it would do.  It actually almost works on address 0, and does practically nothing on address1.  Go figure. 

Are there any easy definitive ways to test the hardware other than to substitute other units?

Brian

[Robert M]

Hi Brian,

The fact that you are getting a FALSE reply but no bus errors indicates that something is out there listening but not necessarily on address 1.  Do you have other instruments on your GPIB network?  Is it possible that your instrument is set to a different address?  Have you tried setting the instrument to a higher address?

Our first step is to any kind of response from the instrument and I know of no other way to do it than what we are trying with your current resources.  Without Measurement and Automation Explorer and its associated utilities we really are limited in our options.  Have you considered the GPIB-USB-HS for use with your laptop?

Hope this helps,

Robert Mortensen
Applications Engineer
National Instruments

[Harmonicwave]

Robert,

I thought you would be interested in knowing our test results. 

Apparently, the GPIB interface in my Tektronix 2710 Spectrum Analzyer is not working properly.

Hi, Brian --

Well, I got the adapter and cables this evening, and just got through trying

them on the Win98SE box in the basement lab. It looks like you are in good

shape vis-a-vis the GPIB hardware; it all worked perfectly.

I was able to talk to the 8566, the 494AP, and the

2430A. All of the settings are at their defaults; I didn't have to change

anything.

There seems to be a long startup period associated with sending or receiving

traffic (not sure which). My phase-noise utility does a lot of

back-and-forth communicating with the SA, and it took about 10 minutes to

run on the GPIB232 versus 2 minutes to take the same series of traces via my

PCI-GPIB. But I never saw any errors or flaky behavior.

Not sure what to recommend at this point. 😞 , but I

guess you're running out of stuff to try!