摘要
简要介绍了Modbus协议的结构和通信实现方式,结合法国施耐德电气Twido小型PLC、艾默生公司EV2000变频器和台达DOP-A系列触摸屏的编程实例,讨论基于Modbus协议的触摸屏-PLC-变频器通信控制方法。
This article gives a brief introduction to the structure of the Modbus protocol, the realization way of the communication. Also it explains the control way of HMI-PLC-frequency inverter communication based on the Modbus protocol by combining the samples of the programming of the Schneider Electric Twido PLC、EMERSON EV2000 frequency inverter and DOP-A series HMI.
