Modbus TCP/IP Global Parameters
If you are using the Modbus TCP/IP protocol on a computer where you will also be running the Modbus TCP/IP Server application option, you will need to add the following to the global parameters:
MBETH_DISABLE_UNSO_DATA|1|Y
This global parameter disables the use of the socket for the receipt of unsolicited data in the Modbus TCP/IP device communications.