Having trouble writing to bits in Schneider M258 PLC through Modbus TCP. Error :Bad

[Kevin.Herron]

Yeah, for the Write Expression of a Derived Tag that seems right-ish.

The original post, for reference:

Troubles making a Derived Boolean Tag work as a mask for a Short Tag

I’ve made it work using the following expressions: Read: (toInt({source}) >> N) & 1 Write: if({value}, toInt({source}) | (1 << N), toInt({source}) & ~(1 << N)) Where N will vary based on the bit number (0-15 for a Modbus register). You should also turn on the “OPC Optimistic Writes” flag for the scan class these tags belong to or you’re going to have a race condition if you try to write to multiple bits in the same word too quickly.