Design And Realization Of Matrix Switch System With Self-checking Function

With the rapid development of electronic information technology,the application of automatic test systems has become more and more extensive.As the center of information exchange in the ATS,the switch system is responsible for the important function of connecting the test equipment with the UUT,so it becomes an essential part of ATS.Because of the high integration and flexible structure of matrix switch,it is increasingly used in automatic test systems.However,due to frequent use and its own structural characteristics,the reliability of the matrix switch is not high.In order to ensure the normal operation of the ATS,the research on the self-check function of the switch system is particularly important.Based on the missile equipment test system,a matrix switch system with selfchecking function are discussed in this thesis.In the system,we choose electromagnetic relay switches with low line impedance and suitable for transmitting analog signals as matrix switching devices.Through the introduction of its fault detection principle and the idea of boundary scan,the hardware self-checking circuit of the matrix switch system is designed.Afterwards,using the pseudo-exhaustive method and the ideas of equal division and dichotomy in the detection of digital circuit faults,a matrix switch self-checking path algorithm was designed.Through this method,the matrix switch system has full coverage detection of all switches and the function of locating faulty switches.Compared with other matrix switch self-inspection methods,the self-inspection circuit and selfinspection path algorithm designed in this thesis enable the tester to realize the selfinspection function when offline without connecting any external equipment or connectors.And the working circuit is separated from the self-checking circuit,so that the two working modes can operate independently of each other.On the other hand,when the fault switch is located in the same column,the detection times of the self-checking path algorithm in this thesis and the step-by-step grouping method have little difference,but when the fault switch is located in two adjacent columns,the detection times of the algorithm in this thesis are less.In addition,the upper computer software system is designed for the matrix switch and the self-check program is written.The tester can realize the different control of matrix switch system through the control of different functions in the interface.After testing,the matrix switch system with self-checking function designed in this thesis can complete two basic functions.One is that the self-test program is automatically started after the machine is turned on to complete fault detection and fault location.The other is that the tester can control the closure of different switches to form the working path and realize the control function.