基于Modbus协议的S7-200系列PLC与单片机主从通信研究

Master-slave Communication Between S7-200 PLC and MCU Based on Modbus Protocol

介绍了Modbus协议主从网络结构,提出了使用Modbus协议主站库指令的S7-200系列PLC与单片机串行通信的方法,描述了单片机采用串口接收和定时中断传递消息帧的设计方案,给出了从站通信程序流程图。

This paper introduced master-slave network structure of Modbus protocol.It proposed the method of serial communication between S7-200 PLC based on Modbus Protocol master-station library instruction and MCU,described the design project that MCU transmit message frame using serial port receive and timer interrupter,and gave the program flow chart of slave-station.