Abstract:

RS422A and RS485 asynchronous serial communication technologies are widely used real-time control of the onboard computer system to improve the maintainability and scalability of the aircraft.Its stable operation requires both reliable hardware platform and software algorithms.This paper describes an onboard computer to achieve asynchronous serial communication with multiple devices in real time,and designs a unified hardware platform and software algorithms based on different communication protocols for each device with emphasis on the software design and principle.Products developed under the principle have been tested,united tested and put into practical uses,and prove to be reliable and good in performance.

Key words: RS422A;RS485;communication software design