visadev cannot close connection

I use visadev to connect instrument through LAN. It can connect and send commands, no problems. But when I want to disconnect the instrument, sometimes MATLAB just shows busy. It will take very long time to disconnect. Sometimes I have to close MATLAB. Does anyone have the same issue, or any suggestions? Thanks.

Below it shows when I close the connection, it calls Channel.m and line 177 takes 9 minutes.

[Akshayaa Pandiyan]

How do you disconnect the instrument?

[chrisw23]

I recommend to install the vendor specific VISA tools (typically niMax or Keysight ConnectionExpert) and use the IOTrace Tool to monitor communication, when trying to close the instruments session. Probably there's Matlab polling (loop functionality) active and it takes a long time to get the slot to execute your close cmd.

Another point maybe that there are multiple unclosed (older) session objects from debug runs that cause sooner or later communication blocks until Matlab was restarted. So be sure to clear up your object references when debugging will be stopped.

Unfortunately the code provided is not suited to analyze the problem deeper.