TECHNICAL FIELD

[0001] The invention relates to an alarm system detector suitable for monitoring opening status of a door or window.

SUMMARY OF THE INVENTION

[0002] The present application discloses an alarm system detector for an alarm system in accordance with the independent system claim.

[0003] According to a first aspect, there is provided an alarm system detector for use with a door or window, the detector comprising a

magnetometer for measuring strength and direction of a magnetic field, and a processor connected to the magnetometer, wherein the magnetometer is configured to sense the magnetic field in the vicinity of the magnetometer, wherein the processor is configured to analyze the strength and/or direction of the magnetic field, and wherein the processor further is configured to analyze the strength of the magnetic field in two different directions.

[0004] Advantageously the field strength for each direction is compared with a threshold, or two thresholds for each direction and send a signal to a displaced control unit, indicative of the result of the comparisons. This primarily to determine the opening or closed status of the window or door.

[0005] Further there is provide an alarm system detector that can handle to determine the status of two windows or door using a single detector using a single magnetometer and a permanent magnet for each of the

doors/windows.

[0006] According to a second aspect there is provided a method for installing a sensor with an adjustable detection field the following steps may be included

- Mounting a magnetometer sensor at a non-movable window frame;

- Mounting a magnet at a movable window frame; [0007] Check alarm trigger position of window (by opening it) using default values of magnetic strength

- If needed, adjust x, y and z parameter values in the installation tool.

- Open window to test the new settings.

- Save the new magnetic field strength and direction settings into installation memory unit as“alarm trigger point

[000S]

[0009] Additional advantages will be set forth in part in the description which follows or may be learned by practice. The advantages will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments and together with the description, serve to explain the principles of the systems and methods. In the drawings,

Fig. 1 is a schematic view of an installation of a home wireless system controlled in accordance with one embodiment of the invention

Fig. 2 is a front view of a window with two moveable window frames and a non-moveable frame, provided with a detector main unit and one permanent magnet per moveable frame.

Fig. 3 is detailed view of the window with detector of Fig. 1.

Fig. 4 is a flowchart of a detection method

Fig. 5 is a flowchart of an installation method

Fig. 6 is a flowchart of another installation method

DETAILED DESCRIPTION

[0011] In the embodiment shown in Fig. 1 an installation comprising a home wireless system is installed in a building 10. The home wireless system is an alarm system installation and comprises a plurality of wireless peripheral nodes including wireless peripheral devices, a first gateway 12 and a second gateway 12’. The second gateway 12’ is mains powered and normally is not provided with battery backup. One wireless peripheral node is a first infrared detector 14 mounted in the corner of a room close to the ceiling. The first infrared detector 14 has a sensing area that covers the first gateway 12. A first perimeter alarm detector 16 is mounted at a window 17 in the same room. The infrared detector operates in a conventional manner to detect presence and movements of objects emitting infrared radiation. The perimeter alarm detector also operates in a conventional manner to detect when a door or a window is opened. In various embodiments the perimeter alarm detector comprises a magnetic sensor that will detect when a magnet attached to the door or window is moved.

[0012] Second gateway 12’ is arranged in a second room separated from the room where the first gateway 12 is arranged. A second infrared detector 14’ is mounted in the same room as the second gateway 12’ to cover it within its operative area and a second perimeter alarm detector 16’ is mounted at a window 17’ in the same room. A keypad 19 is mounted close to a front door 20 of the building 10. The keypad 19 is used by an operator of the alarm system to arm and to disarm the alarm system. The keypad 19 also is a wireless peripheral node. The front door 20 is covered by a third perimeter alarm detector 21. Another type of wireless peripheral device is a smoke detector 23 mounted in the ceiling of building. In various embodiments a plurality of smoke detectors 23 are arranged throughout the building 10 to ensure that fire can be detected at an early stage.

[0013] Depending on different circumstances the first gateway 12 and the second gateway 12’ are connected to a remote central monitoring station 22 either through a wired connection 24 or through a wireless connection such as GSM or a similar digital cellular network. The connection to the remote central monitoring station 22 can also be through the internet 26. In the embodiment shown in Fig. 1 , internet connection is provided through a wireless router 32 that is connected to internet by fibre, cable or Digital Subscriber Line, such as ADSL. In the embodiment shown in Fig. 1 second gateway 12’ is connected by wire 33 to wireless router 32. The wired connection 24 can be part of a public switched telephone network 25. In various embodiments the remote central monitoring station 22 comprises an interface module 27, a database 28 and a web server 29. The database 28 stores installation and application data relating to the installation including all wireless network nodes and alarm settings.

[0014] The first gateway 12 can be capable of communicating with the second gateway 12’ because of the more powerful radio transmitting means. By placing gateways strategically within a building it is possible to guarantee that every peripheral node has an adequate RF link with at least one gateway. As long as the gateways can all communicate with each other, the installation will function properly. To achieve full redundancy the installation should include enough gateways for every peripheral node to be able to communicate with at least two gateways.

[0015] An installation such as the alarm system shown in Fig. 1 holds a large amount of dynamic state information, such as arm state, alarm status, peripheral battery status, etc. in a total system state information dataset. Similar information is stored also in other types of home wireless systems. Each gateway or controller continuously receives inputs from different authenticated sources such as peripheral nodes, a RCMS, adjacent systems, etc. that affects a distributed state of the application or system.

[0016] In various embodiments, a second gateway can utilize the RF communication link of another gateway for tunneling messages to a remote central monitoring station (RCMS). For example, if the second gateway up link to RCMS is very slow or unreachable, or has a higher cost, another gateway up-link can be utilized.

[0017] The detector of the present invention is detection changes in magnetic field by use of a magnetometer. Magnetometers are generally available and can be acquired from e.g. Asahi KASEI - AK09970 or equivalent. This enables new features for traditional magnetic contact products: [0018] Enable open/close functionality of two moving window sections 34 by use of two magnets 36 and one main unit/sensor housing is shown in Fig. 2.

[0019] Protection against external manipulation by using a strong magnet 38. Enabled by measuring deviation in magnetic strength and magnetic field direction. Once manipulation is detected then an alarm signal will be sent (function part of“shield protection”).

[0020] Field of magnet detection (x, y, z) can be adjusted (software parameters) at installation to better fit the unique installation which decreases the need of magnet spacers.

[0021] Field of magnet detection (x, y, z) can be adjusted by arranging the door/window in desired position and then this setting is recorded into the system (as an option to use instead of #3).

[0022] Since field of magnetic detection is adjustable this could enable a solution were a possible smaller and/or cheaper magnet is used.

[0023] Possible to identify the magnet(s) used and thus to detect tampering attempts.

[0024] Possible to market shell (perimeter) protection because of use of one main unit covering two windows (lower customer costs)

[0025] Thus, there is provided an alarm system detector for use with a door or window 34, the detector comprising a magnetometer 40 for measuring strength and direction of a magnetic field, and a processor (not shown) connected to the magnetometer, wherein the magnetometer 40 is configured to sense the magnetic field (drawn as field lines in Fig. 3) in the vicinity of the magnetometer. The processor is further configured to analyze the strength and/or direction of the magnetic field. The magnetometer and the processor may be housed in a magnetometer housing 40

Further, the processor may be configured to compare the strength of the magnetic field in one, two, three or more directions with one, two or more thresholds for each direction and send a signal to a displaced control unit, indicative of the result of the comparisons. [0026] The detector advantageously further comprises one or more permanent magnets 36 configured to be mountable on a moveable portion of one or more door or windows 34.

[0027] The detector, wherein the processor is advantageously connected to a wireless unit for communicating status information to a displaced control unit

[0028] The processor may be configured to analyze change in the magnetic field and/or direction.

[0029] The processor may be configured to detect one or more of the following: a door/window being in an open position, a door/window being in a closed position. The processor may be configured to detect one or more of the following: opening of a door/window, closing of a door/window;

[0030] The detector, wherein the processor is configured to detect opening of a sliding door/window, closing of a sliding door/window, opening of a swinging door/window, closing of a swinging door/window;

[0031] The magnetometer may be configured to be mounted between two doors/windows, and the processor is configured to detect which one of the doors/windows that are in an opened or closed position.

[0032] The processor may be configured to detect a magnetic field change corresponding to an attempt to tamper with the detector by applying an external magnetic field. This may be the case if a burglar uses a strong hand held magnet to try to fool the system.

[0033] The processor may be configured to compare the magnetic field to a third, higher threshold for determining a tamper attempt.

[0034] The detector, wherein the processor and/or the magnetometer may be configured to sample the magnetic field at a first sample frequency, and upon detecting an increasing magnetic field shift to a second, higher sample frequency, thereby increasing the possibility to detect a tampering attempt.

[0035] The detector, wherein the processor may be configured to detect a tampering attempt by identifying an increasing magnetic field over time.

[0036] Main unit (magnet sensor) can detect any of the following cases by measuring magnetic strength(T):

[0037] To = no magnet is present => both windows are open

[0038] T 1 = one magnet is present => one of the windows are open

[0039] T2 = two magnets are present => both windows are closed

[0040] In an external protection example of Fig. 4 processor polls and reads 420 magnetic field strength (T) and magnetic field direction (D). Processor may be configured to analyze 430 such that if change DT of magnetic field strength over predetermined time and/or magnetic field direction AD is greater than predetermined threshold then processor sends an alarm signal.

[0041] Fig. 5 discloses an installation method for achieving an adjustable detection field. The method may comprise the following steps:

- Mounting 520 sensor at non-moveable window frame;

- Mounting 530 magnet at movable window frame 34;

- Checking 540 alarm trigger position of window (by opening it) using default values of magnetic strength

- If needed, adjusting 550 x, y and z parameter values in an installation tool;

- Opening 560 window to test the new settings

- Saving 570 the new magnetic field strength and direction settings into an installation memory unit as“alarm trigger point”

[0042] Fig. 6 discloses an installation method for teaching detection field called“Teachable detection field”. The method may comprise the following steps:

- Mounting 620 sensor at non movable window frame;

- Mounting 630 magnet at movable window frame;

- Opening 640 window to desired position where alarm should be triggered;

- Reading 650 present magnetic field strength B (Tesla) from magnetic field;

- Reading 660 present magnetic field direction D from magnetic field;

- Save 670 magnetic field strength T and direction D into installation memory unit as“alarm trigger point"; [0043] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the inventive concept. Other embodiments will be apparent to those skilled in the art from

consideration of the specification and practice disclosed herein. It is intended that the specification and examples be considered as exemplary only.