Multipoint bidirectional communication over single line - using decoders validating messages and rejecting doubtful bits by majority logic

摘要

A central processor is connected to remote appts. with interchangeable decoders at intervals along the line, each decoder having its own address assigned when the system is initialised. A binary code obtd. from line polarity switching is memorised in a register, and a series switch is closed, connecting the central processor to the next decoder along the line. - In operation the decoders may be addressed in any order with a message including the destination address and a code defining the required local processing. The central processor can identify and locate faults on the line, or in any decoder, which can then be isolated.