EP0098553A1 - Method and device for automatically demanding signal measure values and/or signal identification in an alarm installation - Google Patents

Abstract

1. A method of automatically calling up the alarm measured value and/or the alarm code in a hazard alarm system, with a central control and with at least one alarm line to which a plurality of alarms are connected in a chain formation, where, during a cyclic interrogation, in each alarm, a timer which can be influenced by the alarm measured value via a measured value converter, is set in motion at a time which is characteristic of the alarm address, and where, during the operation time of the associated timer, control commands for a specific alarm can be produced on the alarm line and can be received by the alarm in question and analysed as a switching command, characterised in that in the individual alarms (M) at least for the duration of the following interrogation cycle, the control command or switching command incoming during the operation time of the associated timer (T1) switches over (US) the timer (T1) from the measured value converter (MW) to a code generator (R3/R4) which is arranged in the alarm in question and, for the duration of the switch-over, is set at a characteristic time by the coder generator (R3/R4) or characterised in that the code generator (R3/R4) changes the alarm measured value by a predetermined value for this period of time (SE) and in the central control the code of the alarm (M) is determined from the operation time of the switched-over (US) timer (T1) or from the degree of the change in the original alarm measured value.

Description

The invention relates to a method for automatically querying the detector measured value and / or the detector detection. In a hazard alarm system according to the preamble of claim 1 and a device for performing this method.

Hazard detection systems are often equipped with different types of detectors. An example is a fire alarm system to which smoke, heat, flame and push-button detectors are connected. The measured physical fire parameter is evaluated in the detector using a suitable algorithm. Only a standardized, generally transmit digital signal. Different parameters are often evaluated in the detector using different algorithms. Alarm systems are also known which no longer evaluate the fire parameter in the detector, but instead pass it analogously to the signaling center in a suitable transmission method, in which an evaluation device, preferably a microcomputer, processes the measured values of all the detectors. Such alarm systems are also used for intrusion protection.

Such a signaling system is described for example in DE-PS 25 33 330. There, when each detector on a line is polled after a characteristic lead time which is characteristic of it, the detector is prompted to emit a current pulse with a pulse duration proportional to its measured value leaves. In the control center, the address of the individual detector and the analog detector measurement value are determined by measuring the lead time using an evaluation device.

In DE-PS 25 33 382, a method is described for such alarm systems, which electrically disconnects all detectors from the detection line at the beginning of each polling cycle and then. switches on the detectors in a predetermined order in such a way that each detector also switches on the following detector after a time delay corresponding to its measured value to the line voltage. In the control center there is an evaluation device that determines the respective detector address from the number of previous increases in the line current and the measured value from the length of the relevant switching delays. There, the analog detector measured values are linked to obtain differentiated fault or alarm messages.

However, it is not always possible or sensible to evaluate and process the measured values of different detector types using a uniform procedure. For automatic smoke detectors, for example, integrating behavior is desirable in order to switch off short-term disturbance variables. An alarm should only be given if the signal is present for a defined time. In the case of manual detectors, on the other hand, immediate reporting is required after a push button detector has been activated.

On the other hand, detectors that are triggered for test purposes, such as revision, must not cause an alarm. They should only show the response at the headquarters. In such cases, it is necessary to identify different types of detectors or operating states and to inform the control center.

In the above-mentioned signaling systems, a detector identification, namely the type or status of the detector, can generally be entered manually in the control center for the relevant detector. Detector-specific identifiers (detector type, detector in revision, detector not connected, etc.) can be saved in the control center for each detector in the system. This entry of a detector identification, which is generally carried out manually, is correspondingly stored via switches or a keyboard. The data entered must exactly match the current status of the system. Errors caused during input or when replacing a detector can not be reliably detected by the system and can have serious consequences in the event of an alarm. If a change is made to such systems, e.g. one detector type is replaced by another, - because the room is used for other purposes, this must also be entered accordingly in the control center.

From DE-PS 25 33 354 a device for transmitting control commands in a fire protection system is known. In the device described there, the individual detectors have timers, as described in the above-mentioned patents. These are used for the transmission of control commands on the zone to the individual detectors, whereby the detector is only ready to receive during the running time of the timer, and only one timer can be switched on with the control devices provided in the detector within a control cycle on the zone, and the The starting time of the individual time elements can be evaluated in the central office as the address of the control element assigned to the relevant time element.

The object of the invention is therefore to avoid manual entry of the detector detection in the control center and to specify a method and a device for the automatic interrogation of the detector detection and / or the detector measurement value. A detector-specific identification is to be made using a known transmission method of control commands automatically recorded and, if necessary, evaluated with the detector measured value in the control center.

This object is achieved with the invention. Method according to the characterizing features of claim 1 solved. With the control commands transmitted from the control center to the detectors, switching directions are specifically controlled in the individual detectors, which switch from detector measurement value transmission to detector detection transmission or change the detector measurement value by a defined value. A device is provided in each detector with which the detector identification, e.g. Detector type or detector status, is set in the detector. With the detector detection, a timer in the detector can be set to a characteristic value or the change value for each detector differently. With the subsequent query cycle, the respective detector identification is then transmitted to the control center, where it is stored and further processed.

With the method according to the invention, the control commands are evaluated as changeover commands in the detector. As a result, the timing element is switched from the transducer to the identifier, which sets the timing element to a characteristic time. For example, this time corresponds to the identifier for the detector type. Depending on the detector type, a corresponding detector detection is set. With the next interrogation cycle, the running time of the timer for the relevant detector as its identifier is e.g. Detector type, evaluated.

With the method according to the invention it is therefore possible to transmit control commands from the central alarm unit to the individual detectors. This detector control is used to cause the detector to transfer its identifier. The detector whose identifier is to be queried is therefore first activated. With the switching command, a defined change in the detector measured value can be effected in the individual detector instead of switching to detector detection. percentage enlargement or reduction of the original detector measured value, the generally microcomputer-controlled center can determine the detector detection and at the same time also calculate the original measured value. With this procedure, no detector measured values are lost. Another advantage is that not an absolute, but only a relative accuracy of the measuring device is required in the center.

It is expedient for the duration of the switchover to detector detection or for the duration of the defined influencing of the detector measured value as a function of the detector detection to be determined by a further timing element arranged in the detector. This second timing element is controlled by the switching command. The duration of the switchover or the predetermined change in the measured value can be set for one polling cycle or for several polling cycles with this second timer. It can thus be the detector detection in several successive queries, which is for transmission security, and transmitted to the control center.

With regard to the device, the object is achieved by the characterizing features of claim 4 / claim 6. In the known detectors, which can receive control commands using the method described at the outset, a switching device, a further timing element and an identifier are additionally arranged for the method according to the invention.

In the arrangement according to claim 4, the analog measured value reaches the first timing element from the transducer via the switching device, which is formed by a changeover switch. The second timing element, which is acted upon by the first timing element and by a threshold switch via a coincidence element, switches the switchover to a second switching position, at the second input of which the detector recognition from an adjustable identifier is present. The toggle switch is therefore between the identifier, transducer and the first Arranged timer and is switched by the second timer. The control command or changeover command, via a coincidence element, only reaches the second timing element via the threshold switch. when a signal is present at the second input of the coincidence element, which is acted upon by the first time element.

With the device according to claim 6 for a predefinable, defined change in the detector measured value, a switching device which is assigned to the identifier is provided in each detector. As is known, each detector has a threshold switch for the targeted reception of the control commands, which is connected to a coincidence element. This receives a signal from its second input only during the duration of a first timing element, so that the coincidence element only issues a switching command pending on the signaling line to a second timing element connected downstream of the coincidence element during this time. For the period of time determined with the second timer, this controls the switching device which is assigned to the identifier. The identifier is one Transducer connected in parallel so that the detector measured value is routed via the identifier to the input of the first timer. If the switching device is not activated, the unaffected detector measurement value reaches the first timer. If a certain detector has received a switching command, the detector measured value is changed by a defined value that can be set on the identifier due to the identifier.

• Fig. 1 einen prinzipiellen Aufbau eines Melders für die - wahlweise Abfrage der Melderkennung oder des Meldermeßwerts,
• Fig.- 2 und 3 verschiedene Schaltungsanordnungen eines einzelnen Melders für die erfindungsgemäße Umschaltung auf Melderkennung und
• Fig. 4 und 5 jeweils ein Prinzipschaltbild eines Melders für eine vorgebbare , definierte Meldermeßwertveränderung.

Further details of the invention emerge from the subclaims. The method and devices according to the invention for this purpose are explained in more detail with reference to several exemplary embodiments. Show

• 1 shows a basic structure of a detector for - optionally querying the detector identification or the detector measured value,
• Fig. 2 and 3 different circuit arrangements of a single detector for the inventive switch to detector detection and
• 4 and 5 each show a basic circuit diagram of a detector for a predefinable, defined detector measured value change.

In Fig. 1, a detector with identifier for switching to detector detection is shown in the schematic diagram. The detector M is connected to the control center via an alarm line ML, which is not shown here. The message line ML consists of conductors 1 and 2, between which a voltage U is applied. The detector M essentially contains a timer T1, which is started when the voltage U is applied. The running time of the timer T1 is influenced by the transducer MW. At the beginning of a query cycle, the line voltage U is briefly switched off for synchronization. Only when voltage U is applied does timer T1 turn on encountered. So that the transducer MW is supplied with current during the disconnection of the line voltage U, a capacitor C1 is provided which supplies the transducer MW in the short time of the disconnection. A diode D1 prevents feedback. A threshold value switch SW is arranged in the detector M, which compares the voltage on the signal line ML via the voltage divider R1 / R2 with a predetermined threshold value sw. Changes in the time in which the timer T1 'runs, the voltage on the signal line ML such that the threshold switch SW responds, this temporal coincidence of both signals is evaluated via the coincidence element KO as a control or changeover command. With the output signal of the coincidence element KO, a second time element T2 is started for a predeterminable time. This time is adjustable and is at least as long as the duration of the next interrogation cycle. The second timer T2 controls a changeover switch US. This switch US is arranged between the transducer MW and the first timer T1. For the detector measured value query, the transducer MW is connected to the first input E1 of the switch US. The output A of the switch US is connected to the input E of the first timer T1. The identifier (R3 / R4) leads to the second input E2 of the switch US.

For all the exemplary embodiments described, the identifier (R3 / R4) is formed by a voltage divider R3 / R4. In the exemplary embodiments according to FIGS. 1 to. 3 is connected to conductors 1 and 2. The center tap of the voltage divider R3 / R4 leads to the second input E2 of the switch US. To set the detector type, a certain division ratio is set for the detector type in question, so that the voltage present at input E2 of the switch US indicates the detector identification (eg the detector type). These

The identifier will be transmitted to the control center instead of the measured value during the next polling cycle. Since the control is also carried out by the control center, the received signal is correctly interpreted as detector recognition and processed further. The type of detector for the detector concerned is stored in a memory provided in the control center in order to be readable for the detector evaluation. After the set time of the second timer T2, the changeover switch US is switched back to its starting position. i.e. the analog detector signal signal arrives again. the first timer T1, so that the measured value can be transmitted to the control center again in the next query.

In Fig. Z a detector M is shown in which the switch US of. a relay REL with the switch contacts E1, E2 and A is formed. The timing element T2 is formed by a monoflop MF which is acted upon by an RC element R _T and C _T. The output of the monoflop MF controls the relay REL, which switches from position El to position E2, so that the voltage of the voltage divider R3 / R4 is present at the input E of the first timing element T1 for the next interrogation cycle.

3 shows a further exemplary embodiment of a detector M, in which the changeover switch US is formed by an analog changeover switch AS. The timer T2 consists of a capacitor C2 and a resistor R5. The capacitor C2 is slowly charged to the line voltage via the resistor R5. If a changeover command is received, the output of the coincidence element KO drives the transistor TR2, which becomes conductive and discharges the capacitor C2. The voltage across capacitor C2 controls the analog switchover via control input St ter AS. This means that if there is a low voltage at control input St of the analogue switch AS, the signal for detector detection goes from E2 to A, if there is a high voltage at control input St, a signal (detector measurement value) flows from E1 to A. Time for switching can be set with resistor R5 and capacitor C2.

Fig. 4 shows the circuit diagram of a detector M according to the invention, which is connected to the central alarm unit via a signal line ML. The signal line ML consists of the conductors 1 and 2, between which the voltage U lies. The detector essentially contains a first timing element T1, which is started when the voltage is applied. The running time T1 of the timing element is influenced by the transducer MW. Since the line voltage U is briefly switched off for synchronization at the beginning of a query cycle, a capacitor C1 is provided which supplies the measured value converter with voltage during this time. A diode D1 prevents feedback.

A threshold switch SW compares the voltage on the signal line ML via the voltage divider R1 / R2 with a predetermined threshold value sw. If the time in which the timer T1 is running changes the voltage on the line in such a way that the threshold value switch SW responds this temporal coincidence of both signals is evaluated as a control command via the coincidence element KO. This control command serves as a switching command for a defined change in the detector measured value. The control command is carried out via a second timer T2, with which the duration of the measured value change can be set. The second timer T2 is formed by a monoflop MF. With the output signal of the coincidence element KO, the monostable multivibrator MF is triggered, which the control command min save for the duration of the query. The storage time is determined by R _T and C _T. The output Q of the monoflop MF controls the switching device SE. This has a first transistor TR4, which becomes high-resistance and blocks the second transistor TR ₃ via the resistors R6 and R7. As a result, the voltage divider with which the detector detection is set, consisting of the resistors R3 and R4. effective and reduces the output signal of the transducer MW according to the division ratio R3 / R4.

The detector detection is determined by the voltage divider R3 / R4. After the time determined by R _T and C _T , the monoflop MF drops. The transistors TR4 and TR3 become low-resistance, so that R3 is short-circuited. The voltage divider R3 / R4 is ineffective. The full output voltage of the transducer MW is again present at the input of the timer T1.

Fig. 5 shows a circuit arrangement similar to Fig. 4. Instead of the transistors TR2 and TR3, an analog switch AS is used. Instead of the monoflop MF there is a capacitor C2 and a resistor R5. Capacitor C2 is slowly charged via resistor R5 to the voltage across capacitor C1. When a switching command is received, the output of the coincidence element KO drives the transistor TR2. This becomes conductive and discharges the capacitor C2. The voltage across the capacitor C2 controls the analog switch AS via the control input St. A low voltage at the control input St causes the connection between I and A of the analog switch AS to become high-resistance. In this case, the reduced detector value, which contains the identifier, is transferred to the control center. When the measured value is transferred, the connection from E to A of the analog switch AS has a low resistance, ie the transistor TR2 is blocked and the capacitor C2 is charged.

The duration of the timer T2, i.e. the storage time of the elements MF or R5 and C2 can be dimensioned such that the identifier is only passed to the head office once or in the case of several successive queries in order to identify possible transmission errors.

13 claims 5 figures

Claims (13)

1. A method for automatically querying the detector measured value and / or the detector detection in a danger alarm system with a control center and at least one alarm line to which several detector loops are connected in a chain-like manner, with a cyclical query in each detector having a timer that can be influenced by the detector measured value via a transducer at one time the detector address characteristic time is set in motion, and wherein control commands for a particular detector can be generated on the signaling line and can be received by the detector concerned during the runtime of the associated timer, characterized in that one of the individual detectors (M) control command arriving during the running time of this associated timer (T1 ') is evaluated as a switching command and thereby the timer (T1) is switched from the measured value converter (MW) to an identifier (R3 / R4) arranged in the respective detector (US) at least for the duration of the subsequent interrogation cycle ) and for the duration of the switchover from the identifier (R3 / R4) to a characteristic time, or that the detector measured value (R3 / R4) changes the detector measured value by a predetermined value for this period of time, and that in the Central the identifier of the respective detector (M) from the runtime of the switched. (US) timer (T1) or from the amount of change in the original detector measured value is determined. 2. The method according to claim 1, characterized in that the switching command recognized by the relevant detector (M) controls a second timer (T2) with which the duration of the switchover (US) or the duration of the switch-on (SE) for the predetermined change in measured value is set. 3. The method according to claim 1 or 2, characterized in that the duration of the connection (US or SE) of the identifier (R3 / R4) is longer than the duration of a query cycle. 4. Device for performing the method according to claim 1, wherein each detector (M) for evaluating the switching command has a threshold switch (SW) with a downstream coincidence element (KO), the second (T1) input of which is connected to the output of a first timing element / is characterized in that the coincidence element (KO) is followed by a second timing element (T2) for setting the switching time, and that each detector for switching the first timing element (T1) from the transducer (MW) to the identifier (R3 / R4 having) a of the second timer (T2) ansteuerbareu changeover switch (US) whose first input (El _') having a measuring transducer (MW) of the second input _s (E2) with an identification generator (R3 / R4) and whose output (a) with the input (E) of the first timing element (T1) is connected. 5. Device according to claim 4, characterized in that the identifier is formed by a voltage divider (R3 / R4) connected in parallel to the signal line (ML), the center tap of which leads to the second input (E2) of the changeover switch (US). 6. Device for performing the method according to claim 1, wherein each detector for evaluating the switching command has a threshold switch (SW) with a downstream coincidence element (KO), the second input of which is connected to the output of a first timing element (T1), thereby marked-records that for setting the switching duration a second timer (T2) is connected downstream of the change in measured value to the coincidence element (KO), that each detector has a switching device (SE) which can be controlled by the second timer (T2) and is assigned to the identifier (R3 / R4) for the defined change of the detector measured value, and that the output of the transducer (MW) is connected to the identifier (R3 / R4) and this is connected to the input (E) of the first timing element (T1). 7. Device according to claim 6, characterized in that the identifier of. a voltage divider (R3 / R4) connected in parallel to the transducer (MW) is formed, the center tap of which leads to the input (E) of the first timing element (T1), and that. a resistor (R3) of the voltage divider: (R3 / R4) of the switching device (SE) is connected in parallel. 8. Device according to claim 4 or 6 ,. characterized ,. that the second timing element (T2) is formed by a monoflop (MF) to which an RC element (R _T and CT) is applied, the output ( Q ) controls the switching device (US) or the switching device (SE). 9. Device according to claim 4 or 6, characterized in that the second timing element (T2) is formed by a capacitor (C2), a resistor (R5) and a transistor (TR2). 10. Device according to claim 4, characterized in that the changeover switch (US) is formed by a relay (REL) with a changeover contact (E1, E2 and A). 11. The device according to claim 4, characterized in that the switch (US) is formed by an analog switch (AS) with a control input (St). 12. Device according to claim 6, characterized in that the switching device (SE) is formed by a first transistor (TR4) and a second transistor (TR3) connected downstream thereof via resistors (R6 and R7). 13. The device according to claim 6, characterized in that the switching device (SE) is formed by an analog switch (AS) with a control input (St)

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