Integrated alarm transponder

• US 4,885,568 A
• Filed: 11/21/1988
• Issued: 12/05/1989
• Est. Priority Date: 11/21/1988
• Status: Expired due to Fees

• Current Assignee: Interactive Technologies, Inc. (Fiserv Incorporated)
• Original Assignee: Interactive Technologies, Inc. (Fiserv Incorporated)
• Inventors: Hackett, Kenneth R.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US07/273,927
• Time in Patent Office: 379 Days
• Field of Search: 340/518, 340/531, 340/505, 340/506, 340/536, 340/829.54, 340/825.06-825.13, 340/825.14, 340/525, 340/825.2, 340/870.13, 340/870.14, 370/77, 370/90, 370/96, 370/91
• US Class Current: 340/518
• CPC Class Codes: G08B 26/004 with common interrogation of substations

Abstract

A time multiplexed integrated alarm contact for reporting detected alarm conditions to a system controller in a hardwired alarm system and wherein distinguishable binary frequencies are used for synchronizing/responding and for programming the contact. During programming, an identity code is written into an included shift register and non-volatile memory defining the system reporting interval and the contact'"'"'s reporting interval within the system interval. Controller initiated synchronizing signals induce each contact'"'"'s status transmission with or without resetting an alarm buffer and whereby redundant alarm reports may be obtained.

Claims

1. In a time multiplexed hardwired alarm system having a local controller monitoring each of a plurality of distributed alarm points, apparatus for identifying the alarm status of each alarm point during an assigned response interval within a system reporting interval comprising:

(a) a magnetic switch;

(b) transceiver means hardwired to said controller for receiving programming signals defining a reporting interval of said switch and synchronizing signals initiating and defining the number of times the alarm status of said switch is to be reported to said local controller, said transceiver means comprising;

(i) means for quantifying the amplitude of received signals,

(ii) a crystal oscillator,

(iii) means for synchronizing the quantified signals with said crystal oscillator,

(iv) means responsive to the received signals for distinguishing a binary pair of programming frequencies from a binary pair of synchronizing frequencies,

(v) means responsive to received signals at said programming frequencies for writing a start of response time into a shift register and a non-volatile memory,

(vi) means for enabling a counter upon receipt of one of said pair of synchronizing frequencies and producing a transmit control signal upon concurrence of an accumulated count with said start of response time, and

(vii) means for transmitting one of a pair of binary frequencies corresponding to switch status upon receipt of said transmit control signal; and

(c) wherein said switch and said transceiver means are included in a single package mountable in obscured relation to a monitored alarm point.

2. Apparatus as set forth in claim 1 including means for transmitting the alarm status of said switch once upon receipt of one of said pair of synchronizing frequencies and for re-transmitting the detected alarm status each reporting interval thereafter so long as the other of said pair of synchronizing frequencies is received each following response interval.

3. Apparatus as set forth in claim 1 including means for selectively varying the start of the response time

4. Apparatus as set forth in claim 1 including means for enabling the programming of said transceiver means only when said switch contact in one of a plurality of switch positions.

5. Apparatus as set forth in claim 1 wherein said counter comprises first and second counter portions and includes means for serially coupling said first and second counter portions to one another upon receipt of either of said pair of synchronizing signals.

6. In a time multiplexed hardwired alarm system having a local controller monitoring each of a plurality of distributed alarm points, apparatus for identifying the alarm status of each alarm point during an assigned response interval within a system reporting interval comprising:

(a) a magnetic switch;

(b) transceiver means hardwired to said controller for receiving programming signals defining a reporting interval of said switch and synchronizing signals initiating and defining the number of times the alarm status of said switch is to be reported to said local controller, said transceiver means comprising;

(i) a clock source,

(ii) means for synchronizing received programming and synchronizing signals with said clock source,

(iii) means responsive to the received signals for distinguishing a binary pair of programming frequencies from a binary pair of synchronizing frequencies,

(iv) means responsive to received signals at said programming frequencies for writing a start of response time into a shift register and a non-volatile memory,

(v) means for enabling a counter upon receipt of one of said pair of synchronizing frequencies and producing a transmit control signal upon concurrence of an accumulated count with said start of response time, and

(vi) means for transmitting one of a pair of binary frequencies corresponding to switch status upon receipt of said transmit control signal; and

(c) wherein said switch and said transceiver means are included in a single package mountable in obscured relation to a monitored alarm point.

7. In a time multiplexed hardwired alarm system having a local controller monitoring each of a plurality of distributed alarm points, apparatus for identifying the alarm status of each alarm point during an assigned response interval within a system reporting interval comprising:

(a) means for monitoring a physical condition for an alarm condition; and

(b) transceiver means hardwired to said controller including a nonvolatile, eraseable memory for receiving a first binary pair of frequencies and programming a unique alarm reporting interval within the system interval different from the other alarm points into said memory and for receiving a predetermined one of a second binary pair of frequencies different from said first pair and redundantly reporting the alarm status of said switch each successive system reporting intervals initiated thereafter by the predetermined one of said second pair of frequencies.

8. Apparatus as set forth in claim 7 including transmitter means for reporting alarm status as a third pair of binary frequencies and a trouble condition as no transceiver response during the response interval.

9. In a time multiplexed hardwired alarm system having a local controller monitoring each of a plurality of distributed alarm points, apparatus for identifying the alarm status of each alarm point during an assigned response interval within a system reporting interval comprising:

(a) bistate means for distinguishing an alarm from a non-alarm condition;

(b) transceiver means hardwired to said controller including a nonvolatile, eraseable memory for receiving a first binary pair of frequencies and programming a unique alarm reporting interval within the system interval and different from the other alarm points into said memory and for initiating the reporting of the alarm status of said bistate means at least once during successive system reporting intervals upon receipt of either of a second binary pair of frequencies different from said first pair and further including;

(i) clock means for producing a plurality of clock signals at different frequencies;

(ii) switch means coupled to said clock means and having at least first and second switch positions, and

(iii) means coupled to said switch means for counting clock signals of respective first and second frequencies when said switch means is in said respective first and second switch positions,

(iv) means for comparing the accumulated count of said counter means to distinguish the received signal relative to said first and second pairs of binary frequencies at said first switch position and to detect a predetermined relation to said programmed reporting interval at said second switch position.

10. Apparatus as set forth in claim 9 including means coupled to said counter means and said memory for selectively defining the duration of said system reporting interval.

11. Apparatus as set forth in claim 9 including means for transmitting a third binary pair of frequencies corresponding to the alarm status of said bistate means and not transmitting during any programmed response interval upon detecting a trouble condition.