This error occurs when you are trying to access a VISA session that is already in use.
To close VISA sessions that are open:
- View the sessions that are left open and close them through a LabVIEW built example, or
- Close and reopen LabVIEW to release all open VISA sessions
Use the "VISA close" VI to end the specific VISA session when you are done using it within your code. If you do not close your VISA reference, the computer will continue to reserve that port until you close LabVIEW. When LabVIEW closes, it closes all open VISA sessions until they are reinitialized next time your LabVIEW code runs.
To see a properly built example using "VISA Close," see the LabVIEW example "GPIB with VISA functions" in the LabVIEW example finder.