US 4,755,792 A · Security control system

Abstract

A security and control system for use in a home or building which utilizes a coded audio link between the entry detectors/transmitters and the relay modules, and a digital pulse coded power line communication ("PLC") link between the relay modules and the system controller as well as between the system controller and the various remotely located slave units which control the energization of lamps, appliances, and alarms. The relay modules and controller include constant false alarm rate ("CFAR") receivers for isolating the coded audio signal from background noise and unique exclusion circuitry for decoding the isolated signal. The PLC messages are generated by impressing a pulse code modulated high frequency carrier signal onto the AC line at selected points in the AC waveform. The location of each carrier frequency pulse relative to the 60 Hz AC line cycle determines the digital value of the pulse. Both before and during a PLC message transmission, the controller and relay modules are adapted to check the status of the AC power line for the presence of intelligence or excessive noise levels and delay transmission if either condition is detected. In the security mode, the system has three major states: INSTANT-ARM, ARM-DELAY, and DISARM. In the INSTANT-ARM state, the system responds immediately to the detection of an intrusion event. In the ARM-DELAY state, a 40-second delay is implemented before alarm action is taken to permit an authorized entrant to DISARM the system. Significantly, the 40-second delay is implemented by each of the remotely located slave modules so that destruction of the controller by an intruder within the 40-second period will not defeat the system.

Claims36

Dependent claims

A security system for detecting an intrusion into a protected premises having an AC power line and signaling the detection of the inrusion event, including:

one or more entry detectors operatively associated with a corresponding number of selected entryways to the protected premises for sensing an entry through said respective entryways and producing a coded audo signal in response thereto;
at least one signal relay device adapted to be electrically connected to the AC power line in the protected premises and located within the audio range of an entry detector, including audio receiver means for receiving said coded audio signal and separating said coded audio signal from extraneous noise in the received signal, PLC transmission means for impressing a coded relay signal onto said AC power line, and processor means for decoding said coded audio signal and enabling said PLC transmission means in said relay device to transmit said coded relay signal in response to the detection of a valid coded audio signal;
a controller adapted to be electrically connected to the AC power line of the protected premises, including PLC receiver means for receiving said coded relay signal and separating said coded relay signal from extraneous signals on said AC power line, PLC transmission means for impressing a coded controller signal onto said AC power line, and processor means for decoding said coded relay signal and enabling said PLC transmission means in said controller to transmit said coded controller signal in response to the detection of a valid coded relay signal;
and
at least one slave device adapted to be electrically connected between the AC power line and an alarm device for controlling the activation of said alarm device, including PLC receiver means for receiving said coded controller signal and separating said coded controller signal from extraneous signals on said AC power line, output means for activating said alarm device, and processor means for decoding said coded controller signal and enabling said output means to activate said alarm device in response to the detection of a valid coded controller signal.

2 more elements

A security system for detecting an intrusion into a protected premises and signaling the detection of the intrusion event, including:

intrusion detection means for detecting an intrusion into the protected premises and producing a coded signal in response thereto;
controller means for receiving said coded signal from said intrusion detection means and producing alarm signals in response thereto, said controller means being selectively operable in either a first mode wherein a first alarm signal is produced in response to the receipt of a coded signal from said intrusion detection means, or a second mode wherein a second alarm signal is produced in response to the receipt of a coded signal from said intrusion detection means;
and
slave means located remotely from said controller means and connected to an alarm device for controlling the activation of said alarm device, said slave means being responsive to the receipt of said first alarm signal from said controller means to immediately activate said alarm device and being responsive to the receipt of said second alarm signal from said controller means for implementing a predetermined time delay before activating said alarm device.

1 more element

In a security system including detection means for detecting an intrusion into a protected premises having an AC power line and producing an intrusion signal in response thereto, a signal relay device adapted to be electrically connected to the AC power line in the protected premises for impressing a coded relay signal onto said AC power line in response to the receipt of said intrusion signal, a controller adapted to be electrically connected to said AC power line for impressing a coded controller signal onto said AC power line in response to the receipt of said coded relay signal, and a slave device adapted to be electrically connected between said AC power line and an alarm device for activating said alarm device in response to the receipt of said coded controller signal, and wherein said coded relay signal and said coded controller signal comprise predetermined carrier frequency signals that are digitally pulse code modulated with one complete cycle of the AC power line waveform being used to transmit each bit of information in said coded signals with a digital "1" corresponding to a carrier frequency pulse being generated during the positive (negative) half cycle of the AC power line waveform and a digital "0" corresponding to a carrier frequency pulse being generated during to the negative (positive) half cycle of the AC power line waveform;

the improvement comprising:
processor means in said signal relay device and processor means in said controller for determining if other coded signals are being transmitted over said AC power line both prior to and during the transmission of said coded relay and coded controller signals, respectively, and delaying or aborting said respective transmissions in the event other intelligence on said AC power line is detected.

Dependencies are inferred from the claim text.

Security control system

Life of this patent

Security control system

Life of this patent

Abstract

Claims36