基于自由口模式的通信软件开发及应用  

Development and Application of Communication Software Based on Free Port Mode

作　　者：侯东明[1] 赵志诚[1] 张井岗[1] 

机构地区：[1]太原科技大学电子信息工程学院,太原030024

出　　处：《太原科技大学学报》2010年第1期14-18,共5页Journal of Taiyuan University of Science and Technology

基　　金：山西省研究生优秀创新项目(20081088)

摘　　要：介绍了基于自由口模式的S7-200PLC与上位机之间通信程序的开发及其在液压支架试验台监控系统中的应用。上下位机之间的通信方式选择主从方式,其中上位机处于主动态,通信程序采用VB中的MSComm控件进行开发,由于该控件巧妙地将复杂的Windows编程封装起来,从而使得编程简单。在对PLC中特殊寄存器设置的基础上,完成自由口通信协议的定义,并通过接收中断、发送中断、发送指令(XMT)和接收指令(RCV)实现了监控系统的通信。将该方法应用于液压支架试验台监控系统,实验结果表明系统通信过程稳定、效果良好,具有一定的实际意义。This paper discusses the program development of communication between S7-200 PLC and upper computer based on the free port mode and the application in the supervisory control system of hydraulic support test-bed. The master-slave mode is chosen, and the upper computer is always active. The communication program of the upper computer is developed using MSComm in VB which makes programming easy clue to packing complex Windows codes ingeniously. On the base of setting special register in PLC, the communication protocol of the free port is defined and the communication is realized by receiving and sending interruption, XMT and RCV. The method is applied in the supervisory control system of hydraulic support test-bed and the result shows that the communication is stable and effective. So the method introduced in this paper has some practical significance.

关 键 词：S7-200 PLC VB MSCOMM 自由口模式 

分 类 号：TP393[自动化与计算机技术—计算机应用技术] TP311[自动化与计算机技术—计算机科学与技术]