Data communication equipment for railway signalling - has transmitter and receiver in signalling box transmitting point setting information to computer centre

摘要

An equipment for data transmission between a computer centre and a signalling box of a railway system. The computer centre sends instructions to the signalling box and the box returns information on the positions of various pieces of equipment such as rail points and level crossings. The signalling box has a data transmitter connected to a line. The transmitter has its own clock frequency. The box also has a data receiver connected to another line. The lines are also connected to a computer centre. The data receiver is synchronised by a pulse from the binary synchronisation elements of an incoming instruction. The data transmitter is also synchronised by a pulse obtained from the binary elements. The binary elements are at the beginning of the instruction word.