GPIB Addressing

[vivek_sony]

In my Labview program, in which I am remotly communiacting with CMU200, I am getting "GPIB0::20::4::INSTR 27" as the instrument resource name in the middle of my program. I understand that 20 is the primary and 4 is the secondary address.
But I am not sure about 27. Also, this last number keeps changing with every run. Any explanations. Thnaks!

[Dennis_Knutson]

I think the 27 is refering to the session number. If you do a VISA Open without doing a VISA Close and you're running an older version of VISA, you will have multiple open sessions. This is not a good idea. Make sure that you do a VISA Close for every Open. In fact, there's no reason to do any more than a single open and close. Do a single open at the beginning of your program, and do a single close at the end.