Design And Implementation Of Mls Central Monitor And Control Cabinet Based On Vxworks

Microwave Landing System (MLS) is an all-weather and precision approach landing system, providing angle and distance guidance information for approaching aircrafts. Central monitoring and control cabinet (CMC) is the monitoring and control center of the ground equipments of the most updated MLS. It can monitor and control the other cabinets in real time. CMC connects with the higher leading system by the network to report the overall running status of the ground equipments of MLS. CMC also serves as the human-computer interaction center of the ground equipments of MLS. Via pilot lamps, control switches and human-computer interface,users can get a full picture of the running status of system and effect centralized control. CMC is also an important platform for system maintenance.Firstly, this thesis introduces VxWorks OS, Tilcon developing tools and the communication protocol for the ground equipments of MLS. Then, the thesis analyzes the functions and the hardware environment of CMC and gives a global design. After that, the preliminary design of CMC software is discussed, which makes an exhaustive study on requirement analysis,software architecture design,task partitioning,task scheduling,task priority allocation,intertask communication mechanism and watch dog timer. Finally, the thesis picks out several representative tasks and makes a detailed design which focuses on the functions and applications of the binary semaphores, pipes and watchdog timers in the tasks. During the integrated test of the system, CMC operated stably, realized all its functions and met the target.