多种通信协议在智能PLC中的应用分析

Application Analysis of Multiple Communication Protocols in Intelligent PLC

以加热炉电气控制系统为例说明多种通信协议在西门子S7-200smart系列PLC中的使用方法及注意事项。系统中S7-200smart CPU同时使用了Modbus-RTU、USS和以太网通信协议分别与系统中的不同设备进行通信。实践证明,该PLC通过合理的编程使用,可以实现多种通信方式混合使用,成本低廉、功能强大、通信可靠,成为小型自动化系统的首选产品。

In this article,the electric control system of heating furnace is taken as an example to show how to use various communication protocols in SIEMENS S7-200 smart series PLC. The system uses Modbus-RTU,USS and ethernet communication protocol in S7-200 smart CPU to communicate with different devices in the system.Through the use of reasonable programming, practice has proved that the PLC can be used to achieve a variety of communication methods.With the advantage of low cost,powerful function and reliable com- munication, it will become the first choice for the small automation systems.