Research On Test Methods Of Complex Photoelectric Payload Multi-bus System

A certain spaceborne hyperspectral atmospheric sounder is mainly used for the three-dimensional distribution of atmospheric temperature and humidity detection. In order to realize the communication of detector and external equipment, data exchange between internal modules. Multi-bus system is adopted in the detector, which consist of 1553 B as external bus and RS422 as internal bus. As the data exchange and communication center, the stability and reliability of the multi-bus system is related to the indices of avionics system. It has important practical application value to study the test methods of such multi-bus system..The test methods of 1553 B and RS422 bus in physical and protocol layer are analyzed and summarized in the basis of theory the two buses. In addition to the serial bus consistency test such as basic waveform and noise, different kinds of error injection are also included in the physical layer test. The test methods in the protocol layer contain frame synchronization, effective data, terminal address, command mode, check bit and error injection(such as bit flip and wrong terminal address). In addition, according to the protocol layer test requirement of RS422 bus, the function of 1553 B three kinds of working mode(BC/RT/BM) is proposed to be applied to the RS422 bus to realize the monitoring and control of the RS422 bus system.A ground test platform for multi-bus system is designed based on the combination of test methods, test requirements of the detector, high-level communication protocol specification of internal and external bus. This test platform connects both 1553 B bus and RS422 bus into satellite payload. And different kinds of bus terminal characteristics(bus control, remote terminal, bus monitor) are applied in the test platform. It implements the functions about data monitoring, function test, fault detection and record by developing the PC platform. Ground experiments and function verification of the load are carried out by the test platform and test methods. It shows that the platform can effectively and comprehensively tested for multi-bus system, and ensure the reliability and stability of the multiple bus system works.