The jModbus project is a Java based master & slave implementation of the ModbusASCII, ModbusRTU and ModbusTCP protocols.
1. javax.comm.*, so, there is no windows support. 2. there is no ability for com port settings setup.
deseo bajar jmodbus gratis
Could post a small example of how to read Modbus Holding Register as RTU Serial Master. Thank you.