Design and realization of acquisition and excitation system based on USB bus

In order to enhance the avionics´ ground maintenance capabilities, a kind of signal acquisition and excitation system is designed. This paper describes the system overall design, hardware, software configuration and work flow, establishes the system hardware and software architecture, and designs the system´s typical circuit, communication protocols, interrupt programs and USB drivers in detail. By using the USB bus as the computer communication bus, the Plug-and-Play (PNP) and Hot-plug problems are solved. Using computer control technology meets the demand on aviation system discrete signals control and detection. The cascade topology structure based on RS-485 bus is employed to solve the problems that the measured signal numbers are uncertainty.