JP2006004139A - Fire alarm system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a function from being stopped caused by a drop of a voltage in a sensor line by transmission of a common fire signal due to an alarm issue from a fire sensor connected to the same sensor line. <P>SOLUTION: This P type fire alarm system is connected with the plurality of fire sensors to the fire sensor line drawn out from a receiver. The fire sensor transmits the common fire signal, when detecting a fire to issue an alarm, before receiving a transmission stop command signal 26 from the receiver, and stops the transmission of the common fire signal, when detecting the fire to issue the alarm, after receiving the transmission stop command signal 26 from the receiver. The receiver receives the common fire signal transmitted from the fire sensor in a unit of the sensor lines to issue the alarm, and outputs the transmission stop command signal 26 for stopping the transmission of the common fire signal common to the sensor line, when the issued alarm detection number of the common fire signal received from the same sensor line reaches a prescribed number. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a fire alarm system in which a plurality of fire detectors are connected to a sensor line drawn from a receiver, and fire alarms are received and alarmed on a line basis.

  Conventionally, in the fire alarm system known as P type, a plurality of fire detectors are connected to the sensor line drawn from the receiver, and the alarm signal from the fire detector is received for each line. The fire is alarmed.

  On the other hand, in the fire alarm system known as the R type, a terminal device such as a repeater or an analog fire detector having a transmission function is connected to the transmission line drawn from the receiver, and when a fire is detected, for example, Based on the fire interrupt from the terminal device, issue the search command to identify the address of the terminal device that was issued, display the fire occurrence address, and collect and monitor the fire data from the identified terminal device Yes.

  Knowing the address of the fire detector or repeater that detected the fire in this way makes it possible to conduct appropriate evacuation guidance and extinguishment activities, and is an indispensable function especially for fire monitoring of large-scale facilities.

  However, in the P-type fire alarm system, the receiver knows which sensor line has fired, but which sensor out of the multiple sensors connected to the alarm line that has fired has fired. I don't know if I reported it.

  Therefore, in recent years, the P-type fire alarm system is also able to identify the fire detector that has been notified by transmitting an address signal from the fire detector that has issued the alarm. FIG. 7 is a time chart of a detector line voltage and a fire detector switching circuit when a fire is triggered in a conventional P-type fire alarm system.

  Of a plurality of fire detectors connected to the same detector line, for example, if a fire detector with address 2 set as shown in FIG. By turning on the switching circuit provided in the fire detector that has issued the alarm, the alarm current as a common fire signal is caused to flow through the sensor circuit, and the voltage of the sensor circuit in FIG. Subsequently, as shown in FIG. 7 (C), when the fire detector set at address 3 issues an alarm and transmits a common fire signal, the detector line voltage further decreases.

In the receiver, a common fire signal transmitted from the fire detector at address 2 that fired at time t1, that is, the alarm current that flows from the receiver to the fire detector is received and alarmed. If necessary, the fire detector address that has been issued is identified from the address signal received following the common fire signal, and necessary indications such as the area where the fire occurred are displayed.
JP 2001-184571 A

  However, in the P-type fire alarm system in which a common fire signal is transmitted from such a fire alarm that has been reported in the prior art, as shown in FIGS. When the fire detector at address 7 detects fires one after another and sends a common fire signal, the current flowing through the detector line increases, the power supply voltage supplied to the fire detector decreases greatly, and fire detection operation There is a problem that communication with the receiver becomes impossible.

It is an object of the present invention to provide a P-type fire alarm system that prevents a malfunction due to a decrease in sensor line voltage caused by transmission of a common fire signal due to a fire alarm connected to the same sensor line. To do.

  In order to achieve this object, the present invention is configured as follows. The present invention relates to a fire alarm system in which a plurality of fire detectors are connected to a sensor line drawn from a receiver. The fire detector detects a fire before receiving a transmission stop command from the receiver. A fire alarm control unit that sends a common fire signal when receiving a notification and detects the fire after receiving a transmission stop command from the receiver and stops sending a common fire signal The receiver has a reception control unit that receives and alerts the common fire signal transmitted from the fire detector in units of sensor lines, and the number of detected detections of common fire signals received from the same sensor line. A command output unit that outputs a transmission stop command for stopping transmission of a common fire signal to the sensor line when the predetermined number is reached is provided.

  Here, the command output unit of the receiver outputs a transmission stop command for stopping the transmission of the common fire signal to the sensor line when, for example, one common fire signal received from the same sensor line is received. Stop sending common fire signals for the second and subsequent reports.

  According to another aspect of the present invention, in a fire alarm system in which a plurality of fire detectors are connected, the fire detector detects a fire and transmits a common fire signal. When a transmission stop command is received from an alarm, the alarm control unit stops the transmission of a common fire signal, and the receiver receives the common fire signal transmitted from the fire detector for each sensor line. And a transmission stop command to stop the transmission of the common fire signal to the sensor line when the number of detected alarms reaches the predetermined number of common fire signals received from the same sensor line. And an instruction output unit for performing the operation.

Also in this case, when the fire detector receives a transmission stop command, if it is the first fire detector, it will continue to transmit a common fire signal and it will not be the first one Stop sending common fire signals.

According to the present invention, it is possible to limit the number of fire detectors that transmit a common fire signal on the same sensor line by outputting a transmission stop command from the fire sensor, For example, even if the fire detectors fire one after another, a common fire signal can be transmitted until the second report, for example, but the third and subsequent reports can stop the transmission of a common fire signal. The voltage drop of the sensing line due to the signal transmission should not be lower than the allowable power supply voltage at which the fire detector can operate. It is possible to reliably prevent communication with the system from being disabled, and to improve system reliability.

  FIG. 1 is an explanatory diagram of a fire alarm system according to the present invention. In FIG. 1, the sensor lines 2-1, 2-2,... N fire detectors 3 set with addresses 1 to n are connected together with a terminating resistor 4. As the fire sensor 3 connected to the sensor lines 2-1 to 2-m, various fire sensors such as a smoke sensor and a heat sensor can be connected.

  The receiver 1 is provided with an MPU 5 for the receiver, and an operation unit 7, an alarm display unit 8, a district display unit 9, a transfer output unit 10, and a memory 11 are provided for the MPU 5. In addition, receiving circuit units 6-1, 6-2,..., 6-m are provided on the sensor line side of the MPU 5 for each line, and each of the receiving circuit units 6-1 to 6-m has a sensor. Lines 2-1, 2-2 to 2 -m are drawn out.

  The reception circuit units 6-1 to 6-m receive the alarm current transmitted as a common fire signal by the fire alarm of the fire sensor 3 connected to the sensor lines 2-1 to 2-m. At the same time, a common fire signal transmission state, that is, an address signal transmitted in a state where the alarm current flows through the sensor line is received.

  The MPU 5 of the receiver 1 is provided with functions of the reception control unit 12 and the command output unit 25. The reception control unit 12 sequentially reads the reception signals of the reception circuit units 6-1 to 6-m, discriminates a common fire signal for each line, and displays an alarm, that is, a fire representative display and a district display (alarm line display). I do.

  The command output unit 25 issues a transmission stop command to stop transmission of the common fire signal to the corresponding sensor line when the number of detected detections of the common fire signal received from the same sensor line reaches a predetermined number. Output. In order to output this transmission stop command, command output circuits 24-1 to 24-m are provided on the receiving circuit units 6-1 to 6-m, and the corresponding sensor line 2- A transmission stop command composed of a pulse train of predetermined code bits is output at 1 to 2-m.

  Corresponding to the output function of the transmission stop command by the command output unit 12 of the receiver 1, the fire detector 3 is common when a fire is detected and reported before receiving the transmission stop command from the receiver 1. After a fire signal is transmitted and a transmission stop command is received from the receiver 1, a function is provided to stop the transmission of a common fire signal when a fire is detected and an alarm is issued.

  FIG. 2 shows an embodiment of the fire detector 3 of FIG. 1, taking a scattered light type smoke detector as an example. In FIG. 2, the fire detector 3 includes a rectifier circuit noise absorbing circuit 13, a switching circuit 14, a constant voltage / current limiting circuit 15, an operation indicator 16, an address setting circuit 17, an alarm control unit 18 composed of a CPU, The oscillator circuit 19, the light emitting element 20, the light receiving element 21, the amplifier circuit 22, and the comparison circuit 23 are configured.

  Here, the rectifier circuit / noise absorption circuit 13 makes the current between the lines L and C nonpolar by, for example, a diode bridge, a Zener diode, a capacitor, and the like, and further suppresses noise. The constant voltage / current limiting circuit 15 limits the supply current to the subsequent circuit section to a constant value in order to prevent transient currents on the lines L and C.

  During normal monitoring, the light emitting element 20 is pulse-driven by the oscillation circuit 19 to emit light periodically. When smoke is generated by a fire, light from the light emitting element 20 is scattered by the smoke and enters the light receiving element 21. The incident light is converted into a photocurrent, and after being amplified by the amplifier circuit 22, the signal is input to the comparison circuit 23.

  When this signal exceeds the specified value, the alarm control unit 18 counts in synchronization with the light emitting element 20 and transmits the signal to the switching circuit 14 when the predetermined count number is reached. In response to this, the switching circuit 14 performs switching, and causes an alarm current as a common fire signal to flow between L and C of the sensor line. Also, the alarm control unit 18 turns on the operation indicator lamp 16 at the same time.

  The alarm control unit 18 monitors the signal state of the sensor line by incorporating the input side of the constant voltage / current limiting circuit 15 and detects a fire before receiving a transmission stop command from the receiver 1. When a notification is issued, a common fire signal is transmitted. However, after receiving a transmission stop command from the receiver 1, even if a fire is detected and a notification is issued, the common fire signal is stopped without being transmitted.

  FIG. 3 is an explanatory diagram showing a fire alarm control function according to the present invention by taking out one of the sensor lines of FIG. In FIG. 3, the sensor line 2 drawn from the receiver 1 has no. 1-No. A fire detector 3 having addresses 1 to n indicated by n is connected.

  The fire detector 3 is shown with the alarm control unit 18 and the switching circuit 14 taken out, and the switching circuit 14 has a resistor R1 and a transistor Q1 connected in series between the detector lines 2.

  The receiver 1 includes a receiving circuit unit 6 and a command output circuit 24. The power supply line of the power supply voltage + Vcc of the receiver 1 is connected to the plus side (L side) of the sensor line 2 via the reception resistor R2, and supplies the power supply voltage to the sensor line 2. The output of the command output circuit 24 is provided with a transistor Q2. The transistor Q2 is connected in series with the output resistor R3, and is connected between terminals L and C to which the sensor line 2 is connected.

  When the fire detector 3 detects a fire and issues a notification, the transistor Q1 of the switching circuit 14 is turned on by a notification signal from the notification control unit 18 and the resistor R1 is connected between the detector lines 2 to receive the signal. The alarm current is passed through the sensor line 2 via the reception resistor R2 of the machine 1 and the resistance R1 of the fire detector that has reported, thereby sending a common fire signal to the receiver 1.

  In the receiver 1, from the received output of the receiving circuit unit 6, the command output unit 25 of the MPU 5 shown in FIG. The number of fire signals received is counted, and when a predetermined number of reports, for example, the third report is detected, the command output circuit 24 outputs a transmission stop command to stop transmission of a common fire signal. Instruct.

  In response to the output instruction of the transmission stop command, the command output circuit 24 turns the transistor Q2 on and off to connect and disconnect the resistor R3 between the sensor lines 2 and connect the resistor R3. The voltage of the sensor line 2 is lowered by the flowing current, and a transmission stop command signal is output to the sensor line 2 as a pulse signal of a voltage change caused thereby.

  When the transmission stop command signal is output from the receiver 1 to the sensor line 2, the fire detector 3 in the non-reporting state captures the signal state of the sensor line 2 from the receiver 1. The transmitted transmission stop command signal is decoded, and even if a fire is detected after the decoding and the alarm is issued, the transmission of the common fire signal, that is, the on operation of the transistor Q1 by the alarm control unit 18 is stopped. .

  FIG. 4 is a time chart showing the common fire signal transmission operation at the time of the fire alarm in FIG. 3, when fire detection is performed in the order of the fire detectors in which address 2, address 3 and address 5 are set. Is taken as an example. 4A is a sensor line voltage, FIG. 4B is an on / off operation of the transistor Q2 of the command output circuit 24, and FIGS. 4C, 4D, and 4E are fires at addresses 2, 3, and 5, respectively. The on / off operation of the transistor Q1 of the switching circuit 14 in the sensor is shown.

  In FIG. 4, when the fire detector at address 2 detects a fire at time t1, the transistor Q1 is turned on as shown in FIG. 4C, and a common fire signal is output to the detector line 2. As a result, as shown in FIG. 4A, the sensor line voltage is lowered by the voltage drop of the receiving resistor R2 due to the alarm current that flows when the transistor Q1 of the fire detector at address 2 is turned on. .

  Next, when fire detection is performed by the fire detector at address 3 at time t2, the transistor Q1 is turned on as shown in FIG. This further reduces the sensor line voltage.

  In the receiver 1, the transmission of the first common fire signal at time t1 and the transmission of the second common fire signal at time t2 are read from the reception circuit unit 6, and the number of detected detections is 2. It is determined at time t2 that the notification has been reached, and since the preset number of notifications has been reached, at time t3 the transistor Q2 is turned on in accordance with an instruction from the command output unit 25 to the command output circuit 24 as shown in FIG. In this way, the transmission stop command signal 24 is output to the sensor line 2 by turning the transistor Q2 on and off three times, for example.

  When the transmission stop command signal 25 is output by turning ON / OFF the transistor Q2 by the command output circuit 24, the voltage of the sensor line decreases three times at the ON timing of the transistor Q2 in the output operation of the transmission stop command signal 26. A transmission stop command signal, which is a pulse train, is sent on the sensor line.

  As a result, the fire detectors 3 other than the fire detectors at addresses 2 and 3 that have already transmitted a common fire signal due to fire detection receive and decode the transmission stop command signal 26 output from the receiver 1, Stop the transmission of common fire signals in the alarming action by the fire detection.

  For this reason, even if a fire detection is performed by the fire detector at address 5 at time t4, since a transmission stop command signal has already been received from the receiver 1, a common fire signal is not transmitted. As a result, even if multiple fire detectors connected to the detector line 2 are triggered by fire detection one after another, only up to the second report, which is the allowable number of alerts set on the receiver 1 side, will fire. The common fire signal is not transmitted from the sensor 3, and the transmission of the common fire signal is stopped for the third and subsequent reports, and the common fire signal is transmitted by the operation of a large number of fire sensors 3, and the sensor line voltage Is greatly reduced, and it is possible to prevent fire detection and communication with the receiver from being disabled due to a decrease in power supply voltage to the fire detector 3.

  FIG. 5 is a flowchart showing the alarm control process by the fire detector of the present invention. In FIG. 5, the presence or absence of a fire report is checked in step S1, and if there is no fire report, the process proceeds to step S2, the signal state of the sensor line is read, and the common signal from the receiver is read in step S3. It is checked whether or not there is a fire signal transmission stop command, and if there is a transmission stop command, a common fire signal transmission stop is set in step S4. In addition, even if the fire detector that has already issued a notification receives a transmission stop command, it ignores it and continuously transmits a common fire signal.

  If it is determined in step S1 that the fire has been issued, the process proceeds to step S5, where it is checked whether or not a common fire signal transmission stop setting has been made. Send a fire signal. If the common fire signal transmission stop has been set, step S6 is skipped and the common fire signal is not transmitted. Subsequently, in step S7, it is checked whether or not there is a fire recovery. If there is a fire recovery, an initialization process is performed in step S8, and then the process returns to step S1.

  FIG. 6 is a flowchart showing reception control processing by the receiver of the present invention. In FIG. 6, the signal state of the sensor line is sequentially read for each of the receiving circuit units 6-1 to 6-n shown in FIG. 1 in step S1, and the presence or absence of reception of a common fire signal is checked in step S2. .

  If it is determined in step S2 that a common fire signal has been received, the process proceeds to step S3, where a representative fire display is performed and a district display corresponding to the received sensor line is performed. Subsequently, in step S4, it is checked whether the received common fire signal is less than the third report. In the first report, the process of step S5 is skipped. Proceeding to step S5, a common fire signal transmission stop command is transmitted.

  Subsequently, fire recovery is determined in step S6, and the processing from step S1 is repeated until there is a fire recovery. When the fire recovery is determined, the recovery process is performed in step S7, and then the process returns to step S1.

  The above embodiment is an example in which only a common fire signal is transmitted to the receiver 1 from a fire detector that detects a fire, but an address signal is transmitted following the common fire signal, The receiver 1 may identify and display or control the sensor address. In this case, since the common fire signal is not transmitted after the transmission stop command is output from the receiver 1, only the address signal may be transmitted.

  In the above embodiment, transmission is stopped for the third and subsequent reports. However, the present invention is not limited to this, and transmission may be stopped for the second and subsequent reports. If so, it may be set to an arbitrary number.

  Also, in the above embodiment, when the fire detector receives a transmission stop command, the fire detectors that have been issued thereafter do not transmit a common fire signal, but have received a transmission stop command. In the case of a fire detector that has already been reported in the case and the self has been fired since the second report, the transmission of the common fire signal is stopped and only the first report has transmitted the common fire signal. When other fire detectors that have not yet been reported have entered a state, a common fire signal may be transmitted.

  After that, when the number of fire detectors more than the predetermined number is being triggered at the same time, a transmission stop signal is sent again and only the first report is set to send a common fire signal. You may make it.

  In this embodiment, the number of alarms reported by the sensor can be recognized by the receiver. If the fire detector is capable of transmitting an address, the fire detector's reporting order can be continuously recognized.

Further, the present invention includes appropriate modifications that do not impair the object and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

Explanatory drawing of the fire alarm system to which the present invention is applied Explanatory drawing which showed embodiment of the fire detector of FIG. Explanatory diagram showing a fire alarm control function according to the present invention by taking out one of the sensor lines of FIG. Time chart showing common fire signal transmission operation at the time of fire alarm in FIG. The flowchart which showed the alarm control processing by the fire detector of this invention The flowchart which showed the reception control processing by the receiver of this invention Time chart showing common fire signal transmission operation in conventional systems

Explanation of symbols

1: Receivers 2-1 to 2-m: Sensor line 3: Fire sensor 4: Termination resistor 5: MPU
6-1 to 6-m: reception circuit unit 7: operation unit 8: alarm display unit 9: district display unit 10: message output unit 11: memory 12: reception control unit 13: rectifier circuit / noise absorption circuit 14: switching Circuit 15: Constant voltage / current limiting circuit 16: Operation indicator lamp 17: Address setting circuit 18: Alarm control unit 19: Oscillating circuit 20: Light emitting element 21: Light receiving element 22: Amplifier circuit 23: Comparison circuits 24, 24-1 -24-m: Command output circuit 25: Command output unit 26: Transmission stop command signal

Claims (4)

In a fire alarm system in which a plurality of fire detectors are connected to a sensor line drawn from a receiver,
Before receiving the transmission stop command from the receiver, the fire detector transmits a common fire signal when a fire is detected and issued, and after receiving the transmission stop command from the receiver It has an alarm control unit that stops the transmission of a common fire signal when a fire is detected and reported,
The receiver
A reception control unit for receiving and alarming a common fire signal transmitted from the fire sensor in units of sensor lines;
A command output unit for outputting a transmission stop command for stopping transmission of the common fire signal to the sensor line when the number of detection detections of the common fire signal received from the same sensor line reaches a predetermined number;
A fire alarm system characterized by comprising:
2. The fire notification system according to claim 1, wherein the command output unit of the receiver receives a common fire signal received from the same sensor line, and outputs a common fire signal to the sensor line. A fire alarm system characterized by outputting a transmission stop command for stopping transmission and stopping transmission of a common fire signal for the second and subsequent reports.
In a fire alarm system in which a plurality of fire detectors are connected to a sensor line drawn from a receiver,
The fire detector has a notification control unit that stops transmission of a common fire signal when receiving a transmission stop command from the receiver when a fire is detected and a common fire signal is transmitted. Prepared,
The receiver
Reception control for receiving and alarming a common fire signal transmitted from the fire sensor for each sensor line;
A command output unit that outputs a transmission stop command for stopping transmission of a common fire signal to the sensor line when the number of detection detections of the common fire signal received from the same sensor line reaches a predetermined number;
A fire alarm system characterized by comprising:
  In the fire alarm system according to claim 3, when the fire detector receives a transmission stop command, if it is the first fire detector, it continuously transmits a common fire signal, A fire alarm system that stops transmission of a common fire signal when the self is not the first report.

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