The Mil-std-1553b Bus-based Avionics System Bus Communication

In the design of avionics integrated system., using CAD and computer emulation can improve the efficiency and quality of system design. Designers can make a quantitative evaluation to system topology and function allocation, thereby optimized system design can be achieved . So the development of emulation software of avionics integrated system is very useful and significant.In the design of the emulation, based on the network model and message model of 1553B system, the system emulation model with the method of discrete event system emulation is established, and the system emulation program by using the Visual C++ platform is developed. And with the supposed ICD and system topology, the bus loading and rate of bus utility and rate of average delay which indicate the performance of bus are obtained.The stay and flow of token in Petri net is very like the storage and flow of information in avionics integrated network system, and bus system topology can be very well described with Petri net . So during designing this emulation, 1553B protocol .colored Petri net and Petri net are analyzed and study, then the way of the storage and flow of information in 1553B communication system is known. Then, the system emulation network model is obtained based on the above work. Next, the performance of 1553B system is fatherly analyzed for the consideration of any factor which effects the performance so that to make some corresponding records in the emulation .This can make the performance obtained in the emulation close to the one of the real system. The optimization algorithm of building message model ,which is the scheme of bus optimization, is obtained based on ICD which is given by the designer of the system. The objective of bus optimization is reasonable arrangement of message transmission order ,to make bus loading balance and avoid message block on bus under the condition of meeting the maximum delay time of every message, finally, the emulation tool of 1553B system is developed based on the network model and message model, it has good user interface and easy to operate. The emulation of this software begins running after inputting the time of emulation ,the time of the message gap and the responding time. Then the bus loading ,the rate of the bus utility, the rate of the average delay, the sum of the message and the traffic of message are obtained, and the graph of these are given.Finally, the result of the emulation is simply discussed.