eth_mod_mast showing error code 12289
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Try typing "coupler settings" in the PLC Browser & check to see if the TCP protocol is Listening on local port 502, which is the Modbus TCP/IP port. If it is then something is setup wrong with your ETH_MOD_MAST function block. If not then you probably need to setup the Modbus configuration in Control builder, update the configuration and re-open codesys. The ETH_MOD_MAST function block will not work unless the "Modbus_on_TCP_IP" driver is attached to the Onboard Ethernet.