基于RS485可编程控制器光纤通信网应用研究

Investigation and Application of a New PLC Optical Fiber Communication Network Based on RS485 Communication Protocol

研究一种用于高速公路照明智能监控系统的可编程控制器 (PLC)光纤通信网 .指出基于RS485通信标准的FX2N系列PLC基本单元作为子站 ,最多只能接入 16台PLC的联网方案存在的局限 .探讨了该网络拓展的可行性 ,提出拓展此PLC网络通信系统的方法并进行了相应试验运行 .结果表明 :新构建的PLC网络通信系统一次性接入PLC数可达2 5 6台 ,网络性能稳定 ,效果良好 。

A DCS system developed for monitoring and control of highway lighting system, which is composed of an industrial computer, a RS485 network and F X2N PLCs made by MITSUBISH ELECTRONIC is presented. The disadvantage of this kind of network is that only 16 PLCs can be linked together to work based on RS485 communication protocol. In order to extend the number of PLCs when RS485 communication protocol is utilized, an optical fiber communication network is introduced and investigated. As a result, 256 PLCs can be linked together based on RS485 communication protocol and the optical fiber network. It has been shown that the new PLC communication network has high performance such as high reliability with lower price.