Fire alarm system
First Claim
1. A fire alarm system for detecting a fire condition in a plurality of monitor areas, comprising:
- a plurality of sensor combinations respectively located in said monitor areas and each of which includes an analog type sensor adapted to produce analog detection data corresponding to changes in a surrounding physical phenomenon caused by the fire in response to a polling signal received thereby and one or more on-off type sensors connected to said analog type sensor and adapted to produce a fire signal when the changes in the surrounding physical phenomenon exceed a preset threshold value;
a receiver adapted to poll said analog type sensor in each of said sensor combinations sequentially and to detect a fire based on said analog detection data contained in a response signal from said analog type sensor;
a transmission line interconnecting said receiver and said analog sensor in each of said sensor combinations for transmitting said polling signal and said response signal; and
said analog type sensor including analog detection means for producing said analog detection data, fire detection means for detecting said fire signal from said on-off type sensor connected thereto and transmission control means for transmitting said response signal containing said analog detection data from said analog detection means and the data concerning the presence or absence of said fire signal from said fire detection means in response to said polling signal from said receiver.
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Accused Products
Abstract
A fire alarm system in which an analog type sensor (3) is connected to a transmission line (2) from a receiver (1) and in which one or more on-off type sensor (7) located in the same monitor area (14, 15, 16) as that in which the analog type sensor (3) is provided is connected to a signal line (6) led out from the analog type sensor (3). The analog type sensor (3) is provided with a fire detection circuit (12) for detecting a fire signal from the on-off type sensor (7) and a transmission control circuit (11) for transmitting its own analog detection data and fire detection data from the fire detection circuit (12) to the receiver (1).
11 Citations
3 Claims
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1. A fire alarm system for detecting a fire condition in a plurality of monitor areas, comprising:
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a plurality of sensor combinations respectively located in said monitor areas and each of which includes an analog type sensor adapted to produce analog detection data corresponding to changes in a surrounding physical phenomenon caused by the fire in response to a polling signal received thereby and one or more on-off type sensors connected to said analog type sensor and adapted to produce a fire signal when the changes in the surrounding physical phenomenon exceed a preset threshold value; a receiver adapted to poll said analog type sensor in each of said sensor combinations sequentially and to detect a fire based on said analog detection data contained in a response signal from said analog type sensor; a transmission line interconnecting said receiver and said analog sensor in each of said sensor combinations for transmitting said polling signal and said response signal; and said analog type sensor including analog detection means for producing said analog detection data, fire detection means for detecting said fire signal from said on-off type sensor connected thereto and transmission control means for transmitting said response signal containing said analog detection data from said analog detection means and the data concerning the presence or absence of said fire signal from said fire detection means in response to said polling signal from said receiver. - View Dependent Claims (2, 3)
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Specification