计算机与FX2N型PLC的串行通信

Serial Communication between Computer and FX2N Series PLC

以某电机调速控制系统为背景,该系统中的PLC作为下位机主要完成电机速度的采集,上位计算机提供人机交互界面,主要实现电机速度等数据的存储、设置、打印以及速度实时显示等监视功能。介绍利用MSComm控件实现该系统中上位计算机与下位机PLC进行串行通信的程序设计方法,并对通信协议作简要介绍。

Studies the background of a motor timing system, in the system, velocity of the motor is acquired by a PLC, the man-machine conversation program runs on a computer, and this computer is also used to store, set, print and display real-time data. Introduces a method of serial communication between computer and PLC by MSComm ActiveX control of VB in Windows, and the communication protocol.