基于Modbus通信协议的串口通信程序。通过串口和单片机通信。程序主要分为串口类，Modbus类，和主界面操作类，有详细的注释。类封装的很好，可重用。-Modbus communication protocol based on serial communication program. Communication via the serial port and the microcontroller. Programs are divided into serial category, Mo