Alarm system with interconnected alarm terminals

An alarm installation comprises a central alarm station and a number of alarm units. The alarm units can send messages to the central alarm station and the central alarm station can send messages such as voice messages or recorded spoken messages to a number of alert units. All sending and receiving operations are preferably performed on the public telephone network. The alarm units contain at least one operating device and/or detector for an emergency situiation and will at the activation of such a device or detector send a message thereof to the central alarm station. The latter receives the message and will send a corresponding message, e.g. in the shape of a spoken message, to the different alert places. These different alert places can then be interconnected by the central alrm station in order to interchange information in regard of suitable measures to be made.

FIELD OF THE INVENTION 
The present invention relates to an alarm system or alarm installation 
designed to connect a number of alarm units such as shops, homes or other 
premises with a central alarm station, preferably through the public 
telephone system, that is, by means of common telephone communication. 
PRIOR ART 
An alarm system is disclosed in the International patent application WO 
92/22883, wherein all of the communication is performed in the public 
telephone network and wherein the central alarm station is capable of 
dialling successively a number of alert stations by means of a recorded 
list. 
SUMMARY OP THE INVENTION 
The system as previously known is provided with a central alarm station, 
which dials, when an alarm is triggered in an alarm unit, in the same way 
as in the prior system, guided by a previously recorded list a number of 
alert or monitoring stations, that is principally telephone sets connected 
to the public telephone network, and then establishes a conference state 
between those telephone sets, where a person has answered the call, so 
that several persons can consult each other in regard of possible measures 
to be made. The central alarm station must then have a number of outgoing 
lines which is equal to the number of connected telephone sets. By this 
arrangement, also the calling of the different alert stations may be 
performed more or less simultaneously. 
Like the prior system, the central alarm station is attached to a generally 
large number of telephone lines and comprises a computer of suitable type, 
e.g. a microcomputer or personal computer, which is provided with 
circuitry for communication over the telephone lines and with a permanent 
mass memory, e.g. a hard disk. 
The central alarm station is also provided with circuitry to store, for 
example in the mass memory, recorded voice messages, and has circuitry to 
play back, that is, send on a telephone line, these messages, and/or is 
provided with circuitry to play up synthesized speech on a telephone line. 
The telephone circuitry can also perform telephone number dialling; 
automatic answer upon call reception, that is, simulate that off-hook, 
etc.; send and receive dialling or touchpad signals of DTMF type; send and 
receive voice messages; detect that a line is in use or busy, etc. The 
circuitry can advantageously in addition be configured so that a number of 
different telephone connections can be established by the central alarm 
station, and thus, with a simultaneous transmission of recorded messages. 
The telephone circuitry can also perform an interconnection of a number of 
telephone lines. 
The central alarm station also contains a control program to perform all of 
these functions. The central alarm station is normally 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 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 interfaces, drive circuits, and terminals for operating 
means such as emergency switches and push buttons of assault alarm and for 
different detectors as for burglary or break-in, fire, overflow, 
temperature; for sirens, for example located both inside and outside the 
house; telephone circuitry for sending alarm messages to the central alarm 
station, a receiver for signals from a hand-held transmitter producing 
signals for activating and turning off the alarm. All of these different 
apparatus need not exist, but a control unit with a memory, at least some 
detector for an emergency condition, and means for sending messages to the 
central alarm station are required. The expensive and more delicate 
circuitry for speech synthesis and/or 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 and a number 
of alarm units, the alarm units being arranged to send messages to the 
central alarm station and the central alarm station being able to send 
voice messages or recorded messages to a number of alerting or monitoring 
locations. All transmission and reception is performed on the public 
telephone network. The central alarm station can get confirmation of 
reception of played up messages by means of some simple sending method 
such as by means of signals obtained by operating the keypad of a 
receiving telephone set. 
The alarm units comprise at least one detector or operating means arranged 
to be activated by a person, for an emergency situation and will 
immediately, upon activation of such a detector or operating means, send a 
message thereof to the central alarm station. The station receives the 
message and will send a corresponding voice message to the various 
monitoring stations. Then the interconnecting operation of the different 
telephone sets, with which connections have been established, is 
performed. In this state comprising several interconnected telephone sets 
it is also possible to attach, on a particular command, e.g. by depressing 
a suitable key on one of the interconnected telephone sets, to the 
interconnected state further telephone sets, such as the police, so that 
the conference situation or state is widened. In that case the central 
alarm station retrieves a suitable telephone number/suitable telephone 
numbers from a secondary list linked to the list by means of which the 
interconnection has been previously established. 
Generally the alarm installation can comprise a central alarm station and a 
number of alarm units, which are placed at the locations which are to be 
monitored, and alarm terminals, which are placed at a number of monitoring 
locations or turn-out response locations. The alarm units, the central 
alarm station and the alarm terminals are connected with each other, 
preferably by means of lines in the public telephone network. The alarm 
units include devices for communicating, for instance for dialling, the 
central alarm station and for transferring on the established connection 
line alarm information, the central alarm station then comprising means 
for receiving alarm information. The central alarm station comprises for 
each associated alarm unit 
a stored list of those alarm terminals to which a message shall be conveyed 
when the central alarm station receives alarm information to the effect 
that an alarm has been triggered in this alarm unit, 
means for establishing a connection with, e.g. for dialling on the public 
telephone network, those alarm terminals which correspond to the numbers 
in that list, and 
means for interconnecting those connections, which are established with 
alarm terminals at the triggering of an alarm, so that these alarm 
terminals can communicate with other. 
In addition, a secondary list of telephone numbers of alert places may be 
provided.

DESCRIPTION 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 S. The alarm units 1 include push-buttons for 
assault alarm, for other emergency situations and/or a number of different 
detectors for various emergency situations, e.g., break-in detectors, fire 
detectors, etc. The alarm units 1 are also generally connected to an 
ordinary telephone line, to which an ordinary private telephone 6 can also 
be connected. Ordinary telephone sets 7 without alarm units are also of 
course connected to the public telephone network 5. A central alarm 
station, as generally indicated at 9, is also connected to the public 
telephone network 5 by means of several lines 11. 
In FIG. 2 a block diagram of an alarm unit 1 is shown. The central part 
thereof is a control unit 13 in the shape of a simple processor. 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 15 other 
data are stored, which are variable but must not be lost when power to the 
alarm unit fails. In the permanent section of the non-volatile memory 15 
is in this way stored for example the serial number of the alarm unit, a 
particular code number or identification number for the alarm unit 1 and 
the telephone number of the central alarm station 9. In the writable 
portion the user's authorization code and 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. The telephone circuitry 17 comprises 
normal functions for performing automatic dialling, which for example are 
found in conventional fax machines and telephone modems. These functions 
include, for example, automatic answering ("Off-hook"), conversion of a 
digital number sequence to dual-tone (DTMF) signals and the transmission 
of these signals, and detecting establishment of a connection with the 
telephone number with which one will communicate. 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, with the digits 0-9 and two 
control keys. Additionally, there are a few indicator lamps 20. 
The control unit 13 is via a device 21, which generally can include 
different types of interfaces, drive circuits, and radio frequency 
receivers, connected to the various detectors and operating devices, and 
signalling devices which can be placed at the location which shall be 
monitored, and at which generally the control unit plus accessories are 
also installed. When the device 21 includes a rf-receiver, it also has an 
antenna 23 connected thereto. 
The various actuating or operating devices or detector means include a hand 
actuated remote control 25 or hand held transmitter of the same type as is 
used for the control of automobile alarms. It comprises a radio frequency 
transmitter and operating buttons. Additionally, a key-switch 27 can be 
connected, for example via a permanent cable, to the interface and drive 
unit 21. Additionally, break-in detectors such as 29 and 31 of magnetic 
type and IR type respectively are arranged, for detection of different 
movements within a certain volume, for example also communicating with the 
interface and drive unit 21 via radio frequency transmitters. Other 
detectors for emergency situations can include smoke detectors 33, 
thermometers 35, etc. Other control devices such as a unit 36 for 
signalling an assault or an alarm for the handicapped and similar persons 
can of course also be arranged. Additionally a siren 37 in connected via a 
permanent cable to the interface and drive 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 example an ordinary 
personal computer with a monitor or display 41 and a keyboard 43. The 
computer 39 has a permanent mass memory 45, for example a hard diskdrive, 
which is suited for permanent storage of a large amount of information. A 
number of accessory boards are arranged for the computer 39, such that the 
computer 39 is 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 arranged to perform principally the same 
functions as the telephone circuitry 17 in the alarm units (FIG. 1), that 
is, they can establish telephone connections, send and receive, encode and 
decode DTMF signals, etc. The lines from the line units 49 are also 
connected to a switch unit or exchange unit 51, which, commanded by the 
computer 39, is capable of interconnecting lines 11 as selected by the 
computer. 
For each connected alarm unit, in the mass memory 45 identification 
information, authorization code, telephone number to the alarm unit, the 
telephone numbers of the first list comprising those telephone numbers 
which are dialled automatically upon reception of an alarm from the alarm 
unit, and the telephone numbers of the secondary list which are dialled at 
a particular command in a conference interconnection state, voice messages 
for various emergency situations such as burglary, fire, assault, 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, 
it is performed in the same way as in the previously known system. The 
user of the alarm unit 1 can thus himself enter those telephone numbers 
which are to be dialled when an alarm is triggered. These telephone 
numbers can also, in a simple way be deleted or changed. Further, 
telephone numbers of a secondary list can also be entered. 
When an alarm has been triggered, the central alarm station 9 performs 
alarm diallings or calls, so that all telephone numbers on the monitor 
stations list of the alarming unit will be contacted. If desired, then a 
message can be played up in a connected telephone set of type: "If you 
wish to participate in a telephone conference with other monitoring 
stations, please press button 1. Otherwise press button 0." The depressed 
key is then recorded by the central alarm station. When all monitoring 
locations or stations have been asked and corresponding to those cases 
where the answers 1 (="Yes") are obtained, the computer 39 send signals to 
the interconnection box 51, that the corresponding telephone lines are to 
be interconnected. Alternatively, also an interconnection ay be always 
performed of the dialled telephone numbers. After the interconnection of 
another telephone line, possibly a message thereof can be replayed in the 
interconnected telephone lines. In this message information can also be 
inserted in regard of the possibility of interconnecting further telephone 
lines to the conference, such as "If you desire the participation of the 
police, then please press button 7." When the circuitry of the central 
alarm station then detects that the key 7 has been depressed on one of the 
interconnected telephone sets, the central alarm station dials the 
telephone number of the secondary list which then comprises a single 
telephone number. Alternatively, also e.g. a depression of the key 8 may 
signal dialling the telephone number having order number 2 in the 
secondary list, etc.