The Research And Implementation Of Network-Based Telecontrol System

The technologies of computer network evolve continually, and are applied in various fields of modern society. Besides it's use in information sharing, computer network can be used to transmit controlling data in order to implement network-based telecontrolling. Then man can control device from more distant area. The system implementation in this way is discussed in this paper, which enable remote operater to telecontrol the numerical control device only through universal browser.The technologies about telecontrol and network-based telecontrol are presented and analysed in the paper. Supervisory control method and B/S based C/S model are choosed as the control mode and architecture of the system to be implemented. Object-oriented technologies, such as UML and Java are used to analyse, design and implement the system . Because of the incapacity of Java in hardware accessing, JNI is used to be the interface between Java and C code to access the hardware.The system is implemented as a Web application, and Tomcat is used as web Server to provide the web page for remote accessing. The telecontrol client program which is actually an Applet and embeded in web page is distributed to client computer through B/S model. This Applet, on one hand, is user interface of the system, and on the other hand, runs as the client program of data transmitting to communicate with the server program of data transmitting running on the server side through C/S model to transmit the controlling data and enable user to telecontrol the device. In addition, proper measures are adopted to guarantee the real time property and safety of the system.