WO2001018762A1

WO2001018762A1 - Improvements in or relating to detection systems

Info

Publication number: WO2001018762A1
Application number: PCT/GB2000/003408
Authority: WO
Inventors: Alan Henness; Paul Martin Kenny; Robert John Probin
Original assignee: Ademco Microtech Limited
Priority date: 1999-09-07
Filing date: 2000-09-05
Publication date: 2001-03-15
Also published as: AU7021200A; GB9920981D0

Abstract

A dual signalling interface (10, 50) for enhanced communications between a control panel (104, 170) and one or more detection devices (102a-e, 122, 124, 126, 128) in a detection system (100, 120) such as an intruder, security (i.e. access control) or a fire system. The interface (10, 50) includes means (60, 80) for passing two signals having substantially the same information content to provide added security and/or reliability in the detection system (100, 120).

Description

IMPROVEMENTS IN OR RELATING TO DETECTION SYSTEMS

The present invention relates to detection systems and in particular, though not exclusively, to a dual signalling interface for enhanced communications between a control panel and detection device (s) of a detection system such as an intruder, security (i.e. access control) or fire system. A conventional detection system comprises a number of detection devices such as contact switches, key switches, key pads, PIR (passive infra red) detectors, smoke detectors or the like positioned throughout a premises to be protected. Each device may be individually wired to a^' control panel via typically a minimum of six dedicated lines i.e. ground, DC power, two alarm and two tamper connections. The interface at the devices is a terminal block with a minimum of six contacts and the control panel has an interface which includes a similar terminal block for each device connected in the system.

These systems have disadvantages such as requiring a large amount of multicore cabling and lack means to transfer additional data between the control panel and devices without adding more lines.

U.S. Patent No. 5 347 515 (Pittway Corporation), the content of which is incorporated herein by reference, discloses a global polling system which can be used with detection systems. This system is commercially available as the "Vplex" (Trade Mark) system distributed by Ademco Microtech Ltd, Scotland. In that system, a plurality of serially addressable detection devices are connected together and to a central controller via a two-wire loop. The system uses a tri- level line signal over the two wires to concurrently provide both DC power and bi-directional digital data transfer. An interface at each device is a two terminal block and the interface at the control panel accommodates two terminal connections for the devices . Each interface also includes the necessary decoding circuitry to decode the digital data signal.

Although this system has an advantage of reducing the amount of cabling and providing digital data transfer, the removal of direct dedicated alarm and tamper lines poses a potential reduction in security as activation of the alarm or tamper on any device is not transmitted until the device is polled by the central controller.

An object of at least one embodiment of the present invention is to obviate or mitigate at least one of the aforementioned disadvantages of existing detection systems.

It is a further object of at least one embodiment of the present invention to provide a dual signalling- interface which when incorporated into a detection device allows the device to be used with a control panel of a conventional detection system or a "Vplex" (Trade Mark) system.

It is a further object of at least one embodiment of the present invention to provide a dual signalling interface which when incorporated into a control panel, the control panel can be used with detection devices currently- available for conventional or for "Vplex" (Trade Mark) detection systems.

It is a further object of at least one embodiment of the present invention to provide a dual signalling interface which when incorporated into both a detection, device and a control panel provides a detection system, the detection devices of which may be remotely accessed for- commissioning, maintenance and service requirements. It is a further object of at least one embodiment of the present invention to provide a dual signalling interface which when incorporated into both a detection device and a control panel provides a detection system with, built-in redundancy in the form of two communication methods between detection device (s) and the control panel so that, for example, in the event of an alarm two signals are independently relayed from the detection device to the control panel for added security or increased reliability. According to a first aspect of the present invention there is provided an interface for passage of signals between a control means and at least one detection device in a detection system, the interface including means for passing at least two signals having substantially the same information content . Such an interface may conveniently be termed a "dual signalling interface".

Preferably, the detection system may be chosen from an intruder alarm system, fire detection system or security- system (i.e. access control system) . The detection device may be a contact switch, a key switch, a key pad, a PIR (passive infrared) detector, a smoke detector, microphone, acoustic detector or the like. Additionally the detection device may include a microprocessor or ASIC chip to acquire, store or evaluate data to be transmitted.

In a preferred embodiment the detection device is a PIR detector incorporating the dual signalling interface.

In use, the two signals may be passed from the at least one detection device to the control means. The interface may receive and/or transmit signals to and/or from the control means via at least one bus.

Additionally or alternatively, the interface may receive and/or transmit signals to and/or from the at least one detection device via at least one bus. In one embodiment the dual signalling interface includes at least two outputs wherein the at least two outputs are capable of transmitting signals carrying substantially the same information but relaying the information via different transmission means. Preferably a first transmission means is by the loss or drop of signal on an electrical wire and a second transmission means is by a digitally encoded signal on a power supply line. Alternatively the first or the second transmission means may be selected from different electromagnetic or acoustically radiated signals in which the frequency, amplitude or duration of the signal is varied.

Preferably the interface also includes at least one input wherein this input is connected to a power supply line. This power supply line may be AC or DC. Further inputs may be included and comprise a ground or earth connection or alternatively a negative DC.

More preferably the at least one input connected to a power supply line is connected to a digital decoder such that digital data encoded on the power supply line can be transmitted across the interface. The digital decoder may comprise a comparator circuit .

In a preferred embodiment the interface comprises at least three pairs of inputs and outputs. A first pair may be 0V and 12V power rails which may also be capable of transmitting digitally encoded data; a second pair may be an NC (normally closed) alarm relay/switch and a third pair may be an NC tamper relay/switch. The transmission means of the relays/switches may be by signal loss when the relay/switch is triggered OPEN.

According to a second aspect of the present invention there is provided a detection device for use with a control means in a detection system, the detection device including an interface according to the first aspect. Preferably, the detection system may be chosen from an intruder alarm system, fire detection system or security system (i.e. access control system) .

The detection device may be a contact switch, a key switch, a key pad, a PIR (passive infrared) detector, a smoke detector, microphone, acoustic detector or the like. Additionally the detection device may include a microprocessor or ASIC chip to acquire, store or evaluate data to be transmitted.

According to a third aspect of the present invention there is provided a control panel for use with at least one detection device in a detection system, the control panel including at least one interface according to the first aspect.

Preferably the control panel includes a means such as a key pad to allow a user to input a code to set/arm or unset/disarm the detection system.

Additionally the control panel may include a microprocessor means which may be programmable via an operator inputting keystroke commands, by data transfer from an infrared or microwave remote device, or from remote signals such as telephonic line signals from a connected PSTN (Public Switched Telephone Network) , ISDN (Integrated Services Digital Network) link ,ADSL (Asymmetric Digital Subscriber Line) or the like.

According to a fourth aspect of the present invention there is provided a detection system comprising a control means, at least one detection device, and at least one interface according to the first aspect.

Advantageously at least one of the control means or detection device (s) includes the interface.

Advantageously the control means and each of the detection device (s) includes an interface. Alternatively the detection system may include at least one bus . The at least one bus may be connected between the control means and the at least one detection device .

The detection system may also include a portable device, the portable device including remote signalling means, the remote signalling means provides a signal, such., as an electromagnetic or acoustic signal, which may be used to program or operate the detection system remotely.

According to a fifth aspect of the present invention there is provided a method of relaying information within a detection system, the method comprising the steps of: providing a detection system including control means and at least one detection device generating an information signal within the detection device; generating two signals encoded with the information signal ; and transmitting the two signals to the control means.

Preferably the system also includes an interface according to the first aspect . Preferably also, the two signals may be transmitted to the control means on the interface .

The information signal may be indicative of an alarm state or other state of the detection device.

In a preferred embodiment the information signal is digitally encoded onto a power supply line as a transmission means for the first signal, and an NC relay/switch is opened as the transmission means for the second signal.

According to a sixth aspect of the present invention there is provided a method for remotely accessing a detection device (s) in a detection system in order to provide remote maintenance and/or monitoring and/or commissioning of the system, the method comprising the steps of : providing a detection system including a control means and at least one detection device; transmitting a signal from a remote site to a/the at least one detection device via the control means; receiving the signal at the detection device; decoding the signal; performing instructions provided by the signal; optionally encoding a response signal and transmitting the response signal to the remote site via the control means . Preferably the detection system also includes an interface according to the first aspect .

Preferably also the signal transmitted from the remote site is transmitted to the detection device (s) via the interface . Preferably also the response signal is transmitted to the remote site via the interface.

The remote site may be an ARC (Alarm Receiving Centre) .

These and other aspects of the present invention will become apparent from the following description when taken in combination with the accompanying drawings in which:

Figure 1 is a schematic diagram of a dual signalling interface configured for a detection device, in accordance with the present invention; Figure 2 is a schematic diagram of a dual signalling interface configured for a control panel, in accordance with the present invention;

Figure 3 is a schematic diagram of a data transmission and receiver circuit for use in a detection device with the interface of Figure 1;

Figure 4 is a schematic diagram of a data transmission and receiver circuit for use in a control panel with the interface of Figure 2;

Figure 5 is a schematic diagram of a detection system connected to an ARC (Alarm Receiving Centre) in accordance with an embodiment of the present invention; and

Figure 6 is a schematic diagram of an embodiment of a detection system in accordance with the present invention. Reference is first made to Figure 1 of the drawings which depicts a dual signalling interface, generally referenced by numeral 10, in accordance with a preferred embodiment of the present invention. Interface plane 12 separates input lines 14, 16, 28, 20, 22, 24 from output lines 26, 28, 30, 32, 34, 36, 38, 40, 42. The interface plane 12 provides a bus connection for additional output lines 34, 40, 42 from one or more of the input lines 26-42. This arrangement has the advantage in reducing the number of auxiliary lines between a detection device and a control panel . The number and purpose of the input and output lines may be varied depending on the specification of the detector and/or control panel in use .

The interface 10 is configured for use in a detection device where input lines 14, 16, 18, 20, 22, 24 are formed from a multi-core cable bundle which is wired to the control panel, sometimes referred to as control and indicating equipment (CIE) . Input lines 18, 20 are hardwired and are used for NC (normally closed) alarm relay/switch. Input line 18 is directly connected to output line 30. Output line 30 is connected through an. alarm relay/switch to line 32 and back to the control panel to complete a loop by line 20. A constant voltage is maintained on this loop. In the event that the alarm relay/switch is activated, the loop is broken and the consequent loss of signal on line 20 is noted at the control panel, where sirens, alarms, communication through links to the ARC or the like will be activated. Additionally the loss of signal in the loop will be detected on the bus of the interface plane 12. This signal will be encoded onto another line, as described hereinafter, and passed to the control panel also. In this way, if the alarm relay/switch loop 18, 20, 30, 32 is rigged, by an intruder to maintain the voltage level in the loop, the alarm may still be detected by the control panel via the additional signal carried on the line 16. Lines 22, 24, 36, 38 are also hardwired and operate in the same manner as the NC alarm relay/switch loop. This loop contains the tamper relay/switch which detects an. intruder interfering with the detection device itself.

The hardwired lines 18-24, 30, 32, 36, 38 are identical, excepting the bus connection to those of conventional detection systems. Power lines 14, 26, 28, 16 operate in a similar manner to those of a "Vplex" (Trade

Mark) system disclosed in US Patent No 5,347,515.

Reference is now made to Figure 2 of the drawings which depicts a dual signalling interface, generally indicated by numeral 50, in accordance with an embodiment of the present invention. Interface plane 12a separates input lines 14, 16, 18, 20, 22 and 24 from output lines 44, 46, 48, 52, 54 and 56. The number and purpose of the input and output lines may be varied depending on the specification of the control panel and/or detection device in use.

The interface 50 is configured for use in a control panel where input lines 14, 16, 18, 20, 22, 24 are formed from a multi-core cable bundle which is wired to a detection device. A similar interface 50 may be used for each detection device in a system. Input lines 18, 20 are hardwired and are used for NC (normally closed) alarm/switch relay. Input line 18 is directly connected to output line 48. Output line 48 is connected to a zone alarm which in turn is connected to line 52 and back to the detection unit to complete the loop by line 20. A constant voltage is maintained on this loop. In the event that the loop is broken via the alarm relay/switch in the detection device being activated, consequent loss of signal on lines 18 and 20 activates the zone alarm and in turn sirens, alarms, communication through links to the ARC or the like will be activated. Additionally the loss of signal in the loop will be detected on the bus of the interface plane 12a. This signal will be encoded onto another line, as described hereinafter, and passed to the control panel also. In this way, if the alarm relay/switch loop 18, 20, 30, 32, 48, 52 is triggered by an intruder, say, to maintain the voltage level in the loop, the alarm may still be detected by the control panel via the additional signal carried on the line 14, 44.

Lines 22, 24, 36, 38, 54, 56 are also hardwired and operate in the same manner as the NC alarm relay/switch loop. This loop contains the tamper relay/switch at the detection device which detects an intruder, say, interfering with the detector itself, and is connected via lines 54, 56 to a tamper zone alarm in the control panel.

Lines 44, 46 represent the power lines providing current and voltage to each detection device. The lines 14, 16, 44, 46 operate in a similar manner to those of a "Vplex" (Trade Mark) system disclosed in US Patent 5,347,515.

A "Vplex" (Trade Mark) system operates by using a serially addressable detector. The power lines 26, 28, 14, 16, 44 46 form a polling loop which provides both power and bi-directional data transfer between the detector and the control panel. In this way the "Vplex" (Trade Mark) system transmits alarm and tamper signals by digitally encoding signals onto the power lines. A tri-level baseband technique is used to provide both suitable power levels and logic 0 and 1 digital signalling simultaneously.

In the preferred embodiment the features of the "Vplex" (Trade Mark) system are incorporated on the power lines 14, 16. An interface circuit is used to detect the data signal from the incoming signal and provide the necessary drive to transmit data back to the control panel . A schematic of the interface circuit, generally indicated by numeral 60, for the detection device is shown in Figure 3. In transmitting data mode, when data has been requested by the CIE the power supply lines 14, 16 are held at approximately half the normal level and current is limited by the interface circuitry 60 at the CIE. To transmit a digital 1, no action is taken. To transmit a digital 0 the detection device drives the power supply line to substantially 0 V with the driver 62. In receiving data mode, two comparators 64 and 66 level detect data received from the CIE via the power supply lines 14 and 16. The thresholds for these comparators 64, 66 will typically be approximately 75% and 25% of the power supply respectively. Thus the comparator 64 recovers the clock signal from the tri-state digital data and comparator 66 recovers the data. These signals are then sent to a microprocessor or other circuit for decoding via lines 68, 70.

Because the tri-state digital present on the power supply (whether initiated from the CIE or the detection device) may affect the operation of the detection device, the power supply must be filtered to remove the tri-state signal before being passed to the remaining circuit in the detector. This is achieved with the diode 72 and the filter 74. The diode 72 also provides reverse polarity protection. Typically, the filter 74 is a capacitor and this supplies power to the detector whilst voltage levels other than the normal supply are present on the power supply lines 14, 16. Figure 4 shows an interface circuit, generally indicated by numeral 80, for use with the interface in a control panel. When transmitting data, the current limited source 82 is switched off allowing the full supply to be connected to a resistor 84. Because resistor 86 is of a similar value, the voltage level on the +12V power terminal will be approximately halved. This level corresponds to a digital 1. If a digital level 0 is required, the power supply is driven to substantially 0V with the driver 88. To receive data, the CIE monitors the power supply line 14 with the comparator 90. The threshold for the comparator 90 will typically be approximately 25% of the power supply. Since it is the CIE that generates the clock signal that is put onto the bus, the CIE can easily decode the data received from the bus. Reference is now made to Figure 5 of the drawings which, depicts a security system, generally designated 100, in accordance with a preferred embodiment of the present invention. Detectors 102 represent contact switches, PIR detectors, smoke detectors or the like. Each detector is positioned within a zone of the premises to be protected. Each detector 102 is hardwired (not shown) to the control panel 104 for tamper and alarm relays. ^■ Power lines 106 from each detector 102 are coupled to a bus 108 which in turn is connected by power lines 106f to the control panel 104. Bus 108 represents the "loop" of a "Vplex" (Trade Mark) system described hereinbefore. The loop 106, 108 transfers power and data between the control panel 104 and the detection devices 102a-e.

For each detection device, 102a-e, the dual signalling interface within the detection device is used to transfer signals from the alarm relay/switch and tamper relay/switch. to the hardwired lines; transfer signals from the digitally encoded power lines to the decoding circuitry, and the decoding data to the microprocessor within each detection device. The microprocessor also produces data which is encoded onto the power lines to be transferred via the dual signalling interface onto the bus for transmission to the control panel . The control panel includes a dual signalling interface onto which the hardwired lines are connected to represent each zone. In this way, an alarm or tamper signal from a detection device is uniquely identified to a zone at the control panel 104. The dual signalling interface at the control panel 104 also receives the power lines 106 with encoded data going to and from the detection devices 102 via the bus 108. In use if a detection device, say, identifies an intruder, the alarm relay within the detection device will be triggered. This results in the relay loop being broken and a change in the signal will occur on the interface of the detection device and be transmitted by hardwire, to the interface of the control panel . In addition, the signal loss will be relayed on the interface of the detection device to the encoding circuitry which will encode the address of the detection device and a digital signal representing the alarm onto the power line. This encoded signal is "picked up" on the "loop" and transmitted to the interface of the control panel . The signal is decoded at the control panel . In this way both the interface of the detection device and the interface of the control panel have transferred two signals one hardwired and one digitally encoded onto a power line, with the same information content, an alarm signal from an identifiable detection device. This provides redundancy within the system so that if either line is tampered with, the alarm signal should still be transmitted to the control panel for added security.

Additionally, the redundancy within the system ensures reliability if required. This is done by setting the control panel so that it only recognises a signal if it receives it from both transmissions and the data is identical .

Figure 5 also shows a link 112 to an ARC 110. The link 112 is by modem which is dialled-up automatically from the control panel in the event of an alarm or tamper being activated.

The ARC 110 can also send data through the link 112 to the control panel 104. This data transfer allows the ARC

110 to monitor the control panel 104 for faults and performance checks . Through the use of the interfaces and via the bus 88, the present invention allows data to be transmitted directly from the ARC 110, through the link 112, over the interface of the control panel 104, via the bus 108 to any one of the detection devices 102. This transmitted data may commission a detection device, check the status of a detection device, provide a test signal, change controls on a detection device or turn on, off or reset a detection device after an alarm or tamper has been activated. In addition to this remote accessing feature a similar feedback occurs so that the microprocessor or ASIC within each detection device can transfer data on its status and performance across its own interface, via the bus 108, over the control panel interface, and through- the link 112 to the ARC 110. This remote accessibility reduces the number of servicing visits required by engineers. Reference is now made to Figure 6 of the drawings which depicts a detection system, generally designated by numeral 120, in accordance with an embodiment of the present invention. The system 120 comprises collections of detection devices 122, 124, 126, 128 grouped in zones 130, 132, 134, 136 which may represent levels such as floors in a building. Each collection of detection devices 122, 124, 126, 128 are connected via a bus 140, 142, 144, 146 as described in Figure 5. The detection devices 122, 124, 126, 128 are connected to a concentrator 150, 152, 154, 156 which introduces an intermediate point between the detection devices 122, 124, 126, 128 and the control panel 170. Each concentrator 150, 152, 154 156 may include an interface to reduce the number of signals relayed to the control panel 170 and provide alarm means on each level 130, 132, 134, 136. Each concentrator 150, 152, 154, 156 is connected to a bus 160 to communicate between concentrators and the control panel 170. This control panel 170 communicates with the alarm receiving centre 172 in the same manner as described in Figure 5. The advantage of this embodiment is that it provides a system which can remain operational when a fault occurs in one of the levels or detection devices. It also provides flexibility in control and installation.

A feature of the present invention is in the ability of any detection device fitted with a dual signalling interface to be used with a conventional or "Vplex" (Trade

Mark) control panel. In this case, the digitally encoded data transfer feature or the hardwired tamper and alarm lines, respectively are inoperable and the system is reduced to operating as a conventional or "Vplex" (Trade

Mark) system respectively. The advantage of the dual signalling interface detectors being able to operate within the conventional or "Vplex" (Trade Mark) systems is that a distributor now need only stock one type of detection device since conventional and "Vplex" (Trade Mark) detection devices cannot be interchanged.

The dual signal interface when fitted to a control panel provides a control panel which can be used in systems with conventional or "Vplex" (Trade Mark) detection devices. Thus the control panel of the present invention provides a panel which works with any available detection devices, or a mixture of detection devices. By using this control panel, a detection system can be upgraded at any time by switching the conventional or "Vplex" (Trade Mark) detection devices at a time chosen by the user and this does not require replacement of an entire system to adopt the advantages of a system of the present invention.

Further advantages of the present invention are that neither a detection device or control panel requires any additional block connections to provide for the dual signalling interface: the normal power connections are used for all communication, little hardware needs to be added to either a control panel or a detector to interface with the "Vplex" (Trade Mark) bus, in addition to specific detection devices being produced, transponders that can be used with passive devices (e.g. contacts) or other non- "Vplex" (Trade Mark) detection devices may also be produced.

Adding the components for the interface to a standard control panel is straightforward, and requires nominally three I/O pins on its microcontroller. The circuitry at the detection device is much simpler, but also requires nominally three microcontroller I/O pins. Additionally, if the reset is not required the number of I/O pins is reduced.

When the interface is used in the conventional mode, it would not require the installer to even be aware of any other modes. It would be entirely transparent to him and would not require any knowledge or action to enable him to use the system conventionally.

When the interface is used in the "Vplex" (Trade Mark) mode it would enable a system to be wired using a two-wire bus. There would be no restriction on the connection topology, although there would be a restriction on the total cable length (dependant on the cable and its gauge) . Detection device control and diagnostics information can be transmitted over the "Vplex" (Trade Mark) bus giving benefits to the installer.

When the interface is used in both detection devices and the control panel according to the present invention this dual mode would allow conventional transmission of alarms and tampers from a detection devices, perhaps using EOL (End of Line) techniques. This may allow some systems to meet particular approval requirements. Control of the detector (e.g. test mode) and diagnostic information would be transmitted over the "Vplex" (Trade Mark) bus, giving far greater control than a conventional system can provide.

In dual mode, the transfer of data to the detection devices provides improved control of detection devices including the pulse count and sensitivity. This allows these parameters to be controlled either from the control panel/keypad or remotely from the ARC.

The transfer of data also provides additional detection diagnostics including (depending on the design of the detection devices) terminal voltage, current drawn, signal level, noise level, sensitivity and pulse count, mask status, self-test analysis, and bus error report. The terminal voltage, current drawn and bus error reporting would be useful for finding wiring faults, especially at the time of installation. Any of this diagnostic data could be further transmitted to the ARC if required to provide additional remote diagnostic capabilities . Further enhancements include giving an audible indication at the control panel or keypad (or roving diagnostics unit) of the detection signal. This would ease coverage checks of detection devices.

Advantages of the present invention to the installer include : i) lower wiring costs and quicker installation - only two terminals are wired. Two-core cable could be used if available and cost effective; ii) improved reliability because of fewer cable cores and terminal block connections; iii) better diagnostics and control available at control panel and ARC, and iv) only one product variant need to be held for repairs and new installations.

A advantage to the distributor is that only one product variant needs to be stocked. It will be appreciated that various modifications may be made to the embodiments hereinbefore described without departing from the scope of the invention.

For example, although only two modes of signalling have been described, hardwired and digitally encoded, other signalling modes could be used such as radio frequency transmission, or fibre optic cabling.

Additionally, the description has been directed towards an intruder security system but the detection system could be used for access control systems, fire systems or the like with appropriate detection devices.

Claims

1. An interface for passage of signals between a control means and at least one detection device in a detection system, the interface including means for passing at least two signals having substantially the same information content .

2. An interface as claimed in claim 1 wherein the interface receives and/or transmits signals to and/or from the control means via at least one bus .

3. An interface as claimed in claim 1 or claim 2 wherein the interface receives and/or transmits to and/or from the at least one detection device via at least one bus .

4. An interface as claimed in any preceding claim wherein the interface includes at least two outputs wherein the at least two outputs are capable of transmitting signals carrying substantially the same information but relaying the information via different transmission means.

5. An interface as claimed in claim 4 wherein a first transmission means is by the loss or drop of signal on an electrical wire and a second transmission means is by a digitally encoded signal on a power supply line.

6. An interface as claimed in any preceding claim wherein the interface comprises at least three pairs of inputs and outputs; a first pair being OV and 12V power rails which may also be capable of transmitting digitally encoded data; a second pair being an NC (normally closed) alarm relay/switch and a third pair being an NC tamper relay/switch.

7. A detection device for use with a control means in a detection system, the detection device including an interface according to any one of claims 1 to 6.

8. A detection device as claimed in claim 7 wherein the detection device is a contact switch, a key switch, a key pad, a PIR (passive infrared) detector, a smoke detector, microphone, acoustic detector or the like.

9. An detection device as claimed in claim 7 or claim 8 wherein the detection device includes a microprocessor or ASIC chip to acquire, store or evaluate data to be transmitted.

10. A control panel for use with at least one detection device in a detection system, the control panel including at least one interface according to any one of claims 1 to 6.

11. A control panel is claimed in claim 10 wherein the control panel includes a means such as a key pad to allow a user to input a code to set/arm or unset/disarm the detection system.

12. A control panel as claimed in claim 11 wherein the control panel includes a microprocessor means which is programmable via an operator inputting keystroke commands, by data transfer from an infrared or microwave remote device, or from remote signals such as telephonic line signals from a connected PSTN (Public Subscriber Telephone Network), ISDN (Integrated System Digital Network) link, ADSL (Asynchronised Digital Subscriber Loop) or the like.

13. A detection system comprising a control means, at least one detection device, and at least one interface according to any one of claims 1 to 6.

14. A detection system as claimed in claim 13 wherein at least one of the control means or detection device (s) includes the interface.

15. A detection system as claimed in claim 13 wherein the control means and each of the detection device (s) includes an interface.

16. A detection system as claimed in any one of claims 13 to 15 wherein the detection system includes at least one bus, the at least one bus being connected between the control means and the at least one detection device.

17. A detection system as claimed in any one of claims 13 to 16 wherein the detection system includes a portable device, the portable device including remote signalling means, the remote signalling means providing a signal, such as an electromagnetic or acoustic signal, which is used to program or operate the detection system remotely.

18. A method of relaying information within a detection system, the method comprising the steps of: providing a detection system including control means and at least one detection device generating an information signal within the detection device; generating two signals encoded with the information signal ,- and transmitting the two signals to the control means.

19. A method as claimed in claim 18 wherein the detection system also includes an interface according to any one of claims 1 to 6 and the two signals are transmitted to the control means on the interface .

20. A method as claimed in any one of claims 18 or 19 wherein the information signal is digitally encoded onto a power supply line as a transmission means for the first signal, and an NC relay/switch is opened as the transmission means for the second signal .

21. A method for remotely accessing a detection device (s) in a detection system in order to provide remote maintenance and/or monitoring and/or commissioning of the system, the method comprising the steps of: providing a detection system including a control means and at least one detection device; transmitting a signal from a remote site to a/the at least one detection device via the control means; receiving the signal at the detection device; decoding the signal; performing instructions provided by the signal; optionally encoding a response signal and transmitting the response signal to the remote site via the control means .

22. A method as claimed in claim 21 wherein the detection system also includes an interface according to any one of claims 1 to 6 and the signal transmitted from the remote site is transmitted to the detection device (s) via the interface .

23. A method as claimed in claim 21 or claim 22 wherein the response signal is transmitted to the remote site via the interface.