Alarm communications system with supervision signal RSSI analysis

• US 5,801,626 A
• Filed: 07/24/1996
• Issued: 09/01/1998
• Est. Priority Date: 05/20/1996
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: Pittway Corporation (Honeywell International Inc.)
• Inventors: Addy, Kenneth L.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US08/685,539
• Time in Patent Office: 769 Days
• Field of Search: 340/539, 340/506, 340/514, 340/825.69, 340/825.72, 340/825.06, 364/138, 364/140, 364/141, 455/134
• US Class Current: 340/539.21
• 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 29/123 of line circuits

Abstract

A self testing wireless data communications system suitable for use with an alarm system, the receiving element of the communications system is capable of measuring the signal strength (RSSI) of the received message signal and comparing it, if it is a supervision message, to a predetermined threshold value. When the supervision RSSI signal is above the threshold, the received message is passed to the control as being validly received; when the supervision RSSI signal is not above the threshold, then the message is ignored.

Claims

1. In a communications system comprising a plurality of remote transmitting devices and a receiving station having a receiver associated therewith, each of said remote transmitting devices capable of transmitting a supervision signal and a non-supervision signal, a method for automatically testing the communications system comprising the steps of:

a) receiving at said receiving station a signal from a transmitting device;

b) generating an RSSI signal indicative of the signal strength of said received signal;

c) determining if said received signal is a supervision signal or a non-supervision signal;

d) when said received signal is determined to be a supervision signal, then performing the steps of;

i) determining if said RSSI signal is above a predetermined threshold level;

ii) subsequently processing said received signal as being a validly received supervision signal when said RSSI signal is above said predetermined threshold level; and

iii) not processing said received signal as being a validly received supervision signal when said RSSI signal is not above said predetermined threshold level; and

e) when said received signal is determined to be a non-supervision signal, then subsequently processing said received signal as being part of a validly received non-supervision signal without determining if said received signal is above said predetermined threshold level.

2. The method of claim 1 wherein said transmitting devices and said receiver communicate with electromagnetic wave transmission.

3. The method of claim 2 wherein said electromagnetic wave transmission is radio frequency wave transmission.

4. The method of claim 1 wherein said communications system is an alarm system, at least one of said remote transmitting devices is associated with an alarm sensor, and wherein said non-supervision signal from said transmitting device associated with an alarm sensor is an alarm signal comprising alarm messages encoded with alarm sensor data.

5. A self-testing data communications system comprising

a) a plurality of remote devices, each of said remote devices comprising means for transmitting supervision signals and non-supervision signals;

b) a receiving station comprising;

i) means for receiving said supervision signals and said non-supervision signals;

ii)means for generating an RSSI signal indicative of the signal strength of the received signal;

iii) signal type determination means for determining if said received signal is a supervision signal type or a non-supervision signal type;

iv) comparison means for comparing said RSSI signal to a predetermined threshold;

v) means for disallowing further processing of said received signal when said signal type determination means indicates that said received signal is a supervision type signal and when said comparison means indicates that said RSSI signal is below said predetermined threshold.

6. The communications system of claim 5 wherein said remote devices and said receiving means communicate by electromagnetic wave transmission.

7. The communications system of claim 6 wherein said electromagnetic wave transmission is radio frequency wave transmission.

8. The communications system of claim 5 wherein at least one of said remote devices is associated with an alarm sensor.

9. A receiving station for use in a data communications system comprising a plurality of remote devices, each of said remote devices having a transmitter for transmitting supervision signals and non-supervision signals, said receiving station comprising:

a) means for receiving said supervision signals and said non-supervision signals;

b) means for generating an RSSI signal indicative of the signal strength of the received signal;

c) signal type determination means for determining if said received signal is a supervision signal type or a non-supervision signal type;

d) comparison means for comparing said RSSI signal to a predetermined threshold; and

e) means for disallowing further processing of said received signal when said signal type determination means indicates that said received signal is a supervision type signal and when said comparison means indicates that said RSSI signal is below said predetermined threshold.