Sorry Henryp, I assumed you wanted the ECOM100 to be the Modbus TCP Client (Master). That is what you use the peer-to-peer table for; to configure the ECOM100 as the client (master). If, however, you want the ECOM100 to be the Modbus TCP Server (Slave), then, no, it is not possible to have it answer on any other TCP port other than 502 for Modbus TCP comms.