System for transmitting alarm information over telephone lines
First Claim
1. An alarm system for transmitting alarm information to desired terminal stations via telephone lines comprising:
- a plurality of transmitters which are located at telephone subscribers'"'"' premises, each transmitter having an alarm circuit associated therewith and being adapted to transmit signals indicative of the state of its associated alarm circuit to a telephone line, said signals being in the form of modulated carrier waves,a respectively corresponding plurality of receivers located at one or more local telephone exchanges, each receiver being associated with a respectively corresponding transmitter for receiving the transmitted signals therefrom,the or each local exchange having a local processor which is arranged to sequentially scan the outputs of the receivers located at its exchange and, when it detects a signal indicative of an alarm condition, to transmit a signal coded with information indicative of subscriber identity and of the desired terminal station to which the alarm information is to be routed, anda central processor including a store for storing alarm information which allows the alarm information to be redirected from one terminal station to another, which central processor is connected to receive such coded signals transmitted from said local processor and to direct the alarm information to a desired one of a number of said terminal stations, wherein each said transmitter is arranged to produce a carrier wave which is modulated with one or more of a plurality of other frequencies according to the state of the alarm being monitored.
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Accused Products
Abstract
An alarm system for transmitting alarm information via telephone lines has a plurality of alarm transmitters which are located at subscribers'"'"' premises and are adapted to transmit signals indicative of the state of alarms associated with the transmitters along telephone lines to associated receivers. The receivers are located at one or more local exchanges and the receivers at a local exchange are all connected to a local processor. The or each local processor is connected to a central processor which can direct alarm information to one of a number of terminal stations. The local processors continuously scan the outputs of the receivers. When a local processor detects a signal indicative of an alarm condition it transmits a signal coded with the subscriber identity and destination for the alarm information to the central processor which routes the alarm message to the appropriate terminal station. Each transmitter produces a carrier wave which is modulated with one or more other frequencies according to the state of the alarm being monitored.
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Citations
32 Claims
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1. An alarm system for transmitting alarm information to desired terminal stations via telephone lines comprising:
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a plurality of transmitters which are located at telephone subscribers'"'"' premises, each transmitter having an alarm circuit associated therewith and being adapted to transmit signals indicative of the state of its associated alarm circuit to a telephone line, said signals being in the form of modulated carrier waves, a respectively corresponding plurality of receivers located at one or more local telephone exchanges, each receiver being associated with a respectively corresponding transmitter for receiving the transmitted signals therefrom, the or each local exchange having a local processor which is arranged to sequentially scan the outputs of the receivers located at its exchange and, when it detects a signal indicative of an alarm condition, to transmit a signal coded with information indicative of subscriber identity and of the desired terminal station to which the alarm information is to be routed, and a central processor including a store for storing alarm information which allows the alarm information to be redirected from one terminal station to another, which central processor is connected to receive such coded signals transmitted from said local processor and to direct the alarm information to a desired one of a number of said terminal stations, wherein each said transmitter is arranged to produce a carrier wave which is modulated with one or more of a plurality of other frequencies according to the state of the alarm being monitored. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A system of the type having local processor having a plurality of transmitters located at subscribers'"'"' premises, each transmitter being adapted to transmit signals indicative of the state of its associated alarm to a telephone line, said signals being in the form of modulated carrier waves, a respectively corresponding plurality of receivers located at one or more local exchanges for receiving the transmitted signals, the or each local exchange having a local processor which is arranged to sequentially scan the outputs of the receivers at its exchange and, when it detects a signal indicative of an alarm condition, to transmit a signal coded with information indicative of subscriber identity and the desired destination of alarm information to a central processor which is, in turn, operative to direct the alarm information to a desired one of a number of terminal stations, said system comprising:
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means at each local processor for continuously scanning the outputs of the receivers connected thereto, memory means at each local processor for storing data indicative of alarm conditions sensed during the previous scanning sequence, means at each local processor for comparing the condition of each alarm with its condition during the previous scanning sequence, means located at the central processor for storing alarm information which allows the alarm information to be redirected from one terminal station to another, and means at each local processor responsive to said comparing means detecting a predetermined change in the condition of an alarm for transmitting a signal indicative of said alarm and of its desired terminal station destination to the central processor. - View Dependent Claims (27, 28, 29)
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30. A central processor for a system of the type which has a plurality of transmitters located at subscribers'"'"' premises, each transmitter being adapted to transmit signals indicative of the sate of its associated alarm to a telephone line, said signals being in the form of modulated carrier waves, a respectively corresponding plurality of receivers located at one or more local exchanges for receiving the transmitted signals, the or each local exchange having a local processor which is arranged to sequentially scan the outputs of the receivers at its exchange and, when it detects a signal indicative of an alarm condition, to transmit a signal coded with information indicative of subscriber identity and the desired destination of alarm information to a central processor which is, in turn, operative to direct the alarm information to a desired one of a number of terminal stations, said local processor comprising:
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a plurality of local processor terminations, one for each local processor, a plurality of terminal station terminations, highways linking the processor terminations and terminal station terminations, a store for storing alarm information thereby maintaining the alarm information available for use if it is to be redirected from one terminal station to another, and means for sequentially scanning the local processor terminations, each terminal station termination being responsive to an alarm signal received by a processor termination and addressed with a particular code to direct that alarm signal to the appropriate terminal station termination. - View Dependent Claims (31, 32)
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Specification