SIMATIC WinCC Open Architecture Forum

Hello everyone

we have a project, where we must establish communication with a Modbus server, at the time of establishing the communication everything works correctly, but the driver constantly reports loss of communication, reconnection and connection.

this happens with the Wincc OA 3.16 Patch 002, in view of the problem we decided to try the same connection from WinccOA 3.14 Patch 020 and it works correctly the communication is stable and never loses communication.

attached configuration of the equipment in Wincc OA 3.14 and WinCC OA 3.16.


some idea to solve the problem.



https://www.winccoa.com/fileadmin/image ... ccOA_3.png

Perhaps the default alive check coil 1 does not get answered. See manual on Possible WinCC OA config entries -> [ Mod ] -> aliveTimeoutMsg & aliveTimeout

For instance alivecheck with holding register 1001
[mod_3]
aliveTimeoutMsg = 3 1001
#aliveTimeout = 0