Radio frequency communications scheme in life safety devices

• US 7,339,468 B2
• Filed: 10/17/2005
• Issued: 03/04/2008
• Est. Priority Date: 10/18/2004
• Status: Active Grant

• Current Assignee: Walter Kidde Portable Equipment Incorporated (Carrier Global Corporation)
• Original Assignee: Walter Kidde Portable Equipment Incorporated (Carrier Global Corporation)
• Inventors: Silver, Travis, Buchholz, Matthew J., Burnette, Stan, Andres, John J.
• Primary Examiner(s): BUGG, GEORGE A
• Application Number:
  US11/253,289
• Publication Number:
  US 20060082455A1
• Time in Patent Office: 869 Days
• Field of Search: 340/539.1
• US Class Current: 340/539.1
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• CPC Class Codes: G08B 25/007 Details of data content structure of message packets; data protocols
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: G08B 29/145 of fire detection circuits
• CPC Class Codes: G08B 29/181 due to failing power supply
• 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

A method of radio frequency communication for a life safety device including a controller, a hazardous condition sensor, an alarm device, and a radio frequency communications device including transmitting and receiving capability. One method includes receiving a test signal using the radio frequency communications device, lowering a voltage to the hazardous condition sensor to simulate a hazardous condition to test the hazardous condition sensor, and emitting an alarm using the alarm device if the hazardous condition sensor passes the test. Another method includes before transmitting a radio frequency signal, turning on the radio frequency communications device for a period of time, and delaying transmission if the radio frequency communications device receives a header, deadtime and startbit. Yet another method includes sending a test signal at a first transmission power level, and sending an alarm signal at a second transmission power level greater than the first transmission power level.

Claims

1. A method of radio frequency communication for a life safety device including a controller, a hazardous condition sensor, an alarm device, and a radio frequency communications device including transmitting and receiving capability, the method comprising:

receiving a test signal using the radio frequency communications device, wherein the test signal is at a first duration that is shorter than an alarm signal at a second duration;

lowering a voltage to the hazardous condition sensor to simulate a hazardous condition to test the hazardous condition sensor; and

emitting an alarm using the alarm device if the hazardous condition sensor passes the test.

2. The method of claim 1, further comprising:

receiving a silence signal using the radio frequency communications device;

if the device is a master, desensitizing the hazardous condition sensor; and

stopping the alarm from the alarm device.

3. The method of claim 1, further comprising:

before transmitting a radio frequency signal, turning on the radio frequency communications device for a period of time; and

delaying transmission if the radio frequency communications device receives a header, deadtime and startbit.

4. The method of claim 3, further comprising:

calculating a time of a next transmission; and

adding an unpredictable time to the time of the next transmission.

5. The method of claim 1, wherein receiving further comprises receiving the test signal at approximately one-half of a transmission power of an alarm signal.

6. A method of radio frequency communication for a life safety device including a controller, a hazardous condition sensor, an alarm, and a radio frequency communications device including transmitting and receiving capability, the method comprising:

before transmitting a radio frequency signal, turning on the radio frequency communications device for a period of time; and

delaying transmission if the radio frequency communications device receives a header, deadtime and startbit.

7. The method of claim 6, further comprising:

calculating a time of a next transmission; and

adding an unpredictable time to the time of the next transmission.

8. The method of claim 6, further comprising:

sending a test or silence signal of a first duration; and

sending an alarm signal at a second duration greater than the first duration.

9. A method of radio frequency communication for a life safety device including a controller, a hazardous condition sensor, an alarm, and a radio frequency communications device including transmitting and receiving capability, the method comprising:

sending a test signal at a first transmission power level; and

sending an alarm signal at a second transmission power level greater than the first transmission power level.

10. The method of claim 9, wherein the first transmission power is approximately one-half of the second transmission power.

11. The method of claim 9, further comprising:

receiving a second test signal using the radio frequency communications device;

lowering a voltage to the hazardous condition sensor to simulate a hazardous condition to test the hazardous condition sensor; and

emitting an alarm using the alarm device if the hazardous condition sensor passes the test.

12. The method of claim 9, further comprising:

receiving a silence signal using the radio frequency communications device;

if the device is a master, desensitizing the hazardous condition sensor; and

stopping an alarm from the alarm device.

13. The method of claim 9, further comprising:

sending the test signal at a first duration; and

sending an alarm signal at a second duration greater than the first duration.