基于Modbus总线的多路继电器控制仪表设计

Design of control instrument for multiple relays based on Modbus

目前,微型处理器的飞速发展为智能仪表带来了根本性的变革,但以PLC为核心的处理器价格高昂,故文中介绍了一种以单片机为核心的继电器控制仪表。这种多路继电器控制系统在结构上包括单片机、继电器以及485总线三大部分,其中,该系统三大部分之间的通信主要由Modbus总线协议控制。通过Modbus总线协议,单片机控制5入5出继电器以控制外接设备,高效简便,价格低廉。

At present,the rapid development of micro processor for intelligent instruments brought fundamental changes,but with PLC as the core processor costs too much,therefore,this paper introduces a relay control instrument with a single chip microcomputer as the core processor.The multi-channel relay control system includes a single chip microcomputer,a relay and a485bus in the structure.Among them,the communication between the three parts of the system is mainly controlled by the Modbus protocol.Through the Modbus protocol,MCU control5in5out of the relay and the external equipments,it has high efficiency and simple,low price.