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EP0093095A2 - A method and an apparatus for identifying a detector giving an alarm in a loop circuit having a predetermined number of detectors connected in parallel - Google Patents

A method and an apparatus for identifying a detector giving an alarm in a loop circuit having a predetermined number of detectors connected in parallel

Info

Publication number
EP0093095A2
EP0093095A2 EP19830850093 EP83850093A EP0093095A2 EP 0093095 A2 EP0093095 A2 EP 0093095A2 EP 19830850093 EP19830850093 EP 19830850093 EP 83850093 A EP83850093 A EP 83850093A EP 0093095 A2 EP0093095 A2 EP 0093095A2
Authority
EP
Grant status
Application
Patent type
Prior art keywords
alarm
circuit
signal
line
unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19830850093
Other languages
German (de)
French (fr)
Other versions
EP0093095A3 (en )
Inventor
Benni Göran Ingemar Glanshed
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cerberus AG
Original Assignee
Cerberus AG
Telefonaktiebolaget LM Ericsson
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

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Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B25/00Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
    • G08B25/01Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium
    • G08B25/04Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium using a single signalling line, e.g. in a closed loop

Abstract

The invention relates to a method and an apparatus for identifying a detector giving an alarm, said detector being one of a predetermined number of detectors (2) connected in parallel in a loop circuit connected to a line unit (1). The line unit (1) supplies the loop circuit with a first signal and the detectors (2) in an alarm state are adapted to give a predetermined voltage drop across the loop circuit in response to the first signal. This voltage drop in turn gives rise to an alarm signal from the line unit (1). In accordance with the invention, the line unit (1) is adapted to supply the loop circuit with a second signal in response to this voltage drop, and in response to this second signal the detector in an alarm state is adapted to emit a preprogrammed identifying signal to the line unit (1) for identifying said detector. The identifying signal can also include priority information.

Description

    TECHNICAL FIELD
  • [0001]
    The present invention relates to a method of identifying a detector giving an alarm, said detector being one of a predetermined number of detectors connected in parallel in a loop circuit connected to a line unit, which supplies the loop circuit with a first signal, said detectors in their alarm state giving a predetermined voltage drop across the loop circuit in response to the first signal, said voltage drop giving rise to an alarm signal from the line unit, the invention also relating to an apparatus for carrying out the method.
  • BACKGROUND ART
  • [0002]
    In fire detector systems, for example, it is essential that when there is an alarm, information is quickly received as to what detector the alarm comes from. It is known in the art to provide each detector with an identifying component which changes the loop circuit impedance in a manner characteristic to the detector when it gives an alarm, so that the particular detector can be identified. The identifying information is not obtained directly from the respective detector, however, which is a disadvantage, since alterations in the self-impedance of the loop circuit can give rise to false alarms or to the wrong detector being identified. Furthermore, this solution gives no possibility of differentiating priorities between different alarm states, which is a further disadvantage.
  • DISCLOSURE OF INVENTION
  • [0003]
    The object of the present invention is to provide a method and an apparatus enabling the reception of both identity and priority information from a detector giving an alarm.
  • [0004]
    This object is obtained by the method and apparatus in accordance with the invention being given the characterizing features disclosed in the claims.
  • BRIEF DESCRIPTION OF DRAWING
  • [0005]
    The invention will now be described in detail below with reference to the accompanying drawing, on which Figure 1 illustrates an embodiment of a loop circuit connected to a line unit and having a plurality of detectors connected in parallel, said loop circuit being terminated by an end circuit, Figure 2 illustrates an embodiment of a detector connected into the loop circuit of Figure 1, Figure 3 illustrates an embodiment of the line unit illustrated in Figure 1 and Figure 4 is a diagram of the voltage across the input of the line unit for both the alarm and normal state of the detector in Figure 2.
  • MODE FOR CARRYING OUT THE INVENTION
  • [0006]
    Figure 1 illustrates a line unit 1, to which there is connected a loop circuit having a plurality of detectors 2, e g fire detectors, connected in parallel. In parallel with the detectors 2 there is also connected to the loop circuit an end circuit 3, which may consist of a flipflop. In the non-alarm state or normal state of the loop circuit this flipflop provides an idling pulse train over the line circuit 1, and this pulse train will be described in detail in conjunction with Figure 4.
  • [0007]
    The line circuit 1 is also connected to a central unit (not shown) via lines 4, 5 and 6.
  • [0008]
    Figure 2 schematically illustrates an embodiment of a detector 2 in Figure 1. It should be pointed out in this connection that all the detectors illustrated in Figure 1 do not need to be constructed in the manner illustrated in Figure 2. The detector 2 of Figure 2 is of the type giving a predetermined voltage drop across the loop circuit when in an alarm state. In the alarm state, a contact 7 in the detector 2 closes, this contact being connected in series with a component 8, e g a Zener diode, giving said predetermined voltage drop across the loop circuit when the contact 7 is closed. This contact does not need to be mechanical, but can e g be a transistor or a thyristor. A resistor 9 is connected in series with the contact 7 and diode 8. This resistor 9 is connected between the base and emitter of a transistor 10, the emitter thereof being connected to one conductor of the loop circuit, while its collector is connected to the other conductor of the loop circuit via a reference voltage generator 11. The generator 11 is in turn connected to a memory 12, which has been preprogrammed with detector identification information. The output of the memory 12 is connected to the base of a transistor 13, the collector-emitter path of which is connected between both conductors of the loop circuit.
  • [0009]
    An embodiment of the line unit 1 of Figure 1 is illustrated in Figure 3. In the line unit 1 the terminals A and B connected to the loop circuit are connected such that A is connected to the positive pole of a direct voltage source, and B is connected to the input of a voltage decoder 14 as well as to the output of a signal generator 15. The voltage decoder 14 is adapted to sense the voltage at the terminal B and in response thereto to cause the signal generator 15 to change the current fed to the loop circuit via terminal B. The decoder 14 is also connected to the unillustrated central unit for emitting alarm and identity signals to it.
  • [0010]
    The function of the apparatus illustrated in Figures 1-3 will now be described in conjunction with Figure 4, where the diagram illustrates the voltage UB between the terminal B and the minus pole of the DC source in Figure 3.
  • [0011]
    At the start of the diagram, i e in the normal state, when none of the detectors 2 is in the alarm state, the impedance of the end circuit 3 changes and the signal generator 15 in the line unit 1 causes the voltage at the point B to form an idling pulse train 16. As long as no detector 2 is in'the alarm state, this idling pulse train will continue to occur, and is accepted by the line unit 1 as the normal state.
  • [0012]
    When a detector 2 gives an alarm, by its contact 7 closing, the voltage will rise at the point B, and accordingly the idling pulse train will cease, e g at the time tl. The voltage decoder 14 in the line unit 1 is adapted to accept this voltage increase as an alarm state and emit an alarm signal to the central unit via the line 4. The signal generator 15 is also controlled by the voltage decoder 14 such as to increase the current in the loop circuit, the voltage across the resistor 9 then making the transistor 10 conductive. The reference voltage generator 11 thus obtains current for exciting the memory 12 to read out its preprogrammed identity signa! fcr controlling the transistor 13. The identity signal from the transistor 13, which can be a pulse train 17, is decoded with the aid of the voltage decoder 14 in the line unit 1, and the decoded identity signal is fed from the line unit 1 to the unillustrated central unit via the line 16 for presentation on a display.
  • [0013]
    Detectors in the same room, for example, may be programmed with the same identity signal to obtain an area alarm within a monitored section.
  • [0014]
    The identity signal can also contain priority information, which is also decoded with the aid of the voltage decoder 14 and sent to the unillustrated central unit via the line 5.
  • [0015]
    The pulse train from the memory 12 is intended to be fed to the voltage decoder 14 a predetermined number of times, so that identification is ensured.
  • [0016]
    What detector is giving an alarm and what priority the alarm has are thus easily determined in a simple manner with the aid of the apparatus in accordance with the invention.

Claims (7)

1 A method of identifying a detector giving an alarm, said detector being one of a predetermined number of detectors (2) connected in parallel in a loop circuit connected to a line unit (1), which supplies the loop circuit with a first signal, said detectors in their alarm state giving a predetermined voltage drop across the loop circuit in response to the first signal, said voltage drop giving rise to an alarm signal from the line unit (1), characterized in that the line unit (1) supplies the loop circuit with a second signal in response to the voltage drop, causing the detector giving the alarm to emit a preprogrammed identification signal to the line unit (1) for identifying said detector.
2 A method as claimed in claim 1, characterized in that the second signal is supplied to the loop circuit either before or after the line unit has emitted the alarm signal.
3 A method as claimed in claim 1 or 2, characterized in that the second signal causes the detector giving the alarm also to emit to the line unit (1) a preprogrammed priority information signal for causing the line unit (1) to emit alarm signals of different priority.
4 An apparatus for identifying a detector giving an alarm, said detector being one of a predetermined number of detectors (2) connected in parallel in a loop circuit, connected to a line unit (1), which is adapted for supplying the loop circuit with a first signal, said detectors (2) being adapted, when in an alarm state, to give a predetermined voltage drop across the loop circuit in response to the first signal, the line unit being adapted to emit an alarm signal in response to said voltage drop, characterized in that the line unit (1) is adapted to supply the loop circuit with a second signal in response to said voltage drop and that the detector giving the alarm is adapted to emit a preprogrammed identifying signal to the line unit in response to the second signal for identifying the detector giving the alarm.
5 An apparatus as claimed in claim 4, characterized in that the line unit (1) is adapted to emit the second signal either before or after the alarm signal is emitted.
6 An apparatus as claimed in claim 4 or 5, characterized in that the preprogrammed identifying signal includes priority information and that the line unit (1) is adapted to emit alarm signals of different priority in response to the priority information.
7 An apparatus as claimed in any of claims 4-6, characterized in that the identifying signal is the same for several detectors.
EP19830850093 1982-04-23 1983-04-12 A method and an apparatus for identifying a detector giving an alarm in a loop circuit having a predetermined number of detectors connected in parallel Withdrawn EP0093095A3 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
SE8202566 1982-04-23
SE8202566 1982-04-23

Publications (2)

Publication Number Publication Date
EP0093095A2 true true EP0093095A2 (en) 1983-11-02
EP0093095A3 true EP0093095A3 (en) 1986-12-30

Family

ID=20346627

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19830850093 Withdrawn EP0093095A3 (en) 1982-04-23 1983-04-12 A method and an apparatus for identifying a detector giving an alarm in a loop circuit having a predetermined number of detectors connected in parallel

Country Status (3)

Country Link
EP (1) EP0093095A3 (en)
DK (1) DK179483D0 (en)
FI (1) FI830990L (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0167669A1 (en) * 1984-06-05 1986-01-15 Siemens Aktiengesellschaft Method of and device for identifying an alarm triggering sensor in a danger signalling device
EP0178474A2 (en) * 1984-09-20 1986-04-23 Siemens Aktiengesellschaft Method and arrangement for the detector identification of a hazard detection system
FR2580100A1 (en) * 1985-04-09 1986-10-10 Hochiki Co
DE4104590A1 (en) * 1990-02-15 1991-08-29 Needs Electronics Co Building alarm system - has central unit to which are coupled two signal lines with series-connected sensor discriminators
FR2723232A1 (en) * 1994-07-29 1996-02-02 Lewiner Jacques Improvements in alarm detectors for monitoring buildings
WO1997020295A1 (en) * 1995-11-28 1997-06-05 Rolf Edman A controlling and/or registration system
GB2321747A (en) * 1997-01-30 1998-08-05 Rafiki Protection Limited Fire alarm system
WO2007096523A2 (en) 2006-02-24 2007-08-30 Airbus France Fire detection system and aircraft equipped with such a system
US8902760B2 (en) 1998-04-10 2014-12-02 Chrimar Systems, Inc. Network system and optional tethers

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3757301A (en) * 1971-06-17 1973-09-04 Eaton Corp Single cable signaling system
US3778796A (en) * 1970-03-31 1973-12-11 Nittan Co Ltd Fire alarming system
US3803594A (en) * 1972-07-17 1974-04-09 Johnson Service Co Programmed time division multiplexed coded tone transmission system
US3846794A (en) * 1973-03-15 1974-11-05 Baker Ind Inc Alarm retransmission system
US4228424A (en) * 1978-10-16 1980-10-14 Baker Protective Services, Incorporated Central station alarm

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3778796A (en) * 1970-03-31 1973-12-11 Nittan Co Ltd Fire alarming system
US3757301A (en) * 1971-06-17 1973-09-04 Eaton Corp Single cable signaling system
US3803594A (en) * 1972-07-17 1974-04-09 Johnson Service Co Programmed time division multiplexed coded tone transmission system
US3846794A (en) * 1973-03-15 1974-11-05 Baker Ind Inc Alarm retransmission system
US4228424A (en) * 1978-10-16 1980-10-14 Baker Protective Services, Incorporated Central station alarm

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0167669A1 (en) * 1984-06-05 1986-01-15 Siemens Aktiengesellschaft Method of and device for identifying an alarm triggering sensor in a danger signalling device
EP0178474A2 (en) * 1984-09-20 1986-04-23 Siemens Aktiengesellschaft Method and arrangement for the detector identification of a hazard detection system
EP0178474A3 (en) * 1984-09-20 1988-07-20 Siemens Aktiengesellschaft Berlin Und Munchen Method and arrangement for the detector identification of a hazard detection system
FR2580100A1 (en) * 1985-04-09 1986-10-10 Hochiki Co
DE4104590A1 (en) * 1990-02-15 1991-08-29 Needs Electronics Co Building alarm system - has central unit to which are coupled two signal lines with series-connected sensor discriminators
FR2723232A1 (en) * 1994-07-29 1996-02-02 Lewiner Jacques Improvements in alarm detectors for monitoring buildings
WO1996004629A1 (en) * 1994-07-29 1996-02-15 Jacques Lewiner Improvements relating to alarm detectors for building surveillance
WO1997020295A1 (en) * 1995-11-28 1997-06-05 Rolf Edman A controlling and/or registration system
GB2321747A (en) * 1997-01-30 1998-08-05 Rafiki Protection Limited Fire alarm system
GB2321747B (en) * 1997-01-30 2000-10-18 Rafiki Protection Limited Alarm system
US9049019B2 (en) 1998-04-10 2015-06-02 Chrimar Systems, Inc. Network equipment and optional tether
US9812825B2 (en) 1998-04-10 2017-11-07 Chrimar Systems, Inc. Ethernet device
US8902760B2 (en) 1998-04-10 2014-12-02 Chrimar Systems, Inc. Network system and optional tethers
WO2007096523A3 (en) * 2006-02-24 2007-10-11 Airbus France Fire detection system and aircraft equipped with such a system
US8094030B2 (en) 2006-02-24 2012-01-10 Airbus Operations Sas Fire detection system and aircraft equipped with such a system
CN101389381B (en) 2006-02-24 2012-12-26 空中客车运营简化股份公司 Fire detection system and aircraft equipped with such a system
WO2007096523A2 (en) 2006-02-24 2007-08-30 Airbus France Fire detection system and aircraft equipped with such a system
FR2897968A1 (en) * 2006-02-24 2007-08-31 Airbus France Sas Concerned area`s fire detection system for aircraft, has two detectors connected to terminals of fire detection unit and providing respective values of electrical magnitude in their determined state, where two values differ from each other

Also Published As

Publication number Publication date Type
FI830990D0 (en) grant
FI830990A0 (en) 1983-03-23 application
FI830990L (en) 1983-10-24 grant
EP0093095A3 (en) 1986-12-30 application
DK179483D0 (en) 1983-04-22 grant
FI830990A (en) application
DK179483A (en) 1983-10-24 application

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Legal Events

Date Code Title Description
AK Designated contracting states:

Designated state(s): CH DE IT LI NL

RAP1 Transfer of rights of an ep published application

Owner name: CERBERUS AG

AK Designated contracting states:

Kind code of ref document: A3

Designated state(s): CH DE IT LI NL

17P Request for examination filed

Effective date: 19870121

17Q First examination report

Effective date: 19871002

18D Deemed to be withdrawn

Effective date: 19890301

RIN1 Inventor (correction)

Inventor name: GLANSHED, BENNI GOERAN INGEMAR