CA2264055A1 - Improvements relating to event detection and recordal - Google Patents

Abstract

A method and apparatus to assist in testing of fire alarms and other emergency warning systems. Such a system typically contains annunciator devices (14) such as sounders, speakers or strobe lights and these must normally be checked for acceptable operation on a regular basis. The invention enables a single or married individual to activate the alarm system briefly, without creating undue disturbance for surrounding occupants of an office or apartment block for example. The individual can then inspect an event recorder (20) located near or integral with each annunciator, to check that the respective annunciator has operated correctly. Operation of the annunciator may be assessed by monitoring input or output of the annunciator, such as current levels, or audible or visible output. Alternatively, each annunciator may communicate an indication of acceptable operation directly to a main control panel (11).

Description

?101520253035WO 98/08205CA 02264055 l999-02- 19PC T/N Z97/00099- 1 -IMPROVEMENTS RELATING TO EVENT DETECTION AND RECORDALBACKGROUND TO THE INVENTIONThis invention relates to monitoring of the operation of electrical devices, particularly but notsolely low voltage devices such as annunciators which are commonly used in ?re alarm or otheremergency warning systems.The invention generally involves event recorders which are ?tted to annunciators such as soundersin an existing alarm system, or are provided as integral parts of each annunciator in a new system.This enables the annunciators, which are subject to vandalism, to be tested as generally requiredby building and safety laws.In New Zealand various standards require that manual and automatic ?re alarm systems be testedregularly. Each alarm sounder in a building must be con?rmed as operational on a monthly basis.However, there are some logistical difficulties for building owners who seek to comply with therequired tests. Considerable annoyance and inconvenience can be created for tenants in an o?iceblock for example, or guests at a hotel. Tests lasting a few minutes or less are often carried outin a hurried and haphazard manner under these circumstances.The standards suggest that individual ?re wardens report to a coordinating person such as thechief building warden if they do not hear the alarm in their vicinity during a test procedure. Thisrequires a stringent regime of coordination and reporting which may not be ?il?lled. For example,a individual wardens who are absent will not report and their respective alarms will simply beassumed operational, while wardens who are present o?en do not take their responsibilityseriously. It is possible for the sounders in a system to be consecutively checked by a singleresponsible technician, using either continuous or intermittent activation of the sounders. Thiscreates annoyance as indicated above however, and takes time during which the alarm signals fromthe main panel are not recognised by the usual monitoring services.Standards of this kind and the difficulties of their enforcement are common in developed countries.SUMMARY OF THE INVENTIONIt is therefore an object of the present invention to provide for more convenient and reliable testingof sounders or similar devices in a ?re alarm system.?101520253035CA 02264055 l999-02- 19WO 98/08205 PCT/NZ97/00099-2-Accordingly in a first aspect, the invention may broadly be said to consist in a method oftesting an alarm system having annunciator devices such as sounders or speakers,comprising: installing event recorders to monitor at least some of the annunciator devicesin the system, activating the system during a test procedure, detecting operation of themonitored devices with the respective event recorders, and inspecting each recorder todetermine whether the respective monitored device has operated in an acceptable fashion.Preferably the event recorders monitor either output strength of the aimunciators, such asthe audible output of sounders or the visible output of strobe lights, or current ?owthrough the armunciators, or a combination of these. The recorders will generally haveinternal power supplies, but may alternatively draw and store power from the ?re alarmsystem. In either case, they should have sufficient power available to provide a clearindication of each device's operation, for perhaps an hour or more after the system isactivated.In a second aspect the invention may broadly be said to consist in event recorderapparatus for monitoring the operation of an armunciator device comprising: outputdetecting means which determines whether output from the device has reached apredetermined level and/or current detecting means which determines whether current?ow through the device has reached a predetermined level, and indicating means whichprovides an at least temporary indication for an observer as to whether the predeterminedlevels have been reached.Preferably the event recorder includes a microphone to monitor audible output of theannunciator device, and may be connected in series with the device to monitor current?ow through the device. Preferably the recorder also includes an internal power supply,but may also draw current from a supply provided to the device.In a third aspect the invention may also be said to consist in an annunciator for anemergency warning system. including an event recorder for monitoring operation of theannunciator, wherein the event recorder monitors a physical output of the annunciatorand/or current drawn by the annunciator, and generates an indication of whether or notthe annunciator has operated acceptably during activation of the emergency warningsystem.Preferably the event recorder monitors audible output of the annunciator by way of amicrophone, but could also monitor strobe output for example. In one embodiment theevent recorder generates a visible indication of acceptable operation of the annunciator,?101520253035CA 02264055 l999-02- 19WO 98108205 PCT/NZ97/000994-3-for inspection at the annunciator itself. In another embodiment the event recordergenerates an indication signal which is transmitted to a control panel located elsewherein the emergency warning system.In a fourth aspect, the invention may also be said to consist in an emergency warningsystem having annunciators and event recorders which monitor operation of respectiveannunciators, wherein the event recorders provide an indication of whether theannunciators have operated acceptably during a test procedure, and either provide theirindications for subsequent inspection at the annunciators, or transmit respective indicationsignals to a control panel.Preferably the event recorders are integral with respective annunciators. although theymay be installed separately near the annunciators. Preferably the event recorders monitoraudible outputs of their respective annunciators, and may also monitor other physicaloutputs, and/or current ?ow through the annunciators.Other aspects of the invention will become apparent to a skilled reader from the followingdescription and drawings.BRIEF DESCRIPTION OF THE FIGURESPreferred embodiments of the invention will be described with respect to theaccompanying drawings, of which:Figure I is a schematic layout of electrical connections for an existing annunciatorsystem, such as a ?re alarm system;Figure 2 is a schematic layout for a system which incorporates an event recorderfor each annunciator according to the invention;Figures 3a and 3b are circuit diagrams showing alternative preferred eventrecorders which might be used in the system of Figure 2;Figure 3c is a diagram of an additional circuit for use with ac annunciators;Figure 4 is a block diagram for a testing device which might be used with the eventrecorders of Figures 3a or 3b;Figure 5 is a schematic layout for a further system in which information from eachevent recorder is transmitted to a main panel.?101520253035CA 02264055 l999-02- 19WO 98/08205 PCT/NZ97/00099_ 4 -DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSReferring to the drawings it will be appreciated that details of the invention are still underdevelopment. Various alternative event recorders, and their accompanying testers, maybe constructed without departing from the concepts which are summarised above. It willalso be appreciated that the invention is described in relation to monitoring and testing ofa fire alarm system by way of example only, and may also ?nd use in relation to otheremergency warning systems involving remotely positioned annunciators or analogousdevices.Figure 1 shows simpli?ed wiring arrangements in a conventional fire alarm system whichmight be installed in a building or similar structure. A number of responders 10 aredistributed throughout the building, perhaps several on each ?oor, connected to a maincontrol panel 11 which is typically positioned in a service area on the ground ?oor or inthe basement. The main panel is usually connected to an external monitoring service overthe telephone lines. Each responder is connected to a number of manual call points andperhaps other devices such as smoke detectors, which have not been shown. The MCPsare generally well known in the form of small wall-mounted boxes each having a glasscover and a push-button or switch actuator. The responders are typically powered inparallel through low voltage (eg. 12 or 24V) lines 12 from an ac or dc supply in the mainpanel 11, and communicate with the main panel through a bus 13.A number of annunciators 14 in the form of speakers, sounders, or strobe lights are alsodistributed throughout the building, usually close to the MCPs. Each annunciator istypically powered along lines 15 from a low voltage ac or do supply at the main panel 11,similarly to the responders, or may be separately powered from the main panel. Soundersgenerate a predetermined output when power is applied and in some cases may requireseparate communication with the panel. Speakers and equivalent devices in other systemswill generally require a communication bus, which has not been shown, to receive audiosignals or other complex signals as appropriate. The alarm system may be activatedthrough input from an MCP or smoke detector to an individual responder 10, tluough thepanel 11, or from elsewhere through a connection to the main panel which has not beenshown. If the system is in working order the annunciators 14 will each generate anaudible output as required, or some other output in other systems. It will be appreciatedthat the responders may not always be present, however, with the system only beingcapable of activation from the main panel 1 1, for example.?101520253035CA 02264055 l999-02- 19WO 98/08205 PCT/NZ97/00099-5-Figure 2 shows wiring arrangements in a fire alarm system according to the invention, inwhich the operation of each annunciator 14 is monitored by an event recorder 20. Onceagain each annunciator is powered from the main panel ll along lines 15, although theresponders and related equipment which would usually be present have been omitted forclarity. Each event recorder monitors a physical output of the respective annunciator,such as sound or light levels, and/or monitors voltage or current supplied to theannunciator, or a combination of the various parameters. The event recorders are usuallypowered by an internal power supply such as a lithium battery, but may also be poweredfrom the main panel along lines 15. Monitoring of the annunciator output provides anindication that the device has operated as required during a system test procedure.Monitoring of the current provides an additional or alternative indication that theannunciator has in fact been activated, whether or not it operated satisfactorily. The eventrecorders are generally able to visibly display the results of their monitoring processes insome fashion, typically by way of light emitting elements such as LEDS, or may transmita signal to a central control panel as described below.Installing an event recorder 20 at each annunciator 14 enables the fire alarm system to betested by an individual, who briefly activates the system, then visits and observes eachrecorder throughout the building in turn. The recorders are able to indicate at leasttemporarily, or when required during a visit, whether an activation event has occurred attheir corresponding annunciators. A test for satisfactory operation of the annunciators can _then be carried out without activating the system for an undue length of time which wouldannoy people inside the building, and without relying on several observers tosimultaneously check and report on respective annunciators. A series of recorders maybe installed by way of retro?t to an existing system, or initially when a new system is setup. They can be generally compact and reasonably cheap devices which cause relativelyminimal inconvenience during installation and require minimal amounts of power. Theoperation of each recorder itself must also be checked, and appropriate testing can becarried out using a portable device which applies power to both the annunciator and eventrecorder simultaneously, as will be described below.Figure 3a is a circuit diagram for a preferred event recorder according to the invention.The recorder detects physical output from the device which is being monitored, andgenerates a visible indication for inspection as to whether the device operated acceptably.In this case the device is a sounder in a fire alarm system and the physical output is soundat or above a predetermined loudness. The recorder uses power from the sounder supplywhen the sounder is activated to monitor the activation and latch whether the activationwas effective. When the sounder supply is present and after a satisfactory sound level is?101520’253035CA 02264055 l999-02- 19WO 98/08205 PCT/NZ97/00099-6-reached, an appropriate display lamp is turned on and remains on after the sounder isdeactivated for a predetennined time, typically half an hour to an hour or more. Powerfor the display lamp is supplied by a long life battery contained within the lamp circuit.The display lamp must remain turned on for sufficient time to enable a person checkingthe recorder to visit and inspect the lamp to assess the performance of the sounder. If thesounder supply or sounder does not perform properly, or the event recorder is faulty, thelamp will not illuminate.Positive power is supplied from the main panel to the recorder through the +ve in terminalof the signal connector T2 and passed on to the sounder through the +ve out terminal ofT2. A blocking diode D1 is connected between the +ve in and +ve out terminals of T2.Diode D1 in conjunction with test connector Tl provide for the recorder and sounder tobe isolated from the main panel power supply for the purpose of localised performanceassessment. The test connector T1 incorporates a switch which has one pole connectedto the +ve temrinal of T1, the we out terminal of T2 and the cathode of D1. The secondpole of the T1 switch is connected to the +ve in terminal of T2 and the anode of D1. TheT1 switch is normally closed unless a plug has been seated in the test connector andswitches out the current blocking ?mction of D1. During normal operation the T1 switchretains the main panel wire circuit to the sounder when the recorder is connected and D1provides a backup power circuit to the sounder should the switch fail. The -ve terminalsof T1 and T2 are connected together and form a common negative terminal for the mainpanel, sounder and recorder.The +ve terminals of signal connector T2 provide the positive power source for the eventdetection part of the recorder circuit. Polarity protection diode D2, current limitingresistor R1, voltage regulator diode D3 along with filter capacitors Cl and C2 form theevent detector power supply and are connected across the +ve and -ve terminals of T2 andT1. These components stabilise the supply voltage and ?lter out electrical noise for theevent detection circuit and limit the power the recorder draws from the main panel.A microphone M 1 for detecting output from the sounder is powered through resistor R2which limits microphone current and contributes to microphone sensitivity by formingpart of the microphone load circuit. Diodes D4, D5 and capacitor C3 connected acrossthe microphone provide non linear loading on the microphone and reduce the signaloutput from the microphone as sounder loudness increases above the event detect soundloudness threshold. This increases the range of sound loudness the microphone amplifierby Q1, C4, R3, R4, C5 and R5 is capable of amplifying. Sound received by themicrophone causes a varying signal voltage to present across the microphone terminals,?101520253035CA 02264055 l999-02- 19W0 98/08205 PCT/NZ97/00099-7-which capacitor C4 couples to the ampli?er transistor Q 1. Capacitor C4 also isolates theampli?er from the microphone direct current supply. Resistors R4 and R5 provide theamplifier output signal resistive load and contribute to setting the voltage ampli?cationacross transistor Q1. Resistor R4 is connected to the recorder power supply and providesthe power source for transistor Q1 and in conjunction with resistor R3 contribute tosetting the direct current state of the ampli?er. Resistors R3 and R4 are the primarycomponents in conjunction with the characteristics of transistor Q1, which set the signaland power properties of the microphone amplifier. Capacitor C5 couples the ampli?edmicrophone signal to the peak signal detection components D6, R6 and C6 and isolatesthem from the amplifier direct current circuit.Diode D6 provides a path for positive current ?ow through capacitor C6 during cycles ofthe ampli?ed microphone signal output by transistor Q l. Capacitor C6 stores energy fromthis current ?ow resulting in an increase in direct current voltage across C6. Duringnegative parts of the microphone signal cycle, current through D6 ceases and some of theenergy stored in C6 ?ows out of C6 through the discharge resistor R6. The componentvalues of C6 and R6 are arranged so that the direct current voltage across C6 re?ects thepeak value of the amplified microphone signal. The peak value of voltage acrosscapacitor C6 is monitored by pin 4 of the voltage comparator IC1. This voltage iscompared against the event detect reference voltage Vre? on pin 3 of IC1. When thevoltage across C6 is less than Vre?, the output pin 1 of IC1 is approximately the same asthe battery Bl voltage. When the voltage across C6 is higher than Vre?, the output pin1 of IC1 is approximately zero or at ground potential. The transition of IC1 output pin 1from battery voltage to ground is used by C7, R7, R15 and Q2 as the event effectiveactivation trigger. The voltage comparative IC1 is continuously powered by the long lifebattery B1.Capacitor C7 is initially charged through resistor R7 and transistor Q2 when the batteryB1 is first connected to IC1. Once C7 is fully charged, current ceases to ?ow through R7and Q2. Transistor Q2 operates as a switch connected across capacitor C8. When theevent trigger signal is provided by [C1 switching pin 1 to ground, the charge stored in C7is discharged through D7, R7 and R8. While the sounder loudness remains above theeffective activation threshold, IC1 holds pin 1 at ground and C7 remains discharged.When the sounder loudness drops below the effective activation threshold, IC1 pin 1 pullscapacitor C7 back up to battery voltage. This causes C7 to recharge drawing currentthrough R7 and Q2. The current ?ow through Q2 switches the transistor on whichdischarges the effective activation lamp timing capacitor C8. Once C7 has recharged, the?1015202535CA 02264055 l999-02- 19WO 98/08205 PCT/NZ97/00099-3-charging current ceases ?ow through Q2 and this switches the transistor off. Thetransistor is then held in the off state by resistor R8.When uansistor Q2 is switched off the lamp timing capacitor C8 charges up to a voltageapproaching the battery Bl voltage through resistors R10 and R9. The values of C8, R10and R9 are arranged so that the time C8 requires to fully charge is sufficient time to fora person checking the recorder to visit and inspect the lamp to assess the performance ofthe sounder. The voltage across C8 is monitored by pin 6 of the voltage comparator IC1.The voltage is compared with a reference voltage We]? on pin 5 of IC1. When thevoltage across C8 is less than Vref2, IC1 sets its output on pin 8 to ground causing currentto ?ow through resistor R11 and lamp D8 causing the lamp to illuminate. When thevoltage across C8 rises above Vref2, IC1 sets its output on pin 8 to rise to approximatelythe B1 battery voltage. This causes the current ?ow through lamp D8 to cease along withillumination. Resistor R11 determines how much current ?ows through the lamp and thisis set at a level which preserves the battery life while ensuring adequate lamp illumination.Jumper J2 can be removed from its default position across resistor R9 to extend the lampdisplay time by reducing the charge current available to capacitor C 8. Extending the lampillumination time will also reduce the battery life.The voltage comparators use two reference voltages provided by diodes D9, D10, D11and resistor R12. Current flow through these diodes and resistor is arranged so thatsuitable reference voltages are obtained from the component chain. Jumper J3 acrossdiode D10 can be removed to increase the minimum sound loudness level that will berecorded as an effective sounder activation.Figure 3b is a circuit diagram for an alternative event recorder according to the invention.The recorder detects both load current and physical output from the device which is beingmonitored, although a record of either parameter would often be satisfactory. In this casethe device is a sounder in a fire alarm system and the physical output is sound at apredetermined loudness and pitch. The recorder stores power from the supply when thesounder is activated and is thereby able to indicate whether the activation was effective.When a satisfactory current, sound and/or light output level is reached an appropriatedisplay lamp is turned on and remains on after the sounder is deactivated until the storedpower supply is exhausted. Sufficient power must be stored to enable a person checkingthe recorder to visit and inspect the lamps to assess the performance of the sounder. Aninternal power supply may also be provided. Alternatively the lamps can turn off untilthe person arrives and operates a manual control on the recorder which will illuminate the?101520253035CA 02264055 l999-02- 19W0 93/03205 PCT/NZ97l00099-9-lamps using the stored power. If the sounder does not perform properly then the lampswill not illuminate.Positive power is supplied from the main panel to the recorder through terminal T2 anda blocking diode D1 before passing to the sounder through terminal T1. A fuse F1 andcurrent limiting resistor R0 lead to a voltage regulator VR1. This regulates the supply to12V and through diode D2 provides a positive supply point S at 1l.5V. Current from thispoint passes to a microphone circuit through resistor R1, to a capacitor storage and an op-amp circuit through diode D5, or to the op-amp reference circuit through resistor R2 asrequired. The op-amp circuits include ampli?ers A1 and A2 which monitor current andsound levels respectively. Either or both may be used in an event recorder according tothe invention. These circuits are similar and will be described brie?y below althoughtheir operation and adaptation for use in other recorders should be generally selfexplanatory.A microphone M1 for detecting output from the sounder is powered through a sensitivitycontrol P1 and current limiting resistor R1. Sound received by the microphone causes avarying impedance and generates an alternating voltage. A dc voltage blocking capacitorC1, divert resistor R3 for negative going currents, and rectifying diode D3 generates directcurrent. A smoothing capacitor C4. with bleed resistor R4, passes this current throughblocking diode D4 and resistor R7 to generate a voltage at the positive input of op-ampA2. The current magnitude is controlled by P1 and R7 at an appropriate level for the op-amp. If the positive input voltage is greater than the negative input voltage then the op-amp will generate a positive going output voltage and consequently a current ?ows fromsource 12 to illuminate lamp L2. Resistors R10 and R11 determine the current throughthe lamp and a minimum hold current through terminals T6 and T7 which will beexplained below. Current from the illuminated lamp passes the positive input of the op-amp and latches the lamp on.Load current through the sounder also passes through the recorder by way of terminalsT3 and T4, and a resistor network R12 and R13. Terminals T4 and T5 may or may notbe connected depending on whether the main panel provides a 12V or 24V supply.Approximately 0.5V appears across T3 and T4 when the sounder is activated, with therecorder being protected by fuse F2, and a sensitivity adjustment being provided bypotentiometer P2. Current passes through diode D6 and resistor R6 to create a voltage atthe positive input of op-amp A1. When this voltage is greater than that applied to thenegative input the op-amp will generate a positive going output voltage and consequentlya cmrent ?ows from source 11 to illuminate lamp Ll. Resistors R8 and R9 determine the?10I520253035CA 02264055 l999-02- 19WO 98/08205 PCT/NZ97/00099-10-magnitude of current through the lamp and a minimum hold current which will beexplained below. Current from the illuminated lamp passes through resistor R6 andlatches the lamp on.The recorder begins to power up when the sounder is activated from the main panel.Capacitors C2 and C3 are wired in series to maintain a suitable voltage rating, and chargewith current which is limited by resistor R5. They store power for subsequent operationof the recorder. There is a minimum charge time of several seconds for which the powermust remain on in order to reach a sufficient voltage for the op-amps and permitillumination of the lamps L1 and L2. Diodes D4, D5 and D6 ensure that the capacitorsfeed only the op-amp circuits when power to the sounder and recorder is removed.Ampli?ers having low quiescent current requirements (eg. MAX332) should be used toensure that the lamps can remain illuminated for a suf?ciently lengthy period of at leasta few minutes after power removal.Lamps L1 and L2 will be illuminated immediately on satisfactory operation of the sounderand may be con?gured to draw upon capacitors C2 and C3 as soon as the sounder isturned off, or to preserve the stored power until an observer has arrived at the recorder.If terminals T6 and T7 are connected, or terminals T8 and T9 are connected, then currentwill ?ow respectively from the sources 11 and I2 and continue until the capacitors C2 andC3 have discharged to a voltage below that required by the op-amps. This at least about30 minutes in the circuit as shown. However, it is conceivable that the observer will notarrive before the stored power is exhausted and the lamps are turned off. If one or otheror both pairs of terminals are not connected. the respective lamp currents will barely ?owuntil button PB1 has been pushed by the observer. The capacitors discharge slowly overa period of approximately one hour which is normally ample for the observer to inspecteach sounder and recorder in an entire fire alarm system during a test procedure.Figure 3c shows the circuit of an optional rectification module which enables an eventrecorder to monitor ac devices. It also enables power to be stored in the recorder withoutoperating the particular device. This can assist in reducing the length of time over whicha potentially annoying device such as an annunciator is required to operate during a testprocedure. The module is connected across the power supply to the device and toterminals T2 and T4 of the recorder.Figure 4 is a block circuit diagram for a hand held tester which may be used to check theoperationof an event recorder such as shown in Figure 3a or 3b. The tester is plugged orotherwise connected into the recorder at contacts TP1, TP2 and TP3 which are shown in?1015204253035CA 02264055 l999-02- 19WO 98/08205 PCT/NZ97/00099-11-both ?gures. Once in place it may be operated manually through push-button controls 40or remotely through a radio signal receiver 41 and output 42. A selector 43 and associatedswitches are used to enable either form of operation as required. Various tests may thenbe carried out on a recorder through interface 49 by choosing an appropriate setting onselector 44 as explained below. A battery power supply 45 energises the tester, andthrough a selector 48 applies appropriate voltage and current to the recorder and theannunciator or other device which the recorder has been installed to monitor. A charger46 is connected to mains power through a terminal 47 and associated interlocked switcheswhen the batteries are to be recharged.One test applies supply voltage to the event recorder through TP1 and TP2, to checkoperation of the circuit relating op-amp Al, and also to the monitored device. Thisactivates the device and illuminates the lamps L1 and L2 on the recorder if the requiredcurrent and sound levels from the device are reached. The lamps should remain on for ashort period after the supply voltage is removed, for subsequent observation as describedabove. The supply voltage and current can be checked by voltage/current meter 50 whichis used for performance testing of the device in conjunction with sound level readingsfrom nearby areas. A second test uses a calibrated sound source 51 and transmitter 52 tocheck the operation of microphone M1 and the circuit relating to op-amp A2. Outputfrom the monitored device is disabled so that the microphone picks up only soundsproduced by the tester.The blocking diode D1 of the recorder can also be tested in both forward and reversecurrent ?ow directions. A positive going current is first applied from TP3 to TPl asshown in Figure 3a. The current passes through a shunt and returns via interlockedcontacts on the tester. A lamp illuminates if the diode is performs acceptably underforward bias and a measurement of the voltage and current is presented on meter 50. Anegative going current is then applied to check that the diode is acceptable under reversebias, or is at least open circuit. Once again an appropriate lamp is illuminated and ameasurement of voltage and current is presented.Figure 5 indicates a fire alarm system in which event recorders 20 were installed with thesystem itself rather than in a retro?t. Two of three event recorders are shown as integralparts of their respective annunciators 14, and another is shown installed separately. Theevent recorders are able to indicate acceptable test operation of their respectiveannunciator devices 14 directly on the main panel 11. This is achieved over lines 50 tocorresponding responders 10 which in turn are normally able to communicate with themain panel as described above in relation to Figure 1. A simple digital signal is?10CA 02264055 l999-02- 19W0 98/08205 PCT/NZ97/00099-12..transmitted on lines 50 in each case. The event recorders could also conceivablycommunicate directly with the main panel 51. Either way, information conceming theoperation of each annunciator is thereby transferred to a suitable pictorial display 51 onthe main panel. The circuit of Figure 3b may be modi?ed in this system as the powerstorage by capacitors C2 and C3 will not normally be required.My invention enables compliance of emergency warning systems with safety requirementsor recommendations. It enables an alarm system such as a ?re alarm system, to be testedon a regular basis without creating an unacceptable noise intmsion for occupants of amultistory office or apartment block, for example. Numerous versions of the inventionwill be possible within the scope of the following claims.

Claims (12)

CLAIMS:

1. A method of testing an alarm system having annunciator devices such as sounders or speakers, comprising: installing event recorders to monitor at least some of the devices in the system, activating the system during a test procedure to produce audible and/or visual output from the devices, detecting operation of the monitored devices with the respective event recorders, and inspecting each recorder to determine whether the respective monitored device has operated in an acceptable fashion.

2. A method according to claim 1 further comprising:
detecting operation of the monitored devices with their respective event recorders by detecting a physical output from the devices.

3. A method according to claim 1 further comprising:
detecting operation of the monitored devices with their respective event recorders by detecting current flow in the devices.

4. Event recorder apparatus for monitoring the operation of an annunciator device comprising: output detecting means which determines whether audible and/or visual output from the device has reached a predetermined level and/or current detecting means which determines whether current flow through the device causing an audible and/or visual output has reached a predetermined level, and indicating means which provides an indication for an observer as to whether the predetermined levels have been reached.

5. An event recorded according to claim 4 wherein the physical output detecting means comprises a microphone for detecting sound level output by the device.

6. An event recorder according to claim 4 wherein the indicating means comprises a light emitting diode which is illuminated on acceptable operation of the remotely operating device and remains illuminated for half an hour or more after the device has ceased operation.

7. An annunciator for an emergency warning system, including an event recorder for monitoring operation of the annunciator, wherein the event recorder monitors a physical output of the annunciator and/or current drawn by the annunciator when producing a physical output, and generates an indication of whether or not the annunciator has operated acceptably during activation of the emergency warning system.

8. An annunciator according to claim 7 wherein the event recorder monitors audible output of the annunciator by way of a microphone.

9. A annunciator according claim 7 wherein the event recorder generates a visible indication of acceptable operation of the annunciator, for inspection at the annunciator itself.

10. A annunciator according to claim 7 wherein the event recorder generates an indication signal for transmission to a control panel located elsewhere in the emergency warning system.

11. An emergency warning system having annunciators and event recorders which monitor operation of respective annunciators, wherein the event recorders provide an indication of whether the annunciators have operated acceptably to produce an audible and/or visual output during a test procedure, and either provide their indications for subsequent inspection at the annunciators, or transmit respective indication signals to a control panel.

12. An emergency warning system wherein at least some of the event recordersare integral with respective annunciators.