FreeModbus

FreeModbus使用说明 FreeModbus is a Modbus ASCII/RTU and Modbus TCP implementation for embedded systems. It provides an implementation of the Modbus Application Protocol v1.1a and supports the RTU/ASCII transmission modes defined in the Modbus over serial line specification 1.0. Since version 0.7 FreeModbus also supports Modbus/TCP. Version 0.9 added the first Modbus/TCP port for embedded systems using the lwIP TCP/IP stack.