Data communication circuit between home security's guard room and household

摘要

The control data can be transmitted and received through the data communication circuit 102 while being commonly connected to each household and the guard room by the bus system and the control data inputted from the data communication circuit 102 can be transmitted to the central processing unit 102 And generates a control signal for calling each household and the guard room, controls the channel to select a voice transmission channel, and controls the call line to be connected to the CO line and the door phone.;Then, under the control of the central processing unit 10, the hand-held communication circuit 104 controls the handset ST1 to make a call, The call is switched by the hand cell ST1 through the hand cell communication circuit 104 between the trunk line and the door phone and the security room so that the voice path circuit 106 The user selects a channel that has been communicated with the guard room and the call lines L3 and L4.