I use an USB based - Virtual Serial port - communication unit in my application. It uses the supply to send a signal to my DUT. Voltage one way and Current the other way. It is plugged directly into the PC, not via an USB hub
For every DUT the Serial port is opened and closed again after communication is done.
The problem is that once in a while the VISA Close is FREEZING. I see it maybe once for 1000-5000 units which is about 2-3 months of production. I have seen it on 3 different LABVIEW/TestStand versions with different VISA driver versions. Each are running on different computers
Could it be the VISA Driver?
Could It be the HW in the communication unit?
Could it be the Driver of the communication unit?
I have only seen the VISA Close to freeze in relation to this Hardware.
If it is related to the Hardware, why is the VISA Close freezing instead of returning an error?
The workaround is to unplug and re-plug the communication unit
Any suggestions are welcome