Addressable security monitoring system

A security monitoring system with addressable capability, which comprises:

• a cable having a first end and a second end;
• a central control unit connected at the first end of the cable, capable of issuing a first signal;
• at least one addressable video camera connected at the second end of the cable connected to the central control unit, the addressable video cameras receiving the first signal from the central control unit and comparing the first signal with a preset value, wherein if a match is achieved, the addressable video camera sends out a video signal via the cable back to the central control unit;
• a monitoring device for displaying the video signal in visual form;
• a sync signal detector, connected to the cable, for generating a status signal in response to the received second signal;
• a microprocessor coupled to the sync signal detector, the microprocessor generating an address signal and a control signal in response to the status signal;
• a modulator, coupled to the microprocessor, for modulating the address signal;
• an amplifier, coupled to the modulator, for amplifying the modulated address signal, the output of the amplifier serving as the first signal;
• and
• a switch connecting the amplifier and the first end of the cable, the switch being turned to the connected state under control by the control signal from the microprocessor.