Implementation Of Process Data Marshalling Subsystem In UIC556 Gateway

Train network control which is the develop tendency of train control influences the entire performance of the train. Train Communication Network (TCN) is Control-oriented data communication system, which can be used to connect different vehicles and equipments carried in vehicle. And it is the core of distributing train control and malfunction diagnosis system.TCN comprises two-level topology structure, the Wire Train Bus (WTB) connecting the vehicles and the Multifunction Vehicle Bus (MVB) connecting the equipments aboard a vehicle (or group of vehicles). However, the TCN standard only describes the basic communication mechanism between WTB and MVB. It doesn't define an application specific profile, such as the contents of the processing datas, concrete meaning of each bit, definition of vehicle address, description of train static and dynamic properties. Therefore, for freely composed trains, it can't ensure the mutually operation between vehicles from different manufacturers. UIC556 standard protocol established by UIC is to solve this problem. The telegrams based on UIC556 protocol can ensure the consistency of data frame on WTB. So UIC international train communication technology based on TCN technology can promote the network application capability and really realize the mutual operation.Firstly, IEC61375-1 standard and UIC556 protocol are studied, and UIC556 is analyzed as connecting TCN and the functions of applications. The design and implementation of Process Data Marshalling (PDM) subsystem are presented based on the research. Secondly, according to the overall design, PDM subsystem is divided into four modules: Application Variable Interface module,Link Process Data Interface module,PDM host module,PDM_DB disposition database module. The implementation of all the function of the four modules is detailed on Nucleus RTOS by C language. Finally, the simulation platform is designed to test the program in laboratory condition. The result proves that the protocol software is right and effective.