The Design And Implementation Of Data Communication Protocol Of Industrial Process Monitoring System

The network database laborotory which the autor has done a lot of research and actual development for years about industry process monitoring system such as oil, chemicals, metallurgy, paper making industries and other industrial manufacturing. With the development of information technology and the extensive demand of enterprise information, we began to research the assembly platform of process industrial monitoring system. Industrial process distributed monitoring system which is constructed by the assembly platform is composed of data collection subsystem, data service subsystems, data monitoring subsystem, Web subsystem and report processing subsystem.The problem which industrial process distributed monitoring system faces is how to realize information exchanging among subsystems. In this paper , the communication mechanism served to realize information exchanging among subsystems was designed, which was on the basis of the framework model of the dynamically updating distributed monitoring system. The design of communication mechanism is the design of communication protocol. First, structural and technical features of typical distributed monitoring systems were analyzed in this paper, and key issues were discussed which were encountered in the design of architecture and communication protocol of industrial process distributed monitoring system . In order to improve these issues, a architecture of dynamically updating distributed monitoring system was proposed which is based on the summary and analysis of the exist monitoring system, and communication demand of the system was analyzed from the view of application layer.Second, the way of XML-based communication protocol design and implementation was proposed, which improved the scalability and cross-platform of the protocol, and was applied in the implementation of data communication protocol. Then, based on the framework model of dynamically updating distributed monitoring system, four kinds of data communication protocols were designed - System status information exchange protocol, production data exchange protocol, dynamically updating protocol and user management protocol. The design ideas,contents and the formats of the four data communication protocols were detailed. The data communication protocols were formally described using DTD, and examples for key protocols were given in the paper.Finally, packing and parsing processes for the protocols were detailed , design ideas of the XML parser based on DOM was given, and the data service interfaces for upper application which are provided by communication components of distributed monitoring system data service interface was designed. By using the interface, upper application don't need to care about the underlying data transmission and the seperation of protocols and upper logic is realized.