METHOD FOR PASSING A FAILSAFE ALARM SIGNAL THROUGH A LIFE SAFETY SYSTEM THAT EXPERIENCES A CATASTROPHIC FAILURE

• US 20090160669A1
• Filed: 12/20/2007
• Published: 06/25/2009
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: UTC Fire & Security Americas Corporation, Inc. (Carrier Global Corporation)
• Original Assignee: UTC Fire & Security Americas Corporation, Inc. (Carrier Global Corporation)
• Inventors: Becker, Donald Edward
• Granted Patent: US 7,907,049 B2
• Time in Patent Office: Days
• US Class Current: 340/679
• CPC Class Codes: G06F 11/0721 within a central processing unit [CPU]
• CPC Class Codes: G06F 11/0769 Readable error formats, e.g. cross-platform generic formats, human understandable formats
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• CPC Class Codes: G08B 25/14 Central alarm receiver or annunciator arrangements
• CPC Class Codes: G08B 29/10 Monitoring of the annunciator circuits

Abstract

An improved life safety system provides ability to detect a catastrophic failure within a network node of the life safety system, and to subsequently pass a failsafe alarm signal through a network node, and through the life safety system, despite the catastrophic failure, which may be a failed main processor of a main panel, a failed main processor of a loop expander module, a failed main processor of an amplifier, or a failed main processor of a liquid crystal display controller.

Claims

1. A method, comprising:

detecting a catastrophic failure within a network node of a life safety system;

generating a fault signal indicative of the detected catastrophic failure;

detecting an alarm condition indicative of a life safety emergency; and

passing a failsafe alarm signal through the network node despite the detected catastrophic failure.

2. A method in accordance with claim 1, wherein the detecting a catastrophic failure further comprises:

detecting a failure of a main processor.

3. A method in accordance with claim 1, wherein the passing a failsafe alarm signal through the network node further comprises:

annunciating at least one of visual, textual, and audible indications on a user interface of a liquid crystal display.

4. A method in accordance with claim 3, wherein the annunciating at least one of visual, textual, and audible indications further comprises:

one of blinking and blanking the liquid crystal display.

5. A life safety system, comprising:

a network node including one or more expansion panels communicatively coupled with a data bus, wherein each of the one or more expansion panels includes a main processor and a subcomponent, and

wherein the subcomponent is configured to detect a failure of the main processor, to detect an alarm condition indicative of a life safety emergency, and, in response to the alarm condition, to pass a failsafe alarm signal through the network node via the data bus despite the detected failure of the main processor.

6. A life safety system in accordance with claim 5, wherein the subcomponent is configured to pull the data bus low when the failure of the main processor is detected, and an alarm condition indicative of a life safety emergency has also been detected.

7. A life safety system in accordance with claim 5, wherein network node includes a main panel coupled with the data bus.

8. A life safety system in accordance with claim 7, wherein the subcomponent is a network adapter included in the main panel.

9. A life safety system in accordance with claim 5, wherein the network node includes a loop expander module coupled with the data bus.

10. A life safety system in accordance with claim 9, wherein the subcomponent is a loop adapter included in the loop expander module.

11. A life safety system in accordance with claim 5, wherein the network node includes an amplifier coupled with the data bus.

12. A life safety system in accordance with claim 5, wherein the network node includes a liquid crystal display controller coupled with the data bus.