W092/22883 2 11 1~ '~ 6 PCT/SE92/ ~ 05 Alarm installation The present invention relates to an alarm ~ystem or alarm installation designed to connect a number of alarm units located in homes or other buildings with an central alarm station via the public telephone system, that i8, by means of common telephone communication.
Background of the invention In order to protect homes against different types of threats ~uch a~ burglary or break-ins, fire, etc., various kind6 of alarm installations are employed which, in the simplest case, only activate an audible siren when an alarm is triggered, while aore advanced alar~ installations can perform a dialling of a central alarm 6tation where emergency personnel are present.
There are also installations that can dial a number of telephone numbers sequentially. These advanced sy6tems are, however, expensive, since enough processor power must be pre6ent in every hoae from which an alar~ ~hall be able to be triggered.
There is thus a need for an alarm installation with inexpensive apparatu6 which can be placed in every home and which are ea~ily installed. Such a sy~tem shall also be able to execute an automatic dial-up of various freely cho~en telephone number6, for example to homes or apartments situated nearby the place from which the alarm i6 triggered.
Prior art Fro~ U.S. Patent No. 3,492,426 a telephone based alarm system i6 previously known having alarm locations from which an alarm can be-triggered; a central ala D station connected thereto through lines of the pUblic telephone network; and per~anent lines fro~ the-central alarm station to various locations, where supervi~ing or emergency turn-~ut persons are present for various kinds of alarms, e.g. to a police station, the fire department, health service. When an alarm is triggered at an alarm location, a message is sent from the alarm location by means of telephone circuits over a telephone line with a code for the type of alarm to the central alarm station, which contains suitable telephone circuits for automatic reception of telephone messages and decoding circuits for these messages.
Guided by the sent code the central alarm station chooses the alerting locations, which shall receive the alarm, and sends a w092/2~3~ 6 PCT/SE92/0~05 recorded voice me~sage to that alerting or guard location. There is no possibility here to sequentially or simultaneously dial a number of eguivalent subscriber~ on the public telephone network from the central alarm ~tation upon reception of an alarm from an alarm location.
From the European patent application EP Al 0 051 383 a telephone alarm system is previously known having an alarm location in which a person residing at the alarm location can trigger an alarm. At the alarm location a central alarm device is installed which is provided with telephone circuits and is connected to the public telephone network. Upon the triggering of an alarm the central alarm device sequentially dials a number of telephone numbers which are stored in the central alarm device. When a call i8 successful, a recorded voice message is played over the telephone line, after which the next telephone number in the sequence is dialled. Certain set time periods in the central alarm device can be changed by a call to the central al~r~ dev~ce over the telephone network and entry of a special ~cces~ code plus codes for these times by means of key depre~ion~ on a normal keypad telephone. The central alarm device can al~o activate an audioalarm audible at the alarm location, resulting in dialling the stored telephone numbers, provided that the alarm is not deactivated by a manual interce~sion at the alarm location.
From U.S. Patent No. 4,482,785 a system for monitoring freezers i~ previously known, which includes alarm sensors at the fre~zers, and an alarm centre connected to said sensors.
Upon reception of an alarm telephone circuits in the alarm cent~e dial the first telephone number in a list which is stored in the alarm centre. If the call is answered, a voice message is played up over the telephone line over and over again. At this the answering party is expected to use a push-button telephone keypad to enter a particular code. At this, touch-tone signals are sent, which are received and decoded by the alarm centre, which compares the received code to a previously stored code in the alarm centre. If agreement is reached, the alarm message is con~idered as received, and then no more calls to telephone numbers in the list are made. If the call does not succeed, the next number in the list is taken.
WOg2/2~3 21 1 ~ 2 2 6 PCT/SE92/00405 From U.S. ~atent No. 4,652,859 an alarm system i6 previously known, ~n which an alarm centre, upon reception of an alarm signal from Qome alarm sensor, ~enas a wireles~ signal to a di~tantly placed portable unit. If an answer or acknowledgment i6 not received from the portable unit within a previously determined time, telephone and logic circuits are used to dial a telephone number, decode an acces~ code received from this connection and compare with a reference in the alarm centre, and lastly play up an audible ~e~sage.
~ escription of the invention The invention relates to an alarm installation with attributes and characteristics a6 defined in the appended claims. By the invention an inexpensive alarm installation i8 attained, which i8 at the same time very easily installed.
The alarm centre ic attached to a generally large number of telephone lines and compri~es a computer of suitable type, e.g.
a microcomputer or per~onal computer, which is provided with circuitry for co~munication over the telephone lines and with a permanent mas~ memory, e.g. a hard disk.
The central alar~ station is also provided with circuitry to tore, for example in the ma~s memory, recorded voice me~sage~, and has circuitry to play back, that is, send on a telephone line, the~e ~e~sages, and/or is provided with circuitry to play up synthesized ~peech on a telephone line.
The telepbone circuitry can also perform telephone number dialling; auto~atic an~wer upon call reception, that is, ~imulate that off-hook, etc.; ~end and receive dialling or touchpad signals of DTMF type; send and receive voice messages;
detect that a line is in use or bu~y, etc. The circuitry can advantageously in addition be configured so that a number of different telephone connections can be established by the central alarm ~tation, and thus, with a simultaneous transmission of recorded ~essages.
The central alarm station also contains a control program to perform all of these functions. The central alarm station is no.~ally unmanned, but an operator can of course directly control it via the keyboard attached to the computer.
The alarm units have considerably less expensively built control centres. These include, as is conventional, a controller wo 92/2~3 2 1 i 1 2 ~ 6 pcT/sE92/n1~s such as a microprocessor having a suitable control program; and with for example a control panel with a keyboard of essentially telephone type having keys for digits and some control characters and indicator lamps, a small non-volatile memory;
additionally with an interface, drive circuits, and terminals for different detectors as for burglary or break-in, fire, overflow, temperature; for sirens, for example located both in~ide and outside the house; telephone circuitry for sending alarm messages to the central alarm ~tation, a receiver for ~ignal6 from a hand-held transmitter producing ~ignals for activating and turning off the alarm. All of these diferent apparatus need not exist, but a control unit with a memory, àt least some detector for an emergency condition, and means for ~ending messages to the central alarm station are required. The ~xpensive and more delicate circuitry for speech synthesis and for the storing/replaying of voice messages thus are arranged only in the central alarm station.
The alarm installation thus comprises a central alarm station ~nd a nu~ber of alarm units, said alarm unit~ being arranged to ~end me~ages to the central alarm station, said central alarm station being able to ~end voice messages or recorded messages to a nurber of alerting or monitoring locations. Al1 sending is performed on the public telephone network, wherein the mobile t~lephone system is included. The central alarm station can get confir~ation of reception of played up messages by means of some i~ple ~ending method such as by means of signals from the keypad of a receiving telephone set.
- The alarm units comprise at least one detector for an mergency situation and will i D ediately, upon activation of ~uch a detector, send a message~thereof to the central alarm ~tation. The station receives the message and will send a corresponding voice message to the various monitoring stations, only in the case where an additional message that the alarm ~hould be turned off has not arrived to the central alarm ~tation within a predetermined time period after the reception of the first, immediately sent message.
This function, that alarm units at the monitored locations directly send an alarm message to a centre, which later in turn alarms guard personal, emergency personal or police, if a new W092/2~3 2 1 1 1 2 2 ~ PCT/SE92/~os me~age ha~ not arrived to the central alarm station within a certain time period, said ~es~age meaning that the ~larm wa~
actually a false alar~, does not itself presuppo~e a central alar~ 6tation of the type described above; the central alarm station can thus, for example, be a conventional type, constantly manned guard centre.
Detectors in the alarm units can be provided with a transmitting device for wireless connection, for example by eans of radio frequency signals, to the central unit, which includes a corresponding receiver unit. When a condition monitored by a detector changes, the detector sends identifying ~ignals which unambiguously inform which detector is sending the ~essage, and information that said condition has changed. The control unit of central alarm station compares the received signals with information stored in the memory of the control unit in order to determine from which detector a received re~sage originates, and with knowledge of this performs a previously determined function, e.g., to activate an alarm, ignore the ~e~sage, or store it for later u6e, for example when the alar- i~ activated.
In the detector a battery for power supply thereof is provided and a sensor circuit for checking or testing the battery voltage. Every time the detector sends a ~essage about a condition change, info D ation about battery voltage is also ~ent, particularly if said condition is the fact that the battery voltage is too low.
The control device of the alarm unit derives that part of ~uch wireles~ly received messages which refers to the battery voltage of a detector and, with guidance thereby, performs a -previou~ly determined function,~for example, activates ~ome indicator or ~aves the received message for later u~e.
For a ~i~ple way to regi~ter connection of ~uch a detector the control device of the alarm unit has a particular connection or reception mode, wherein the control device can wirelessly receive information ~ent from a detector which is activated only for this purpo~e, and which for example, on this occasion, is held or placed next to the receiver section of the control device. The control unit of alarm unit stores the identifying signals contained in this information for a later identification 21112~
W092/2~3 ~ PCT/SE92/~OS-of the detector upon reception of the wirelessly tran~mitted ~ignals.
Brief descri~tion of drawinas The invention ~h~ll now be described in more detail with reference to the attached diagrams, in which:
Fig. 1 schematically shows the general configuration of the alarm in~tallation, Fig. 2 ~hows a block diagram of an alarm unit, Fig. 3 ~hows a block diagram of a central alarm station, Fig. 4 shows a block diagram of a break-in detector, Fig. 5 shows a block diagram of a hand held transmitter.
~ etailed descri~tion of the invention In Fig. 1 a number of alarm units are shown, which are generally indicated by the numeral 1, and which by means of connecting wires are linked with the public telephone network 5.
The alarm unit~ 1 include a number of different detectors for different emergency situations, e.g., break-in detectors, fire detector~, etc. The alarm unit~ 1 are al~o in general connected to a co~on telephone line, to which a common private telephone 6 al~o is connected. Common telephone apparatus 7 are also of cour~e connected to the public telephone network 5. A central alar~ ~tation, generally indicated at 9, is also connected to the public telephone network 5 by means of ~everal lines 11.
In Fig. 2 a block diagra~ of an alarm unit 1 is shown. The central part thereof is of a control unit 13 in the shape of a ~imple proces~or. Belonging to it are, among other things, a non-volatile memory 15. The latter has a permanent portion, in which of course the program for the control unit is stored along with certain data. In a writable part of the memory lS other data are stored, which are vari~ble but may not be lost when power to the alarm unit fails. In the permanent section of the non-volatile ~emory 15 is in this way ~tored for example the ~erial number of the alarm unit, a particular code number or identification number for the alarm unit 1 and the telephone number to the central alarm station 9. In the writable portion the u~er's authorization code, identification number, and channels for connected detectors and other devices are stored.
The control unit 13 is, via telephone circuitry 17, connected to the line 3 to the public telephone network.
W092/22W3 2 1 i 1 ~ 2 6 PCT/SE92/ ~ 05 The telephone circuitry 17 comprises normal function6 for performing automatic dialling, which for example are found in conventional fax machines and telephone modems. These function6 include, for example, automatic answering (~Off-hook~), oonver~ion of a digital number sequence to dual-tone (DTMF) ~ignals and the transmis6ion of these signals, and detecting establishment of a connection to the telephone number with which one will co~unicate. The telephone circuits 17 also include functions for reception of DTMF signals and conversion thereof to suitable digital signals.
A control panel 19 is connected to the control unit 13 and comprises a simple keyboard for telephone communication, wit~
the digits 0 - 9 and two control keys. Additionally, there are indicator lamps, for example 4 in number, for signalling the status of the alarm unit 1.
The control unit 13 i~ via a device 21, which generally can include different types of interfaces, drive circuits, and radio freguency receivers, connected to the various detectors, actuating devices, and signalling devices which can be placed at the location which shall be ~onitored, and at which generally the control unit plus acce~sorie~ al~o are installed. When the device 21 includes rf-receivers it also has an antenna 23 connected thereto.
The variou~ actuating means or detector means include a hand actuated re~ote control 25 or hand held transmitter of the same type a~ i~ u~ed for steering automobile alar~s. It comprises a radio frequency transmitter and two operating buttons, one for OFF and one for ON.
Additionally, a key-~witch 27 can be connected, for example via a per~anent cable, to the interface and drive unit 21.
Additionally, break-in detectors such a8 29 and 31 of ~agnetic type and IR type respectively are arranged, for detection of different movements within a certain volume, for example also communicating with the interface and driver unit 21 via a radio frequency transmitter.
Other detectors for emergency situations can include smoke detectors 33, thermometers 35, etc. Other control devices such as a unit for signalling an assault or an alarm for the handicapped can of course also be arranged. Additionally a siren W092/2~3 21112 2 6 PCT/SE92/~05 ~-37 in connected via a permanent cable to the interface and driver unit 21.
In Fig. 3 a block diagram of the central alarm station 9 is shown. It comprises as its main component a computer 39, for exa~ple a common personal computer with an monitor or display 41 and keyboard 43. The computer 39 ha~ a permanent ma~s memory 45, for example a hard diskdrive, which is ~uited for permanent ~torage of a large amount of information. Further, the computer 39 i~ connected to lines 11 to the public telephone network via voice or speech processors 47 and line interface units 49. The speech processors 47 convert information received from the computer 39 to audible speech. The line units 49 are arrange~ to perform principally the same functions as the telephone circuitry 17 in the alarm units (Fig. 1), that is, be able to establi~h telephone connections, send and receive, encode and decode DTMF signal~, etc.
The operation of the alarm installation will now be described.
When a new alarm unit 1 shall be connected to the central alarm station 9, the owner, operAtor of the alarm unit, or the person responsible thereof is given an authorization code consisting of a number combination. By means of the keyboard of the control panel 19 various control codes or programming codes and infor~ation are fed in. With a certain progra~ming code plus the authorization code the alarm unit 1 thus enters programming ~ode. Another prograrming code causes the alarm unit to dial up the central alarm ~tation 9. At this the alarm unit retrieves the correct tele p one number out of its non-volatile memory 15 and perfor~s the dialup. When the connection with the central alarm ~tation later is establi~hed, it is indicated in a suitable way, for example by lighting or blinking an indicator la~p on the control panel 19. After entry of another programming code the personal authorization code can be changed. A list of i~portant functions is given below:
code + authorization code alarm unit in programming mode code dial up central alarm station code + own telephone no. alarm unit telephone number placed into alarm unit code + new authorization code new authorization code stored in wo 92/22883 2 i 1 1 2 2 ~i pcr/sEg2/oo4o5 alarm unit and central alarm ~tation code + li~t po~ition number + telephone number to designated telephone nu~ber receiving station i6 placed in central alarm station code + list position number corresponding telephone number to de~ignated alar~ receiving ~tation removed from central alarm station code exit prograr~ing mode and return to normal mode When establishing telephone contact with the central al~rm ~tation 9, the telephone circuit~ of the alarm unit them~elves perfor~ dialling, and checks that the telephone connection is established, performing as usual a nu~ber of re-dials if the connection can not be made. When a telephone connection is e~tabli~hed, the alarm unit sends, b~v mean~ of DTMF signals or re generally, by ~eans of dialling signals, identifying information ~uch a~ the production or ~erial number of the alarm unit, a particular code nu~ber or authorization nu~ber for the alar~ unit 1 and the user's authorization code. It waits ther~after for a ~ignal fro~ the central alarm station 9, this al~o being a DTNF ~ignal or a ~ingle frequency signal, for confirmation of the authorization of the alarm unit. When ~uch ~ignal~ arrive on the telephone line 3, they are decoded to appropriate digital signals and are forwarded to the contxo}
un~t 13, which performs the suitable logical choices. If a confir~ation signal i~ not received within a predetermined time poriod, the identification infor~ation is ~ent in the usual fashion once again. When confi~ation is received, that the connection i~ establi~hed and that the alarm unit is authorized, it is indicated suitably by ~eans of the visual indicators of the alar~ unit on it~ control p~nel 19 and/or the siren 37. In the latter case, the siren 37 should naturally be placed inside the premi~e~.
When other information shall be stored or changed in the central alarm ~tation 9 from the alarm unit 1, a suitable code is sent as above, which identifies the type of information which shall be added or changed, and thereafter the information W092/22883 21 1 1 2 2 6 PCT/SE92/~05~
it~elf. The alarm unit 1 wait~ for confirmation that the information is received, as deEcribed above, and produces a suitable visual and/or audible signal after received confirmation.
The user of the alarm unit 1 thus himself enters tho~e telephone numbers which shall be dialled when an alarm is triggered. These nu~bers can also easily be removed or changed.
Of the information mentioned above, only the user's authorization code is stored in the individual alarm units 1.
This code and all the other information is stored centrally in the mass memory 4s of the central alarm station 9.
Several of the above given particulars can also be stored and changed from a common telephone set or apparatus. Therefor the u~er of course then requires knowledge of a suitable telephone number to the central alarm station 9, which can be intended only for this type of communication. The user dials this number on his telephone apparatus and when the connection has come through to the central alarm station, he will hear a spoken me~sage, synthetically produced or previously stored, at the original installation programming of the central alarm station, for example, ~Welcome to central alarm station XX. Please identify yourself by entering your authorization code on the keypad of your telephone set." The authorization code functions here both as identification of the alarm unit with which this call is concerned, and as a security code 80 that no unauthorized person will enter the system.
When the caller later has entered his authorization code, for exa~ple on the nowadays common type of dialling equipment having pushbuttons and DTMF signalling, it is received by the DTNF
circuitry arranged in the central alarm ~tation 9, and is checked against a list which is stored in the memory 45 of the central alarm ~tation control unit 39. When authorization is establi~hed, the control unit 39 produces new voice messages that provide different alternatives which the caller can choose by the depression of ~uitable keys on the telephone equipment.
These can for example be "Add telephone number to the monitor stations listH: The caller can here add telephone numbers which shall be dialled when an alarm has been triggered in the caller's alarm unit.
W092/2~3 2 1 1 1 2 2 ~ PCT/SE92/~05 The~e telephone numbers are in~erted by the control unit 39 of the central alarm station into a list for said alarm unit that is held in tbe memory 45 of the central alarm station.
~ Remove telephone number from monitor stations list": It may be neces~ary to remove telephone numbers from the monitor ~tations list stored in the memory 45 of the central aiarm ~tation.
~ Record the alarm mes~age which shall be sent to the members of your ~onitor stations list upon alarm. Begin after the tone heard soon!~ The caller can himself here store the voice ~es~age, which will be played back on a telephone 7 when the central alarm station 9 has received an alarm from the alarm unit 1 and has dialled the number to a member of the monitor stations list, and the connection has been established. Such a message ~ight be, ~This is Carl Andersson's alarm ~ystem on 26 ~ainstreet. An alarm has been triggered in my apartment. Hurry there! Confirm reception cf this ae~sage by pressing key 8."
Different ~essages can here be stored for alarms from different connected detectors 29 - 35, and then of course the instruction to speak in the message is formulated accordingly.
The alarm unit 1 is activated or deactivated either through operating a suitable pu~h button on a remote control 25 or through operating a key-switch and/or by typing in a particular code on the control panel 19 of the alarm unit 1 along with the authorization code. When the alarm unit is deactivated, normal alar-s can not be triggered, with the exception of fire alar~s which can be prograr~ed to alway~ give alarm, both audibly with the siren 37 and by ~eans of a call to the central alarm station 9. In the deactivated ~tate the control unit 13 however always receive~ signal~ from the attached detectors and stores their last received status. In the activated state naturally all types of alar~s are triggerable.
Assume now that a break-in alarm is triggered in a connected alarm unit 1. By means of the telephone circuitry 17 in the alarm unit 1, a message is immediately sent to the central alarm ~tation 9 informing it that the break-in alarm is triggered. The ~èssage contains, as above, identifying information for the alarm unit 1 and inormation about the channel number of the detector which has triggered the alarm. The alarm unit 1 awaits W092~2~3 2 ~1 12 2 ~ 12 PCT/SE92/~05 ~
confirmation that the alarm me66age has been received. Normally, when thi6 mes~age i8 ~ent, the connected siren~ 37 ~1BO 6tart to ~ound. An authorized person at or nearby this alarm unit can now turn off the alarm, for example with a key which fits the keyed-~witch 27. The alarm can al60 be turned off by means of the ræmote control 2S by depressing it6 OFF-button. Additionally, the alarm can be turned off by entering a particular code followed by the authorization code on the keyboard of the control panel 19. When such an authorized turn-off signal arrives to the control unit 13 of the alarm unit 1, it sends a ~essage to the central alarm station 9 as to this event. The ~es6age contains, if a new call must be made, as previously, identifying information for the alarm unit, and then a code corresponding to the occurred event. If such an alarm cancellation me6sage has not arrived at the central alarm 6tation within a previou61y determined short time, 6ay 30 ~econd6, after the central alarm station has received the original alarm mes~age, then it begins its alarm procedure.
If the alarm has been unintentionally triggered, an authorized person thus can within 30 - 45 second6 ~reak off a bsgun alar~ call. All other attempt6 to sabotage the alar~ will oppositely result in the alarm call being completed according to the following.
The central alarm ~tation 9 identifies thus fir6t, which the alar ing unit is and fetches the monitoring stations list belonging to this unit. By ~eans of its telephone circuits 49 and ~iscuit~ 47 for replaying 6peech it simultaneously performs, on 80 ~any outgoing telephone lines as possible, calls to telephone nu~bers on the monitor stations list. When a conversation has been coupled up to such a number, the answering party will hear a message regarding what has happened in his telephone earpiece. This message can, for example contain a general portion ~uch as ~Here is a message from central alarm ~tation XX. n Then a message portion is played up, which originates from an earlier recording by telephone from an authorized user's call, for example, ~This is Carl Andersson's alarm equipment at 26 Nainstreet. A break-in alarm has been set off in my apartment. Hurry there! Confirm reception of this message by pushing key 8. n The central alarm station 9 checks W092/2~3 2 1 1 12 2 6 PCT/SE92/~05 that the right key get pressed and notes thereafter in it~
monitor station~ li6t that the corresponding telephone number has been alarmed or alerted.
The central alarm station continues then calling 80 that all the telephone number~ on the monitor station~ li6t are informed.
In the event that a telephone conversation can not by coupled up, for example because a busy tone iB received, the central alar~ station control unit 39 can be ~etup for ~ome suitable redialling procedure, for example redial every minute for a maximum of ten tries.
The various logical functions that the control unit 39 in the central alarm station 9 shall perform are uncomplicated and include few logical choice~. The control unit 39 can be configured BO that it continually tests the different connected telephone lines 11 by means of their line units to ~ee if a call has occurred. After the call in, the control unit waits for a predeter~ined time for a sequence with identification infor~ation shall be received. If thi~ does not occur, then the control unit 39 a~sumes that the call i8 from a normal telephone app~ratus and that then some sequence as de~cribed above will be perfor~ed in order to change some alarm sub~criber's ~tored infor~ation.
If the call is from an alar~ unit, its identifying infor~ation is compared to the information stored in the mass r~ory 45. If the infor~ation is correct a check for more sent infor-ati~n is done. If this information contain~ report of a triggered alarm along with the channel number for the detector which ha~ triggered the ala D, this information is immediately ~tored in the per~anent memory 45 and an internal timer in control unit 39 is started. Dur~ing the time which follows hereafter, until the timer times out, the control unit 39 continually checks if an cancellation message is received from the ~ame alarm unit 1. In that ca~e, no calls are made to the telephone numbers on the list belonging to this alarm unit. On the other hand, if no such message is received, the control unit 39 starts dialling all of these telephone numbers. The telephone number~ are retrieved therefore from the mass memory 45 and the control unit determines which telephone lines 11 are free. Then starts simultaneous sending on as many line as is needed or are W092/2~3 2 ~ 1 12 2 ô PCT/SE92/~05 ~
u~able; that i8 dialling telephone numbers and the playing of voice ~e6~age6 i8 performed. By means of the channel number from the alarm information the control unit 39 can roughly divide alarns into break-in alar~s, fire alarms, etc., and the corre~ponding mes~age i6 played up. Confir~ation by pre6sing a key on the telephone equipment as instructed in a voice ~essage, i8 received and decoded by the line units 49. Re-dialling in the conventional way can be perforuQd when no telephone connection can be Qstablished or no confirmation is received.
When the control unit 39 of the central alarm station 9 instead receive6 m~ssages with programming information from an alar~ unit 1, the ~ent information i8 simply stored.
Confir~ation is sent as ~entioned above, for example by the central alarm station sending a single frequency tone.
In Fig. 4 a block diagram is shown for a break-in detector 29 of ~agnetic type. It comprises as its main component a control circuit 101 coupled to a radio frequency transmitter 103, which can ~end radio signals to the alarm unit 1 and, specifically, its antenna 23 and interface and driver unit 21. A magnetically actuated ~witch 105 is provided. This ~witch 105 can al80 be actuated ~anually by ~eans of a push-button 107 arranged on the detector unit 29. A unique identifying number is stored in a per-~nent ~ecory 109 in the detector 29. The detector is powered by a battery 111. Between the poles of the battery 111 a sensing circuit 113 there is arranged for sen~ing the battery voltage, and ~pecifically to produce a signal to the control circuit 101 if the battery voltage is too low.
Upon alarm activation of the detector 29 the alarm switch 105 clo~es which i6 sensed by the control circuit 101. The control circuit 101 then send~ by means~of the radio frequency tran~itter 103 a ~essage, which comprises first the identifying ~equence stored in the ~emory 109, followed by information that indicates if switch 105 has been closed or opened, further followed by information reporting if the battery voltage is ~atisfactory or not.
Also, the detector 29 always sends a signal whenever the ~witch 105 changes its contact status, and the corresponding signal i8 also always received by the interface and driver unit 21 and is relayed to the control unit 13, which stores this W092t2~3 2111 2 ~ ~ PCT/SE92/ ~ 05 .
information for po~sible later u~e. The ~ame signals are naturally ~ent when the switch 105 i8 actuated manually by pushing the button 107.
The remote control 25 i8 built similarly to the above detector 29 and a block diagram for 6uch a unit i8 shown in Fig.
5. The hand held transmitter 25 includes two switches 115 and 117, which can be actuated manually by push-buttons 119 and 121 respectively. Pushing the ON-button 121 80 that switch 115 closes means an activation of the alarm unit 1. In this case the re4ote control 25 sends, by mQans of its radio frequency transmitter 103, in a ~imilar way as above, first its identification sequence, stored in the memory 109, followed by information which communicates that the ON-switch has been clo~ed. The corresponding process i8 carried out when the other switch 117 is closed by pushing the OFF-button 121, but of cour~e with different information or code, which are sent by means of the radio transmitter 103.
When the alar~ unit 1 i~ powered up, its control unit 13 checks that all the connected break-in detectors have their nor al status. If this is not the case, the alarm unit 1 emits an audible signal using the ~iren 37 and/or by means of the indicator~ of the control panel 19. one can then deactivate the ala D unit 1 to explore the cau~e of the ~ignal, but if it is not done the control unit 13 will a~sume that the corresponding detector i~ faulty and will ignore it in the future. If a signal ha~ been received indicating that the battery voltage in a detector is too low, it is also indicated in a corresponding way by the control unit 13.
Connection to the alarm unit 1 of an additional detector of the type having a built-in tra~smitter as above or a hand held trang~itter 25 is done in a very simple way. Entry of a particular code on the keyboard of the control panel 19 followed or preceded by the authorization code, followed by entry of a channel number for the detector or hand held transmitter places the control unit 13 in receiving mode. The corresponding detector or hand-held transmitter 25 is manipulated so that it ~ends out its signal as above, for example by pressing push-button 107, or the ON- or OFF-pushbuttons 119, 121, and the signal is received by the interface and driver unit 21, W092/2~W3 2 i 112 2 ~ 16 PCT/SE92/~05~
whereafter the identification number of the sending device is entered in the non-volatile memory 15 together with its channel number. After this a particular exit code is entered on the keyboard of the control panel 19. Particular channel numbers within a certain number interval can thus be a~signed to hand-held transmitters, while other~ are assigned to break-in detectors, and further others can be a~signed to detector~ of another type, which require permanently enabled alarming, such a8 for fire, water, etc.
The connection of a wirele~ly connected detector or hand-held tran~mitter 25 can be removed in a corresponding way by entering another particular code at the keyboard of the control panel 19, along with the authorization code. After this the channel number of the connected unit is entered, and thereby the corresponding detector or hand-held transmitter i8 removed from the li~t ~tored in the memory of the control unit.