On line test crashes on communication loss

[bm_engineering]

I have just been noticing this recently using Version 9.5.0 build 0 on windows XP, on a project with a V1040 connected by USB . Turning off the PLC or disconnecting the cable while monitoring results in a fatal error message, and then the program crashes. It happens every time. Even worse, the Visilogic.exe process remains running and cannot be manually stopped, so you can't restart Visilogic. On several trials, it cleared itself after about a minute. However, on one occasion I could not restart the program and I could not stop the running process. Rebooting the computer was the only solution. Attached graphics show the error messages. I don't have earlier program versions running so I can't verify whether this happened on them and I just never noticed, however that is easy enough to determine. I also don't know if it happens with serial or Ethernet as well. Regardless, this is a bit of an extreme reaction. As a suggestion, a far more elegant approach would be a warning message, and then just dropping out of on line test mode. This is what happens if you try to initiate it with no connection. Just a warning message.

[Simon]

I recall this being the case going right back to when the on-board USB port was first introduced.  I think I said similar things to you at the time - a more elegant failure mode would be nice.  I get caught out from time to time, but generally I remember to stop online monitoring before unplugging the PLC.