The Design And Implementation Of The External System Equivalent Device Based On On The Dual Mode

The main role of the real-time measurement system is to accurately monitor and record the performance parameters of the aircraft system in a reliable way. In order to ensure the reliability of the aircraft system, need to design a device that can be simulated interface signals and control signals during the investigation stage and experimental stage in the development stage and the pilot phase measurement system, in order to achieve laboratory test of aircraft system in the closed-loop.An external system equivalent device is one of automated test systems. Combining automated test systems research status and development trends at home and abroad, This paper implements a design of the external system equivalent device based on dual-mode communication in a modular, standardized,and universal way. According to the signal requirements of the measurement system, the system can output analog dc signal, the digital signal (RS485signals and PCM), the command signal and the pulse signal. In the design, PC communicates with the external system equivalent device with PCI bus or USB bus so as to improve the reliability of the equipment.In this paper, the designs of the system protocol and dual-mode communication protocol are described in detail, including a system of standardized protocol agreement, PCI interface, USB interface with the host computer communication protocol and function board agreement. In addition,According to the function, the paper introduces hardware circuit design of the dual-mode communication interface card, analog board, digital boards, instruction boards, and pulse board, besides,logic implementations of each module in the design process as well as the problems and solutions are introduced. By testing the feasibility of this experiment design, reliability, stability, and versatility are verified, the test results show that the design requirements of the task book and scalability, versatility is strong.