Wide-area Surveillance System Protocol Parser In The Design And Realization

The diversity and complexity of the controlled object in Wide-area Monitoring System(WAMS) determine the variability of the data communication protocol, and the analysis of the protocol data unit(PDU) is the core part of data process in Wide-area Monitoring System,when communicate with controlled object that have various application-layer protocols,to write particular communication interfaces to connect every controlled object is essential,but this always causes complexity and redundancies. as a result,it is very necessary to design and realize a unified protocol parser,which is used to accomplish data exchange between field layer and monitoring layer.With enterprise engineering vehicle as controlled object,this paper use Vehicle Monitoring System as a special case of WAMS and investigate the parsing and building method of the protocol data unit.First,design the Extensible Data Communication Protocol(EDCP) by analyzing user needs and describe the EDCP in the form of XML configuration file to make the PDU parse program independent from the protocol frame format. Besides,the XML schema document is designed to validate the XML configuration file and standardized protocol parser which protocol field can be parsed in design level and application level,also summarized the design principles of schema.At last, divide analytic process of PDU into the two procedure:initial parse and second parse, complete the implementation of the protocol parser by design patterns,dependency injection and other software development technology, and achieve system design requirements in data reliability and parse efficiency. When the EDCP is updated, Protocol parser can still reconfigure its structure according to the revised XML configuration file and parse the new PDU correctly.