EP0834846A2 - Wireless hazard signalling system and method - Google Patents

Abstract

The intruder alarm system has several detectors communicating with a central device (1). This evaluates the alarm condition from the signals provided from the detectors, as transmitted radio signals. The transmitted signals are provided via two different signal frequencies, to include a handshaking signal arrangement. A test transmitter and receiver within the central device use a test signal with at least one of these frequencies for checking the alarm signal transmission channel.

Description

The invention relates to a wireless hazard alarm system with a reporting center and at least one Reporting device, the reporting center one of the Notification device issued in the event of a notification-relevant event Radio message receives and evaluates.

Such notification systems and procedures are, for example for the delivery of burglary, fire, home automation or other fault messages or for emergency signaling used.

Previously common wireless hazard detection systems have technical features very simple radio modules that are easy to get through Interference fields, such as those from local oscillators, TV sound carriers or computer clock signals and their Harmonics are caused, can be influenced.

Therefore, either the false alarm rates of such hazard alarm systems high or their reception is so disturbed that the Alarm message from a reporting device from the reporting center cannot be received at all.

For reasons of reliability, therefore, the wired Danger reporting systems the default compared to the given wireless, although the wired systems the Disadvantage of a high installation effort and thus one have little flexibility.

In the German trade magazine "W&S", issue 10/94, page 1058 to 1061 is a wireless hazard detection system from described type with improved interference immunity.

5 shows a block diagram of such an alarm system with a signaling center 1 and various signaling devices such as sensors 2 (motion detectors, glass break sensors or door contact sensors), an emergency transmitter 5 and a radio lock transmitter 6, which when locking a door a radio signal to activate the building to be secured from the alarm system.

Every reporting device participating in radio communication is identified with an individual code, a so-called Unique code. Learns in an installation mode the alarm center 1 all existing alarm devices.

The control center 1 permanently transmits the transmission channel monitored for malfunction or sabotage by unauthorized access and the user is constantly informed about the effectiveness the backup informed.

When a report-relevant event occurs, i.e. at Triggering a sensor sends the sensor in question short coded radio signal from the control panel is received and regarding the delivery of an alarm a signaling device 7 (flash of light and / or siren) and / or the forwarding of the alarm message via a public Telephone network 4 is evaluated.

The alarm message is forwarded via the telephone network 4 via a telephone dialer 3.

With such complex signal coding methods, however only security from false alarms or the conscious A fake transmitter sends out a forged code signal elevated.

The problem of the system blocking by an external On the other hand, the jammer cannot do so due to the signal coding be solved. A block is after a certain Time displayed on control panel 1, but does not to trigger an alarm.

According to FTZ guideline 17 TR 2100 for "telecontrol radio systems small power of the non-public land mobile radio (nömL) "is only permitted for alarm purposes, for a maximum of 30 seconds of radio signals in one Transfer direction.

For this reason, the reporting devices send the wireless Hazard detection system only in the event of a relevant event, i.e. a short radio signal only when triggered whose duration may not exceed 30 seconds, a duration of approximately 1 second is usually selected becomes.

In order to minimize battery consumption, the reporting devices after an alarm signal for a predetermined period of time deactivated and in a so-called "Sleep state" moved.

This fact may result in a potential burglar are advantageously used below.

The burglar interferes with the alarm system by means of a jammer such that the signals from the signaling devices are no longer identifiable by the control center 1. It is therefore impossible to trigger an alarm and the system is blocked. After the approx. 1 second transmission time has expired the activated signal sensors are put to sleep, so that the burglar turn off the jammer and pass the deactivated signaling devices without triggering the alarm can.

Since usually the external signal message only after a External signal exposure time of 30 seconds is thus passing through the hazard detection system without any Alarm triggering or fault display possible.

According to your article "EMC" in the British trade magazine "RADIO COMMUNICATION", February 1995 edition, pages 76 to 78, is also more practical than previous wireless Hazard detection systems have often been found in the wireless hazard detection systems according to CEPT (European Conference of Postal and Telecommunications Administrations) assigned UHF frequency band between 433.05 and 434.79 MHz Frequently interference from harmonic frequency components of Local oscillators and computer clock signals as well Television sound or television picture carrier frequencies occur that lead to a blocking of the hazard detection system.

An increase in blocking reliability the system by third party transmitters can, however, be replaced by a more complex signal coding of the alarm signals was not achieved will.

It is therefore an object of the invention to provide a wireless hazard detection system and a notification procedure of the aforementioned type to further develop such that increased interference immunity with regard to blocking by external signal interference is made possible.

The above object is achieved by a wireless hazard detection system according to the preamble of Claim 1, characterized by a test transmission device, the when an external signal is detected by the Reporting center a radio test signal of at least one frequency issues, thereby the availability of the transmission channel to check.

The provision of a test transmitter for automatic Checking the transmission channel when a External signal enables blocking to be recognized immediately the hazard detection system regardless of activation a reporting device. This can block the system can already be recognized in the uncritical state and the Suitable countermeasures are initiated.

Further advantageous embodiments of the invention are in the sub-claims defined.

Fig. 1 ein Blockschaltbild einer drahtlosen Gefahren-Meldeanlage gemäß dem Ausführungsbeispiel;

Fig. 2 eine perspektivische Ansicht und eine teilweise geöffnete Seitenansicht eines Empfangsteils der Meldezentrale gemäß dem Ausführungsbeispiel;

Fig. 3 eine Vorderansicht eines Anzeigefelds der Meldezentrale;

Fig. 4A eine Vorderansicht eines Bewegungsmelders gemäß dem Ausführungsbeispiel;

Fig. 4B eine Vorderansicht des Bewegungsmelders nach Entfernung der Frontplatte und der Sensoreinheit sowie eine Seitenansicht der im Inneren des Bewegungsmelders befindlichen Platinenanordnung;

Fig. 4C eine Vorderansicht des Bewegungsmelders nach Entfernung der Frontplatte, der Sensoreinheit und der inneren Platinenanordnung; und

Fig. 5 ein Blockschaltbild einer drahtlose Gefahren-Meldeanlage gemäß dem Stand der Technik.

The invention is explained below using an exemplary embodiment with reference to the accompanying drawings. Show it:

Figure 1 is a block diagram of a wireless hazard detection system according to the embodiment.

2 shows a perspective view and a partially opened side view of a receiving part of the signaling center according to the exemplary embodiment;

Fig. 3 is a front view of a display panel of the control panel;

4A shows a front view of a motion detector according to the exemplary embodiment;

4B shows a front view of the motion detector after removal of the front plate and the sensor unit and a side view of the circuit board arrangement located inside the motion detector;

4C shows a front view of the motion detector after removal of the front plate, the sensor unit and the inner circuit board arrangement; and

Fig. 5 is a block diagram of a wireless hazard detection system according to the prior art.

A block diagram of the wireless Hazard detection system according to an embodiment is in Fig. 1 shown.

The hazard detection system consists of a notification center 1 with a receiving part 10 and a transmitting part 11, one or several motion detectors 21, contact detectors 20, smoke detectors 22 and temperature or water alarms 23 as alarm devices, a hand transmitter 5, a remote control 8 and one Lock transmitter 6 as control devices for the hazard alarm system, as well as a universal receiver 710 for an optical and acoustic signaling device 71 and an optical and acoustic signaling device 70 with integrated Universal receiver. To check the availability of the The signaling center is the transmission channel when exposed to external signals 1 equipped with a test transmitter that is connected with a remote test recipient or Transponder 24 is used for checking.

The receiving part 10 of the signaling center 1 has two antennas 90 and 91 for dual frequency operation. Furthermore are on the front of the housing a display panel 100 and a Key switch 110 for activation (arming) or Deactivation (deactivation) of the hazard alarm system ordered.

Furthermore, the receiving part 10 of the control panel 1 is included an internal tone generator with volume control and one acoustic signal generator arranged on a main circuit board such as a piezo buzzer.

The signaling devices send when a corresponding occurs alarm-relevant events, one alarm signal each, a third-party warning signal (sabotage signal) or on Battery discharge warning signal on two different frequencies out.

The receiving center 1 receives one of these signals on both frequency channels leads to a corresponding signaling.

Depending on the geographical use of the hazard alarm system and the associated national frequency usage regulations, frequencies from the following frequency range pairings can be used in dual-frequency operation, with one of the frequency values being used in a single-frequency operation that is also possible: Germany, Austria, Switzerland: 40/433 MHz Great Britain: 173/418 MHz France: 152/433 MHz

Is one of these in the deactivated operating state of the system Signals disturbed by the influence of external signals, so this will be by an optical external signal interference display on the display panel 100 displayed. If the fault lasts longer than 30 seconds, so there is an acoustic message by means of the internal Tone generator of the alarm center 1. Are the signals of both Frequencies disturbed, the acoustic message is given immediately.

Of course, it is also a hazard alarm system conceivable in which the radio message consists of more than two radio signals different frequency.

According to the regulations, the transmitters of the reporting devices may only Radiate a radio signal for a maximum of 30 seconds. Therefore, and for reasons of energy saving, the Motion detector 21 after emitting an alarm signal in one temporary deactivation state (sleep time).

However, the above-mentioned possibility of blocking the hazard detection system by means of an external signal with the aim the subsequent passing of the now deactivated Avoiding motion detector 21 is both the duration of sleep as well as the number of possible alarm signal deliveries predeterminable before initiating the sleeping time, although only a new alarm trigger, but not a signal extension is possible.

This enables an intruder to be detected two or more times before the motion detector goes to sleep becomes.

The sleep time of the motion detectors can, for example, in 3 Levels between 1 and 6 minutes can be set.

Is the hazard alarm system in the activated, i.e. armed, operating state, for example an evaluation is carried out in such a way that an alarm signal must be received on both frequency channels in order to become one Alert if not one of the frequency channels is disturbed by an external signal. An external signal interference on a frequency channel connected to reception an alarm signal on the other frequency channel be evaluated as an alarm condition and thus become a Lead alarm.

Since the alarm center 1 both the alarming and the evaluates disturbed frequency channel, it is also possible to Hazard detection system initially for a period of 30 seconds to put into a pre-alarm state during which the Receiving a second alarm signal from the corresponding one or another motion detector for an alarm leads.

That means that in case an intruder stays in the detection area of the hazard alarm system, with or without Maintaining the blocking attempt, another alarm signal by the same or, if the location changes quickly of the intruder, by another motion detector takes place, which then results in an alarm.

If an external signal interference is detected on both frequency channels, this can also be used as an alarm condition be and thus lead to an alarm, since it is likely to be an intended one Disturbance.

An intentional interference signal with the aim of Blocking the hazard alarm system can therefore be reliable distinguished from an unintentional external signal interference will.

The above-mentioned measures can reduce the susceptibility to faults with regard to external signal interference from external electromagnetic Sources of interference can be considerably reduced.

With lower security requirements, the hazard alarm system also operated in single-frequency mode be, each of the signaling devices an alarm signal, a sabotage signal or a battery discharge warning signal emits on a frequency.

The receiving center 1 receives one of these signals leads to a corresponding signaling.

Is one of the signals in the deactivated state of the alarm system longer than 30 seconds due to external signal exposure disturbed, there is an optical and a means acoustic signal generated by the internal tone generator.

In the activated operating state of the hazard alarm system an external signal interference to a display and / or one delayed alarm if the fault lasts longer than 30 Seconds.

To increase security, a so-called Detector monitoring can be carried out at the notification facilities at a random time within a predeterminable Duration of, for example, 6 hours each Issue a signal and thereby signalize its operational readiness.

This is in both single-frequency and double-frequency Operation possible.

Is more when the hazard detection system is deactivated as a signal from a signaling device from the signaling center 1 is not received, a detector monitoring fault signal is generated generates one to the relevant reporting device indicates the relevant zone.

In the activated operating state of the hazard alarm system the generation of the detector monitoring interference signal is a full value Alerting or fault indication by means of an optical Display when the hazard alarm system is subsequently deactivated have as a consequence.

The hazard alarm system can be radio-controlled or wired being controlled.

The key switch 110 has three switch positions Deactivate, partially activate (internal alarm) or reset the alarm system.

Furthermore, the receiving unit 10 of the control center 1 comprises three wired inputs for full activation (external alarm), Partially activate (internal alarm) or to activate the zones, that are not among the partially activated (Two-range switching). These inputs are, for example controlled via a switched terminating resistor and supervised.

In addition, there is both full activation and partial activation radio controlled possible.

• ein Handsender 5 mit vier Tasten zum Deaktivieren, Vollaktivieren, Teilaktivieren und zur Überfallmeldung;
• ein Schloßsender 6, der mit einem mechanischen Schließkontakt gekoppelt ist; und
• eine ferngesteuertes Codierschloß 8.

For example, the following radio transmitters can be used to activate the hazard alarm system:

• a hand-held transmitter 5 with four buttons for deactivating, fully activating, partially activating and for reporting an attack;
• a lock transmitter 6 coupled to a mechanical make contact; and
• a remote-controlled coding lock 8.

The lock transmitter 6 can be constructed according to the contact detector with the exception of the lock monitoring input, through an input for a remote key switch contact is replaced. The lock transmitter 6 can be both Activation and a deactivation signal to the alarm center 1 transmitted and can be programmable in such a way that it has a signal for partial or full activation of the Issues hazard alarm system.

By means of the remote-controlled coding lock 8 is a wireless Activation of the system using three different codes possible, with partial activation, full activation or just an activation of the for complete Alarming programmed zones can be selected. Of a raid report to reporting center 1 is also possible.

To further increase the reliability of the hazard detection system with regard to external signal interference can also consisting of a test transmitter and a test receiver 24 External signal verification system may be provided, the Test transmitter can be arranged in the control center 1.

The test receiver 24, which in turn is a transmitting device can contain and thus performs a transponder function, is within the surveillance area of the danger alarm system preferably in one of the largest radio ranges distance from the alarm center 1 corresponding to the system arranged.

If the alarm center 1 receives an external signal, the Test transmitter activated, which then switches on depending on the operating mode Sends test signal on one or two frequencies. Of the Test receiver 24 receives the test signal and transmits if sufficient In turn, receiving one or more test signals back as acknowledgment.

The acknowledgment can also take place via a wired signal, whereby however the installation effort of the Danger alarm system rises.

If the alarm center 1 does not receive an acknowledgment, it is Transmission path for message signals blocked and one External signal display can be independent of the occurrence of a signal-relevant Event occur so that an early signaling the blocking of the hazard detection system becomes.

In two-frequency detector monitoring mode, two Radio test signals of different, corresponding to the message signals Frequency emitted by the test transmitter of the control center 1 and both frequency channels for blocking checked.

If one of the frequency channels is blocked, i.e. will not Acknowledgment received on a frequency channel an external signal fault display with reference to the disturbed frequency channel at the control panel 1.

If no acknowledgment is received on both frequency channels, so an alarm and corresponding display on the Reporting center 1.

An external signal disturbance is thus not only detected, but also also with regard to their impact on the transmission channel evaluated.

Since a repeated activation of the contact 20, for example extremely by opening a door or window is unlikely to be deployed to these sleep time can be waived. Depending on the application A sleep time of 3 minutes, for example, can also be programmed be.

Programming of the contact detectors 20 can also be carried out in this way be provided that opening and closing signals or only Opening signals are given. The contact detector 20 can also a wired input for a glass break sensor and an integrated evaluation circuit for evaluating the Glass break sensor emitted signals, so that an additional Message signal can be given in the event of glass breakage.

The smoke detector 22 is activated after an alarm signal has been given also deactivated for 3 min, for example (sleep time). This prevents the smoke detector 22 from immediately re-alarming in an alarm state because in smoke is still in its measuring chamber. Such an ongoing one Alarm signal could interfere with other alarm signals to lead.

To control the signaling devices 70 and 71 can a universal receiver 710 may be provided, either as Alerting interface or as a communication interface is programmable. The universal receiver can be a Metal housing with externally arranged antennas and 10 outputs such as relay outputs, the States of the relay outputs arranged on the housing Illuminated displays such as LEDs can be displayed are.

The metal housing causes a reduction in the coupled electromagnetic interference and thus an improved Reception behavior.

An additional second receiver can be used for dual-frequency operation be pluggably connected to the main receiver. Furthermore, a transmitter can be present for the delivery of a Sabotage signal to the alarm center 1 upon receipt of a External intervention message via a wire-bound, for example Sabotage entrance.

The universal receiver 710 is used as an alarm interface operated, it generates directly via its relay outputs Control signals for the signaling devices 70, 71.

• optische Alarmierung
• akustische Alarmierung
• Brandalarmierung
• Aktivierung der Gefahren-Meldeanlage (Scharfanzeige)
• Fremdsignal erfaßt.

The following control signals can be used:

• visual alarm
• acoustic alarm
• Fire alarm
• Activation of the hazard alarm system (arming display)
• External signal detected.

- Alarm

- Technischer Alarm

- Aktivierung

- Batteriestörung

- Brand

- Netzstörung

- Sabotage

- Melderüberwachungsstörung

- Überfall

- Fremdsignalstörung

If the universal receiver is programmed as a communication interface, the relay outputs are used to display the received signal type and are connected to the signaling device 70, 71, which generates the alarm control signals itself. The relay outputs can have the following meanings, for example:

- alarm

- Technical alarm

- activation

- battery failure

- fire

- grid failure

- sabotage

- Detector monitoring fault

- raid

- External signal interference

In the following, the receiving part 10 of the control panel 1 is under With reference to Fig. 2 described in more detail. Fig. 2 shows one perspective and a partially open side view the receiving part 10.

The receiving part 10 can be opened by a metal housing be surrounded with separate front part 12 and back part 13. The metal housing protects the receiver circuit from electromagnetic Interference. A motherboard 14 is on the inside of the back part 13 and a display board 15 attached to the inside of the front part 15 of the housing. On the display board 15 are display elements such as Light-emitting diodes (LEDs, 19) of the display panel 100 are arranged. The Display board 15 is via a pluggable line connection such as. a flat cable 16 with plug device with the Motherboard 14 connected.

The power supply is arranged separately and has one Transformer 17 and an accumulator 18, the Power supply also via a pluggable cable system is connected to the main board 14.

The main receiver with integrated signal coding circuit can, for example, be plugged onto the motherboard 14 be an additional one for dual-frequency operation Second receiver can also be plugged into the main board 14 can be arranged.

The second receiver can be connected to a further signal coding circuit be dispensed with, since the signal coding already in the signal coding circuit of the main receiver or the Motherboard 14 can be performed.

According to the frequency values mentioned above, the 40 MHz and the 152/173 MHz receiver quartz-controlled and the 418/433 MHz receiver using a sawtooth generator or can also be controlled by means of a quartz.

The receivers work according to the overlay principle (super heterodyne receiver) with a narrow intermediate frequency bandwidth and therefore high selectivity.

The number of possible system codes is preferably larger than 5000 and the number of available channels is preferred greater than 200. The system coding enables a distinction the radio signals regarding the system (system code), the zones and the types of alarm signals

The 40 MHz receiver can either be from a ferrite rod antenna or fed by a flexible wire antenna 90. The 152/179 MHz receiver can use a stub antenna with coaxial connection and the 418/433 MHz receiver from one Full wire antenna 91 can be fed.

The receiving part 10 of the signaling center 1 can also have two field strength measuring devices 25, by means of which the reception level noticeable when testing the hazard alarm system is.

The transmitting part 11 of the control center 1 can be in its own housings protected against external interference and has a universal transmitter that is pluggable Line connection such as a flat cable with the Main board of the receiving part 10 is connected. The universal transmitter controls the remote optical and acoustic Signaling devices 70, 71 or other remote transmitter devices.

For this purpose, the universal transmitter sends output signals accordingly the programming of the main board 14 of the receiving part 10 out, which also from two radio signals corresponding Frequency can be formed. Thus also in the transmitting part 11 two plug-in receivers for the two Frequency channels are available. The output signals are around for example, delayed 10 seconds to avoid the risk of Signal collision with incoming message signals from the To prevent signaling devices.

The external intervention (sabotage) signaling can, for example via a wire connection to one of the wired Inputs of the receiving part 10 take place. The same happens Power supply of the transmitting part 11 is wired via the Receiving part 10 of the control center 1.

The signaling center 1 has a terminating resistor wired inputs, e.g. a zone entry, a sabotage entrance and a robbery entrance.

There is also a wired lock input for input the closed state of the outer doors and a wired Communication error input (AWUG) for reporting a communication fault with a central office such as one Emergency call center available.

Furthermore, a reset input for the external reset of for example technical alarms, saved detector monitoring, External signal and glass break indicators are provided be.

The signaling center 1 can transmit radio signals from, for example 8 or 16 wireless zones with corresponding assigned reporting devices can be evaluated.

The receiving part 10 of the control center 1 has, for example 4 relay outputs, 10 communication outputs and 3 outputs for illuminated display elements (LEDs) 19.

Furthermore, two individually protected voltage supply outputs can be used to supply external devices be. Individual protection is of particular importance since this triggers a short circuit when cutting not the entire hazard alarm system decommissioning.

• Steuerung der optischen Signalisierung
• Steuerung der akustischen Signalisierung
• Steuerung eines internen Signalisierausgangs
• Steuerung eines internen Signalgebers.

The relay outputs are used to control the transmitting part 11 via the line connection, and the following functions can be assigned to them, for example:

• Control of optical signaling
• Control of acoustic signaling
• Control of an internal signaling output
• Control of an internal signal generator.

• Alarm oder Überfall
• Störanzeige (Fremdstörung, Netzstörung, Sabotagestörung, Batteriestörung)
• Aktivierung der Anlage

The outputs for the light indicators can have the following meanings:

• Alarm or robbery
• Fault display (external fault, mains fault, sabotage fault, battery fault)
• Activation of the system

The 10 communication outputs can, for example, with your Activation can be switched to a high potential and by driving additional light display elements 19 Display of certain system states can be used.

The illuminated display elements 19 are located on the display field 100 of the receiving part 10.

In Fig. 3, the display field 100 of the receiving part 10 is the Reporting center 1 shown.

Two-color or three-color can be used as illuminated display elements Light emitting diodes (LEDs) are used.

Each of the 16 zones present in this embodiment is a light emitting diode 19 for displaying a message assigned. The zones 1 to 6 can be deactivated individually.

The field strength measuring devices 25 are also displayed via LEDs 251, with each of the two Frequency channels a separate display can be provided. In addition, the field strength measuring devices 25 can be assigned indicator light as an external signal interference Cause of reception are displayed.

When the hazard alarm system is activated externally, all are Illuminated display elements switched off.

Due to the complex structure of the alarm center 1 is a extremely logical and easy to understand programming process the hazard detection system is required.

This is arranged by using the control center 1 Switch arrangements (jumpers) reached, each the switch has three switch positions. In addition, a DIP switch (Dual In Line Package) for defining the zones be provided for detector monitoring.

This will make the programming process simple and gradual based on yes / no decisions, a microprocessor control system being dispensed with can. The system installer follows simple Programming instructions such as "Do you want this function or not?" and doesn't need a complicated one Input keyboard still difficult to understand and prone to errors Programming codes.

- Meldegruppen 1 bis 16:

Teil- oder Vollaktivierung

- Relaisausgänge 1 bis 3:

Dauerbetrieb oder nur bei aktivierter Meldeanlage

- Aktivierung:

drahtgebundene Aktivierung vorrangig oder nicht

- einmaliger Alarm

Alarmierung durch die gleiche Meldegruppe bei autom. Wiederscharfschaltg. möglich oder nicht

- Melderüberwachung:

Überwachung Ja oder Nein ein- oder zweifrequent Signalisierungsart bei ein- bzw. zweifrequentem Betrieb

- Fremdsignalstörung:

Signalisierungsart bei ein- bzw. zweifrequentem Betrieb

Possible programming functions of the hazard alarm system are given below:

- zones 1 to 16:

Partial or full activation

- relay outputs 1 to 3:

Continuous operation or only when the alarm system is activated

- activation:

wired activation priority or not

- one-off alarm

Alerting by the same zone with autom. Re-arming possible or not

- Detector monitoring:

Monitoring yes or no single or double frequency signaling mode with single or double frequency operation

- External signal interference:

Type of signaling with single or double frequency operation

The following types of signaling can be programmed, for example:

With detector monitoring, either with deactivated Danger alarm system internal alarm and when activated System complete alarm, or when deactivated System internal alarm and activation when system is activated a relay output and the internal encoder.

In the case of external signal interference and single-frequency operation, either activation the corresponding communication output after 30s Fault duration or complete alarm.

In case of external signal interference and two-frequency operation with one Interference on both frequency channels immediate complete Alerting with activated system or a delayed complete alarm after 30s of fault duration or one immediate "silent" alarm.

4A shows a front view of the motion detector 21, the three different detection zones 30 and a focusing device such as a flat lens 31 which both horizontal and vertical coverage zones or a Standard 12x12 masking pattern can contain.

4B shows the motion detector 21 with the front plate removed 32 and sensor unit and a side view of the im Internal board arrangement.

A transmitter board 35 with transmitter circuit can be plugged on the motherboard 37, the motherboard in turn on a fixable on the housing of the motion detector 21 Carrier plate 34 is arranged pluggable. The one for the dual frequency Operation requires additional transmitter board 36 with a second transmitter circuit can also on the Main board 37 can be plugged in next to the transmitter board 35 be arranged.

Alternatively, the additional transmitter board 36 on the Transmitter board 35 can be arranged pluggable.

Of course there is also a permanent connection between the transmitter boards 35, 36 and the main board 37 conceivable.

One can be used as the transmitting antenna for the 40 MHz frequency range Ferrite rod antenna 38 may be present on the front the support plate 34 is arranged, the main and Transmitter boards are located on the back of the carrier plate 34.

There is also another one for the higher frequency channel Transmitting antenna, for example on the main board 37 or the corresponding transmitter board 35, 36 arranged integrated.

If the 40 MHz frequency range is not used, you can also both transmit antennas on the corresponding transmitter boards 35, 36 can be arranged integrated, the ferrite rod antenna not applicable.

4C is located between a housing rear wall 39 and the board assembly a battery compartment with a battery 40 or an accumulator.

A battery discharge warning signal will either be on detection movement or automatic detector monitoring delivered by the transmitter or transmitters.

The structure described above enables a compact Design of the motion detector 21.

In summary, a wireless hazard detection system is disclosed with a reporting center and at least one Reporting device, the reporting center one of the Notification device issued in the event of a notification-relevant event Radio message receives and evaluates. To the susceptibility to failure the hazard alarm system with regard to external signal effects to reduce by external jammers the radio message from two radio signals different Frequency, making the probability of interference dramatic is reducible. This can also be done from the registration center a control signal emitted by a signaling device be two-frequency, which also makes a radio-controlled, interference-free Signaling is made possible. One more way to increase security against external signal interference is the provision of reporting facilities at which the duration of a deactivation phase and the number of renewed signaling until the deactivation phase is initiated is programmable. In addition, by means of a External signal verification system consisting of test transmitter and - Receiver has an interference signal before an alarm is triggered evaluated with regard to the blocking of the system and thus the interference immunity can be further increased.

Wireless hazard alarm system with a central alarm system and at least one reporting device, the reporting center one from the reporting device for a reporting-relevant Event received radio report receives and evaluates. Around the susceptibility of the alarm system to failure with regard to Reduce external signal effects from external jammers the radio message consists of two different radio signals Frequency, reducing the probability of interference is drastically reducible. In addition, that of the Central reporting unit delivered to a signaling device Control signal to be two-frequency, which also means interference-free, radio-controlled signaling enables becomes. Another way to increase security against external signal interference is the provision of Notification devices where the duration of a deactivation phase and the number of report signals until Initiation of the deactivation phase is programmable. In addition can consist of an external signal verification system from test transmitter and receiver even before an alarm is triggered an extraneous signal interference regarding the blocking evaluated the system and thus the interference immunity be further increased.

Claims (4)

Wireless hazard warning system with a reporting center (1) and at least one reporting device, the reporting center (1) receiving and evaluating a radio message issued by the reporting device in the event of a reporting event,
marked by
a Prüfsendeeinrichtung that a Funkprüfsignal at least emits a frequency in detecting an external signal by the signaling center (1) to thereby check the availability of the transmission channel. Wireless hazard detection system according to claim 1,
marked by
a reception test device (24) for receiving the radio test signal and for emitting an acknowledgment signal to the signaling center (1) when the radio test signal is received sufficiently. Wireless hazard detection system according to claim 2,
characterized in that
the acknowledgment signal is wired from the test receiver (24) to the alarm center (1) . Wireless hazard detection system according to claim 2,
characterized in that
the test receiver has a transponder (24) which in turn emits at least one radio test signal of at least one frequency to the signaling center (1) .

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