Property Node (arg 1) in VISA Close.vi

[belanger]

I am trying to connect to a Rohde and Schwarz Spectrum analyzer through TCP/IP communication. It works for most of the time, but then I get this error "Property Node (arg 1) in VISA Close.vi" and it stops working or connecting to my instrument. The same thing happens when using the connection VI from the instrument driver.Any ideas on how to fix itn?

[Kyle97330]

Note the hex code on the error you have there... that's what you actually need to look up.  It points to this:

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019LPESA2&l=en-US

So basically it means that the VISA reference is invalid.

Without seeing any of your code it's hard to guess why, but it's most likely that you're either trying to use the reference after closing it, or somehow you're passing a bad reference around by accident.  One thing that might cause that is if you have part of your code where the reference value gets reset to default, like if it goes through a FOR loop set to run zero times, or it's output from an event structure that didn't wire the reference across.