基于多层网络的Q系列PLC通信系统设计

Design of Q-Series PLC Communication System Based on the Multi-layer Network

为实现对工业现场的实时在线远程监控,针对三菱Q系列PLC设计了一种多层网络控制系统,给出了不同网络层次之间的通信系统设计方案。多层控制网络由现场控制层、中间决策层和远程管理监控层构成,各层分别采用CC-Link现场总线、MELSECNET/H网络和以太网进行通信,层与层之间设计了专门的通信模块。以Q系列PLC为例,给出了系统的软硬件设计方案,基于MCGS组态软件在线调试结果显示整体通信系统运行良好,有效解决了信息冗余和丢包现象。

In this paper, we design a multi-layer network control system for Mitsubishi Q-Series PLC, which can achieve real-time industrial field online remote monitoring. The Communication system design scheme between different network layers is given. The multilayer control network is composed of the field control layer, intermediate decision-making layer and remote monitoring layer, which adopt CC-Link field bus, MELSECNET/H network and Ethernet for communication purpose repectively. A special module is designed for communication between those layers. Taking Q-Series PLC as example, we present a hardware and software design solution for the system. The result of online debugging based on MCGS shows that the whole communication system can run very well, and the problems of information redundancy and packet loss are solved effectively.