Edouard Tisserant [Thu, 18 Apr 2019 14:32:43 +0200] rev 2602
If call to GetPLCstatus can't be executed in PLC, then obtained status is disconnected. Status on "None" is not relevant anymore, and is replaced by Disconnected.
Edouard Tisserant [Thu, 18 Apr 2019 14:29:55 +0200] rev 2601
Enure that all threads are joined before trying to exit