A low-cost serial control and data bus for airframes

This paper describes an inexpensive serial medium-speed control and data bus (with optional redundancy) designed for use in airframes. The advantages of using a bus (significant reduction in the wire count, wiring weight, and wiring complexity for airframes) are discussed briefly, The choice of low cost, readily available technologies is justified. System design decisions are reviewed with some emphasis on the economic aspects of the decisions. Physical and logical aspects of signaling are discussed. The limitations of the bus are discussed (e.g. node count, bus length, bus topology, message rates, etc.). Type and functions of typical nodes are listed. Several examples are presented in some detail, e.g. the landing gear system and the trim system. The project history is outlined and future directions are discussed