Issue writing single coil (FCT 5) from AC500 to ABB 615 series relays in Modbus TCP/IP.
We have an issue when we write from AC500 PLC (FCT 5) to single coils ABB REF615 protection relay in Modbus TCP/IP. After we try it, nothing happens to the REF615 binary outputs and it returns exception code 03 Illegal data value. It is really curious because when we write to same single coils from Modbus test program (ModScan or Modbus Poll), the control command is sent and executed successfully.
Is there something wrong or additional to take into consideration in Automation Builder/CODESYS program?
Project configuration (Automation Builder 1.2 version) and some information about Modbus REF615 relay are attached.
I appreciate your help.
PD: There is no problem reading values (holding register FCT 3).
And also, as per Manual - Only one Modbus Control Operation is allowed. Hence, we should not try to write simultaneously to 2052 & 2053. It should be a separate write query for each control operation.
And your control operation should be configured as pulse command, do not try to write repeatedly value 1 to same coil, will result in exception response.