초록 ▼

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

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.

대표청구항 ▼

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 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.