Fire alarm system

• US 4,996,518 A
• Filed: 01/23/1990
• Issued: 02/26/1991
• Est. Priority Date: 01/31/1989
• Status: Expired due to Fees

• Current Assignee: Nohmi Bosai Limited (Secom Company Limited)
• Original Assignee: Nohmi Bosai Limited (Secom Company Limited)
• Inventors: Tsumiji, Akio, Takahashi, Kaoru, Shutoku, Ryuji
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US07/468,866
• Time in Patent Office: 399 Days
• Field of Search: 340/518, 340/505, 340/506, 340/517, 340/825.06, 340/825.07, 340/825.08, 340/825.1-825.14, 340/825.54
• US Class Current: 340/518
• CPC Class Codes: G08B 26/002 only replying the state of the sensor

Abstract

A fire alarm system includes a receiver unit connected to a plurality of terminal unit groupings, each of the terminal unit groupings made up of a plurality of terminal units. The fire alarm system operates in one of a system polling mode, a point polling mode and a selecting mode. In the system polling mode, the receiver units polls all of the terminal units and provides a grouping response period in which each of the terminal unit groupings is permitted to respond to the receiver unit polling. If one of the terminal units of a particular grouping undergoes a status change, such a terminal unit transmits to the receiver unit a group response signal during the corresponding group response period. Then, the system enters the point polling mode, in which the terminal units of the terminal unit grouping corresponding to the group response period in which a group response signal was received are polled. During a corresponding terminal unit response period, the terminal unit having the status change transmits a terminal unit response period to the receiver unit. Thereafter, the fire alarm system enters the selecting mode, in which status information is transmitted to the receiver from the terminal unit having the status change.

Claims

1. A fire alarm system comprising:

a receiver unit connected to a plurality of terminal unit groupings, each of the terminal unit groupings comprised of a plurality of terminal units, each of the terminal units including at least one of a fire sensor and a remote control means for controlling a remote object;

said receiver unit and said plurality of terminal units including means for operating in a system polling mode wherein all of said plurality of terminal units of said terminal unit groupings are polled, wherein a terminal unit grouping response period is provided for each of said terminal unit groupings, and wherein a group response signal is transmitted from a terminal unit having a change of status to said receiver unit during the terminal unit grouping response period of the terminal unit groping which includes the terminal unit having a change of status;

said receiver unit and said plurality of terminal units further comprising means for operating in a point polling mode wherein all of the terminal units of the terminal unit grouping from which the group response signal was transmitted during the system polling mode are polled, wherein a terminal unit response period is provided for each of the terminal units of said terminal unit grouping from which the group response signal was transmitted group the system polling mode, and wherein a terminal unit response signal is transmitted from the terminal unit having a change of status to the receiver unit during the terminal unit response period of the terminal unit having a change of status;

said receiver unit and said plurality of terminal units further comprising means for operating in a selecting mode wherein status information is transmitted to said receiver unit from said terminal unit from which the terminal unit response signal was transmitted during the point polling mode.

4. A fire alarm system as recited in any one of claims 1, 2 or 3, said receiver unit comprising means for transmitting a common command signal to each of said terminal units during said system polling mode.

5. A fire alarm system as recited in any one of claims 1, 2 or 3, said receiver nit and said terminal units further comprising means for repeatedly polling a predetermined number of times, in the point polling mode, all of said terminal units of said terminal unit grouping from which the group response signal was transmitted during the system polling mode after each transmission of the terminal unit response signal, to thereby verify an identity of said terminal unit having a change of status.

6. A fire alarm system as recited in any one of claims 1, 2 or 3, said receiver unit and said terminal units further comprising line interruption supervisory means for operating in the selecting mode to determine whether an open circuit is present between said receiver unit and at least one terminal unit and to transmit specific information from each of said terminal units to said receiver unit.

7. A fire alarm system as recited in claim 6, said line interruption supervisory means including means for causing said receiver unit to successively request the specific information from at lest one of said terminal units subsequent to each time the system polling mode is carried in which an absence of a group response signal is detected.

8. A fire alarm system as recited in claim 6, wherein the specific information denotes a type of terminal unit, and said line interruption supervisory means includes means for comparing a prestored information of the type of terminal unit and the type of terminal unit denoted by the specific information.

9. A fire alarm system as recited in any one of claims 1, 2 or 3, said receiver unit and said plurality of terminal units including means for repeatedly operating in the selecting mode to verify at least one of the status information and the control of a remote object.

10. A fire alarm system as recited in any one of claims 1, 2 or 3, said receiver unit and said plurality of terminal units further including means for operating in the selecting mode to cause the receiver unit to return the status information from said receiver unit to said terminal unit from which the status information was transmitted, to cause said terminal unit to compare the transmitted and received status information and upon a coincidence to again transmit the status information to said receiver unit, and to cause said receiver unit to compare the thus received status information with the previously received status information.

11. A fire alarm system as recited in claim 4, wherein the common command signal includes at least one of a fire resetting command, a resetting command for a delayed action, and a local alarm silencing command.

12. A fire alarm system as recited in claim 4, said receiver unit and said terminal units further comprising means for repeatedly polling a predetermined number of times, in the point polling mode, all of said terminal units of said terminal unit grouping from which the group response signal was transmitted during the system polling mode after each transmission of the terminal unit response signal, to thereby verify an identity of said terminal unit having a change of status.

13. A fire alarm system as recited in claim 4, said receiver unit and said terminal units further comprising line interruption supervisory means for operating in the selecting mode to determine whether an open circuit is present between said receiver unit and at least one terminal unit and to transmit specific information from each of said terminal units to said receiver unit.

14. A fire alarm system as recited in claim 5, said receiver unit and said terminal units further comprising line interruption supervisory means for operating in the selecting mode to determine whether an open circuit is present between said receiver unit and at least one terminal unit and to transmit specific information from each of said terminal units to said receiver unit.

15. A fire alarm system as recited in claim 7, wherein the specific information denotes a type of terminal unit, and said line interruption supervisory means includes means for comparing a prestored information of the type of terminal unit and the type of terminal unit denoted by the specific information.

16. A fire alarm system as recited in claim 4, said receiver unit and said plurality of terminal units including means for repeatedly operating in the selecting mode to verify at least one of the status information and the control of a remote object.

17. A fire alarm system as recited in claim 5, said receiver unit and said plurality of terminal units including means for repeatedly operating in the selecting mode to verify at least one of the status information and the control of a remote object.

18. A fire alarm system as recited in claim 6, said receiver unit and said plurality of terminal units including means for repeatedly operating in the selecting mode to verify at least one of the status information and the control of a remote object.

19. A fire alarm system as recited in claim 4, said receiver unit and said plurality of terminal units further including means for operating in the selecting mode to cause the receiver unit to return the status information from said receiver unit to said terminal unit from which the status information was transmitted, to cause said terminal unit to compare the transmitted and received status information and upon a coincidence to again transmit the status information to said receiver unit, and to cause said receiver unit to compare the thus received status information with the previously received status information.

20. A fire alarm system as recited in claim 5, said receiver unit and said plurality of terminal units further including means for operating in the selecting mode to cause the receiver unit to return the status information from said receiver unit to said terminal unit from which the status information was transmitted, to cause said terminal unit to compare the transmitted and received status information and upon a coincidence to again transmit the status information to said receiver unit, and to cause said receiver unit to compare the thus received status information with the previously received status information.

21. A fire alarm system as recited in claim 6, said receiver unit and said plurality of terminal units further including means for operating in the selecting mode to cause the receiver unit to return the status information from said receiver unit to said terminal unit from which the status information was transmitted, to cause said terminal unit to compare the transmitted and received status information and upon a coincidence to again transmit the status information to said receiver unit, and to cause said receiver unit to compare the thus received status information with the previously received status information.

2. A fire alarm system comprising:

a receiver unit connected to a plurality of terminal unit groupings, each of the terminal unit groupings comprised of a plurality of terminal units, each of the terminal units including at least one of a fire sensor and a remote control means for controlling a remote object;

said receiver unit and said plurality of terminal units including means for operating in a system polling mode wherein all of said plurality of terminal units of said terminal unit groupings are polled, wherein a terminal unit grouping response period is provided for each of said terminal unit groupings, and wherein a group response signal is transmitted from a terminal unit having a change of status to said receiver unit during the terminal unit grouping response period of the terminal unit grouping which includes the terminal unit having a change of status;

said receiver unit and said plurality of terminal units further comprising means for operating in a point polling mode wherein all of the terminal units of the terminal unit grouping from which the group response signal was transmitted during the system polling mode are polled, wherein a terminal unit response period is provided for each of the terminal units of said terminal unit grouping from which the group response signal was transmitted during the system polling mode, and wherein a terminal unit response signal is transmitted from the terminal unit having a change of status to the receiver unit during the terminal unit response period of the terminal unit having a change of status;

said receiver unit and said plurality of terminal units further comprising means for operating in a selecting mode wherein control command signals for controlling a remote object are transmitted from said receiver unit to said remote control means of one of said terminal units in response to the terminal response signal transmitted during the point polling mode.

3. A fire alarm system comprising:

a receiver unit connected to a plurality of terminal unit groupings, each of the terminal unit groupings comprised of a plurality of terminal units, each of the terminal units including at lest one of a fire sensor and a remote control means for controlling a remote object;

said receiver unit and said plurality of terminal units including means for operating in a system polling mode wherein all of said plurality of terminal units of said terminal unit groupings are polled, wherein a terminal unit grouping response period is provided for each of said terminal unit groupings, and wherein a group response signal is transmitted from a terminal unit having a change of status to said receiver unit during the terminal unit grouping response period of the terminal unit grouping which includes the terminal unit having a change of status;

said receiver unit and said plurality of terminal units further comprising means for operating in a point oplling mode wherein all of the terminal units of the terminal unit grouping from which the group response signal was transmitted during the system poling mode are polled, wherein a terminal unit response period is provided for each of the terminal units of said terminal unit grouping from which the group response signal was transmitted during the system polling mode, and wherein a terminal unit response signal is transmitted from the terminal unit having a change of status to the receiver unit during the terminal unit response period of the terminal unit having a change of status;

said receiver unit and said plurality of terminal units further comprising means for operating in a selecting mode wherein status information is transmitted to said receiver unit from said terminal unit from which the terminal unit response signal was transmitted during the point polling mode, and wherein control command signals for controlling a remote object are transmitted from said receiver unit to said remote control means of one of said terminal units in response to the terminal response signal transmitted during the point polling mode.