Why does my card fail to control the bus when it only has 1 device to control?

[ACSTony]

If the card is attached to a bus with certain devices it will work correctly but in a direct connection it runs for a few minutes then I get a message that says it could not gain control over the GPIB bus.I tried combinations of other devices but could not find any that would work except the pre-exisitng bus which I cannot move or access permenantly. The thought of a grounding issue was tested by grounding the ground pins in the connectors and grounding the connector shell to an earth ground. It did not resolve the issue. The hardware test wizard says everthing passed.

[Ray K]

Hello,
It sounds like the instrument is setting itself up as the system controller.
Are you calling ibrsc to attain system control?
What is the make and model of this device?
If you are using a different gpib cable when you connect to the one device try using another, it could be a broken cable.
Are you able to communicate via IBIC? If not, what command fails.

Ray Kong
NI Applications Engineer

[ACSTony]

Hi Ray
Thanks for the response. I am controlling a R&S ESMI receiver with their ES-K1 software so I am really not too sure what it is doing in the background. I have tried using a known good cable. I have tried controlling the device with both a PCI-GPIB and an AT-GPIB cards. I have not tried to use IBIC (not familiar with it) I will look into it see if I can. The system works when it is all attached to the control room bus but not when it is directly connected. I tried grounding the ground pins and the connector so it is not a ground issue. I am curious is there some minimum number of devices that are needed to load the bus?

[GPIB_Guru]

If you are not familier with ibic, perhaps you could try to run NI-Spy in the background while you are attempting to run your application. If you post the NI-Spy capture, we may be able to determine what is actually happening.

[ACSTony]

OK I have captured a huge quantity of lines (around 10,000) and so am only going to post the last several? I dont know how many are enough but I hope this is.

I have deleted most of the ibwait commands and only included the last couple of minutes worth. Thanks again for the help.
I attached it as a word document. If it is better I can attach the actual NI-Spy file.

[GPIB_Guru]

I would prefer the actual NI-Spy file. They are easier to read since they can be loaded into the graphical NI-Spy application.