Communication protocol for interconnected hazardous condition detectors, and system employing same

• US 6,791,453 B1
• Filed: 08/11/2000
• Issued: 09/14/2004
• Est. Priority Date: 08/11/2000
• Status: Expired due to Fees

• Current Assignee: Walter Kidde Portable Equipment Incorporated (Carrier Global Corporation)
• Original Assignee: Walter Kidde Portable Equipment Incorporated (Carrier Global Corporation)
• Inventors: Andres, John J., Ernst, Stephen M., Gilbert, Chris R., Kleinberg, Craig, Wurtenberger, John, Apperson, Michael W., Ratzlaff, Larry, DeLuca, Joseph G
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Previl, Daniel
• Application Number:
  US09/638,091
• Time in Patent Office: 1,495 Days
• Field of Search: 340/286.05, 340/286.01, 340/287, 340/289, 340/291, 340/293, 340/628, 340/632, 340/639, 340/577, 340/584, 340/693.6, 340/506, 340/539, 340/514, 340/516, 340/517, 340/523
• US Class Current: 340/286.01
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• CPC Class Codes: G08B 19/00 Alarms responsive to two or more different undesired or abnormal conditions, e.g. burglary and fire, abnormal temperature and abnormal rate of flow
• CPC Class Codes: G08B 25/009 Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range
• CPC Class Codes: G08B 25/04 using a single signalling line, e.g. in a closed loop

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.

Claims

1. A distributed hazardous condition detection and alarm system, comprising:

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 detection of carbon monoxide, 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 smoke.