Communication protocol for interconnected hazardous condition detectors, and system employing same
First Claim
1. A method of communicating multiple hazardous condition alarms between distributed hazardous condition detectors over a single signal line, comprising the steps of:
- sensing a first hazardous environmental condition; and
generating an alarm signal on the single signal line upon sensing the first hazardous environmental condition, the alarm signal comprising at least one voltage pulse having a duration less than 100 milliseconds.
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Accused Products
Abstract
Presented is a communications protocol for use by interconnected hazardous condition detectors, such as smoke and carbon monoxide detectors for use in dwellings and other structures. This communications protocol provides conventional signaling to indicate the presence of a smoke condition necessitating the generation of a smoke temporal pattern by all interconnected detectors. The protocol further defines a signaling method by which conventional smoke detectors that are incapable of providing temporal patterns other than that required for a smoke alarm condition will not be sent into an alarm mode of operation upon receipt of a signal other than the conventional smoke alarm signal. This communications protocol defines a pulsed signal to indicate a non-smoke alarm condition that is of a duration that will not trigger the conventional smoke alarms. To allow for the transmission of multiple hazardous conditions alarm notifications, as well as the transmission of additional hazardous condition detector control signals, the communications protocol utilizes a multi-bit signal transmitted via the conventional single signal I/O wire of currently existing interconnect wiring. Through the use of an 8 bit alarm signal, multiple hazardous conditions may be signaled as well as operating modes such as test, hush, reset, low battery, etc. Also presented are smoke, carbon monoxide, and combination hazardous condition detectors that utilize the communications protocol presented herein.
32 Citations
20 Claims
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1. A method of communicating multiple hazardous condition alarms between distributed hazardous condition detectors over a single signal line, comprising the steps of:
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sensing a first hazardous environmental condition; and
generating an alarm signal on the single signal line upon sensing the first hazardous environmental condition, the alarm signal comprising at least one voltage pulse having a duration less than 100 milliseconds. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A hazardous condition detector, comprising:
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an alarm circuit;
an interconnection I/O circuit; and
a microcontroller coupled to the alarm circuit and the interconnection I/O circuit, the microcontroller determining a first environmental alarm condition upon receipt of a pulsed input from the interconnection I/O circuit of less than approximately 100 milliseconds, and a second environmental alarm condition upon receipt of a DC signal, said microcontroller commanding the alarm circuit to generate a first alarm type upon determining the first environmental alarm condition, and to generate a second alarm type upon determining the second environmental alarm condition. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A distributed hazardous condition detection and alarm system, comprising:
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a first hazardous condition detector;
a second hazardous condition detector; and
a 3-wire interconnect coupling said first detector to said second detector, and wherein at least one of said first and said second detectors is operable to generate a multi-pulse alarm message on the interconnect to indicate the detection of a first hazardous condition, and wherein at least one of said first and said second detectors is operable to generate a constant DC level on the interconnect to indicate detection of a second hazardous condition.
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Specification