BUS LINE PHASE SYNCHRONISM SYSTEM

摘要

PURPOSE:To prolong the distance between a subscriber line terminator and a terminal device by transmitting a guard bit and a fixed bit from each terminal device ahead an information signal, and allowing the subscriber line terminator to detect a changing point from the guard bit to the fixed bit. CONSTITUTION:The guard bit G representing no signal state and the succeeding fixed bit thereto having a prescribed code ahead the information signal are transmitted when the information signal is transmitted onto an incoming line frame from each terminal device in the information transmission system where the subscriber line terminator and many terminal devices are connected by a bus transmitting a bi-phase code. In detecting the changing point from the no signal state to the fixed bit on the incoming line frame, the subscriber line terminator generates a gate signal having a time width passing the information signal of the channel and regenerates the extracted information by using the clock of the same phase as the outgoing line frame.