DATA COMMUNICATION CIRCUITS FOR HA SYSTEM

摘要

a data communication circuit commonly connected to each of households and a guard room, for transmitting/receiving control data; a central processing unit for processing the control data to generate a control signal for calling each of households and the guard room and for controlling the selection of a channel through which a voice is transmitted and the connection of a communication line with an office line and a door phone; a handset communication circuit for controlling the communication with a handset under the control of the central processing unit; a matrix circuit for switching the handset to thereby enable the handset to be communicated with the office line, the door phone and the guard room through the handset communication circuit; and a voice path circuit for selecting a communicable channel through communication lines to the guard room under an output control signal of the central processing unit.