I loose "REN" on GPIB, and because of this I get an error 550 when I tried to read from Agilent 34970A

[AlbertJ]

Every seven seconds, I could see that I loose the REN led on the screen of the Agilent 34970A.  This means that the computer is sending some commands to the unit to go to local mode.  When I run NI Spy, I see that every 7 seconds the following commands are sent:

ibfind(GPIB0)

ibonl(GPIB0,0)

I do not know where I can set this commands off. 

Please help

[Steven_T]

Hello AlbertJ,

I may need a little more information to figure out what is happening.  What drivers and commands are you using to communicate with your instrument?  What is happening when these seven second commands show up in NI Spy?  Here is a link to a KnowledgeBase that shows how to get the status of and set the REN line on your GPIB in LabVIEW.  The same types of commands could be used in any programming language.

http://digital.ni.com/public.nsf/websearch/1C8802FDAF0EEABE86256B6000095724?OpenDocument

Steven T

Message Edited by Steven T on 04-25-2006 11:36 AM

[AlbertJ]

Hi Steven

I am using the Agilent IO libraries.

I am trying to program using Visual C#.

I found the problem.  The Agilent "Connection Expert" was scanning the GPIB interface for new equipment every 7 seconds and was turning the REN line off after scanning.  After I exited from this program the REN led stayed lid.

I am having a new problem.  My program will run okay for a long time (1 day, sometimes hours), and then suddenly stop responding.  I get error in the Agilent 34970A like -113, and -410.  Why would the program run okay for a long time and then suddely stop working?.  I am thinking that there might be some interference in that room where I am testing.  I have placed the computer far from the equipment and try to shield the cables.  It has been running for 1 1/2 days already.  Hope this solved my problem.  If you have any ideas please let me know.

I appreciate all the help I could get.

Regards

AJ

[Steven_T]

AJ,

It really depends what the errors refer to in your manual.  If the -113 or -410 errors refer to framing errors or other problems then interference could be the issue.  I would check NI-Spy again to see what commands produce this error. 

I hope this helps.

Steven