This jamod1.2 was enhanced the capability to manipulate data under Modbus RTU over TCP/IP protocol. What i have added to the original jamod1.2 source code. ModbusRTUTCPTransport ModbusRTUTCPTransaction RTUTCPMasterConnection ModbusRTUTCPMaster I have write some test in test.test,it'll show you how to use it.