My GPIB will not control my device.

[Chris Flattery]

I am trying to control a MMR K20 Temperature Controller with my PCI-GPIB+ card, but it keeps giving me an Error-Need Command in the NI-488.2 Communicator, and IBERR=EABO. I have changed the time but I still get this error. But the communicator does work for the other instruments I am using. What command string do I need to give, or what do I do to get the GPIB to control this one device.

[Kura]

Have you checked to make sure that the GPIB address is set correctly on both the instrument and your program?

[Chris Flattery]

We have. The only thing I don't understand is that it will communicate with other devices, just not the K20 Controller. Thank you, if you have any other suggestions please I need help.

[Kura]

I had a somewhat similar problem recently with an MM2000 Motion Controller. It even showed up on the NI GPIB Communicator list but wouldn't talk to me at all. I went over to the instrument panel and accessed the gpib address setting on it and saw that it was still set correctly, but for some reason it wouldn't work until I essentially reconfirmed it as the address. After that communication went fine. So you might try re-entering the address. Other than that I'm not really sure what other things there are to try. I'm a bit new to this myself but have had that problem before.

[Steven B]

Hello Chris,

I have another suggestion for you to try. Is it possible that you are not using the correct termination method for your instrument? It sounds like the method of termination that this instrument needs may be different than your other instruments.

Hope this helps!

Regards,
Steven B.
Application Engineering
National Instruments

[Kura]

That would be a very good thing to check. I had a peice of equipment go haywire on me because I was ending all of my commands with carriage returns instead of linefeeds.

[Chris Flattery]

If I understand you correctly, in the properties of the NI Communicator for each instrument there are options for Termination Methods in the Configure EOS. Those options are set the same between the GPIB and the K20, and I have also tried the different options, along with going into the configuration in DOS and changing the setting to coincide. That unfortuately didn't work.
Now ending my commands with carriage return instead of linefeeds I'm not sure what you mean. Is that in the command string query?

[Steven B]

Hello,

Yes, depending on the kind of termination your instrument is expecting, you have to terminate with the correct termination. Some instruments require a carriage return and some require a line feed. Others will require both. You need to check with the instrument manufacturer to determine what kind of termination your instrument is expecting. Here is a knowledgebase that describes how to do it in LabVIEW.

http://digital.ni.com/public.nsf/websearch/862567530005F09C862565BE005AB500?OpenDocument

Good luck!

Regards,
Steven B.
Applications Engineering
National Instruments

[Steven B]

Hello,

I'm sorry, but attached a KB that described termination in Serial, but I meant to attach this one for termination of GPIB.

http://digital.ni.com/public.nsf/websearch/9BAA60824D8A94FA86256ADA0058F18A?OpenDocument

Regards,
Steven B.
Applications Engineering
National Instruments

[vvknd]

It looks really long time ago this problem was reported. But, now I have issue again. I didn't see the last response in 2004 had a final solution, provided link is not working anymore. Wondering if its ever solved. Anyone plz help asap.