Global VISA Resource

[CHarm]

Hello, I am currently having an issue with a VISA Global Resource. I am currently operating a test where I am polling a Thermotron 2800 Chamber and taking measurements. During this test, It looks like I am intermittently sending an error to the temperature control chamber stopping the chamber during the test. I notice that my VISA Control Number changes when I send information to the Thermotron. Does that number change confuse the Thermotron controller? Also, how do I make sure I am always sending valid data to the Thermotron controller?

[Dennis_Knutson]

I'm a little confused about the terms you are using. Are you using a global variable for your resource name? And what do you mean by 'VISA Control Number' and how are you reading that? If you do a VISA Open once at the beginning of your program and don't close it until the program stops, the session id should stay the same.

Typically, an instrument will have an error query command. During debug, it helps to call this whenever you write something to the instrument. If you have a driver or are writing your own, this is pretty easy to do.

[CKap]

Posting your VI would also be helpful.

Regards,

Chetan K

Application Engineering

National Instruments