GPIB instrument holding up bus

[N8D11]

I am having an intermittent problem with my GPIB system. Occasionally and seemingly randomly, one of my instruments holds the GPIB hostage; no other instruments can use it. The controller is the Agilent GPIB card and is accessed using the NI Tulip Passport. The device is power cycled and the bus is released and normal communications proceed.

My hope and question is: Is there a programmatic way to steal control back from the device by sending for instance the interface clear? My thought is if the interface clear asserts a different line perhaps the instrument's GPIB function would re-initialize and release the hold it has on the bus.

Can anyone help me with this? I am going to try to replicate the problem, but I'd like to know if this is theoretically possible.

Thanks,

Nate

[Che_T.]

Hi Nate,

I believe the following forum post will help you:

http://forums.ni.com/t5/Instrument-Control-GPIB-Serial/how-do-i-tell-labview-to-release-a-GPIB-resou...

To summarize, it seems like you can with VISA. However, using functions from the 488.2 drivers aren't as straight forward.  However, GPIB devices don't really have a "session".  You've got various states, such as talker, listener.  It is up to the controller to keep and set these states for the device.

Hope this helps.

Regards,