Monitoring and control system
First Claim
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1. A monitoring and control system comprising;
- a full duplex central module and a plurality of full duplex station modules, means within the central module for continuously and sequentially monitoring the status conditions of said station modules, said central module including means for transmitting a first synchronously gated sinusoidal carrier current signal on a first carrier current frequency of a full duplex channel pair of carrier current frequencies, wherein each first signal transmitted comprises a plurality of discrete, sequential, synchronously gated sinusoidal carrier current signals on the first carrier current frequency for each interrogation, and means responsive to the same sequential synchronously gated sinusoidal carrier current signals on the second carrier current frequency of the full duplex pair for terminating the generation of signals on the first carrier current frequency upon the receipt and verification of signals on the second carrier current frequency, thereby determining the duration of each of said discrete sequential signals, and wherein each of said station modules includes means for receiving the carrier current signals from said central module and responding to the received signals on said second carrier current frequency to terminate the transmission of said signals by said central module upon receipt thereof, each of said station modules further including logic circuitry for providing a signal to said central module for indicating an off-normal condition.
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Abstract
A carrier current security monitoring and control system utilizes the alternating current power distribution system for residential, commercial, and industrial applications employs a synchronously gated, stable radio frequency carrier. A continuously supervised remote monitoring system comprising a central module and a plurality of remote modules, operating in a full duplex transmission mode for maximum reliability and integrity in a hostile transmission environment is provided.
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Citations
16 Claims
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1. A monitoring and control system comprising;
- a full duplex central module and a plurality of full duplex station modules, means within the central module for continuously and sequentially monitoring the status conditions of said station modules, said central module including means for transmitting a first synchronously gated sinusoidal carrier current signal on a first carrier current frequency of a full duplex channel pair of carrier current frequencies, wherein each first signal transmitted comprises a plurality of discrete, sequential, synchronously gated sinusoidal carrier current signals on the first carrier current frequency for each interrogation, and means responsive to the same sequential synchronously gated sinusoidal carrier current signals on the second carrier current frequency of the full duplex pair for terminating the generation of signals on the first carrier current frequency upon the receipt and verification of signals on the second carrier current frequency, thereby determining the duration of each of said discrete sequential signals, and wherein each of said station modules includes means for receiving the carrier current signals from said central module and responding to the received signals on said second carrier current frequency to terminate the transmission of said signals by said central module upon receipt thereof, each of said station modules further including logic circuitry for providing a signal to said central module for indicating an off-normal condition.
- View Dependent Claims (2)
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3. A monitoring and control system comprising;
- a full duplex central module and a plurality of full duplex station modules, means for continuously monitoring from the central module the status conditions of said station modules utilizing an improved communications system comprising means for generating a synchronously gated sinusoidal carrier current signal located in each of said modules, said carrier current signals having first and second frequencies arranged in a full duplex two frequency transmission pair common to all modules, means for coupling said carrier current signals to an AC power distribution system, said central module including means for continuously and sequentially interrogating all of said station modules by selectively addressing each station module, said station modules having receiving means responsive to synchronously gated carrier current interrogation signals on one frequency of said duplex pair from said central module for rendering the carrier current signal generating means operative to provide a carrier current verification signal on the other frequency of said duplex pair to said central module, wherein said interrogation signals comprise a plurality of discrete, sequential synchronously gated carrier current signals, and have durations controlled by the receipt of the verification signals, said station modules also including means for sensing an off-normal condition and transmitting an off-normal condition indicative signal to said central module upon the occurrence of an off-normal condition.
- View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
Specification