ALARM SYSTEMS

Abstract: An alarm apparatus is disclosed which comprises a plurality of detector devices grouped to provide a plurality of levels of protection. At least one of the detector devices is present in at least two levels and is connected to means for determining different characteristics for the detector in respectively different levels. Detector characteristics such as an option of a time delay or an immediate alarm may be provided for one or more of the alarms.

Description: ALARM SYSTEMS The present invention relates to alarm systems and more particularly to modifications which will make alarm systems more easy to use and to tailor to a user's wishes. In currently available alarm systems a premises is divided into a number of zones each monitored by a single detector. The zones can be collected together into a group called an area and there may be a number of different areas within the premises. On installation, the installer discusses with the user of the alarm system what operation is desired for each detector e.g. whether it is to be a normal alarm or an entry route, and whether or not the detector should only be in operation while the premises are empty. On this basis, the installer divides the premises into one or more areas and also decides which attributes each detector should have within the or each area. Once the attribute of a detector has been determined by the installer, it cannot be changed by the user. One example of this is a detector for the entry zone. It is customary for this detector to be connected to the main alarm circuitry by a delay circuit so that the user has time to de-activate the alarm. This delay is permanent so that if the premises are entered while the alarm is armed, there will always be a time delay before the alarm is sounded. This problem results in conventional alarm systems being broken down into a large number of areas in order to provide the user with the desired alarm capability. UK Patent Application GB 2150333 discloses an intruder alarm system having a plurality of modes of operation whereby different areas of a house, for example, may be protected in different ways at different times. This is achieved by either utilising or not utilising each individual alarm, and not by utilising different characteristics of one or more of the alarms depending on the mode of operation which has been selected. Such adaptability has however increased the complexity of the alarm system and reduced the ease with which an alarm system is armed by the user. The present invention seeks to overcome the problems of increased complexity and difficulty by the user by proposing that one or more zones of an alarm system be provided with programmable stores for storing information indicative of different zone characteristics. Preferably, the different zone characteristics are associated with respective levels each of which relates to a collection of one or more areas linked together. The advantage of this system is that a user simply has to arm the alarm at a particular level in order to achieve the desired operation. This can usually be done with the minimum of difficulty i.e. an access code plus one letter code such as A, B, C, or D or turning a key switch from off to full or part settings. In order that the present invention be more readily understood, one embodiment thereof will now be described by way of example with reference to the accompanying drawings, in which:- Fig. 1 is a diagram illustrating the basic principals of the present invention; Fig. 2 shows a plan of the ground floor of a building using the illustration of Fig. 1; and Fig. 3 shows a plan of the first floor of a building shown in Fig. 2. Referring to Fig. 1, this shows in diagrammatic form how an alarm system for a premises such as a house with a garage can be structured. It will be seen that the premises are divided into three areas namely the ground floor (area 01), the garage (area 02) and the first floor (area 03). These three areas are grouped together in differing combinations into four levels with each level being assigned a single fixed key on a keypad of the main control panel. The levels are as follows: Level A arms the whole system. Level B arms the perimeter zones of the ground floor with the exception of the entry/exit zones. Level C arms the garage and ground floor zones but not the first floor; Level D arms only the garage. Turning now to Figs. 2 and 3, the premises is in the form of a house having ground and first floors, sometimes called first and second floors in some parts of the world, and a garage. The garage is a quite distinctly separate location and constitutes its own area within the alarm system. This is area 02 and includes two alarm zones or detectors one of which, zone 12, is a PIR detector and one of which, zone 11, is a flush door contact. The ground floor of the house is provided with a number of detectors monitoring different zones. The main areas such as the kitchen, dining room, study and lounge are provided with PIR detectors as in the hall. The front and back doors as well as the French doors and the door from the kitchen into the hall are provided with flush contacts. The French doors and windows adjacent them are provided with shock sensors. On the first floor, as will be seen from Fig. 3, there is a single PIR detector monitoring the upstairs landing. Thus far, the alarm installation could be conventional but we would have to decide, in a conventional system how to deal with the front and back doors and the PIR detector in the hall and kitchen. In a conventional system, as these zones are normally entry/exit zones, a time delay would have to be introduced into their operation to allow time to disarm the system. The present invention proposes that one or more of the zones be capable of different functions depending on the level of alarm called for by a user. For example, the front door which is designated Zone 01 in Fig. 2 can be provided with a number of different functions so that on installation the installer can define this zone to operate as a normal alarm i.e. no time delay when level C is set, as a NOT USED zone when level B is set and as a final exit zone i.e. with time delay, when level A is set. Likewise, the rear door which is designated zone 10 in Fig. 2 could be defined in exactly the same way as zone 01 or it could be modified to operate as a normal alarm when both levels B and C are set. This flexibility of function is achieved by the alarm system having a number of zones each of which has a plurality of different functions associated with it. The installer can therefore choose the desired function for such a zone depending on the level of the alarm system. This is best achieved by software in view of the fact that modern alarm systems are now microprocessor based. It will be appreciated that this flexibility results in a user being able to readily set the alarm with a variety of modified functions. With modern alarm systems using keypads, it is possible to assign a single key to a respective level. Alternatively a multi- position key switch can be used.

Claims: CLAIMS : 1. An alarm apparatus comprising a plurality of detector devices grouped to provide a plurality of levels of protection, wherein at least one of the detector devices is present in at least two levels and is connected to means for determining different characteristics for the detector in respectively different levels. 2. An alarm apparatus according to claim 1, wherein the means for determining different characteristics comprises means for storing information indicative of said different characteristics. 3. An alarm apparatus according to claim 1 or 2 wherein the different characteristics are the presence of a time delay and an immediate alarm. 4. An alarm apparatus substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: ARMSTRONG DAVID, ARMSTRONG, DAVID
Applicants: ARMSTRONG DAVID, SCANTRONIC LTD, ARMSTRONG, DAVID, SCANTRONIC LIMITED
Application year: 1995
Main classification: G08B13
IPC codes: G08B13