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Alarm system having bidirectional communication with secured area

  • US 4,918,717 A
  • Filed: 08/23/1988
  • Issued: 04/17/1990
  • Est. Priority Date: 08/23/1988
  • Status: Expired due to Term
First Claim
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1. A security system comprising a master alarm unit for location in a secured area, the unit including means for telephone connection with a central control station, multiple remote detectors for location in different zones in the secured area, at least some of the remote detectors having a microphone for listening in to the zone where located, and means for operationally connecting the detectors with the master unit such that on activation of the master unit due to activation of at least one remote detector, the central control station receives a function signal from the master unit and is enabled to identify which remote detector is activated, the master unit including a speaker phone with an amplifier for selective operation in a high-volume output mode, and means in the master unit for selectively responding to a signal from the central control system to permit operation in a high-volume output mode.

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