Alarm system with radio alarm link and equipment-activating power line link

Claim 2

In an alarm system having: a monitoring station with alarm monitoring equipment; a protected premises which is interconnected with the monitoring station through electrical power lines; a radio link comprising one or more radio transmitters at the protected premises for transmitting an intrusion alarm signal when an intrusion alarm condition is detected there, and a radio receiver at the monitoring station for receiving said radio alarm signals and operatively coupled to said alarm monitoring equipment to actuate the latter when a radio alarm signal is received; and a power line link comprising means selectively operable at the protected premises for transmitting over power lines to the monitoring station signals for activating the alarm monitoring equipment there to respond to intrusion alarm signals broadcast from the protected premises; the improvement wherein said power line link further comprises means at the monitoring station for transmitting over power lines to the protected premises signal information as to whether the alarm monitoring equipment there is activated to respond to intrusion alarm signals broadcast from said protected premises.

Claim 3

An alarm system according to claim 1, wherein said transmitting means at the monitoring station is operative to transmit over power lines to the protected premises a distinctive signal which tells that an intrusion alarm condition exists at said protected premises.

Claim 4

An alarm system according to claim 1, and further comprising signal indicator means at the protected premises for responding to the power line signal coming from the monitoring station.

Claim 5

An alarm system according to claim 3, and further comprising: means for modifying said last-mentioned signal when the radio receiver at the monitoring station receives an intrusion alarm signal from said protected premises.

Claim 6

An alarm system according to claim 4, wherein said transmitting means at the monitoring station transmits a distinctive carrier signal over the power lines to said protected premises which is unmodulated in the absence of an intrusion alarm signal received from said protected premises and which is modulated when such reception occurs; and said means at the protected premises for responding to said last-mentioned signal produces different indications for unmodulated and modulated signals, respectively.

Claim 7

In an alarm system having: a monitoring station with alarm monitoring equipment; a protected premises which is interconnected with the monitoring station through electrical power lines; a radio link comprising one or more radio transmitters at the protected premises for transmitting on intrusion alarm signal when an intrusion alarm condition is detected there, and a radio receiver at the monitoring station for receiving said radio alarm signals and operatively coupled to said alarm monitoring equipment to actuate the latter when a radio alarm signal is received; and a power line link comprising means selectively operable at the protected premises for transmitting over power lines to the monitoring station signals for activating the alarm monitoring equipment there to respond to intrusion alarm signals broadcast from the protected premises; the improvement wherein said selectively operable means at the protected premises comprises; means for applying a carrier signal to the power lines to be transmitted to the monitoring station; means for modulating said carrier signal at either of two different frequencies; and selectively operable means for activating said modulating means and for selecting the modulating frequency.

Claim 8

In an alarm system having: a monitoring station with alarm monitoring equipment; a protected premises which is interconnected with the monitoring station through electrical power lines; a radio link comprising one or more radio transmitters at the protected premises for transmitting on intrusion alarm signal when an intrusion alarm condition is detected there, and a radio receiver at the monitoring station for receiving said radio alarm signals and operatively coupled to said alarm monitoring equipment to actuate the latter when a radio alarm signal is received; and a power line link comprising means selectively operable at the protected premises for transmitting over power lines to the monitoring station signals for activating the alarm monitoring equipment there to respond to intrusion alarm signals broadcast from the protected premises; the improvement wherein said selectively operable means at the protected premises comprises; means for applying a carrier signal to the power lines to be transmitted to the monitoring station; means for modulating said carrier signal at either of two different frequencies; and selectively operable means for activating said modulating means and for selecting the modulating frequency.

Claim 9

An alarm system according to claim 6, and further comprising means at the monitoring station for receiving the modulated carrier sigNal coming over the power lines from said protected premises and for responding separately to the two different modulating frequencies to condition the alarm monitoring equipment at the monitoring station to respond to intrusion alarm signals broadcast by radio from said protected premises.

Claim 10

An alarm system according to claim 7, wherein said means for responding separately to the two different modulating frequencies is sensitive to the sequence in which said two different modulating frequencies are transmitted over the power lines from said protected premises to the monitoring station.

Claim 11

An alarm system according to claim 8, wherein said means for responding separately to the two different modulating frequencies comprises; a first decoder that is sensitive substantially only to a first modulating frequency, F1; a second decoder that is sensitive substantially only to a second modulating frequency, F2; means coupled to the output of said second decoder for conditioning the alarm monitoring equipment at the monitoring station to respond to intrusion alarm signals from said protected premises in response to the activation of the second decoder by an incoming F2 signal; and circuit means interconnecting said first and second decoders for inhibiting the second decoder from being activated by an incoming F2 signal until after said first decoder has received an F1 signal.

Claim 12

An alarm system according to claim 9, and further comprising means acting between said radio receiver at the monitoring station and said second decoder for inhibiting the latter from being activated by an incoming F2 signal when said receiver receives an intrusion alarm signal from said protected premises.

Claim 13

In an alarm system having: intrusion alarm condition-signalling means at a protected premises; alarm monitoring equipment for receiving alarm signals at a monitoring station which is linked to the protected premises through electrical power lines; and selectively operable means at the protected premises for transmitting signals over the power lines to the monitoring station to activate the monitoring equipment there to respond to intrusion alarm signals from the protected premises; the improvement which comprises: a transmitter at the monitoring station for transmitting a signal over the power lines to the protected premises when the alarm monitoring equipment at the monitoring station is conditioned to respond to intrusion alarm signals from the protected premises; and means at the protected premises for responding to said last-mentioned signal.

Claim 14

In an alarm system having: intrusion alarm condition-signalling means at a protected premises; alarm monitoring equipment for receiving alarm signals at a monitoring station which is linked to the protected premises through electrical power lines; and selectively operable means at the protected premises for transmitting signals over the power lines to the monitoring station to activate the monitoring equipment there to respond to intrusion alarm signals from the protected premises; the improvement which comprises: a transmitter at the monitoring station for transmitting a signal over the power lines to the protected premises when the alarm monitoring equipment at the monitoring station is conditioned to respond to intrusion alarm signals from the protected premises; and means at the protected premises for responding to said last-mentioned signal.

Claim 15

An alarm system according to claim 11, and further comprising: means for modifying said last-mentioned signal when the alarm monitoring equipment responds to an intrusion alarm signal from said protected premises.

Claim 16

An alarm system according to claim 12, wherein said transmitter at the monitoring station transmits a distinctive carrier signal over the power lines to said protected premises which is unmodulated in the absence of a response by said monitoring equipment to an intrusion alarm signal from said protected premises and which is modulated when such a response occurs; and said means at the protected premises for responding to said last-mentioned signal produces different indications for unmodulated and modulated signals, respectively.

Claim 17

An alarm system according to claim 13, wherein said selectively operable means at the protected premises may be operated to de-activate the alarm monitoring equipment at the monitoring station from responding to intrusion alarm signals at said protected premises.

Claim 18

In an alarm system having: intrusion alarm condition-signalling means at a protected premises; alarm monitoring equipment for receiving alarm signals at a monitoring station which is linked to the protected premises through electrical power lines; and selectively operable means at the protected premises for transmiTting signals over the power lines to the monitoring station to activate the monitoring equipment there to respond to intrusion alarm signals from the protected premises; the improvement wherein said selectively operable means at the protected premises comprises: means for applying a carrier signal to the power lines to be transmitted to the monitoring station; means for modulating said carrier signal at either of two different frequencies; and selectively operable means for activating said modulating means and for selecting the modulating frequency.

Claim 19

In an alarm system having: intrusion alarm condition-signalling means at a protected premises; alarm monitoring equipment for receiving alarm signals at a monitoring station which is linked to the protected premises through electrical power lines; and selectively operable means at the protected premises for transmiTting signals over the power lines to the monitoring station to activate the monitoring equipment there to respond to intrusion alarm signals from the protected premises; the improvement wherein said selectively operable means at the protected premises comprises: means for applying a carrier signal to the power lines to be transmitted to the monitoring station; means for modulating said carrier signal at either of two different frequencies; and selectively operable means for activating said modulating means and for selecting the modulating frequency.

Claim 20

An alarm system according to claim 15, and further comprising means at the monitoring station for receiving the modulated carrier signal coming over the power lines from said protected premises and for responding separately to the two different modulating frequencies to condition the alarm monitoring equipment at the monitoring station to respond to alarm signals from said protected premises.

Claim 21

An alarm system according to claim 16, wherein said means for responding separately to the two different modulating frequencies is sensitive to the sequence in which said two different modulating frequencies are transmitted over the power lines from said protected premises to the monitoring station.

Claim 22

An alarm system according to claim 17, wherein said means for responding separately to the two different modulating frequencies comprises: a first decoder that is sensitive substantially only to a first modulating frequency, F1; a second decoder that is sensitive substantially only to a second modulating frequency, F2; means coupled to the output of said second decoder for conditioning the alarm monitoring equipment at the monitoring station to respond to intrusion alarm signals from said protected premises in response to the activation of the second decoder by an incoming F2 signal; and circuit means interconnecting said first and second decoders for inhibiting the second decoder from being activated by an incoming F2 signal until after said first decoder has received an F1 signal.

Claim 23

An alarm system according to claim 18, and further comprising means at the monitoring station operable in response to receipt of an intrusion alarm signal for inhibiting the second decoder from being activated by an incoming F2 signal.

Claim 24

In an alarm system having: intrusion alarm condition-signalling means at a protected premises; alarm monitoring equipment for receiving alarm signals at a monitoring station which is linked to the protected premises through electrical power lines; selectively operable means at the protected premises for transmitting signals over the power lines to the monitoring station to activate the monitoring equipment there to respond to intrusion alarm signals from the protected premises; the improvement which comprises means for preventing said selectively operable means for activating the monitoring equipment at the monitoring station when an intrusion alarm condition already exists at said protected premises.

Claim 25

In an alarm system having: intrusion alarm condition-signalling means at a protected premises; alarm monitoring equipment for receiving alarm signals at a monitoring station which is linked to the protected premises through electrical power lines; selectively operable means at the protected premises for transmitting signals over the power lines to the monitoring station to activate the monitoring equipment there to respond to intrusion alarm signals from the protected premises; the improvement which comprises means for preventing said selectively operable means for activating the monitoring equipment at the monitoring station when an intrusion alarm condition already exists at said protected premises.