JP4456895B2 - Fire alarm system - Google Patents

Description

  The present invention connects a plurality of fire detectors to a sensor line drawn from a receiver, and receives a common fire signal or a fire display signal from the fire sensor for each line, and issues a P-type fire alarm. About the system.

  Conventionally, in the fire alarm system known as P type, as shown in FIG. 13, a plurality of fire detectors 104 are connected to the sensor line 102 drawn from the receiver 100, and the fire detectors are connected to each line. A fire signal is received from a fire alarm.

  A termination resistor 106 is connected to the end of the sensor line 102 and the receiver 100 monitors the disconnection. In the disconnection monitoring by the receiver 100, if there is no disconnection in the sensor line 102, it is judged normal because a specified current flows through the termination resistor and a specified line voltage is obtained. The line voltage increases with respect to the specified voltage because no longer flows, and the increase in the line voltage is detected to determine that the line is broken, and a failure alarm indicating the broken line is issued.

  Furthermore, in the conventional P-type fire alarm system, the alarm search unit is provided in the receiver, and when a fire alarm is detected, a fire is generated by sending a search downlink signal to the alarm line. A search response unit is provided for searching for a sensor, and corresponding to this, a search response unit for determining and returning a downstream signal from the receiver to the fire sensor, and identifies the fire sensor that detected the fire (Patent Document 3). .

  FIG. 14 is a timing chart of the response operation of the fire detector according to the downstream signal from the receiver in the conventional P-type fire alarm system, and shows a case where the detector response is performed by the reading operation of the EEPROM provided in the fire detector. .

For example, when any of the fire detectors 104 connected to the sensor line 102-1 in FIG. 13 detects a fire and issues a notification, as shown in FIG. 14D, the alarm current Ic is applied to the sensor line. Run as a common fire signal. Therefore the receiver detects the alarm current Ic flowing through the sensor lines 102-1 performs fire alarm operation alarm level 10 V, lower than this have signal levels 7V and downlink signal varying ternary 4 V A read control signal including a read code and an address is converted and transmitted. On the sensor side, the clock signal is detected from the change of 4V and 7V of the received downstream signal as shown in FIG. 14B, and the change of the voltage signal of 7V and 10V is detected as shown in FIG. As described above, a data signal including a dummy clock, a start bit, a read operation code, an address bit, and a data bit for serial bit output is detected.

The read address of the EEPROM provided in the fire detector 104 notified here stores data in which, for example, only the data bit D2 has a bit value 1 and all the remaining bits have a bit value 0 among 32 bits. Therefore, the bit value 1 is read at the output timing of the data bit D2, and correspondingly, the alarm current Ic of the sensor line is reduced to the sensor response current Ir as shown in FIG. 14 (D). Then, an upstream signal for response is sent to the receiver, and the fire detector that has fired is identified from the response timing. The reason why the ternary value is used as the downstream signal is to detect the clock simultaneously with the data.
JP-A-5-108975 Japanese Patent Laid-Open No. 7-200957 JP 2001-184571 A

  However, in the conventional P-type fire alarm system, a fire test is performed only at the time of inspection. Therefore, even if a fire detector has failed during monitoring, this failure is periodically performed every six months. There is a problem that it can be found only in a fire test of a fire detector that is conducted automatically.

  The present invention has been made to solve such a problem, and it is possible to specify a failure detector at the time of monitoring and to specify a fire detection sensor at the time of fire alarm, and to improve reliability. The purpose is to provide a fire alarm system.

  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, and a common fire signal from a fire detector is received and alarmed for each line. The device is provided with a unique signal response unit that responds a unique signal to the downstream signal from the receiver, and the receiver sends a downstream signal for each sensor line at the time of monitoring to cause the natural signal to respond from the fire detector. A supervisory control unit that judges that a failure has occurred when there is no response signal and displays the failure, and a fire detector that detects a fire by sending a down signal to the detector line that received the fire signal when a fire signal is received And a reception control unit for identifying a fire detector that has detected a fire.

  As a result, a down signal is sent in units of sensing lines even during monitoring so that a specific signal is made to respond from the fire detector. If there is a fire sensor that does not respond to the specific signal, the fire sensor is broken or the sensor line It is possible to display a fault by judging that the line is disconnected.

  Here, the fire detector is provided with an alarm detection circuit that detects the transmission of a fire signal from another fire sensor connected to the same sensor line and suppresses the transmission of the fire signal. As a result, among the plurality of fire detectors connected to the detector line, only the fire detector that first detects the fire transmits the fire signal and responds to the specific signal with respect to the down signal.

  The unique signal response unit of the fire detector includes a nonvolatile memory such as an EEPROM, and stores unique number data in which only one bit at a specific position is distinguished from other bits at a predetermined address of the nonvolatile memory. Then, the unique signal is transmitted at the output timing of a specific bit determined specific to the sensor by the reading operation of the number data in which the predetermined address is designated by the downlink signal from the monitoring control unit of the receiver.

  For this reason, it is not necessary to use a CPU and a simple communication control using a nonvolatile memory such as an EEPROM and its interface circuit and a memory access as a transmission protocol. A unique signal can be made to respond, and compared with a so-called R-type fire alarm system using a data transmission circuit and a data transmission protocol, a significant cost reduction can be realized and the spread thereof is promoted.

  The specific signal response unit of the fire detector is further determined to be specific to the detector by the reading operation of the number data of the non-volatile memory in which the predetermined address is specified by the down signal from the reception control unit of the receiver during the transmission of the fire signal. The fire signal transmission is temporarily interrupted at the output timing of the specified bit.

  The specific signal response unit of the fire detector includes an exclusive OR circuit (EX-OR circuit) that inputs a read response signal from the nonvolatile memory and a fire signal from the fire detection unit to operate the alarm circuit.

  The specific signal response part of the fire detector responds to the down signal of the receiver at the time of monitoring by responding the specific signal by the short circuit operation of the sensor line, and the fire signal is sent by the continuous short circuit operation of the sensor line. In response to the down signal from the receiver when a fire is detected, a unique signal is responded by releasing the short circuit of the sensor line.

  According to such a fire alarm system of the present invention, at the time of monitoring, a downstream signal is periodically sent for each sensor line, and the fire detector connected to the sensor line is inherent to this downstream signal. The fire detector is judged to be normal if the signal is responded in sequence and a unique signal is obtained at the receiver. On the other hand, if the unique signal from a specific fire sensor is not obtained, it is judged that the fire sensor is faulty. The failure of the fire detector can be detected immediately, and measures such as replacement of the fire detector can be taken appropriately, the reliability of the fire alarm system can be improved, and the maintenance and management of the system can be facilitated.

  In addition, when there is no response of a specific signal from multiple fire detectors connected to the sensor line, it can be determined that the sensor line is disconnected at the part of the fire sensor that does not respond. Therefore, it is possible to easily monitor the disconnection of the sensor line without using the conventional technique of providing a termination resistance for monitoring the disconnection at the end of the sensor line and causing the disconnection monitoring current to flow.

  In addition, when a fire is being triggered, a down signal is sent to the sensor line that received the fire alert so that a specific signal is responded from the fire detector that detects the fire, thereby detecting the fire. Fire detectors can be identified and fire response and evacuation guidance can be taken appropriately.

  FIG. 1 is an explanatory diagram of a fire alarm system according to the present invention. In FIG. 1, detector lines 18-1 to 18-m are drawn from the receiver 1, and a plurality of fire detectors 4-11 to 4-mn are connected to each other. The number of fire detectors per detector line is n.

  The fire detectors 4-11 to 4-mn connected to the detector lines 18-1 to 18-m include photoelectric smoke detectors, semiconductor heat detectors, differential heat detectors, and constant temperature heat detectors. Various fire detectors such as firearms can be connected. These fire detectors 4-11 to 4-mn send a fire signal or a fire display signal as a common signal to the receiver 1 by short-circuiting the sensor lines 18-1 to 18-m when a fire is detected. To do.

  In addition to the fire detection unit, the fire detectors 4-11 to 4-mn of the present invention are used for a downlink signal for confirmation periodically transmitted from the receiver 1 during monitoring, and for detecting a sensor when a fire is triggered. An upstream signal response unit that responds to an upstream signal with respect to a downstream signal of the receiver, and a detector for detecting a sensor failure and disconnection during monitoring in the receiver 1 and a fire detector that detects a fire when a fire is triggered by the upstream signal Specific processing is performed.

The upstream signal response unit of the fire detectors 4-11 to 4-mn includes a nonvolatile memory such as an EEPROM, and unique number data in which only one bit at a specific position has a bit value 1 at a predetermined address of the nonvolatile memory. And the upstream signal is transmitted at the output timing of bit value 1 by reading the number data based on the downstream signal from the receiver 1.

  The receiver 1 is provided with an MPU 6. An operation unit 8, an alarm display unit 9, a district display unit 10, a transfer output unit 11, and a memory 12 are provided for the MPU 6.

  Further, monitoring circuit units 7-1, 7-2,..., 7-m are provided on the sensor line side of the MPU 6 for each line. Sensor lines 18-1 to 18-m are drawn out from the monitoring circuit units 7-1 to 7-m, and are connected to fire detectors 4-11 to 4-mn.

  As represented by the monitoring circuit unit 7-1, the monitoring circuit units 7-1 to 7-m include a voltage control circuit 15, an output buffer circuit 16, and a current detection circuit 17. In correspondence with the monitoring circuit units 7-1 to 7-m, the MPU 6 is provided with a function of the monitoring control unit 14 in addition to the function of the reception control unit 13.

  The reception control unit 13 of the MPU 6 detects an alarm signal for each line and performs alarm display, that is, fire representative display and district display (report line display). Furthermore, the reception control unit 13 transmits a down signal to the sensor line that has received the fire signal when receiving the fire signal from the sensor lines 18-1 to 18-m, and detects a fire. Execute the process such as responding to the upstream signal, identifying the fire detector that detected the fire, and displaying the area where the fire occurred.

  The monitoring control unit 14 of the MPU 6 periodically sends down signals in units of sensor lines 18-1 to 18-m at the time of monitoring, and causes the upstream signals to respond from the fire detectors 4-11 to 4-mn. When there is no signal, it is judged that the corresponding fire sensor is broken or the sensor line is broken, and a fault is displayed.

  For example, when a downstream signal is transmitted to the sensor line 18-1, and there is no response of an upstream signal from only the fire sensor 4-11, it is determined that the fire sensor 4-11 is out of order. When there is a response only from the fire detector 4-11 and there is no response from the fire detectors 4-12 to 4-1n connected downstream of the fire detector 4-11, the fire detector 4-11 It can be determined that the sensor line 18-1 is disconnected from the fire sensor 4-12.

Downlink signals from the monitoring controller 14 to the fire detectors 4-11 to 4-mn are read operation signals for predetermined addresses of the EEPROM provided in the upstream signal response units of the fire detectors 4-11 to 4-mn. In the read address of the EEPROM, unique number data corresponding to the sensor line in which only 1 bit at a specific position is 1 and all others are 0 is written in advance.

Thus fire detector 4-11~4-mn is downstream signal by (output period of the bit value 1) output timing of the bit value of 1 by the read unique number data specifying the predetermined address of the EEPROM from the receiver 1 Then, an upstream signal is sent to the sensor line to respond. Note that the upstream signal data of the read address of the EEPROM may have a bit value of 0 only at a specific position and a bit value of 1 at other positions.

The receiver 1, the number of fire detector 4 connected to each sensor lines 18-1 to 18-m, the address, or the like connection order is stored, receives uplink signals from the fire detector Thus, it is possible to specify a fire alarm, a faulty sensor, and a disconnection point.

Periodic transmission of the downlink signal during monitoring by the monitoring control unit 14 of the receiver 1 may be performed simultaneously for all lines when the number of sensor lines is small, but when the number of sensor lines is large Are sequentially transmitted in units of a predetermined number of lines corresponding to the power capacity of the receiver. Of course, confirmation signals may be sent sequentially in units of one line. Moreover, transmission timing of the downlink signal in order to detect disconnection state promptly performed periodically at intervals of less than one minute during normal monitoring.

  The voltage control circuit 15 provided in the monitoring circuit unit 7-1 converts the clock and data required for the EEPROM reading operation of the fire detectors 4-11 to 4-1n into a downstream signal that changes at a binary voltage level. Then, the data is sent to the sensor line 18-1 via the output buffer circuit 16. The signal level of the downstream signal changes between 18 volts for the monitoring level and 24 volts for the signal level higher than that when monitoring.

  On the other hand, when a fire is triggered, the fire detector that detects the fire passes a reporting current Ic determined by a predetermined resistance value to the sensor line 18-1, so that the level of the sensor line during the alarm is, for example, Decreases to 6 volts. For this reason, the down signal sent from the voltage control circuit 15 via the output buffer circuit 16 at the time of fire alerting changes between the alerting level of 6 volts and the higher signal level of 12 volts.

As described above, the downstream signal transmitted from the receiver 1 to the sensor line is changed at the binary signal level. In the present invention, the conversion of the data values 0 and 1 into the downstream signal is performed. , By pulse width modulation. For this reason, the fire detectors 4-11 to 4-mn detect data values 0 and 1 from the length of the 18 volt monitoring level time of the received downstream signal.

  FIG. 2 is a circuit block diagram showing an embodiment of the fire detector of FIG. The fire detector 4 is provided with a rectification / noise absorption circuit 21, an alarm circuit 22, a power supply circuit 24, a signal processing circuit 25, and a detection circuit 26 following the connection terminals L and C of the sensor line.

The detection circuit 26 outputs a detection signal corresponding to smoke or heat from the fire to the signal processing circuit 25. The signal processing circuit 25 outputs, for example, a fire signal E2 to the alarm circuit 22 when the detection signal from the detection circuit 26 exceeds a predetermined fire determination threshold value, and is an EX-OR circuit that will be clarified in later explanation. By switching the transistor 23 by the output of 32, a reporting current Ic determined by the resistor R is caused to flow between the sensor lines L and C, thereby sending a reporting signal to the receiver side.

The signal processing circuit 25, in the case of the light scattering type smoke detector detecting circuit 26 for detecting the light scattered by the smoke example intermittent light emission of the light emitting element, originating in two counts obtained that detection signal in intermittent light emission The report circuit 22 is operated to send a report signal. In the heat detection by a semiconductor element or the like, the alarm signal is output by causing the alarm circuit 22 to operate and causing the alarm current Ic to flow when the threshold value of the fire judgment is exceeded by the comparator.

  Furthermore, the fire detector 4 is provided with a unique signal response unit 27 for returning an upstream signal to the downstream signal from the receiver 1. The unique signal response unit 27 includes a clock detection circuit 28, a data detection circuit 29, a chip select detection circuit 30, an EEPROM 31 as a nonvolatile memory, an EX-OR circuit (exclusive OR circuit) 32, and a notification detection circuit 33. Is done.

  The clock detection circuit 28 inputs a downstream signal from the receiver 1 that changes voltage between 18 volts and 24 volts during monitoring, and between 6 volts and 12 volts during fire alarm, and synchronizes with the level change of the downstream signal. The detected clock pulse is detected and output to the EEPROM 31.

The data detection circuit 29 inputs a downstream signal from the receiver 1 and determines the data value 0, by determining the monitoring level time of 18 volts at the time of monitoring, and by determining the warning level time of 6 volts at the time of fire alarm. 1 is detected, and an operation code, an address, and a data value indicating the data output timing for the reading operation of the EEPROM 31 are output.

  The chip select detection circuit 30 inputs a down signal between the sensor lines, outputs a chip select detection signal over the time when the down signal is obtained, and performs a chip select for the reading operation of the EEPROM 31.

The alarm detection circuit 33 detects the alarm state from the voltage between the sensor lines at the time when the alarm signal is transmitted by the fire detection by another fire sensor of the same sensor line, It suppresses the operation of the signal processing circuit 25, so as to inhibit reading operation of the EEPROM31 for uplink signal response for the downlink signal from且one receiver device 1.

  As a result, among the multiple fire detectors connected to the same detector line, only the fire detector that is triggered by the first detection of fire detects the fire signal output operation and downloads from the receiver. The fire response to the signal is performed, and the fire alarm signal output from the second fire detector that detects the fire and the fire response to the downstream signal are prohibited, so that the signal from the fire detector that detected the fire first is The reliability of the exchange can be improved and the fire location of the first report can be specified.

  FIG. 3 is a time chart of the detection operation of the data detection circuit 29 and the chip select detection circuit 30 of FIG. 2 with respect to the voltage pulse signal between the sensor lines, taking the downstream signal at the time of monitoring as an example. FIG. 3A shows a downstream signal transmitted from the receiver 1 to the sensor line at the time of monitoring, and a voltage pulse changing between a monitoring level of 18 volts and a signal level of 24 volts is transmitted.

Although this downstream signal has a period T, pulse width modulation is performed to change the monitoring level time of 18 volts in accordance with the data values 1 and 0. For example, when sending a data "10011" from the receiver 1, a 18 volt monitoring level time of the second half of the period T and T ₁ hour for data values 1, whereas, the data value 0 is the second half 18 The time at the monitoring level of the bolt is set to a shorter T ₀ time.

Therefore, in the data detection circuit 29 of FIG. 2, the monitoring level time of 18 volts is monitored every pulse period T of the input downstream signal, and if it is T ₁ time, the data value 1 is displayed in the next pulse period. 3 (C), and if it is T ₀ time, the data value 0 is output in the next cycle.

  On the other hand, in the chip select detection circuit 30 of FIG. 2, as shown in FIG. 3A, when the downstream signal is transmitted from the receiver, the voltage of the sensor line is first changed from the monitor level of 18 volts to the signal level of 24. It is detected that the voltage has increased to volts, and the chip select detection signal is turned on to H level as shown in FIG.

After that, the time when the downstream signal between the sensor lines is at the monitoring level of 18 volts is monitored, and when it continues for T ₂ hours longer than T ₁ hour used for the determination of the data value 1, As in 3 (B), the chip select detection signal is turned off from the H level to the L level. As a result, while the downstream signal is obtained from the receiver, the chip select detection signal is turned on when the signal becomes H level, and the chip select operation of the EEPROM 31 is performed.

Note that the determination of the time T ₀ , T ₁ , T ₂ in the downstream signal in FIG. 3A corresponds to the time constant T ₀ , T ₁ , T ₂ using the time constant of the time constant circuit using resistors and capacitors. Or a time measurement clock pulse is counted by the counter over the L level section (18 volt section) of the voltage pulse signal, and T ₀ time is calculated from the count value of the counter. data value 1 if the data value 0, T ₁ hour long, perform off chip select detection signal if further T ₂ hours.

Next, the EEPROM 31 provided in the unique signal response unit 27 in FIG. 2 will be described. EEPROM31 is capable of storing a 32-bit data for each that address. In the EEPROM 31 of the present invention, number data for responding to the upstream signal in response to the downstream signal from the receiver 1 is stored at a specific address, for example, the address 38. As the number data of the address 38, the bit value 1 is stored in one specific bit among the 32 bits of data bits D0 to D31, and the remaining bits are all set to the bit value 0.

FIG. 4 shows EEPROMs 31-11 to 31-mn provided in the fire detectors 4-11 to 4-mn connected to the sensor lines 18-1 to 18-m of FIG. and shows the location of the bit value of 1 in the number data.

For example, taking the EEPROMs 31-11 to 31-1n of the fire detectors 4-11 to 4-1n connected to the sensor line 18-1, as an example, the data bit having the bit value 1 in the number data stored at the address 38 is , Data bits D31, D30,..., D0 are sequentially shifted for each sensor. This also applies to the EEPROMs 31-21 to 31-mn corresponding to the remaining sensor lines 18-2 to 18-m.

  In the read operation of the EEPROMs 31-11 to 31-mn, among the data bits D0 to D31 of the number data, bit output is performed in the order of the data bits D31 to D0 in synchronization with the clock (serial bit output).

Therefore, as shown in FIG. 4, the number data obtained by sequentially shifting the storage bit positions of the bit value 1 is stored for the addresses 38 of the EEPROMs 31-11 to 31-mn for each of the sensor lines 18-1 to 18-m. Thus, on the basis of the down signal designating the reading operation of the address 38 from the receiver 1, the up signal can be made to respond in order from the fire detector of each sensor line.

The numbers data to be set uniquely for each EEPROM31 fire detector 4 may have to duplicate the same sensor lines, in particular trouble with regard be monitored even overlap if different sensor lines are Absent.

If the same sensor line is set redundantly, the upstream signal comes simultaneously from the two fire detectors, so that the value of the current flowing through the sensor line due to the upstream signal becomes different from the normal value. Thus, the two or more fire detectors in the same line can be determined by the receiver that sets the same number data, it is possible to alarm the abnormal setting of the fire detector.

Unique number data to be set in each detector terminating fire detector line, the common end data bits located at address 38 of EEPROM31 of each fire detector 4, for example, is set to the data bits D31, In monitoring the disconnection of the sensor line by sending a downstream signal from the receiver, if no upstream signal is received at the specific bit timing for termination (data bit D31), it may be automatically determined as a disconnection failure. good.

  FIG. 5 shows a list of outputs to the inputs of the response signal E1 and the fire signal E2 by the EX-OR circuit 32 of FIG. 2 and an upstream signal by the alarm circuit 22 based on the output of the EX-OR circuit 32. In FIG. 5, when no downstream signal is output from the receiver 1 at the time of monitoring, both the response signal E1 and the fire signal E2 are L level, and the output of the EX-OR circuit 32 is also L level. The current as an upstream signal is zero.

When a down signal is received from the receiver 1 at the time of monitoring and the EEPROM 31 sets the response signal E1 to the H level by reading out the specific data bit 1 at the address 38, the fire signal E2 is at the L level at this time. The output of the -OR circuit 32 becomes H level. When the output of the EX-OR circuit 32 becomes H level, the transistor 23 of the alarm circuit 22 is switched, and the alarm current Ic determined by the resistance R flows between the sensor lines L-C . To the receiver 1 as an upstream signal.

  On the other hand, in the event of a fire, when the fire signal E2 is H level and the response signal E1 is L level, the output of the EX-OR circuit 32 is H level, and the transistor 23 of the alarm circuit 22 is switched. The alarm current Ic determined by the resistor R is passed through the sensor line as an upstream signal, and a fire alarm signal is sent to the receiver 1.

  If a down signal is sent from the receiver 1 during this fire alarm, the response signal E1 output from the EEPROM 31 becomes H level at the read timing of the data bit 1, and therefore the output of the EX-OR circuit 32 is the response signal. During the period during which E1 is being output, it becomes L level, and the transistor 23 of the alarm circuit 22 is restored to OFF so that there is no upstream signal in which the alarm current is temporarily set to zero.

  For this reason, on the receiver 1 side, even when the fire alarm signal is being received, the alarm signal is temporarily interrupted during that time, so that the upstream signal for the downstream signal from the fire detector 4 It can be recognized that it is a response.

  FIG. 6 is a timing chart showing the response operation of the upstream signal to the downstream signal at the time of monitoring from the receiver 1 of FIG. 1 with respect to the fire detector 4 of FIG. In FIG. 6, in order to simplify the explanation, a confirmation signal is sent only to the sensor line 18-1 drawn from the monitoring circuit unit 7-1 of the receiver 1, and a fire is provided at the end. The case where the sensor 4-1n responds is taken as an example.

6 (A) is based on a confirmation signal from the monitoring control unit 14 that are provided on MPU6 the receiver 1 of FIG. 1, is output to the sensor lines 18-1 from the monitoring circuit 7-1 the downlink signal As shown in FIG. 3 (A), the monitoring level time of 18 volts is set to T ₁ for the data value 1 as shown in FIG. For the time and data value 0, a pulse width modulation is performed with a monitoring level time of 18 volts being a shorter T ₀ time, and a downstream signal is transmitted.

  Such a downstream signal of the sensor line 18-1 is input to the clock detection circuit 28 of the fire detector 4 of FIG. 2, and a clock signal synchronized with the change of the downstream signal as shown in FIG. 6B is detected. , And supplied to the EEPROM 31 as a clock.

  Here, the clock signal in FIG. 6B does not have a fixed clock cycle, but operates with the rising timing as valid, so the difference in clock cycle is not particularly problematic.

Further, as shown in FIG. 6 (D), the first half of the data by the down signal is a dummy clock, a start bit, a read operation code, and an address bit. Therefore, pulse width modulation corresponding to data values 0 and 1 representing this is performed. However, since only the clock timing is given to the data bit used for the serial read output of the 32-bit data of the EEPROM 31 in the latter half, the downstream signal has a normal clock with a duty of 50%. In synchronization with this, the clock in FIG. 6B also detects a clock pulse with a duty of 50%.

Further, as shown in FIG. 6C, the chip select detection circuit 30 detects the voltage increase from the first 18 volts to 24 volts of the downstream signal in FIG. 6A, and turns the chip select signal to the H level. the chip select detection signal monitoring level time 18 volts is interrupted the downstream signal is turned off to the L level is reached T ₂ hours of FIG. In the present invention, there is no restriction on the duty.

  FIG. 6D shows data detected by the data detection circuit 29. From the top, the dummy clock “00”, the start bit “1”, the read operation code “10”, the address bit “100110” (address 38), and 32 The read timing corresponding to the bit data bits D31 to D0 is output.

Of the 32 data bits D31-D0, for example, taking the fire detector 4-1n located at the end as an example, as shown in EEPROM31-1n 4, the bit value 1 to the data bit D31 in advance The remaining data bits D30 to D0 are stored with the bit value 0, and the read bit output of the data bit D31 storing the bit value 1 is the response signal E1 output from the EEPROM 31-1.

Therefore, at the time of monitoring, as shown in FIG. 6E, the read bit output of the first data bit D31 storing the bit 1 value is input to the EX-OR circuit 32 with the response signal E1 as H level. The output is set to H level, the transistor 23 of the alarm circuit 22 is switched, and the alarm current Ic determined by the resistor R is thereby used as a response current at the time of monitoring as shown in FIG. As a result, the fire detector 4-1n responds with an upstream signal to the confirmation signal from the receiver 1.

In the receiver 1, when no upstream signal is received from the terminal fire detector 4-1n, that is, when the upstream signal of the current Ic cannot be received at the position of the data bit D31, the terminal fire detector 4-1n. Or an abnormal alarm is output because the sensor line 18-1 is disconnected.

  Similarly, the other fire detectors 4 return bit 1 at the position of the specific data bit determined for each fire detector as a response signal to the downstream signal from the receiver 1. Therefore, as shown in FIG. 6 (E), the data are sequentially returned from the fire detector 4 at the timing of the data bits D31 to D0.

  The receiver 1 stores the unique data bit position of each connected fire detector 4, and determines that the detector is normal if it receives upstream signals from all of the connected fire detectors. If no upstream signal is received at the stored data bit position, it is determined that the fire detector 4 corresponding to the data bit position is faulty, and an abnormality is displayed.

  In the receiver, the number of fire detectors 4 connected to the sensor line 18 is stored, the number of bits of the upstream signal is counted, and the number of connected sensor connections is compared. Then, it may be determined whether all the fire detectors are normal or abnormal.

  Further, if there is no response from a plurality of fire detectors, if the connection order of the fire detectors is known in advance, it can be determined where the sensor line 18 is disconnected, and a more detailed abnormality display. It can be performed.

  FIG. 7 is a timing chart illustrating the response operation of the upstream signal with respect to the downstream signal from the receiver 1 of FIG. 1 when the fire is triggered, taking the same fire detector 4-1n as FIG. 6 as an example.

  When a fire is detected by the fire detector 4-1n, the fire signal E2 output from the signal processing circuit 25 becomes H level. At this time, the response signal E1 is L level, so the output of the EX-OR circuit 32 is It becomes H level, the transistor 23 of the alarm circuit 22 is switched, and the alarm current Ic determined by the resistance R is continuously supplied to the sensor line 18-1 from the time of the fire as shown in FIG. Send a fire signal to the machine.

When such a fire signal is received by the receiver 1, after performing a so-called P-type fire alarm operation indicating the sensor line 18 where the fire has occurred, the sensor whose reception control unit 13 has detected the fire is detected. As shown in FIG. 7 (A), a downstream signal for searching is sent and changes between a 6-volt signal level and a 12-volt signal level. ₀ hours, is received as the pulse width modulated downstream signal to T ₁ times the data bit 1.

  Therefore, similarly to FIG. 6, as shown in FIGS. 7B to 7D, the clock signal, the chip select detection signal and the data are detected, and the read operation from the address 38 of the EEPROM 31-1n is performed. In the fire detector 4-1n, the response signal E1 becomes H level at the bit output timing of the data bit D31 in FIG. 7D. At this time, the fire signal E2 is also H level. The output of the -OR circuit 32 becomes L level during the reading period of the data bit D31 and the transistor 23 is turned off, so that the alarm current Ic is temporarily cut off as shown in FIG. In case of 1, it is possible to recognize the response of the upstream signal from the fire detector 4-1n detecting the fire.

On the other hand, during the fire detection fire detector 4-1N, when a fire is detected by the other fire detectors connected to the same sensor lines 18-1, Ri by its alarm detection circuit 33 is detected alarm by fire detectors 4-1N, since in other fire sensor is suppressed read operation EEPROM 31 is transmitted to the fire signal from the fire detector detects a fire in the second and subsequent And the response of the upstream signal to the downstream signal is not performed.

FIG. 8 shows another embodiment of the downlink signal transmitted from the receiver 1. In the embodiment of FIGS. 3 and 6, the downstream signal from the receiver 1 is sent by changing the monitoring level time of 18 volts in accordance with the data values 0 and 1 at regular intervals. For example, as shown in FIG. 8, the monitoring level time of 18 volts is common, not a fixed period, and is output to the sensor line as a downstream signal by pulse width modulation with the signal level time of 24 volts changed thereafter. You may do it.

Furthermore, whether the time according to the data values 0 and 1 is the monitoring level time or the signal level time can be arbitrarily determined as necessary.

  FIG. 9 shows another embodiment of the fire detector 4 of FIG. FIG. 9 shows a configuration in which the alarm detection circuit 33 of FIG. 2 is removed. In the same sensor line, the fire signal E2 from the signal processing circuit 25 is EX-ORed regardless of the alarm state of other fire detectors. Output to the circuit 32.

  FIG. 10 is a timing chart of the response operation of each fire sensor when the fire sensor 4 of FIG. 9 is used and a fire is detected by the terminal fire sensor 4-1n. As shown in FIG. 10 (E), the terminal fire detector 4-ln that detects the fire has the response signal E1 and the fire signal E2 both at the H level in the data bit D31, so that the EX-OR circuit 32 responds. During the period in which the signal E1 is being output, the signal becomes L level, and the transistor 23 of the alarm circuit 22 is turned off and recovered to temporarily set the alarm current to 0, ie, no upstream signal. Therefore, the receiver 1 can specify that the fire detector 4-ln at the end detects a fire.

  Subsequently, the fire detector that has not detected the fire outputs a response signal E1 at the timing within the data bits D30 to D0 unique to the detector, the EX-OR circuit 32 becomes H level, and the transistor of the alarm circuit 22 23 is turned on. Then, as shown in FIG. 10 (E), it is superimposed on the alarm current of the fire detector 4-ln. Even with this configuration, it is possible to reliably identify a fire detector that has detected a fire, and display a more detailed alarm display that identifies the location of the fire than the alarm display for each sensor line of the P-type system. be able to.

FIG. 11 shows still another embodiment of the fire detector 4. Figure 11 is the fire detector 4 in FIG. 9, has a configuration having a Zener diode ZD1 in front of the transistor 23 of the alarm circuit 22. If the voltage of the sensor line L-C decreases drastically due to an increase in the number of fire detectors that report simultaneously on the same sensor line, the unique signal response unit 27 in the fire sensor or The fire detection function cannot operate correctly.

  In order to prevent this, when the L-C voltage drops below a predetermined voltage value determined by the Zener diode ZD1, the Zener diode ZD1 is turned off, and the response operation to the receiver is prohibited. The set voltage of the Zener diode ZD1 is set to about 10V, for example.

  The stored data at the address 38 of the EEPROM in FIG. 4 is an example in which the number n of fire detectors provided in each line corresponding to the data size of 32 bits is n = 32. This is a case where the maximum number of fire detectors that can be connected to one line is set to the maximum configuration. If the number is within the maximum configuration, the necessary number of fire detectors can be provided for each detector line.

  The bit specific to the sensor output from the EEPROM is not limited to 1, but the reverse specific bit 0 and all other bits may be set to 1, so that the specific bit can be detected in the receiver. It only has to be.

  In the above embodiment, the circuit configuration on the transmission side and the reception side is simplified by changing the downlink signal between the binary signal levels. As described above, the signal level may be changed by three values.

  When the number connected to one sensor line is larger than the number of data bits 32, all the addresses 38 of the EEPROM 31 are not allocated. In this case, another address of the EEPROM 31, for example, the address 39 is used. The remaining fire detectors may be bit set. In this case, confirmation is made by sequentially sending downstream signals using addresses 38 and 39 to the sensor line.

Moreover, in the normal monitoring state, the function test of the fire detector 4 is not necessary, and only the disconnection monitoring is performed by sending a confirmation signal only to the termination fire sensor, and the function test of the fire detector 4 is monitored for disconnection. If the method may be performed at a somewhat longer interval, as shown in the EEPROM address and stored data in FIG. 12, there are two reading addresses 38 for monitoring disconnection and a reading address 39 for function test of the sensor. set, in the normal disconnection monitoring, to receive only from the response signal whether the terminating fire detector in the transmission of the confirmation signal of the address 38, when the operation of the fire detector 4 performs a functional test of the normal or In the read operation using the address 39, a response signal may be received for each bit allocated from each fire detector, and the test may be performed.

  Furthermore, in the case of a specific operation of the fire detector at the time of fire detection, the fire detector that detected the fire may perform the operation of temporarily canceling the short circuit of the sensor line by the reading operation using the address 39. good.

In this embodiment, the disconnection of the sensor line is determined based on the presence / absence of a return signal from the fire detector for termination. However, as shown in FIG. 13 of the related art, the disconnection monitoring is connected to the termination of the sensor line. It is also possible to perform monitoring by the terminal resistance, and determine the normality of the detector and specify the fire alarm terminal with the configuration of the fire detector of FIG.

  Moreover, in the fire detector of this embodiment, the function of the detector is monitored and the fire detector that detects the fire is identified by the reading operation of the EEPROM address bits. However, the present invention is not limited to this. A similar operation may be performed by providing a CPU.

  For example, for the downstream signal for confirmation from the receiver during normal monitoring, the sensor line is temporarily short-circuited at a timing specific to each sensor, and the sensor line is continued when a fire is detected. The same operation can be performed such as temporarily releasing the short circuit of the short-circuited sensor line when the sensor is specified at the time of fire alarm. In this case, it can also be achieved by eliminating the EX-OR circuit, the EEPROM and the like.

Explanatory drawing of the fire alarm system of the present invention Block diagram of the fire detector of FIG. Time chart of data detection processing by downstream signal and data detection circuit of FIG. 2 in the present invention Explanatory drawing of EEPROM address and stored data in fire detector of FIG. Explanatory drawing of the logical table of specific signal response and fire alarm by EX-OR circuit of FIG. Timing chart of specific signal response operation by reading EEPROM in monitoring of fire detector of FIG. Timing chart of specific signal response operation by reading EEPROM in fire detector of FIG. Time chart of other data detection processing by the data detection circuit of FIG. 2 when the EEPROM read clocks are uneven. Explanatory drawing of other embodiment of a fire detector Timing chart of specific signal response operation when fire detector of FIG. 9 is used Explanatory drawing of other embodiment of a fire detector Explanatory diagram of another embodiment of EEPROM address and stored data Illustration of a conventional P-type fire alarm system Timing chart of sensor response operation when a fire is triggered in a conventional P-type fire alarm system

1: Receiver 4: Fire detector 6: MPU
7-1 to 7-m: monitoring circuit portion 8: the operation unit 9: Alarm display unit 10: District display unit 11: transfer paper output unit 12: memory 13: the reception control unit 14: monitor control unit 15: voltage control circuit 16: output buffer circuit 17: current detection circuits 18-1 to 18-m: sensor circuit 21: rectification / noise absorption circuit 22: alarm circuit 23: transistor 24: power supply circuit 25: signal processing circuit 26: detection circuit 27 : Specific signal response unit 28: Clock detection circuit 29: Data detection circuit 30: Chip select detection circuit 31: EEPROM (nonvolatile memory)
32: EX-OR circuit 33: Alarm detection circuit

Claims (4)

In a fire alarm system for connecting a plurality of fire detectors to a sensor line drawn from a receiver, receiving a common fire signal from the fire detector per sensor line, and alarming,
In the fire detector,
A fire detection unit that detects a fire and outputs a fire signal;
A specific signal response unit that responds to a specific signal corresponding to the presence or absence of a fire signal from the fire detection unit with respect to a downstream signal from the receiver ;
An alarm circuit that operates in response to the fire signal or the specific signal and sends an upstream signal to a sensor line;
Provided,
In the receiver,
During monitoring sensor to the line units transmits a downlink signal to the response of the specific signal from the plurality of fire detectors, a monitoring control unit that the fire detector is no response of the specific signal and determines that a failure to failure indication ,
Upon reception of the fire signal, a down signal is sent to the sensor line that has received the common fire signal, and a specific signal is responded from the fire sensor that detects the fire, and the fire sensor that has detected the fire is identified. A reception control unit,
Provided ,
The specific signal response part of the fire detector is:
A unique number data in which only one bit at a specific position is a bit value distinguished from other bits is stored in a predetermined address, and reading of the number data specifying the predetermined address by a downstream signal from the receiver A non-volatile memory that outputs a response signal at an output timing of 1 bit at the specific position with respect to operation;
An exclusive OR circuit for operating the alarm circuit by inputting a response signal from the non-volatile memory and a fire signal from the fire detection unit;
With respect to the downstream signal from the receiver,
When the fire signal is not output, the response signal is output at the output timing to respond to the specific signal,
At the time of outputting a fire signal, a fire alarm system characterized by responding to a specific signal by temporarily interrupting the output of the fire signal at the output timing .
2. The fire alarm system according to claim 1, wherein the specific signal response unit of the fire detector is caused by a temporary short-circuit operation of the sensor line with respect to a downstream signal of the receiver when no fire signal is output . in response to specific signals, sending fire signal performs continuous short circuit operation of the sensor lines, by a temporary short circuit release of the sensor lines for the downlink signal from the receiver at the output of a fire signal A fire alarm system characterized by responding to a specific signal.
3. The fire alarm system according to claim 2, wherein when the voltage of the sensor line drops below a predetermined value, the specific signal response unit of the fire detector is connected to the receiver by preventing the short-circuit of the sensor line. A fire alarm system characterized by prohibiting response operation.
2. The fire alarm system according to claim 1, wherein the specific signal response unit of the fire detector sets a disconnection monitoring address and a function test address to a predetermined address of the nonvolatile memory, and the downstream from the receiver. In response to the signal, when the monitoring is performed, the disconnection monitoring address is used to respond to the termination fire sensor, and during the function test, the function testing address is used to respond. Fire alarm system.

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