As1773 Avionics Optical Networking Technology

AS1773 optical fiber avionics data bus standard is a standard of airborne inner optical fiber bus, which was issued by Society of Automotive Engineers. It developes on the basis of MIL-STD-1553B which was used widely, such as used on FBC-1 battleplan and Chang'E 1 satellite in China. Because optical fiber is used as AS1773 optical fiber avionics data bus communicational media, it not only supports low rate equipments which used widely nowadays, but also supports high rate equipments, which suits the avionics data bus standard developmental direction. Henceforce, the research on AS1773 optical fiber avionics data bus network has important meanings.The system of AS1773 optical fiber avionics data bus is made up by Bus Controller, Bus Monitor, Remote Terminal and optical network. According to the structure of its network, AS1773 optical fiber avionics network research need to solve problems as followings: 1) The difficulty of modulation scheme in physical layer; 2) Messages process,error management and messages transfers management in data link layer and transport layer; 3) Design in driver layer and application layer.To solve the difficulty of modulation scheme in AS1773 optical fiber avionics data bus, Two-Ary Pulse Width Manchester Bi-phase coding is introduced to optical fiber avionics buses.,and it can be used to efficiently solve the problems associated with the fast identification of correct operation states for optical transmitters while maintaining less complexity of transcivers. It is confirmed by hardware platform test at last.AS1773 bus interface board design divides into hardware design and software design, which includes host computer interface, AS1773 standard realization and optical transceiver. The communication between host computer and board device is through host computer interface. The realization of AS1773 standard is achieved by FPGA. Redundancy and switch control is designed in optical transceiver.In the final section, some experiments are tested on AS1773 optical fiber avionics network, including receiver sensity test, error probability test and analysis through hardware and software. Network experiments include system initiation, message transfer experiments which include cycle message and burst message, the results suit time delay and message formats requirements of AS1773 standard. Bus loading and transfer delay analysis are based on the experiments results.This paper has made progress in the research of AS1773 optical fiber avionics buses modulation sheme, board design and experiments, which provides a valuable reference for further research.