Alarm system having improved communication

• US 20030080865A1
• Filed: 05/28/2002
• Published: 05/01/2003
• Est. Priority Date: 11/10/1999
• Status: Active Grant

• Current Assignee: Johnson Controls Fire Protection LP (Johnson Controls International plc)
• Original Assignee: ADT Security Services SA (Apollo Global Management, Inc.)
• Inventors: Furtado, Michael A., Capowski, Anthony J., Maier, Paul H. Jr.
• Granted Patent: US 6,693,532 B2
• Time in Patent Office: Days
• US Class Current: 340/506
• CPC Class Codes: G08B 26/001 with individual interrogation of substations connected in parallel
• CPC Class Codes: G08B 3/10 using electric transmission; using electromagnetic transmission
• CPC Class Codes: G08B 7/06 using electric transmission , e.g. involving audible and visible signalling through the use of sound and light sources

Abstract

An alarm system is provided which includes multiple notification appliances for signaling an alarm condition. The system controller intelligently controls the notification appliances including notification devices such as an audible or visual alarm through multi-bit digital messages sent over communication lines. The alarm system has both a standby and active mode of operation in which communication between the controller and notification appliances is possible in both modes of operation. In the standby mode, the notification appliances are powered at a first voltage level. Communication between the notification appliances and the system controller is provided by sending data pulses along the communication lines relative to the first voltage level.

Claims

1. A method for communication in a fire alarm system, comprising:

sending a message to a notification appliance that alerts a person during a fire alarm condition, said message comprising a first synchronization signal, a command field, a data field, and a second synchronization signal; and

at said notification appliance, responding as directed by said command field after said second synchronization signal.

2. A notification appliance for use in a fire alarm system, comprising:

at least one notification device that alerts a person during a fire alarm condition; and

an electronic circuit that receives a message comprising a first synchronization signal, a command field, a data field, and a second synchronization signal and responds as directed by said command field after said second synchronization signal.

3. A fire alarm system, comprising:

a system controller for generating a plurality of multi-bit digital messages that control at least one notification appliance, the at least one notification appliance alerting a person during a fire alarm condition;

a pair of communication lines connecting said at least one notification appliance to said system controller; and

said at least one notification appliance including an electronic circuit that receives a message comprising a first synchronization signal, a command field, a data field, and a second synchronization signal, and responds as directed by said command field after said second synchronization signal.

4. A method for communication in a fire alarm system, comprising:

providing a plurality of notification appliances in a standby mode of operation wherein said plurality of notification appliances are powered at a first voltage level, at least one of the plurality of notification appliances alerting a person during a fire alarm condition;

communicating with said plurality of notification appliances in said standby mode with data pulses relative to said first voltage level;

raising said first voltage level to a second voltage level in an active mode of operation; and

communicating with said plurality of notification appliance in said active mode by reducing said second voltage level to about said first voltage level and communicating with data pulses relative to said first voltage level.

5. A fire alarm system, comprising:

a plurality of notification appliances powered at a first voltage level in a standby mode of operation; and

a system controller that communicates with the notification appliances in the standby mode with data pulses relative to the first voltage level, the system controller raising the first voltage level to a second voltage level in an active mode of operation and communicating with the notification appliances in the active mode by reducing the second voltage level to about the first voltage level and communicating with data pulses relative to the first voltage level.