Data distribution system for private automatic branch exchange

摘要

A data distribution system for a private branch telephone exchange for providing information to a plurality of PBX stations. Two embodiments (serial and parallel) including addressable stations are shown. Memory devices driving a plurality of displays at each station are updated in response to command signals from a controller preceded by the station address. Each station may communicate with the controller and transmit keyed-in signals or information reflecting station availability. A novel multiplexed LCD, switching matrix bypass upon controller failure circuit, and bus protection circuit upon remote power supply failure are also shown.