为了消除传统控制器背板通信速率低、扩容难、扩容后数据量庞大等弊端,介绍了一种基于以太网背板总线的可扩容PLC系统,从硬件设计角度介绍了PLC系统的整体结构以及主要子系统部件的硬件设计原理,包括中央处理器模块、通信卡和扩展通信卡模块以及系统扩展方案。从软件设计角度介绍了PLC系统软件类别以及以太网背板总线通信策略。本系统方案能够实现各类I/O功能随意组合,无需进行软件和硬件的大幅度更改即可轻松增加系统容量。

In order to solve the problems of low communication rate of traditional controller backplane,difficult expansion and huge data volume after expansion,an expandable PLC system based on Ethernet backplane bus is introduced.The overall structure of PLC system and the hardware design principle of main subsystem components are introduced from the perspective of hardware design,including central processor module,communication card and expansion communication card module,as well as the system expansion scheme.The PLC system software category and Ethernet backplane bus communication strategy are introduced from the perspective of software design.This system scheme can realize the random combination of various I/O functions,and the system capacity can be easily increased without significant changes in software and hardware.