JP4501787B2 - Fire alarm system - Google Patents

Description

  The present invention relates to a fire alarm system having a plurality of fire detectors for detecting a fire and a receiving device for performing wireless communication using a radio wave as a medium between the fire detectors.

  2. Description of the Related Art Conventionally, various fire alarm systems have been provided that include a plurality of fire detectors that detect a fire and a receiver that receives a fire detection signal transmitted from the fire detector that detects a fire in a wired manner. On the other hand, wireless communication between the fire detector and the receiving device should be performed due to the advantage that the wiring between the fire detector and the receiving device is not required when newly installed in an existing facility. A fire alarm system has been proposed (see Patent Document 1).

  On the other hand, in any of the wired or wireless communication systems, in order to confirm that a plurality of fire detectors are operating normally, a transmission request message is periodically sent from the receiving device to each fire detector. And a response message indicating the operating state of each fire detector is returned to the receiving device, and based on the response message, it is determined whether or not a failure such as a dead battery has occurred in the fire detector.

  Here, in order to improve the reliability of the fire alarm system, it is necessary to exchange the periodic transmission request message and the response message as described above as frequently as possible. For example, in the EN standard (European unified standard), a standard (EN54-25) that obligates the exchange of messages at a rate of once every 300 seconds is planned.

By the way, periodic message exchange is frequently performed as described above, and the more the number of fire detectors included in the system, the higher the probability that a collision will occur due to overlapping transmission timings of the fire detectors. Therefore, it is necessary to avoid such a collision. Therefore, in the thing of patent document 1, while the carrier used for radio | wireless communication is detected, the carrier sense system which transmits a radio signal when a carrier is not detected without transmitting a radio signal is detected. It has been adopted.
Japanese Patent No. 2840367

  However, in the carrier sense system, since a certain time is required for switching between transmission / reception of radio circuits, collision cannot be completely avoided. In addition, in a wireless fire alarm system, a frequency assigned to a radio station that does not require a license is generally used, but in some countries, a severe limitation is imposed on transmission time duty. For example, in the European Union, the transmission time duty must be less than 0.1% at the Alarm frequency used in the fire alarm system.

  On the other hand, as a collision avoidance method when each fire detector adopts a pure aloha method in which packets are transmitted at random, a response message having the same content is continuously transmitted a plurality of times (hereinafter referred to as “continuous transmission”). Although a method is conceivable, if the number of continuous transmissions is increased, the transmission time duty also increases, so that the above condition (less than 0.1%) cannot be satisfied.

  Therefore, as another collision avoidance method, wireless communication between the receiving apparatus and the plurality of fire detectors may be performed by a time division multiple access (TDMA) method. In other words, in the case of the TDMA system, a collision can be avoided because a plurality of fire detectors transmit messages in time slots assigned individually. However, even when such a TDMA system is adopted, a message from the fire detector may not be received by the receiving device due to the influence of the external environment (external noise, interference wave, etc.).

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fire alarm system capable of reliably receiving a response message returned from a fire detector by a receiving device.

In order to achieve the above object, the invention of claim 1 includes a plurality of fire detectors for detecting a fire, and a receiver for performing wireless communication using radio waves as a medium between the fire detectors. The sensor detects a fire by detecting temperature changes and smoke generated by a fire, a wireless transmission / reception means for transmitting / receiving a radio signal to / from the receiver, and at least the detection means detects a fire. Control means for controlling the wireless transmission / reception means to transmit the fire detection information by a wireless signal when received, and the receiving device transmits / receives a wireless signal to / from the fire detector, and wireless transmission / reception means And control means for obtaining fire detection information from a radio signal received by the wireless transmission / reception means, and the control means of the receiving device sends a transmission request message for requesting a predetermined response to all the fire detectors. The wireless detector periodically transmits a wireless signal from the line transmitter / receiver, and the fire detector control unit receives a predetermined response message indicating the operation state of the device from the wireless transmitter / receiver when receiving the transmission request message. Reply with a radio signal, and the control means of the receiving device and the fire detector is one downstream time slot from the receiving device to the fire detector, and from the fire detector assigned to each fire detector to the receiving device. A fire alarm system for exchanging a transmission request message and a response message in a superframe in which a fixed number of frames composed of a plurality of uplink time slots are collected. against fire detector which could not be received, most of the uplink time slots can receive the response message Turn of the early uplink time slot specified again transmission request message transmitted by the radio signal from the wireless transmitting and receiving means, the control means of the fire detector which received the radio signal, the response message in the specified uplink time slots Is transmitted as a wireless signal from the wireless transmission / reception means to the receiving apparatus.

In order to achieve the above object , the invention of claim 2 includes a plurality of fire detectors for detecting a fire, and a receiver for performing wireless communication using radio waves as a medium between the fire detectors. The sensor detects a fire by detecting temperature changes and smoke generated by a fire, a wireless transmission / reception means for transmitting / receiving a radio signal to / from the receiver, and at least the detection means detects a fire. Control means for controlling the wireless transmission / reception means to transmit the fire detection information by a wireless signal when received, and the receiving device transmits / receives a wireless signal to / from the fire detector, and wireless transmission / reception means And control means for obtaining fire detection information from a radio signal received by the wireless transmission / reception means, and the control means of the receiving device sends a transmission request message for requesting a predetermined response to all the fire detectors. The wireless detector periodically transmits a wireless signal from the line transmitter / receiver, and the fire detector control unit receives a predetermined response message indicating the operation state of the device from the wireless transmitter / receiver when receiving the transmission request message. Reply with a radio signal, and the control means of the receiving device and the fire detector is one downstream time slot from the receiving device to the fire detector, and from the fire detector assigned to each fire detector to the receiving device. a fire alarm system composed of a frame to exchange transmission request and response messages in the superframe gathered certain number in a plurality of uplink time slots, the control means of the receiving apparatus, the response message against fire detector which could not be received, a plurality of frames, one upstream Thailand different for each said plurality of frames When the slot is specified, the transmission request message is transmitted again from the wireless transmission / reception means as a wireless signal, and the control means of the fire detector receiving the wireless signal receives the response message in the uplink time slot specified for each frame. It is characterized in that a reply is sent from the wireless transmission / reception means to the apparatus by a wireless signal.

In order to achieve the above object , the invention of claim 3 includes a plurality of fire detectors for detecting a fire, and a receiving device for performing wireless communication using radio waves as a medium between the fire detectors. The sensor detects a fire by detecting temperature changes and smoke generated by a fire, a wireless transmission / reception means for transmitting / receiving a radio signal to / from the receiver, and at least the detection means detects a fire. Control means for controlling the wireless transmission / reception means to transmit the fire detection information by a wireless signal when received, and the receiving device transmits / receives a wireless signal to / from the fire detector, and wireless transmission / reception means And control means for obtaining fire detection information from a radio signal received by the wireless transmission / reception means, and the control means of the receiving device sends a transmission request message for requesting a predetermined response to all the fire detectors. The wireless detector periodically transmits a wireless signal from the line transmitter / receiver, and the fire detector control unit receives a predetermined response message indicating the operation state of the device from the wireless transmitter / receiver when receiving the transmission request message. Reply with a radio signal, and the control means of the receiving device and the fire detector is one downstream time slot from the receiving device to the fire detector, and from the fire detector assigned to each fire detector to the receiving device. A fire alarm system for exchanging a transmission request message and a response message in a superframe in which a fixed number of frames composed of a plurality of uplink time slots are collected. again sending request message to the fire detector which could not be received and transmitted by radio signal from the wireless transmitting and receiving means, the radio signal Control means of the received fire detector is characterized in that it replies with a radio signal from the wireless transmitting and receiving means to the receiving device a response message in a plurality of uplink time slot that is continuous from the beginning.

According to the first aspect of the present invention, the fire detector that could not receive the response message is requested to return a response message again, and the response message is received from the fire detector to the receiving device in response to the request. Since the response message is returned in the uplink time slot that has been completed , the response message returned from the fire detector can be reliably received by the receiving device. In addition, since the response message is retransmitted in the uplink time slot with the earliest order among the uplink time slots that have been received, the response message can be received by the receiving apparatus in a shorter time.

According to the invention of claim 2 , since the response message is retransmitted in different uplink time slots for each of a plurality of frames, even when the response message is not received due to the influence of periodic noise close to the frame period The response message to be retransmitted can be reliably received by the receiving device.

According to the third aspect of the present invention, since the response message is retransmitted in a plurality of uplink time slots continuous from the beginning, the response message can be received by the receiving device in a shorter time and more reliably.

Below, it will be described in detail embodiments of the present invention with reference to the drawings. Before describing the embodiment of the present invention, a reference example having the same basic configuration as the embodiment of the present invention will be described.

FIG. 2 is a system configuration diagram of this reference example , and a fire alarm system is configured by one receiving device 1 and a plurality of fire detectors 10. In the following, when the fire detectors 10 are shown individually, they are indicated as fire detectors 10 ₁ , 10 ₂ ,..., 10 _n, and when they are shown collectively, they are indicated as fire detectors 10.

  The fire detector 10 is installed on the ceiling of a facility, for example, and as shown in FIG. 3A, a detection unit 11 that detects a fire by detecting a temperature change and smoke generated by a fire. And a radio transmission / reception unit 12 for transmitting / receiving a radio signal using a radio wave as a medium to / from the receiving apparatus 1 by modulating / demodulating a data format to be described later to a carrier wave of a prescribed frequency, For transmitting and receiving wireless signals, a control unit 13 for transmitting information and response messages by wireless signals, a sensing unit 11 using a battery as a power source, a wireless transmission / reception unit 12, and a battery power unit 14 for creating an operating power source for the control unit 13 An antenna 15 and a switch 16 that opens and closes a feeding path from the battery power supply unit 14 to the wireless transmission / reception unit 12 under the control of the control unit 13 are provided. The control unit 13 includes a microcomputer and a nonvolatile memory such as an EEPROM as main components, and executes various processes described later by executing a program stored in the nonvolatile memory. Each fire detector 10 is given a unique address at the time of manufacture or construction and is stored in the nonvolatile memory of the control unit 13.

  On the other hand, the receiving device 1 is installed in, for example, a management room of a facility. As shown in FIG. 3B, the receiving device 1 modifies and demodulates a data format, which will be described later, to a carrier wave of a prescribed frequency. A wireless transmission / reception unit 2 for transmitting / receiving a radio signal using radio waves as a medium, an operation switch 3a for performing various settings, and a display device (for example, a liquid crystal display) 3b for performing a fire alarm and various displays In addition, a display operation unit 3 including a speaker 3c that sounds an alarm sound, an alarm message, and the like, a control unit 4 that controls the wireless transmission / reception unit 2 and the display operation unit 3, a wireless transmission / reception unit 2, and a display operation unit 3 from a commercial power source. A power supply unit 5 that creates an operating power supply for the control unit 4 and an antenna 6 for transmitting and receiving radio signals are provided. The control unit 4 includes a microcomputer and a nonvolatile memory such as an EEPROM as main components, and executes various processes described later by executing a program stored in the nonvolatile memory. A unique address different from that of the fire detector 10 is also given to the receiving device 1 at the time of manufacture or construction, and is stored in the nonvolatile memory of the control unit 4.

  Here, a frequency that does not require a license is used for wireless communication between the receiving device 1 and the fire detector 10. For example, radio characteristics conforming to low power security and specific low power radio standards in Japan, FCC Regulations Part 15 SubpartC in the US, and Short Range Device standards in Europe must be satisfied.

  A data format of data exchanged between the receiving device 1 and the fire detector 10 is shown in FIG. This data format consists of a 32-bit preamble (bit synchronization pattern) PR in which 1 and 0 alternate, a 16-bit unique word (frame synchronization pattern) UW consisting of a prescribed bit string, and a 32-bit allocated to the fire alarm system. A unique ID (system ID) SysID, an 8-bit unique ID (sensor ID) NodeID assigned to each fire detector 10, a 16-bit message Msg, and a 16-bit error detection code CRC Is done. That is, the unique address of the fire detector 10 is the system ID + sensor ID, and the unique address of the receiving device 1 is the system ID.

  When the receiving device 1 transmits a message specifying a specific fire detector 10, the detector ID of the fire detector 10 is specified as the sensor ID of the data format, and all the fire detectors 10 are specified. When broadcasting a message, it is only necessary to specify “0 (zero)” for the sensor ID of the data format. Further, when the fire sensor 10 sends a reply to the receiving device 1, the sensor ID of its own device may be set to the sensor ID of the data format and transmitted.

  On the other hand, in the fire detector 10 and the receiving device 1 that have received the wireless signal, the wireless transmission / reception units 12 and 2 amplify the reception signal, demodulate the data format, and output to the control units 13 and 4. The control units 13 and 4 sample the data demodulated by the radio transmission / reception units 12 and 2 at a digital input port provided in the microcomputer, extract the bit timing during reception of the preamble PR, and then successively 16 bits. The unique word is detected by shifting the received bits for one minute at a time until it matches the specified unique word. Furthermore, the control units 13 and 4 collate the received system ID and sensor ID with the unique address stored in the nonvolatile memory, and accept the message Msg when they match and no bit error is detected. .

By the way, in this reference example , wireless communication between the receiving apparatus 1 and the plurality of fire detectors 10 is performed by a time division multiple access (TDMA) system. That is, as shown in FIG. 5, the time slot B in one downstream direction (receiver 1 → fire detector 10) and the time in a plurality (99 in the illustrated example) upstream (fire detector 10 → receiver 1). A plurality of (30 in the illustrated example) frames F1 to F30 including slots D1 to D99 are collected to form a super frame SF, and the upstream time slots D1 to D99 in the frames F1 to F30 are assigned to each fire detector 10. By assigning them individually, even when the interval between periodic message exchanges (exchange of reply request message and response message) is relatively short, for example, once every 300 seconds in the EN standard described above The collision between the radio signals transmitted from the fire detector 10 can be reliably avoided. The time slots B and Di (i = 1 to 99) in the down direction and the up direction have a period of 100 milliseconds, and the breakdown is 50 milliseconds in the above data format. The wireless transmission / reception unit of the receiver 1 and the fire detector 10 20 milliseconds are assigned to the time (startup time) until the transmission is possible at a stable carrier frequency after starting 2 and 12, and 15 milliseconds are assigned to the guard time. The guard time is a free time for absorbing a timing difference caused by an error between the operation clock frequencies of the fire detector 10 and the receiver 1 (the operation clock frequency of the microcomputer configuring the control units 13 and 4). Further, the allocation of the upstream time slots D1 to D99 to each fire detector 10 is set by, for example, a dip switch provided in the fire detector 10, or stored in advance in the nonvolatile memory of the control unit 13 in the manufacturing process. Alternatively, it may be performed by a method such as assigning to each fire detector 10 in order from the receiving device 1 using wireless communication at the time of installation and storing in the nonvolatile memory of the control unit 13.

Next, the operation of this reference example will be described. First, a reply request message is periodically transmitted from the receiving device 1 to all the fire detectors 10, and a response message returned from each fire detector 10 is received by the receiving device 1. The operation for confirming whether the device 10 is operating normally will be described with reference to the time chart of FIG. 1 and the flowchart of FIG.

  When the power is turned on, the control unit 4 of the receiving apparatus 1 sets the sensor ID of the data format to “0” in the downstream time slot B of the first frame F1 of the super frame SF, and sends a reply request message as the message Msg. Is sent to all the fire detectors 10. On the other hand, in the fire detector 10, 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 is in a continuous reception state until a synchronization signal (reply request message) is received. (Steps S1 and S2 in FIG. 6). If the reply request message can be received, the control unit 13 of the fire detector 10 opens the switch 16, cuts off the power supply to the wireless transmission / reception unit 12 and stops continuous reception (step S 3 in FIG. 6), and then built in the microcomputer. The started first timer, second timer, and third timer are started (step S4 in FIG. 6). The first timer is the time from the end of the downlink time slot B in the first frame F1 to the end of the superframe SF (for example, each of the frames F1 to F30 is 10 seconds, the superframe SF is 300 seconds, If the time slot in each of the downstream and upstream directions is 100 milliseconds, 300−0.1 = 299.9 seconds) is counted. In addition, the second timer is configured so that the upstream time slot Di (i = 1 to 99) individually assigned to each fire detector 10 from the time when the downstream time slot B ends in each frame Fk (k = 1 to 30). ) Is counted (for example, 0.1 × (number of upstream time slot Di i−1)). Further, the third timer is a time (for example, 10−0.1 = 9.9) from the time when the downlink time slot B ends in each frame Fk (k = 1 to 30) to the time when the frame Fk ends. Seconds).

  The control unit 13 of each fire detector 10 can determine the start time point of the upstream time slot Di assigned to itself by the end of the counting of the second timer, and the assigned upstream time slot. A response message to the reply request message of the receiving apparatus 1 is transmitted from the wireless transmission / reception unit 12 by Di, and then a fourth timer built in the microcomputer is started (steps S5 and S6 in FIG. 6). The fourth timer is a time from the end time of the uplink time slot Di assigned to itself in a certain frame Fk to the start time of the uplink time slot Di assigned to itself in the next frame Fk + 1 (for example, 10−0.1 = 9.9 seconds).

  On the other hand, the control unit 4 of the receiving device 1 receives a response message returned from each fire detector 10 in the upstream time slots D1 to D99 in the first frame F1 that has transmitted the reply request message. The content of the response message is the presence or absence of an abnormality in the fire detector 10 (for example, the battery voltage drops below a threshold value or the malfunction of the sensing unit 11), and the fire detector returns an abnormal response message. The control unit 4 of the receiving device 1 displays ten sensor IDs on the display operation unit 3 to notify the system administrator. In addition, when the response message from all the fire detectors 10 included in the system is received, the control unit 4 of the receiving device 1 designates “0” for the sensor ID of the data format and sends a reception completion message to the message Msg. As a result, broadcast transmission is performed to all the fire detectors 10 in the downstream time slot B of the second frame F2.

  When the third timer expires, the control unit 13 of the fire detector 10 closes the switch 16 and operates the wireless transmission / reception unit 12 to receive the downlink time slot B in the second frame F2, and the third timer The timer is started again (steps S7 and S8 in FIG. 6). At this time, if the response messages from all the fire detectors 10 are normally received by the receiving device 1, the reception completion message should be received in the downlink time slot B in the second frame F2. Therefore, when the control unit 13 of the fire detector 10 receives the reception completion message (step S9 in FIG. 6), the switch 16 is opened until the first timer expires to stop the operation of the wireless transmission / reception unit 12 (FIG. 6). 6, when the first timer expires and the next super frame SF is started, the switch 16 is closed again to operate the wireless transmission / reception unit 12 to set the downlink time slot B in the first frame F1. (Step S11 in FIG. 6), the first to third timers are started and the above-described processing is repeated for each superframe.

By the way, even if the fire detector 10 is normal, there may occur a case where the reception device 1 cannot receive a response message from the fire detector 10 due to the influence of external noise, interference waves, or the like. For example, as shown in FIG. 1, if the response message of the second uplink time slot cannot be received by the reception device 1, the control unit 4 of the reception device 1 can receive the response message instead of the reception completion message. the detector ID of the fire detector 10 ₂ of the uplink time slot D2 was no assigned as message Msg data format individual reply request message while specifying the detector ID of the data format, the second frame F2 In the downstream time slot B.

On the other hand, the control unit 13 of the fire detectors 10 ₁ , 10 ₃ ,... That has received the response message normally has the sensor ID of the data format transmitted in the downstream time slot B of the second frame F2. Therefore, the reply request message is not accepted (step S12 in FIG. 6), and the switch 16 is opened until the third timer expires to stop the wireless transmission / reception unit 12. Fire detector 10 ₂ of the control unit 13 a response message is not received correctly contrast, sensing detector ID of the data format to be transmitted by the second downlink time slot B of the frame F2 is self vessel The response request message is accepted because it matches the device ID (step S12 in FIG. 6), and the response message is again transmitted in any one or more upstream time slots (D2 and D3 in FIG. 1) in the second frame F2. Transmit (step S13 in FIG. 6). Here, the uplink time slot Di for retransmitting the response message may be determined based on, for example, a random number generated by a microcomputer configuring the control unit 13. Then, the control unit 13 starts one or more timers that count the time corresponding to the determined number i of the uplink time slot Di at the end of the downlink time slot B in the second frame F2, and sets each timer When the communication is completed, the wireless transmission / reception unit 12 is operated to transmit the response message again. In addition, when there are a plurality of fire detectors 10 that could not receive the response message in the first frame F1, the control unit 4 of the receiving device 1 specified each detector ID in the second and subsequent frames F2 and F3. Reply request messages are sequentially transmitted, and transmission of individual reply request messages is repeated until response messages of all the fire detectors 10 can be received. In this case, until the reception completion message is received in the downlink time slot B, the control unit 13 of the fire detector 10 continues to receive the downlink time slot B of each frame Fk, and after receiving the reception completion message, In the frame, the switch 16 is opened to stop the wireless transmission / reception unit 12.

  Next, the operation when a fire is detected by any of the fire detectors 10 will be described with reference to the flowchart of FIG. The following process performed by the control unit 13 of the fire detector 10 when a fire is detected is an interrupt process (subroutine) for the above-described process (main routine shown in the flowchart of FIG. 6) that is always repeated.

  The control unit 13 of the fire detector 10 determines whether the second timer is counting when the detection unit 11 detects a fire (step S1 in FIG. 7). In other words, if the second timer is counting, the uplink time slot Di assigned in the frame Fk has not yet passed, so the uplink direction assigned to the own device when the second timer ends. The fire detection information is transmitted as a message Msg to the receiving device 1 through the time slot Di, and the fourth timer is started after the transmission (steps S2 and S3 in FIG. 7). In addition, if the second timer is not counting, the uplink time slot Di assigned in the frame Fk has already passed, so the control unit 13 of the fire detector 10 That is, the fire detection information is transmitted as the message Msg to the receiving device 1 by the uplink time slot Di assigned in the next frame Fk + 1, and the fourth timer is started after transmission (steps S7 and S3 in FIG. 7).

  The control unit 4 of the receiving device 1 that has received the fire detection information from the fire detector 10 specifies the detector ID of the fire detector 10 that is the transmission source of the fire detection information, and completes reception indicating that the fire detection information has been received. The message is transmitted as a message Msg in the downlink time slot B in the frame Fk + 1 (or Fk + 2) next to the frame Fk (or Fk + 1) that has received the fire detection information.

  The control unit 13 of the fire detector 10 that has transmitted the fire detection information closes the switch 16 when the third timer expires and operates the wireless transmission / reception unit 12 to operate the downlink time slot in the next frame Fk + 1 (or Fk + 2). B is received and the third timer is started again (steps S4 and S5 in FIG. 7). Furthermore, if the control unit 13 receives a reception completion message from the receiving device 1 in the downlink time slot B, the control unit 13 returns to the main routine (flowchart in FIG. 6) without retransmitting the fire detection information. However, since the reception completion message is not transmitted from the reception device 1 unless the reception device 1 can receive the fire detection information from the fire detector 10 due to the influence of external noise or interference waves, the control unit 13 displays the reception completion message. If not received, the fire detection information is transmitted again in any one or more upstream time slots in the next frame Fk + 2 (or k + 3) (step S8 in FIG. 7), and a reception completion message is received from the receiver 1. By repeating the re-transmission of the fire detection information, the receiver 1 is surely notified of the fire occurrence. That is, since the fire detector 10 that has detected a fire with the sensing unit 11 transmits the fire detection information to the receiving device 1 in the frame Fk + 1 next to the frame Fk at the time of detecting the fire at the latest, the frame is detected after the fire is detected. The fire detection information can be transmitted to the receiver 1 within 10 seconds of the cycle, and the standard value (within 10 seconds from detection) of the European EN standard (EN54-25) can be satisfied.

As described above, according to this reference example , the fire detector 10 that has not received a response message is requested to return a response message from the receiving device 1 again, and is received from the fire detector 10 in response to the request. Since the response message is returned to the device 1 in one or more upstream time slots Di, the response message returned from the fire detector 10 can be reliably received by the receiving device 1. In this reference example , the number of uplink time slots Di for retransmitting the response message is two, but may be one or three or more within a range not exceeding the limit of the transmission time duty. In addition, if the response message is retransmitted in a plurality of uplink time slots (for example, D1 and D2) that are continuous from the first uplink time slot D1 in the second frame F2, the response message can be transmitted in a shorter time and more reliably. It can be received by the receiving device 1.

In this reference example , when a fire is detected by the fire detector 10, it is displayed on the display operation unit 3 of the receiving device 1 to notify the system administrator. For example, a plurality of receiving devices 1 are provided. Is connected to the central monitoring board by wire, and the fire detection information received by the receiving device 1 is relayed to the central monitoring board by wired communication, and necessary countermeasures are taken in the central monitoring board (for example, issuing a fire alarm or reporting to the fire department) Etc.).

(Embodiment 1 )
Since the system configuration of the first embodiment of the present invention and the configurations of the fire detector 10 and the receiving device 1 are the same as those of the reference example , illustration and description thereof are omitted.

  The feature of the present embodiment is that the control unit 4 of the receiving device 1 designates the uplink time slot Di in which the response message can be received and transmits the transmission request message from the wireless transmission / reception unit 2 again with a wireless signal. The control unit 13 of the fire detector 10 that has received the radio signal replies with a radio signal from the radio transmission / reception unit 12 to the reception device 1 as a response message in the designated upstream time slot Di.

For example, as shown in FIG. 8, it is assumed that the receiving apparatus 1 cannot receive a response message in the second uplink time slot D2 in response to a reply request message transmitted in the downlink time slot B of the first frame F1. At this time, the control unit 4 of the receiving device 1 has a reception record in the first frame F1, that is, one to a plurality of uplink time slots (for example, among the uplink time slots D1, D3,. , select the D1 and D3), as well as specify the detector ID of the fire detector 10 ₂ of the uplink time slot D2 of the response message is not received is assigned to the detector ID of the data format, the uplink selected The direction time slots D1 and D3 and the individual reply request messages are transmitted as data format messages Msg in the downlink time slot B of the second frame F2.

On the other hand, the fire detector 10 ₂ of the control unit 13 a response message is not received successfully, a second sensing device ID detector ID of the data format to be transmitted in the downlink time slot B of the own vessel frame F2 Since the response request message is received, the response message is transmitted again in the uplink time slots D1 and D3 designated by the receiving apparatus 1 in the second frame F2.

  As described above, in the present embodiment, since the response message is retransmitted from the fire detector 10 in the upstream time slot Di in which the response message can be received (with a reception record), the retransmitted response message is received. The apparatus 1 can reliably receive the data. When the control unit 4 of the receiving apparatus 1 selects the uplink time slot Di, the uplink time slot having the earliest order among the plurality of uplink time slots Di that have been received in the first frame F1 (see FIG. 8, if D1 and D3) are selected, the response message can be received by the receiver 1 in a shorter time. In this embodiment, the number of uplink time slots Di for retransmitting the response message is two, but may be one or three or more within a range not exceeding the limit of the transmission time duty.

(Embodiment 2 )
Since the system configuration of this embodiment and the configurations of the fire detector 10 and the receiving device 1 are the same as those of the reference example , illustration and description thereof are omitted.

  The feature of this embodiment is that the control unit 4 of the receiving apparatus 1 has a plurality of frames F2, F3,... And one upstream time slot D1, D3,. The transmission request message is again transmitted from the wireless transmission / reception unit 2 as a wireless signal, and the control unit 13 of the fire detector 10 that has received the wireless signal transmits the upstream direction specified for each frame F2, F3,. A response message is returned from the wireless transmission / reception unit 12 to the receiving apparatus 1 by a wireless signal in the time slots D1, D3,.

For example, as shown in FIG. 9, it is assumed that the receiving apparatus 1 cannot receive a response message in the second uplink time slot D2 with respect to a reply request message transmitted in the downlink time slot B of the first frame F1. At this time, the control unit 4 of the receiving apparatus 1 selects one different uplink time slot for each of the second and subsequent frames (for example, F2 to Fk), and the uplink time slot in which the response message could not be received. the detector ID of the fire detector 10 ₂ D2 is assigned with specifying the detector ID of the data format, the combination of the frame F and uplink time slot D the selected (e.g., F2 and D1, Fk and D3, etc. ) And the individual reply request message are transmitted as a data format message Msg in the downlink time slot B of the second frame F2.

On the other hand, the fire detector 10 ₂ of the control unit 13 a response message is not received successfully, a second sensing device ID detector ID of the data format to be transmitted in the downlink time slot B of the own vessel frame F2 The response request message is received, and the combination designated by the receiving device 1, for example, the first upstream time slot D1 in the second frame F2, the fourth upstream time slot in the third frame F D4,..., The response message is transmitted again in the third uplink time slot D3 in the kth frame Fk.

And Thus, if the cause of the response message of the fire detector 10 ₂ is not received by the receiving apparatus 1 was the effect of periodic noise close to the period of the frame F, can not receive any frame F of second and subsequent risk However, if the response message is retransmitted in different uplink time slots D for each of a plurality (k−1) frames F2 to Fk as described above, periodic noise close to the period of the frame F exists. Even in such a case, the response message to be retransmitted can be reliably received by the receiving device 1. Note that the number k of retransmissions may be determined in advance and stored in a non-volatile memory that constitutes the control unit 4 of the receiving device 1, or the signal strength of a radio signal received by the radio transmission / reception unit 2 may be controlled. The number of retransmissions k may be increased as the signal strength is detected by the unit 4 and lower.

It is a time chart for demonstrating the operation | movement of the periodic message exchange of the reference example of this invention. It is a system block diagram same as the above. (A) is a block diagram of a fire detector in the same as above, (b) is a block diagram of a receiving device. It is explanatory drawing of the data format in the same as the above. It is a block diagram of the super frame in the same as the above. It is a flowchart for demonstrating the operation | movement of the periodic message exchange same as the above. It is a flowchart for demonstrating the operation | movement at the time of the fire detection in the same as the above. It is a time chart for demonstrating the operation | movement of the periodic message exchange of Embodiment 1 of this invention. It is a time chart for demonstrating the operation | movement of the periodic message exchange of Embodiment 2 of this invention.

DESCRIPTION OF SYMBOLS 1 Receiver 2 Wireless transmission / reception part 4 Control part 10 Fire detector 11 Sensing part 12 Wireless transmission / reception part 13 Control part

Claims (3)

A plurality of fire detectors for detecting a fire, and a receiver for performing wireless communication using radio waves as a medium between the fire detectors;
The fire detector is composed of a sensing means for detecting a fire by detecting temperature change and smoke generated by the fire, a wireless transmitting / receiving means for transmitting and receiving a radio signal to and from the receiving device, and at least a sensing means for fire. Control means for controlling the wireless transmission / reception means when detected to transmit the fire detection information by a wireless signal,
The receiving device includes a wireless transmission / reception means for transmitting / receiving a wireless signal to / from the fire detector, and a control means for controlling the wireless transmission / reception means and obtaining fire detection information from the wireless signal received by the wireless transmission / reception means,
The control means of the receiving device periodically transmits a transmission request message for requesting a predetermined response to all fire detectors from the wireless transmission / reception means as a wireless signal,
The control unit of the fire detector returns a predetermined response message indicating the operation state of the own device when receiving the transmission request message to the receiving device by a wireless signal from the wireless transmission / reception unit,
The control means of the receiving device and the fire detector includes one downstream time slot from the receiving device to the fire detector, and a plurality of upstream directions from the fire detector assigned to each fire detector to the receiving device. A fire alarm system that exchanges a transmission request message and a response message in a superframe in which a certain number of frames composed of time slots are gathered,
The control means of the receiving device designates the earliest upstream time slot among the upstream time slots that can receive the response message to the fire detector that has not received the response message. Send the transmission request message again from the wireless transmission / reception means as a wireless signal,
A fire alarm system characterized in that the control means of the fire detector that has received the wireless signal returns a response message as a wireless signal from the wireless transmission / reception means to the receiving device in the designated uplink time slot. A plurality of fire detectors for detecting a fire, and a receiver for performing wireless communication using radio waves as a medium between the fire detectors;
The fire detector is composed of a sensing means for detecting a fire by detecting temperature change and smoke generated by the fire, a wireless transmitting / receiving means for transmitting and receiving a radio signal to and from the receiving device, and at least a sensing means for fire. A control means for controlling the wireless transmission / reception means to transmit the fire detection information by a wireless signal when sensed,
The receiving device includes a wireless transmission / reception means for transmitting / receiving a wireless signal to / from the fire detector, and a control means for controlling the wireless transmission / reception means and obtaining fire detection information from the wireless signal received by the wireless transmission / reception means,
The control means of the receiving device periodically transmits a transmission request message for requesting a predetermined response to all fire detectors from the wireless transmission / reception means as a wireless signal,
The control unit of the fire detector returns a predetermined response message indicating the operation state of the own device when receiving the transmission request message to the receiving device by a wireless signal from the wireless transmission / reception unit,
The control means of the receiving device and the fire detector includes one downstream time slot from the receiving device to the fire detector, and a plurality of upstream directions from the fire detector assigned to each fire detector to the receiving device. A fire alarm system that exchanges a transmission request message and a response message in a superframe in which a certain number of frames composed of time slots are gathered,
The control means of the receiving device designates a plurality of frames and one different uplink time slot for each of the plurality of frames, and again transmits a transmission request message to the fire detector that has not received the response message. Is transmitted from the wireless transmission / reception means as a wireless signal,
The radio signal control means of the fire detector that has received the fire you, characterized in that reply radio signal from the wireless transmitting and receiving means to the receiving device a response message in uplink time slot specified for each frame Disaster notification system. A plurality of fire detectors for detecting a fire, and a receiver for performing wireless communication using radio waves as a medium between the fire detectors;
The fire detector is composed of a sensing means for detecting a fire by detecting temperature change and smoke generated by the fire, a wireless transmitting / receiving means for transmitting and receiving a radio signal to and from the receiving device, and at least a sensing means for fire. A control means for controlling the wireless transmission / reception means to transmit the fire detection information by a wireless signal when sensed,
The receiving device includes a wireless transmission / reception means for transmitting / receiving a wireless signal to / from the fire detector, and a control means for controlling the wireless transmission / reception means and obtaining fire detection information from the wireless signal received by the wireless transmission / reception means,
The control means of the receiving device periodically transmits a transmission request message for requesting a predetermined response to all fire detectors from the wireless transmission / reception means as a wireless signal,
The control unit of the fire detector returns a predetermined response message indicating the operation state of the own device when receiving the transmission request message to the receiving device by a wireless signal from the wireless transmission / reception unit,
The control means of the receiving device and the fire detector includes one downstream time slot from the receiving device to the fire detector, and a plurality of upstream directions from the fire detector assigned to each fire detector to the receiving device. A fire alarm system that exchanges a transmission request message and a response message in a superframe in which a certain number of frames composed of time slots are gathered,
The control means of the receiving device transmits a transmission request message again from the wireless transmission / reception means to the fire detector that has failed to receive the response message,
The control means of the fire detector which received the radio signal, fire from the wireless transmitting and receiving means to the receiving device a response message in a plurality of uplink time slots sequentially from beginning you characterized in that reply radio signal Notification system .

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