基于TCP/IP网络中多PLC通信的设计和实现

随着工业自动化的发展,在控制领域中PLC应用范围日益广泛,因此与上位机间的通信也越来越频繁。通常PLC同上位机间的通信方式是单线对等连接或通过PLC网络实现。文章提出了一种将上位机和多个PLC通过通信服务器组成通用TCP/IP局域网的方法,上位机以定期主动查询方式和PLC实行通信,介绍了上位机通信程序的设计和实现。

Design and realization of communication with a few PLCs based on the TCP/IP network

With the development of industrial automatization, the application of the programmable logic controller(PLC) becomes more and more extensive in the field of control system,and the communication between the PLC and the host computer gets more and more frequent. In general, the communication is realized through the physical reciprocal connection or the PLC network. In this paper,a method of setting up a common TCP/IP area network is presented which is made up of a host computer,a few PLCs and the communication servers. The host computer communicates with the PLCs in a way of querying actively and regularly. The design and realization of the communication procedures in the host computer is described in detail .