Multiplexed status monitoring with comparison process - indicates change in conditions and registers store old and new conditions with buffer transfer

摘要

A multiplexed status monitoring system operates on series information and indicates any change in status from that already held in storage. The system has a coded address output (A3) for controlling the on-line printer recording status conditions. The output (A1) provides direct indication of the status of relays and the remaining output (A2) provides an actuator signal for the printer. A multiplexer (11) receives the status signal and enters it into a shift register (1) holding new date. Another shift register (2) holds the previous date. A clock generator transfer register outputs into buffer storage elements(10, 20). A comparison is made using an XOR (30) to check if any change in condition has occurred. A counter (8) operated off the clock generates address date.