WO2006131998A1

WO2006131998A1 - Fire alarm system

Info

Publication number: WO2006131998A1
Application number: PCT/JP2005/016505
Authority: WO
Inventors: Masahiro Nagata; Hideki Kasai; Takashi Fujii; Satoshi Hirata; Gon Mozumi
Original assignee: Matsushita Electric Works, Ltd.
Priority date: 2005-06-08
Filing date: 2005-09-08
Publication date: 2006-12-14
Also published as: JP2006343983A; ATE479174T1; DK1855260T3; EP1855260B1; JP4396584B2; EP1855260A4; EP1855260A1; DE602005023219D1

Abstract

A fire alarm system comprises a single receiver (1) and a plurality of fire sensors. The receiver (1) and fire sensors are in wireless communication with each other, using a super-frame (SF) consisting of a plurality of frames (F1-F30) each consisting of a single downstream time slot (B), which is used for the downstream from the receiver to the fire sensors, and a plurality of upstream time slots (D1-D99) used for the upstream from the fire sensors to the receiver. Each of the fire sensors transmits a radio signal by use of a respective one of the different upstream time slots assigned to that fire sensor.

Description

Specification

Fire alarm system

Technical field

[0001] The present invention relates to a fire alarm system including a plurality of fire detectors for detecting a fire and a receiver for receiving a fire signal by receiving a signal of each fire detector force, and more specifically, fire detection. The present invention relates to a fire alarm system in which a receiver and a receiver communicate with each other wirelessly.

Background art

[0002] Japanese Patent No. 3029716 is provided with a plurality of fire detectors for detecting a fire, and a receiver for receiving a signal of each fire detector power and notifying the fire, A fire alarm system that communicates wirelessly with the receiver is disclosed.

[0003] In this fire alarm system, periodic communication is performed at predetermined time intervals in order to confirm that each fire detector is operating normally. In other words, a response request message is sent once every few hours from the receiver to each fire detector. Upon receiving the response request message, each fire detector receives a response indicating its own operating status such as battery information. Send the message back to the receiver. Based on the received response message, the receiver determines whether or not the fire detector has a failure (eg, a battery is dead).

[0004] In recent years, in order to improve the reliability of fire alarm systems, it is required to perform regular communication more frequently. For example, the European standard draft (Pr-EN54-25) is scheduled to require regular communication once every 300 seconds or less.

[0005] If regular communication is frequently performed, the transmission timing of the fire detectors overlap, and the probability of communication collisions increases. The fire alarm system in the above document adopts the CSMA method (Carrier Sense Multiple Access Method), which checks the available frequency and transmits data in order to avoid communication collisions. However, with the CSMA method, it takes a certain amount of time to switch from wireless circuit reception to transmission, and can detect when other fire detectors transmit data during the switch to reception power transmission. Therefore, there was a problem that the collision could not be completely avoided.

[0006] As a collision avoidance method other than the CSMA method, the receiver power is required for each fire detector in turn. A polling method to send a message and a fire detector that sent a receiver response message send an acknowledgment (ACK), and each fire detector sends a response message until an acknowledgment is received ARQ (automatic retransmission Request) method and token ring method (registered trademark) that circulates tokens between fire detectors.

However, in the polling method and the ARQ method, the transmission frequency of the receiver increases in proportion to the number of fire detectors. Generally, a wireless fire alarm system uses a frequency that does not require a license, but such a frequency does not require a transmission time duty (that is, an allowable transmission time per unit time (1 hour)). There are strict restrictions on For example, in the European Union, for alarm frequencies used in fire alarm systems, the duty must be less than 0.1%. Therefore, in the polling method and the ARQ method, if the number of fire detectors increases, the duty exceeds the limit, so the number of fire detectors cannot be increased so much.

[0008] Further, in the token ring system, if a fire detector has a power failure, the token disappears and all the fire detectors may not be able to transmit.

Disclosure of the invention

[0009] The present invention has been made to solve the above problems, and an object of the present invention is to provide a fire alarm system that can reliably avoid a collision even if the frequency of regular communication is high.

[0010] A fire alarm system according to the present invention includes a plurality of fire detectors and receivers.

Each of the fire detectors includes a sensing means for sensing a fire and a wireless transmission / reception means for transmitting / receiving a wireless signal to / from the receiver. The wireless transmission / reception means is configured to detect the fire when the sensing means senses a fire. Periodic communication is performed with the receiver, which transmits a radio signal to the receiver and informs the receiver of the operation state of each fire detector at predetermined time intervals. The receiver includes: a wireless transmission / reception unit that transmits / receives a wireless signal to / from each of the fire detectors; and a notification unit that notifies a fire to the outside when the received wireless signal includes fire detection information. Prepare. A feature of the present invention is that each of the fire detectors and the receiver includes a receiver side force, one downstream time slot to the fire detector side, and a plurality of fire detectors to the receiver side. Wireless communication is performed using a super frame composed of a plurality of frames composed of upstream time slots. The wireless signal is transmitted by being assigned to one of the uplink time slots. Therefore, in the fire alarm system of the present invention, each fire detector transmits a radio signal in a separate uplink time slot, so that it is possible to reliably avoid a collision even if the frequency of regular communication is high.

[0011] Preferably, the receiver transmits a synchronization signal to all the fire detectors at least in a downstream time slot in the first frame included in the superframe.

Each fire detector determines the start timing of the upstream time slot assigned to itself, based on the time when the synchronization signal is received. In this case, all the fire detectors can operate in synchronism by receiving the synchronization signal and performing individual synchronization adjustments. In addition, the reception timing of the downlink time slot of the next frame can be obtained from the timing at which the synchronization signal is received and the frame period, and each fire detector performs the reception operation only during the time period in which the downlink time slot is received. As a result, wasteful power consumption can be reduced.

[0012] With regard to the method of periodic communication, preferably, the receiver transmits a reply request message for requesting the periodic communication in the same downlink time slot as the synchronization signal to all the fire detectors, Each fire detector that has received the reply request message transmits a response message to the receiver in an uplink time slot assigned to the fire detector, informing the operation state of the fire detector. In this case, even if the number of fire detectors increases, regular communication can be performed without increasing the frequency of transmission from the receiver to each fire detector.

[0013] Preferably, when the receiver cannot receive the response message in any upstream time slot, the fire assigned to the upstream time slot that could not be received in the downstream time slot of the next frame. The fire detector that retransmits the reply request message to the sensor and receives the reply request message again sends the response message to the receiver in the next upstream time slot assigned to the fire sensor. Send. in this case

Regular communication can be performed reliably.

[0014] Alternatively, if the receiver does not receive the response message in any uplink time slot, the receiver is assigned to the uplink time slot that could not be received in the downlink time slot of the next frame. Resend the reply request message to the fire detector, The fire detector that has received the reply request message may transmit the response message to the receiver again in a plurality of arbitrary upstream time slots. In this case, periodic communication can be performed more reliably by returning a response message using a plurality of arbitrary uplink time slots.

[0015] Alternatively, when the receiver cannot receive the response message in any uplink time slot, the receiver is assigned to the uplink time slot that could not be received in the downlink time slot of the next frame. The fire detector that has received the reply request message by re-sending the reply request message by designating one or more upstream time slots that have received the reply message to the fire sensor, The response message may be transmitted to the receiver again in the uplink time slot. In this case, it is possible to reliably perform regular communication by sending back a response message using a time slot that has been successfully received.

Alternatively, when the receiver cannot receive the response message in any uplink time slot, the receiver designates a different uplink time slot for each frame and sends the reply request message. The fire detector that has retransmitted and received the reply request message may transmit the response message to the receiver again in the designated uplink time slot. In this case, regular communication can be reliably performed by returning a response message while changing the uplink time slot.

[0017] Further, the receiver determines one transmission time from the transmission time allowed in the superframe, the time required for one uplink Z downlink time slot, and the number of uplink time slots in one frame. Obtain the upper limit of the number of transmissions to each fire detector power receiver allowed in the superframe, and transmit the number of transmissions below the upper limit to all the fire detectors together with the reply request message. Each fire detector that has received the reply request message transmits the response message to the receiver in an uplink time slot assigned to the fire detector until the number of transmissions is reached within one superframe. May be. In this case, regular communication can be reliably performed by returning a response message repeatedly while satisfying the transmission time limit set when using a frequency that does not require a license. [0018] In the above case, the receiver includes detection means for detecting the signal strength of the received radio signal, and the receiver transmits the radio sensor having a relatively high signal strength to the fire detector. It is preferable that the number of transmissions to the fire detector that has transmitted a radio signal with a relatively low signal strength and a relatively low signal strength is relatively increased within the upper limit. In this case, it is possible to reduce unnecessary traffic while reliably performing regular communication.

[0019] When a fire occurs, each fire detector transmits fire detection information to the receiver in the next upstream time slot assigned to the fire detector when the sensing means detects the fire. Is preferred. In this case, it is possible to reliably notify the receiver of the fire without causing the fire detection information to collide with wireless signals such as response messages and fire detection information transmitted from other fire detectors.

[0020] In the above case, preferably, when the receiver receives the fire detection information, the receiver transmits a confirmation message to the fire detector that has transmitted the fire detection information in the next downlink time slot, and the fire detection information is transmitted. The fire detector that transmitted the information transmits the fire detection information to the receiver in an uplink time slot assigned to the fire detector until the confirmation message is received. In this case, even if the receiver cannot properly receive the fire detection information due to the influence of noise or jamming waves, the fire detection information can be reliably transmitted to the receiver.

[0021] Preferably, each of the fire detectors has a unique address, and the lower address of the unique address corresponds to the position of the upstream time slot assigned to the fire detector. In this case, it is not necessary for each fire detector to store the upstream time slot position separately from the unique address of the fire detector.

[0022] In the above case, each of the fire detectors, when transmitting a radio signal to the receiver, serves as information indicating the fire detector of the transmission source, and the higher address excluding the lower address. Send address. In other words, since the receiver is aware of the lower address of the fire detector as well as the position of the upstream time slot, each fire detector needs to transmit only the upper address excluding the lower address from the unique address. Good transmission time can be shortened, and as a result, power consumption can be reduced. [0023] Preferably, each of the fire detectors measures a time from when reception of the time slot including the synchronization signal is completed until reception of the time slot including the synchronization signal is started in the next superframe. An error is calculated between the time measured by the timer and the timing of actually receiving the time slot including the synchronization signal, and the subsequent measurement time of the timer is corrected using the error. . In this case, the error of the operation clock of the receiver and each fire detector can be corrected, and the receiver and each fire detector can be surely synchronized.

Brief Description of Drawings

FIG. 1 is a block diagram of a fire alarm system according to an embodiment of the present invention.

FIG. 2 is a block diagram of each fire detector of the fire alarm system of FIG.

FIG. 3 is a block diagram of a receiver of the fire alarm system in FIG. 1.

FIG. 4 is a diagram for explaining a data format used in the fire alarm system of FIG.

FIG. 5 is a diagram for explaining a configuration of a super frame used in the fire alarm system of FIG. 1.

FIG. 6 is a flowchart for explaining the operation of the fire detector of the fire alarm system of FIG.

FIG. 7 is a diagram illustrating a timer used for the fire detector of the fire alarm system in FIG. 1.

FIG. 8 is a diagram for explaining the operation of the fire alarm system of FIG. 1.

FIG. 9 is a flowchart for explaining the operation of the fire detector of the fire alarm system of FIG.

FIG. 10 is a diagram for explaining the operation of the fire alarm system of FIG. 1.

FIG. 11 is a diagram for explaining another operation of the fire alarm system of FIG. 1.

FIG. 12 is a flowchart for explaining another operation of the fire alarm system of FIG.

FIG. 13 is a flowchart for explaining another operation of the fire alarm system in FIG. 1.

FIG. 14 is a diagram for explaining another operation of the fire alarm system of FIG. 1.

FIG. 15 is a diagram for explaining another operation of the fire alarm system of FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a configuration diagram of a fire alarm system according to an embodiment of the present invention. This fire alarm system consists of one receiver 1 and six fire detectors 10 ~: LO.

1 6

[0026] The fire detectors 10 to 10 are installed, for example, on the ceiling of the facility.

1 6

As shown in the figure, a radio signal is sent between the sensing unit 11 that senses a fire by detecting temperature changes and smoke generated by the fire, and a receiver 1 that modulates and demodulates the data format described below to a carrier wave of a specified frequency. Wireless transmission / reception unit 12 for transmitting and receiving, battery power supply unit 14 for supplying power to each unit using a battery, switch 16 for opening / closing between battery power supply unit 14 and wireless transmission / reception unit 12, wireless transmission / reception unit 12 and A control unit 13 for controlling the switch 16 and an antenna 15 for transmitting and receiving radio signals are provided. The control unit 13 is mainly composed of a microcomputer and a nonvolatile memory such as an EEPROM, and a program for executing various processes is stored in the nonvolatile memory. The wireless transmission / reception unit 12 transmits a wireless signal to the receiver 1 when the detection unit 11 detects a fire, and performs periodic communication with the receiver to notify the receiver 1 of the operation state of the device at predetermined time intervals. Between. Each fire detector 10 is given a unique address, which will be described later, at the time of manufacture or construction, and is stored in the nonvolatile memory of the control unit 13.

On the other hand, the receiver 1 is installed in a management room of a building, for example, and modulates and demodulates a data format to be described later to a carrier wave of a prescribed frequency as shown in FIGS. Wireless transmitter / receiver 2 that transmits / receives wireless signals to / from each fire detector 10 to 10

1 6

Operation switch 3a for setting the alarm, liquid crystal display 3b for performing a fire alarm and various displays, and a notification unit 3 including a speaker 3c for sounding an alarm sound, an alarm message, etc. 3 includes a control unit 4 that performs control 3, a power supply unit 5 that supplies power to each unit of commercial power, and an antenna 6 that transmits and receives radio signals. The control unit 4 mainly consists of a microcomputer and a nonvolatile memory such as an EEPROM, and programs for executing various processes are stored in the nonvolatile memory. A unique address different from that of the fire detector 10 is assigned to the receiver 1 at the time of manufacture or construction, and is stored in the non-volatile memory of the control unit 4.

[0028] The receiver 1 and each of the fire detectors 10 to 10 wirelessly communicate using a frequency that does not require a license. I do. For this reason, it must satisfy radio characteristics in accordance with low-power security and specific low-power wireless standards in Japan, FCC Regulations Part 15 Subpart C in the US, and Short Range Device standards in Europe.

[0029] Data format of data exchanged between receiver 1 and each fire detector 10 ~: L0

1 6

Figure 4 shows. This data format is a 32-bit preamble PR (bit synchronization pattern) in which 1 and 0 alternate, a 16-bit unique word UW (frame synchronization pattern) consisting of a specified bit string, and a fire alarm system. 32 A unique system ID (SysID) of bits, an 8-bit unique sensor ID (Node ID) assigned to each fire sensor 10, a 16-bit message Msg, and a 16-bit error detection code CRC Composed. That is, the unique address of each fire sensor is the system ID + sensor ID, and the unique address of receiver 1 is the system ID.

[0030] When receiver 1 designates a specific fire sensor and sends a message, the sensor ID of that fire sensor 10 is designated as the sensor ID (NodelD) of the data format, and all When broadcasting a message to fire detector 10, specify “0 (zero)” for the sensor ID in the data format. Also, when each fire sensor returns to Receiver 1, set its own sensor ID to the sensor ID of the data format and send it. Each fire detector or receiver 1 that has received the radio signal amplifies the received signal at the radio transmission / reception units 12, 2, demodulates the data format, and outputs it to the control units 13, 4. The control units 13 and 4 sample the data demodulated by the radio transmission / reception units 12 and 2 at the digital input port of the microcomputer, extract the bit timing during reception of the preamble PR, and then receive the next 16 bits of reception. A unique word is detected by shifting the bits one bit at a time until they match the specified unique word. Next, the control units 13 and 4 compare the received system ID and sensor ID with the unique addresses stored in the non-volatile memory, and if they match and no bit error is detected. The message Msg is received and the preprogrammed process is performed.

[0031] The message Msg includes a reply request message in which the receiver 1 requests periodic communication to the fire detector 10, a response message to the reply request message, fire detection information to inform the receiver 1 of the occurrence of a fire, and the like. is there. [0032] The receiver 1 can insert a synchronization signal into the message Msg and transmit the message Msg including the synchronization signal to the fire detector 10. The fire detector 10 that has received the synchronization signal uses the timing at which the synchronization signal is received as a reference, the timing at which the upstream time slot assigned to itself starts, and the time slot that includes the synchronization signal in the next superframe. Determine the time to start receiving.

[0033] In this embodiment, wireless communication between the receiver 1 and each of the fire detectors 10 to 10 is sometimes performed.

1 6

It is performed by the division multiple access (TDMA) method. FIG. 5 shows the configuration of the superframe used for the wireless communication of this embodiment. This super frame SF is composed of 30 frames F1 to F30. Each frame has one time slot B in the downstream direction (receiver side → fire detector side) and 99 upstream directions (fire). It consists of upstream time slots D1 to D99 on the sensor side → receiver side). The time required for each time slot B, D1 to D99 is 0.1 second, the time required for each frame is 10 seconds, and the period of the superframe is 300 seconds. The breakdown of each time slot B, D1 to D99 is that the data format shown in Fig. 4 is 50 milliseconds, and the radio transceivers 2 and 12 of the receiver 1 and fire detector 10 are activated to stabilize the carrier frequency. The start-up time for transmitting with is 20 milliseconds and the guard time is around 15 milliseconds. The guard time is a free time for absorbing a timing difference caused by an error in the operation clock frequency of the fire detector 10 and the receiver 1 (the operation clock frequency of the microcomputer configuring the control units 13 and 4).

[0034] Each fire detector 10 to 10 is connected to any one of the different upstream time slots D1 to D99.

1 6

Assigned to transmit radio signals. Therefore, even if the frequency of regular communication is high, it is possible to reliably avoid the transmission collision of each fire detector.

[0035] As an example of how to assign each fire detector 10 to 10 to upstream time slots D1 to D99,

1 6

For example, the assignment can be set by the dip switch provided for each fire detector 10 ~ 10.

1 6

In the process, the slot number is stored in the non-volatile memory of the controller 13, or there is! / ヽ assigns each fire detector 10 in order from the receiver 1 using wireless communication at the time of installation. There are methods such as storing in the non-volatile memory of the control unit 13. In this embodiment, among the unique addresses of each fire detector, the sensor ID (lower address) is associated with the slot number on a one-to-one basis. In other words, the control unit 13 of each fire detector has a non-volatile memory function. From the lower address of the stored unique address, the own uplink slot number is determined. In this case, it is possible to save the trouble of storing the slot number separately from the unique address and setting the slot number separately.

[0036] Next, the operation of the fire alarm system of the present embodiment will be described. First, the operation of regular communication will be described. In regular communication, receiver 1 sends a reply request message to each fire detector, and each fire detector 10 ~: LO that received the reply request message

1 6

, Send a response message to receiver 1. The content of the response message is the presence or absence of an abnormality in the fire detector (for example, the battery voltage has dropped below a threshold value or a malfunction has occurred in the sensing unit 11). If there is an error in the response message, the receiver 1 displays the detector ID of the fire detector 10 that returned the response message on the notification unit 3, etc. Inform about the occurrence.

[0037] First, when the power of the receiver 1 is turned on, the control unit 4 of the receiver 1 sets the sensor ID of the data format to "0" in the downstream time slot B of the first frame F1 of the superframe SF. Set and send a reply request message including a synchronization signal to all fire detectors 10 as message Msg.

On the other hand, in the fire detector 10, as shown in FIG. 6, immediately after the power is turned on, the control unit 13 closes the switch 16 to supply power to the wireless transmission / reception unit 12, and a response request message including a synchronization signal is sent. Until it is received (steps SI and S2 in Fig. 6).

When each fire detector 10 receives the reply request message including the synchronization signal, the control unit 13 opens the switch 16 to stop the power supply to the wireless transmission / reception unit 12 and stop the reception (step of FIG. 6). S3). Each fire detector 10 simultaneously activates the first timer, the second timer, and the third timer built in the microcomputer of the control unit 13 (step S4 in FIG. 6).

[0040] As shown in FIG. 7, the first timer receives the downlink time slot B including the synchronization signal in the first frame F1 of the super frame SF, and then receives the downlink including the synchronization signal in the next super frame. Measure the time until reception of time slot B begins. In other words, the first timer allows each fire detector to determine the start timing of the downlink time slot B in the next superframe. In the present embodiment, since the period of the super frame SF is 300 seconds and the downlink time slot is 0.1 second, the first timer is 300—0.1 = 299. Counts 9 seconds.

[0041] The second timer starts the upstream time slot Di (i = 1 to 99) in which the power at the time when the downstream time slot B of the first frame F1 of the superframe SF ends is also individually assigned to each fire detector 10. Count time to time. That is, the second timer allows each fire detector to determine the start timing of the upstream time slot Di assigned to itself in frame F1. In this embodiment, since the time required for the uplink time slot is 0.1 second, the second timer counts 0.1 X {(number of uplink time slot Di) 1 1}.

[0042] The third timer counts the time from reception of downlink time slot B to reception of downlink time slot B in the next frame. In this embodiment, the time required for each frame is 10 seconds, and the time required for the downlink time slot B is 0.1 seconds. Therefore, the third timer counts 10−0.1 = 9.9 seconds.

[0043] The control unit 13 of each fire detector 10 sends a response message to the wireless transmission / reception unit 1 2 when the count of the second timer ends (that is, in the upstream time slot Di allocated to the own device). After the transmission, each fire detector starts the 4th timer built in the microcomputer (Steps S5 and S6 in Fig. 6).

[0044] The fourth timer counts from the end time of the uplink time slot Di assigned to the own device to the start time of the uplink time slot Di assigned to the own device in the next frame. In other words, the fourth timer allows each fire detector to determine the start timing of the upstream time slot Di assigned to itself in the next frame. In the present embodiment, the fourth timer counts 10−0.1.9.9 from the end time of the upstream time slot Di.

[0045] After that, each fire detector waits until the third timer ends and the message Msg from the receiver 1 is sent in the downlink time slot B of the next frame (step S7 in FIG. 6).

On the other hand, the control unit 4 of the receiver 1 receives a response message returned from each fire detector 10 while the third timer is activated, that is, in the upstream time slots D1 to D99. When response messages from all the fire detectors have been received, the control unit 4 knows that the reception was successful as the message Msg in the downstream time slot B of the second frame F2. A reception completion message is broadcast to all fire detectors 10.

In each fire detector 10, when the third timer expires, the control unit 13 closes the switch 16 again to operate the wireless transmission / reception unit 12 and receives the downlink time slot B from the receiver 1. After receiving, the third timer is started again (step S8 in Fig. 6).

[0048] At this time, if the received message in the downstream time slot B is an Msg force reception completion message (step S9 in FIG. 6), the control unit 13 of the fire detector 10 switches until the first timer is completed. 16 is opened to stop the operation of the radio transmission / reception unit 12 (step S10 in FIG. 6), and when the first timer ends and the next superframe SF starts, the switch 16 is closed again and the downlink time Slot B is received (step S11 in Fig. 6), and the operations from step S4 above are repeated.

[0049] By the way, even if the fire detector is normal, the receiver 1 may not be able to normally receive the response message from the fire detector due to the influence of noise, interference waves, and the like. In this case, receiver 1 designates the ID of the fire detector that cannot be received as the sensor ID of the data format in FIG. 4 and substitutes for the reception completion message in downstream time slot B of the next frame F2. Again, a reply request message is sent to the fire detector. For example, as shown in Fig. 8, if receiver 1 is unable to receive a response message of 10 fire detectors,

Three

Receiver 1 specifies the ID of fire detector 10 as the detector ID, and the downstream time of frame F2

Three

Send a reply request message again in slot B. In FIG. 8, “T” indicates a transmission state, and “R” indicates a reception state.

[0050] In step S8 of FIG. 6, each fire detector receives the downstream time slot B of the next frame F2, but the fire detectors other than fire detector 10 have the data format sent.

Three

Since the sensor ID does not match the ID of its own device, the data is discarded (steps S9 and S12 in Fig. 6), switch 16 is opened until the end of the third timer, wireless transmitter / receiver 12 is stopped, and reception is completed. Steps S7, S8, S9 and S12 are repeated until a completion message is received.

[0051] On the other hand, the control unit 13 of the fire detector 10 performs the downstream time of the second frame F2.

Three

Since the sensor ID of the data format received in Lot B matches the ID of its own, the reply request message is accepted, and when the 4th timer expires, that is, the upstream time slot of its own in the second frame F2. Send the response message again with D3 (step in Fig. 6). S13, S6).

[0052] When the receiver successfully receives a response message of 10 fire detectors,

Three

Set to 0 and a reception completion message is sent as a message Msg to all fire detectors. However, the receiver can successfully receive the response message from the fire detector 10

Three

If not, a response request message is sent again to the fire detector 10 and the above operation is performed.

Three

Repeat the work.

[0053] If there are multiple fire detectors that are unable to receive the response message, receiver 1 detects each fire in the second and subsequent frames F2, F3, ... within the upper limit of the number of transmissions. A reply request message may be transmitted to the device.

[0054] As described above, each fire detector uses the second and fourth timers to determine the start timing of the upstream time slot assigned to the fire detector based on the time when the synchronization signal is received. . By receiving the synchronization signal in this way and each fire detector individually performing synchronization adjustment, all the fire detectors can operate in synchronization. In addition, each fire detector uses the third timer to perform the receiving operation only during the time period for receiving downlink time slot B, thus reducing unnecessary power consumption. In addition, each fire detector that has finished regular communication uses the first timer 1 to stop the operation of the wireless transmission / reception unit 12 until the reception timing of the next superframe synchronization signal. Can be reduced. In addition, since the receiver 1 transmits a reply request message to all the fire detectors in the same downlink time slot B as the synchronization signal, each receiver 1 receives each response even if the number of fire detectors increases. Regular communication can be performed without increasing the frequency of transmission to the fire detector.

[0055] If all response messages for the reply request message are received normally in the first frame F1, receiver 1 requests a reply in the downstream time slot B of the first frame F1 in the superframe SF of 300 seconds. Since the message is transmitted and the reception completion message is transmitted in the downlink time slot B of the second frame F2, the transmission time duty is 0.1 X 2/300 X 100 = 0.067%. As mentioned above, when performing wireless communication using a frequency that does not require a license, for example, in Europe, it is necessary to satisfy not only the European standard draft (Pr_EN54-25) but also the European Radio Law. The limit value of the transmission time duty of the frequency for the A1 arm in Europe is less than 0.1%. The knowledge system meets this limitation.

[0056] If the response message to the reply request message cannot be received normally in the first frame F1, the upper limit L1 of the number of transmissions from the receiver 1 to the fire sensor is the limit value of the transmission time duty. Limited by. For example, according to the European Radio Law mentioned above, the limit value of the duty cycle of the European Alarm frequency is 0.1%, so the upper limit L1 of the transmission time per hour is

Ll = 3600 () X O. 1 (%) = 3.6 seconds

It becomes. In the case of this embodiment, the time T of the downlink time slot is 0.1 second.

B

The upper limit of the number of transmissions to the fire detector is

3. 6 (seconds) ZO. 1 (seconds) = 36

Therefore, it will be 36 times per hour. If the limit of 36 times per hour is observed, for example, if receiver 1 is unable to receive a response message normally, it will transmit downlink time slot B in several consecutive frames, It is also possible to prohibit transmission of downlink time slot B in the frame after processing is complete. The upper limit of the number of transmissions may be stored in the nonvolatile memory of the control unit 4 or the like. Note that the upper limit of 36 transmissions per hour is between receiver 1 and each fire detector 10-: LO.

1 6 Receiving receiver 1 and fire detector 10

One system with power from 1 to 10 6

V, not a limitation.

Next, the operation when any of the fire detectors detects a fire will be described. The following processing performed by the control unit 13 of the fire detector 10 when a fire is detected is an interrupt processing for the above-described periodic communication operation.

[0058] When each fire detector 10 detects a fire with the sensing unit 11, it determines whether or not the second timer is counting (step Sl in FIG. 9). If the second timer is counting, when the second timer ends, that is, in the upstream time slot Di of the frame F1, the fire that informs the detection of fire instead of the periodic communication response message. The sensing information is transmitted as message Msg to receiver 1, and the fourth timer is started after transmission (steps S2 and S3 in FIG. 9). If the count of the second timer has expired, the fire detector will detect when the fourth timer expires, that is, the upstream time slot assigned to itself in a frame. Di sends fire detection information to receiver 1 and starts the fourth timer after transmission (steps S7 and S3 in Fig. 9).

[0059] In the next downstream time slot B, the receiver 1 that has received the fire detection information transmits a fire detection information reception completion message to the fire detector that is the transmission source of the fire detection information. The system administrator is notified of the fire using the liquid crystal display 3b and speaker 3c of the receiver 1.

[0060] When the third timer expires (step S4 in FIG. 9), the fire detector that transmitted the fire detection information closes switch 16 to receive the next downlink time slot B, and after receiving the third timer, Start again (step S5 in FIG. 9). If the content of message Msg in downlink time slot B is a fire detection information reception completion message, the fire detector that sent the fire detection information returns to the main routine (flow chart in FIG. 6) (step S6 in FIG. 9). .

[0061] If the reception completion message of the fire detection information is not received, the receiver 1 has received the fire detection information normally, and there is a possibility that the fire will be detected when the fourth timer expires. Resend disaster detection information (steps S8 and S3 in FIG. 9). Until the reception completion message is received from receiver 1, steps S3 to S6 and S8 in FIG. 9 are repeated to reliably notify receiver 1 of the occurrence of a fire.

[0062] Specifically, for example, as shown in Fig. 10, two fire detectors 10 and 10 force ahead

2 3 Within the frame F1, fire detector 10 after the upstream time slot D2, and fire

2

Suppose a fire is detected before the uptime slot D3 of sensor 10. Fire detector 1

Three

0 means that the second timer has already expired when a fire is detected.

2

Wait for completion and send fire detection information to receiver 1 in upstream time slot D2 of the next frame F2. Fire sensor 10 has a second timer that has expired when a fire is detected.

Three

Therefore, after the second timer expires, fire detection information is sent to receiver 1 in upstream time slot D3 of frame F1.

[0063] Receiver 1 fires fire detector 10 in downstream time slot B of second frame F2.

3 Send a disaster detection information reception completion message. Fire detector 10 is the second frame

Three

When a reception completion message for fire detection information is received in time slot B of F2, return to the main routine. If no fire detection information reception completion message is received, After the end of the merging, send fire detection information again.

[0064] The receiver 1 is connected to the fire detector 10 in the downstream time slot B of the third frame F3.

2 Send a fire detection information reception completion message. Fire detector 10 is the third

2

When a fire detection information reception completion message is received in downstream time slot B of frame F3, the process returns to the main routine. If the fire detection information reception completion message is not received, the fire detection information is transmitted again after the fourth timer expires.

Thereafter, until the fire detection information reception completion message is received, the fire detectors 10 and 10

3 2 transmits fire detection information continuously. However, the upper limit of the number of transmissions in the superframe SF is set so that the transmission time duty does not exceed the limit value.

[0066] As described above, the fire detector 10 that has detected the fire transmits the fire detection information to the receiver 1 in the frame Fk + 1 after the frame Fk at the time of detecting the fire at the latest. Then, the fire detection information can be sent to the receiver 1 within 10 seconds, which is the required time of the frame. The European EN standard (EN54-25) stipulates that transmission should be made within 10 seconds after detection, so the fire alarm system of this embodiment satisfies this standard.

[0067] In this embodiment, the receiver 1 has a response message of 10 fire detectors.

1-10

6

When a response request message is sent again, the fire detector that received the response request message sent a response message again in the same uplink time slot (see Figure 8). However, a fire detector that has received a reply request message again may send a response message in multiple arbitrary upstream timeslots.

[0068] For example, as shown in FIG. 11, if the receiver 1 is unable to receive a response message as many as 10 fire detectors assigned to the upstream time slot D3 in the frame F1, the fire is detected.

Three

In the next frame F2, the sensor 10 sends a response message in two upstream time slots D3 and D4.

Three

Send a sage. In this way, the response message can be transmitted to the receiver 1 more reliably by transmitting the response message in a plurality of uplink time slots. The plurality of time slots may be determined based on a random number generated by the control unit 13, or a plurality of uplink time slots having an earlier number may be used.

[0069] The operation during regular communication in this case will be described with reference to the flowchart of FIG. The Note that steps S1 to S11 in FIG. 12 are the same as those in FIG.

[0070] When the receiver 1 does not receive the response message normally and sends a reply request message again, each fire detector has the sensor ID of the sent data format matched with its own ID. If they do not match, the data is discarded (step S12 in FIG. 12), and steps S7, S8, S9, and S12 are repeated until a reception completion message is received. The fire detector whose sensor ID matches the ID of the received data format receives the return request message and determines the number of multiple upstream time slots using random numbers. Then, a plurality of timers are set according to the determined start time of the uplink time slot, and when the timer ends, the wireless transmission / reception unit 12 is operated to transmit the response message again (step S13 in FIG. 12).

[0071] FIG. 12 is a flowchart showing the operation at the time of regular communication. Even when the power receiver 1 is unable to receive the fire detection information normally, each fire detector will not perform the steps shown in FIG. As shown in S8, it is preferable to retransmit the fire detection information in a plurality of arbitrary upstream time slots in the next frame. Note that steps S1 to S7 in FIG. 13 are the same as steps Sl to S7 in FIG.

[0072] Instead of using a plurality of arbitrary uplink time slots, the receiver 1 designates one or more uplink time slots in which the message can be received and transmits a reply request message again. This reply request message The fire detector that received the message may send a response message back to the receiver 1 again at the specified time slot.

[0073] For example, as shown in FIG. 14, when the receiver 1 has received a response message as many as 10 fire detectors assigned to the upstream time slot D2 in the frame F1, the receiver 1 cannot receive normally.

2

The device 1 selects one or more uplink time slots, for example, two uplink time slots Dl and D3 from the uplink time slots that have successfully received the response message in the frame F1, and selects the selected uplink time slot Dl, Specify D3 and send a reply again to Fire Detector 10.

2

Send a solicitation message. Fire detector 10 is the finger in second time slot F2.

2

The response message is returned again in the specified upstream time slots Dl and D3.

[0074] In this way, a response message is returned using an uplink time slot with a record of reception. Thus, the response message can be transmitted to the receiver 1 more reliably.

[0075] When the receiver 1 selects the uplink time slot Di, if the uplink time slot with the earliest number is selected from a plurality of uplink time slots Di that have been received, the response message can be transmitted in a shorter time. Can be received by the receiver 1. The number of uplink time slots Di to be selected may be three or more as long as it does not exceed the limit of the transmission time duty.

Alternatively, the receiver 1 may specify a different time slot for each frame and transmit a reply request message again. For example, as shown in Fig. 15, the receiver 1 normally receives a response message of 10 fire detectors assigned to the upstream time slot D2 in the frame F1.

2

If the receiver 1 fails, the receiver 1 designates the time slot D1 in the next frame F2 and transmits a reply request message again. In the next frame F3, the receiver 1 sets a time slot D3 different from the time slot D1. Specify and send the reply request message again. The fire detector 10 returns a response message in the designated upstream time slot.

2

[0077] By transmitting the response message by changing the uplink time slot for each frame, even when there is periodic noise close to the required time of frame F, the response message can be reliably transmitted to the receiver 1. it can.

[0078] Further, in this embodiment, in response to the reply request message from the receiver 1, each fire sensor transmits a response message once, and only the fire sensor to which the reply request message is individually transmitted, Although the reply request message was sent multiple times, each fire detector responded several times within the limit of the transmission time duty in order to send the response message to the receiver 1 more reliably. May be sent. That is, the receiver 1 uses one superframe based on the transmission time allowed in one superframe SF, the time required for one uplink Z downlink time slot, and the number of uplink time slots in one frame. Obtain the upper limit of the number of transmissions allowed to each fire detector in the frame, and send the number of transmissions below the upper limit to all fire detectors together with the reply request message. Each fire detector should send a response message to receiver 1 in the uplink time slot assigned to itself until it reaches the number of transmissions within one superframe. [0079] That is, the time of superframe SF is T, the time of uplink time slot is

SF D

If the time duty limit value is%, the upper limit L2 of the number of transmissions in one superframe SF of each fire detector due to the transmission time duty limit value is

L2 = (T X Z / 100) / Ύ

SF D

It becomes. On the other hand, if the number of uplink time slots in one frame is i, the time of downlink time slots is T, and the time of uplink time slots is T, the time width T of one frame F is

B D F

T = T + (T X i)

F B D

It becomes. Since each fire detector has an uplink time slot Di assigned to each frame, the number of transmissions within one superframe SF of each fire detector is the number of frames included in the superframe SF. Must be less than the maximum number of repetitions of F y (= T ÷ T)

SF F

I must. Therefore, the upper limit of the number of transmissions from each fire detector to receiver 1 allowed in one superframe is y if y≤L2, and L2 if y is L2.

[0080] For example, in this embodiment, T = 300 seconds, Z = 0.1%, T = T = 0.1 second, uplink time

SF B D

Since the number of slots = 99, L2 = 3 times, y = 30 times, and the upper limit of the number of transmissions to the receiver 1 that is allowed in each super-frame is 3 Times (= L2).

[0081] When the upper limit is three times, the receiver 1 designates the number of transmissions within three times, for example, two times, and sends a response request message to all the fire detectors. Sends a response message to receiver 1 twice in one superframe. In this case, the possibility that the receiver 1 receives the response message can be increased.

[0082] The above-described process for obtaining the upper limit value is performed by a contractor operating the operation switch 3a of the display / operation unit 3 during construction to control the time width T of the super frame SF and the transmission time duty.

SCIENCE FICTION

This is executed by the control unit 4 of the receiver 1 by inputting a condition such as a limit value ∑%.

[0083] In the above case, preferably, the receiver 1 includes a sensor (detection means; not shown) that detects the signal strength of the received radio signal, and transmits a radio signal having a relatively high signal strength. For fire detectors, the number of transmissions is relatively low, and for fire detectors that have transmitted wireless signals with relatively low signal strength, the number of transmissions is within the upper limit. Increase relatively. For example, if the signal strength of fire detector 10 is relatively high,

1

Instruct the sensor 10 to send a response message only once, fire detection

1

If the signal strength of the fire detector 10 is relatively low,

twenty two

Instructs to send a response message. In this case, since it is unlikely that radio signals with low signal strength can be received normally, the possibility of normal reception can be increased by increasing the number of transmissions, and radio signals with high signal strength can be received normally. Since there is a high possibility of being able to do V ヽ, useless traffic can be reduced by reducing the number of transmissions.

In this embodiment, when transmitting data to the receiver 1 of each fire detector, the data format shown in FIG. 4 is used and the sensor ID of the own device is designated as the sensor ID. And sent. However, when the lower address (sensor ID) of the unique address of each fire detector is associated with the slot number on a one-to-one basis as in this embodiment, the receiver 1 is the time slot number. Force Can identify the detector ID of the source fire detector. Therefore, it is preferable for each fire detector to transmit only the upper address (that is, the system ID (SysID)) excluding the sensor ID which is the lower address from the unique address. The power consumption can be reduced.

In the present embodiment, the timing at which reception of a time slot including a synchronization signal is started in the next superframe SF by the first timer is estimated. However, an error occurs in the time counted by the first timer due to an error between the operation clock of the microcomputer configuring the control unit 1 3 and the operation clock of the microcomputer configuring the control unit 4 of the receiver 1. there is a possibility. In the present embodiment, as shown in FIG. 5, a guard time of 15 milliseconds is provided before and after each upstream and downstream time slot B, Di. However, if the guard time is 15 milliseconds, only a relative error of 15 milliseconds ÷ 299.9 seconds = 50 ppm is acceptable. In other words, the absolute error allowed for the microcomputer that constitutes the control units 13 and 4 of the fire detector 10 and the receiver 1 is ± 25 ppm, even if the clock of the microcomputer is created using a crystal oscillator. In order to satisfy the absolute error, the cost is considerably increased.

[0086] Therefore, after receiving the time slot including the synchronization signal measured by the first timer, the control unit 13 of the fire detector 10 receives the time slot including the synchronization signal in the next superframe. Time and start time, including the actual synchronization signal It is preferable to obtain an error from the timing at which the timer was received and to correct the subsequent measurement time of the timer using the error. In this case, the allowable error in the operation clock of the microcomputer can be alleviated and the cost can be reduced.

In this embodiment, the synchronization signal is inserted only in the message Msg of the first frame of the super frame SF !, but may be inserted in the message Msg other than the first frame.

[0088] Further, the notification unit 3 of the present embodiment is configured by the liquid crystal display 3b and the speaker 3c. However, a plurality of receivers 1 are connected to the central monitoring panel by wire, and the receivers 1 are fired. When the detection information is received, the notification unit 3 transmits the fire detection information to the central monitoring panel, and the central monitoring panel performs necessary actions (for example, issuing a fire alarm or reporting to the fire department). It doesn't matter.

[0089] As described above, it is obvious that a wide variety of different embodiments can be configured without violating the technical idea of the present invention. Therefore, the present invention is not limited to that except as limited in the claims. It is not limited to the embodiment.

[0090] In particular, the time length of the frames constituting the superframe and the time length of the time slot are not limited to the above values, and the fire radio alarm system is based on the number of fire detectors used and other factors. Of course, the design should be changed accordingly.

Claims

The scope of the claims

[1] A fire alarm system comprising a plurality of fire detectors and receivers,

Each of the fire detectors includes a sensing means for detecting a fire and a wireless transmission / reception means for transmitting / receiving a wireless signal to / from the receiver. The wireless transmission / reception means is configured to detect when a fire is detected by the sensing means. Periodic communication is performed with the receiver that transmits a radio signal to the receiver and informs the receiver of the operation state of each fire detector at predetermined time intervals;

The receiver includes wireless transmission / reception means for transmitting / receiving a wireless signal to / from each of the fire detectors, and notification means for notifying a fire to the outside when the received wireless signal includes fire detection information. Prepare;

The feature is

Each of the fire detectors and the receiver includes a downstream time slot from the receiver side to the fire detector side, and a plurality of upstream time slots from the fire detector side to the receiver side. Wireless communication is performed using a super frame configured by a plurality of configured frames, and each fire detector transmits a wireless signal assigned to one of the upstream time slots different from each other.

[2] In the fire alarm system according to claim 1,

The receiver transmits a synchronization signal to all the fire detectors in a downstream time slot in the first frame included in the superframe,

Each fire detector determines the start timing of the upper time slot assigned to the fire detector based on the time when the synchronization signal is received.

[3] In the fire alarm system according to claim 2,

The receiver transmits a reply request message for requesting the periodic communication in the same downlink time slot as the synchronization signal to all the fire detectors,

Each fire detector that has received the reply request message transmits a response message to the receiver in an uplink time slot assigned to the fire detector informing the operational state of the fire detector.

[4] In the fire alarm system according to claim 3, If the receiver is unable to receive the response message in any upstream time slot, the fire detector assigned to the upstream time slot that could not be received in the downstream time slot of the next frame. Resend the reply request message;

The fire detector that has received the reply request message transmits the response message to the receiver again in the next uplink time slot assigned to the fire detector.

[5] In the fire alarm system according to claim 3,

If the receiver is unable to receive the response message in any upstream time slot, the fire detector assigned to the upstream time slot that could not be received in the downstream time slot of the next frame. Resend the reply request message;

The fire detector that has received the reply request message transmits the response message to the receiver again in a plurality of arbitrary upstream time slots.

[6] In the fire alarm system according to claim 3,

If the receiver is unable to receive the response message in any upstream time slot, the fire detector assigned to the upstream time slot that could not be received in the downstream time slot of the next frame. The response request message is retransmitted by designating one or more uplink time slots that can receive the response message,

The fire detector that has received the reply request message transmits the response message to the receiver again at the designated upstream time slot.

[7] In the fire alarm system according to claim 3,

When the receiver is unable to receive the response message in any uplink time slot, the receiver designates a different uplink time slot for each frame, retransmits the reply request message,

[8] In the fire alarm system according to claim 3,

The receiver determines the transmission time of one superframe from the transmission time allowed in one superframe, the time required for one uplink Z downlink time slot, and the number of uplink time slots in one frame. Each fire detector power allowed in receiver The upper limit of the number of transmissions is sent to the reply request message and the number of transmissions equal to or lower than the upper limit is transmitted to all the fire detectors.

Each fire detector that has received the reply request message transmits the reply message to the receiver in an uplink time slot assigned to the fire detector until the number of transmissions is reached within one superframe. Send.

[9] In the fire alarm system according to claim 8,

The receiver includes detection means for detecting a signal strength of a received radio signal, and the receiver relatively reduces the number of transmissions to a fire detector that has transmitted a radio signal having a relatively high signal strength. The number of transmissions to a fire detector that has transmitted a wireless signal having a relatively low signal strength is relatively increased within the upper limit.

[10] In the fire alarm system according to claim 1!

When each of the fire detectors detects a fire, the fire detection information is transmitted to the receiver in the next upstream time slot assigned to the fire detector.

[11] In the fire alarm system according to claim 10,

When the receiver receives the fire detection information, it transmits a confirmation message to the fire detector that has transmitted the fire detection information in the next downlink time slot,

The fire detector that has transmitted the fire detection information transmits the fire detection information to the receiver in an uplink time slot assigned to the fire detector until receiving the confirmation message.

[12] In the fire alarm system according to claim 1!

Each fire detector has a unique address, and the lower address of the unique address corresponds to the position of the upstream time slot assigned to the fire detector.

[13] In the fire alarm system according to claim 12,

When transmitting a radio signal to the receiver, each of the fire detectors transmits an upper address excluding the inherent address power and the lower address as information indicating the fire detector of the transmission source.

[14] In the fire alarm system according to claim 2,

Each of the fire detectors receives a time slot including the synchronization signal, and then A timer for measuring the time until the reception of the time slot including the synchronization signal in the superframe starts,

Each of the fire detectors calculates an error between the time measured by the timer and the timing of actually receiving the time slot including the synchronization signal, and uses the error to correct the subsequent timer measurement time. To do.