Modbus协议及其在MCU与PLC通信中的应用

作者：彭庆海，胡小强 日期：2010-06-28/span> 浏览：3881 查看PDF文档

Modbus协议及其在MCU与PLC通信中的应用
彭庆海，胡小强
（杭州电子科技大学 自动化学院，浙江 杭州 310018）

摘要：为解决PLC设备的人机交互性能差的问题，分析了已广泛应用于PLC、变频器和自动化仪表等设备的Modbus协议，介绍了Modbus通讯数据如何在芯片中组成消息帧；并结合目前在工业领域使用较为广泛的SIEMENS S7200系列PLC及STC89C58RD单片机，详细阐述了MCU与PLC之间通讯的实现。研究结果表明，该方法使PLC设备可通过系统的人机界面程序进行控制，增加了其交互性能。
关键词：Modbus协议；人机交互；STC89C58RD单片机
中图分类号：TP206文献标识码：A文章编号：1001-4551(2010)04-0052-04

Modbus protocol and application in the communication between MCU and PLC

PENG Qinghai, HU Xiaoqiang
（College of Automation, Hangzhou Dianzi University, Hangzhou 310018, China）

Abstract: In order to solve the poor manmachine exchange performance of PLC equipment, the Modbus protocol was analyzed which has been widely used in PLC, inverter and other automation instrumentation, and also it was introduced that how to composite the message frame in the chip. In addition, combined with SIEMENS S7200 series PLC and STC89C58RD singlechip, it was elaborated that how to realize the communication between the MCU and the PLC. The results show that it lets the PLC devices be controlled by the system manmachine interface program, in order to address their shortcoming in manmachine exchange.
Key words: Modbus protocol; manmachine exchange；STC89C58RD singlechip microcomputer