JP6569981B2 - Automatic fire alarm system parent machine, automatic fire alarm system, automatic fire alarm system slave unit - Google Patents

Description

  The present invention generally relates to a base unit of an automatic fire notification system, an automatic fire notification system, and a slave unit of the automatic fire notification system.

  Conventionally, a P-type (Proprietary-type) automatic fire alarm system is known as an automatic fire alarm system (self-fire alarm system). In the P-type automatic fire alarm system, the fire detector notifies the fire receiver of the occurrence of a fire by electrically short-circuiting a pair of electric wires that are sensor lines. The fire receiver notifies the occurrence of a fire. As a P-type automatic fire alarm system, as shown in Patent Document 1, a plurality of fire detectors (slave units) and a fire receiver (master unit) are electrically connected to a sensor line (a pair of wires). An automated fire alarm system is known. A plurality of fire detectors are connected to a plurality of detector lines derived from the fire receiver.

  In general, as a method in which a parent device communicates with a plurality of child devices, each of the plurality of child devices transmits a response signal in a time division manner with respect to a synchronization signal transmitted from the parent device to the plurality of child devices. "Method" is known.

JP 2002-8154 A

  When each of a plurality of slave units communicates with the master unit in a time division communication system, if the accuracy of the clock element of the slave unit is low, the slave unit with respect to the reception timing of the synchronization signal becomes longer as the synchronization signal reception interval becomes longer. There is a possibility that the start timing of the response signal will shift. If the start timing for transmitting the response signal is shifted, the two response signals may interfere with each other.

  The present invention has been made in view of the above-described problems, and is a main unit of an automatic fire notification system in which response signals transmitted from a plurality of slave units are less likely to interfere, an automatic fire notification system, and an automatic fire notification system in which response signals to be transmitted are less likely to interfere. The purpose is to provide a handset.

A base unit of an automatic fire notification system according to the present invention is a base unit of an automatic fire notification system that transmits a signal to a plurality of slave units electrically connected to a pair of electric wires to which a voltage is applied. A transmission unit that is electrically connected to an electric wire, changes a voltage between the pair of electric wires, and transmits a signal to the plurality of slave units; and controls the transmission unit, and transmits the transmission every time a predetermined time elapses. A transmission control unit that transmits a synchronization signal from a unit, a reception unit that is electrically connected to the pair of electric wires and receives signals from the plurality of slave units based on a change in voltage between the pair of electric wires, A reception control unit that controls the reception unit; and a processing unit that acquires data included in the signal from the output of the reception unit, and the plurality of slave units have received the synchronization signal. After the waiting time has elapsed, the voltage between the pair of wires is The response signal is transmitted, the length of the waiting time is different for each of the plurality of slave units, and the reception control unit receives the response signal from each of the plurality of slave units. said transmit a synchronization signal is received by the reception unit in the reception period after the waiting time has elapsed from the predetermined time, Ri time der the length of the response signal falls within the receiving section, said plurality The length of the waiting time of each slave unit is different at a certain time interval, the length of the reception section is equal to the certain time interval, and the processing unit is near the start timing of the reception section When the voltage value of the pair of electric wires exceeds the upper limit of the predetermined value or falls below the lower limit of the predetermined value near each end timing, it is regarded as noise and distinguished from the signal .

  The automatic fire alarm system of the present invention is connected to the above-described master unit and the pair of electric wires, and changes the voltage between the pair of electric wires after the waiting time has elapsed after receiving the synchronization signal. And a plurality of slave units that transmit response signals.

  The slave unit of the automatic fire notification system of the present invention is used in the above-described automatic fire notification system.

  The base unit of the automatic fire notification system of the present invention can make it difficult to interfere with response signals transmitted from a plurality of sub units.

  Since the automatic fire notification system of the present invention includes the above-described master unit, it is possible to make it difficult to interfere with response signals transmitted from a plurality of slave units.

  The subunit | mobile_unit of the automatic fire alarm system of this invention can transmit the response signal which is hard to interfere.

It is a figure explaining schematic structure of the automatic fire alarm system concerning Embodiment 1. FIG. It is a figure explaining the whole structure of the automatic fire alarm system which concerns on Embodiment 1. FIG. It is a figure explaining each operation | movement regarding communication of the main | base station which concerns on Embodiment 1, and a subunit | mobile_unit. FIG. 4A is a diagram for explaining a signal transmitted by the slave unit according to the first embodiment in the response interval, and FIG. 4B is a diagram for explaining a signal transmitted by the slave unit according to the comparative example in the response interval shorter than that of the first embodiment. It is a figure to do. It is a figure explaining each operation | movement regarding communication of the main | base station and the subunit | mobile_unit which concerns on the modification of Embodiment 1. FIG. It is a figure explaining the whole structure of the automatic fire alarm system which concerns on Embodiment 2. FIG. It is a figure explaining the schematic structure of the automatic fire alarm system which concerns on Embodiment 3. FIG. FIG. 8A is a diagram for explaining a communication state of the parent device and the child device according to the third embodiment. FIG. 8B is a diagram illustrating another communication state between the parent device and the child device according to the third embodiment. FIG. 8C is a diagram illustrating still another communication state of the parent device and the child device according to the third embodiment. FIG. 9A is a diagram for explaining a communication state of the parent device and the child device according to the fourth embodiment. FIG. 9B is a diagram illustrating another communication state between the parent device and the child device according to the fourth embodiment.

(Embodiment 1)
In the present embodiment, an automatic fire notification system 1 that notifies the occurrence of a fire will be described with reference to FIGS. 1, 2, 3, 4A, and 4B.

  As shown in FIG. 2, the automatic fire notification system 1 includes 16 child devices B1 to B16 and one parent device 20. In the automatic fire alarm system 1, the slave units B1 to B16 and the master unit 20 are electrically connected to a pair of electric wires 51 and 52, respectively. In the following description, when each of the 16 slave units B1 to B16 is described without being distinguished, it will be described as “slave unit 10”.

  The subunit | mobile_unit 10 consists of detectors, such as a heat sensor, a smoke sensor, and a flame detector, for example, and when a fire occurrence is detected, the voltage value between a pair of electric wires 51 and 52 is changed, and a fire occurrence is notified. A signal (hereinafter referred to as fire report) is transmitted. In addition, the subunit | mobile_unit 10 is not restricted to the sensor which detects generation | occurrence | production of a fire, A transmitter may be sufficient. The transmitter mentioned here has a push button switch. For example, a person who discovers a fire transmits a fire report by pressing the push button switch.

  The master unit 20 (for example, a receiver) receives a signal transmitted from the slave unit 10 and, when the signal is a fire report, activates an alarm to notify the occurrence of a fire. The base unit 20 is disposed in a management room of a building where the automatic fire alarm system 1 is installed, for example.

  In the following description, the automatic fire alarm system 1 used for an apartment house (for example, an apartment) will be described. However, the automatic fire alarm system 1 is not limited to an apartment house, and may be used as appropriate for commercial facilities, hospitals, hotels, occupancy buildings, and the like. Can be used in buildings.

  The automatic fire alarm system 1 includes 16 slave units 10 and one master unit 20 for one apartment house 60. In the apartment house 60, four pairs of electric wires 51 and 52 are provided. Four sets of a pair of electric wires 51 and 52 are connected to the base unit 20. A plurality of (four) slave units 10 are electrically connected to one pair of electric wires 51 and 52. In each of the four pairs of electric wires 51 and 52, a terminating resistor 40 is connected to the end opposite to the end to which the master unit 20 is connected. The base unit 20 and the plurality of (16 units) slave units 10 are electrically connected to the pair of electric wires 51 and 52, respectively, and send signals to the pair of electric wires 51 and 52. The signal sent to the pair of electric wires 51 and 52 is, for example, a signal based on a change in voltage or a change in current between the pair of electric wires 51 and 52.

  In the automatic fire alarm system 1, 40 to 80 slave units 10 can be connected to each pair of electric wires 51 and 52. Furthermore, a pair of electric wires 51 and 52 can be connected to 50 to 200 lines (50 to 200 sets) in one base unit 20. For example, when a maximum of 40 cordless handsets 10 can be connected to each pair of electric wires 51 and 52 and a maximum of 50 wire pairs 51 and 52 can be connected to one master phone 20, Up to 2000 (= 40 × 50) units can be connected to one master unit 20. In addition, these numerical values are an example, Comprising: It is not the meaning limited to these numerical values.

  The master unit 20 and each slave unit 10 of the present embodiment synchronize based on a synchronization signal SY1 (see FIG. 3) transmitted from the master unit 20 to each slave unit 10, and perform communication in a time division communication system.

  In FIG. 1, one slave unit 10 is connected to one master unit 20 via a pair of electric wires 51, 52, and a plurality of other slave units 10 and another pair of electric wires 51, Illustration of 52 is omitted.

  The configuration and operation of base unit 20 will be described.

  The master unit 20 in this embodiment is a master unit of the automatic fire alarm system 1 that transmits signals to a plurality of slave units 10 that are electrically connected to a pair of electric wires 51 and 52 to which a voltage is applied. As shown in FIG. 1, base unit 20 includes a transmission unit 24, a reception unit 23, and a control unit 27. The control unit 27 includes a processing unit 271, a reception control unit 273, and a transmission control unit 274. The master unit 20 includes an application unit 21, a display unit 25, an operation unit 26, an interlocking unit 28, and a standby power supply 29. The configurations of the display unit 25, the operation unit 26, the interlocking unit 28, and the standby power supply 29 will be described later.

  The application unit 21 applies a DC voltage (for example, 24 V) between the pair of electric wires 51 and 52. The application unit 21 supplies power for operation to the slave unit 10 connected to the pair of electric wires 51 and 52.

  A resistor 22 (for example, a resistor of 400Ω to 600Ω) is connected between the high-potential-side wire (the wire 51 in the present embodiment) of the pair of wires 51 and 52 and the applying unit 21. The resistor 22 has a first function for converting a current signal transmitted to the pair of electric wires 51 and 52 into a voltage signal, and a current flowing through the pair of electric wires 51 and 52 when the pair of electric wires 51 and 52 are short-circuited. The second function to be restricted has two functions.

  The transmission unit 24 is electrically connected to the pair of electric wires 51 and 52, changes the voltage between the pair of electric wires 51 and 52, and transmits signals to the plurality of slave units 10. The receiving unit 23 is electrically connected to the pair of electric wires 51 and 52 and receives signals from the plurality of slave units 10 based on a change in voltage between the pair of electric wires 51 and 52.

  The control unit 27 is composed of, for example, a microcomputer. The control unit 27 implements functions of the processing unit 271, the reception control unit 273, and the transmission control unit 274 by reading and executing a program stored in the memory. The program executed by the control unit 27 may be previously written in a memory, stored in a recording medium such as a memory card, or provided through an electric communication line such as the Internet. May be.

  The transmission control unit 274 controls the transmission unit 24. More specifically, as shown in FIG. 3, the transmission control unit 274 causes the transmission unit 24 to transmit the synchronization signal SY1 every time the predetermined time T1 elapses. In FIG. 3, among the two synchronization signals SY1 arranged in time series, the previously transmitted synchronization signal SY1 is shown as “synchronization signal SY11”, and the later transmitted synchronization signal SY1 is shown as “synchronization signal SY12”. Yes.

  The plurality of slave units B1 to B16 (slave unit 10) change the voltage between the pair of electric wires 51 and 52 after the waiting time W1 to W16 has elapsed after receiving the synchronization signal SY1, and send the response signals SN1 to SN16. Send. More specifically, the slave unit B1 transmits the response signal SN1 by changing the voltage between the pair of electric wires 51 and 52 after the waiting time W1 has elapsed after receiving the synchronization signal SY1. Similarly, the slave devices B2 to B16 transmit the response signals SN2 to SN16 after the respective waiting times W2 to W16 have elapsed since the synchronization signal SY1 was received. The waiting times W1 to W16 are set to different lengths for each of the slave units B1 to B16. The waiting times W1 to W16 in the present embodiment are determined based on unique identification information (for example, addresses) for each of the slave units B1 to B16.

  The reception control unit 273 controls the reception unit 23. The reception control unit 273 receives the response signals SN1 to SN16 from each of the plurality of slave units B1 to B16, and the reception intervals R1 to R16 after the waiting times W1 to W16 have elapsed since the transmission unit 24 transmitted the synchronization signal SY1. The reception unit 23 receives the data at R16. The reception sections R1 to R16 are time slots determined by the processing unit 271 in order to receive the response signals SN1 to SN16 by the receiving unit 23, respectively. More specifically, the reception period R1 is a time slot for receiving the response signal SN1. Similarly, the reception sections R2 to R16 are time slots for receiving the response signals SN2 to SN16, respectively. In other words, the receiving sections R1 to R16 correspond to the waiting times W1 to W16, respectively. Information regarding the length of the waiting times W1 to W16 is stored in a recording medium such as a memory.

  The predetermined time T1 is a time interval of transmission timing when the transmission control unit 274 periodically transmits the synchronization signal SY1 from the transmission unit 24. The predetermined time T1 is determined by the processing unit 271. In other words, the processing unit 271 determines the predetermined time T1. For example, the processing unit 271 reads the initial value for the predetermined time T1 stored in the memory, and determines the length of the predetermined time T1. In addition, the processing unit 271 acquires data included in the response signals SN1 to SN16 from the output of the receiving unit 23.

  The processing unit 271 determines the communication section C1 and the total response section T2 after transmitting the synchronization signal SY1 from the transmission section 24. Base unit 20 transmits a request signal in communication section C1. The request signal is a signal including arbitrary data that causes each slave unit 10 to transmit a signal. The request signal is, for example, a signal including request data that causes the slave unit 10 to perform a self-diagnosis and return a result of the diagnosis. In addition, for example, the request signal is request data that causes only the slave unit 10 that detects a fire to respond. Each cordless handset 10 transmits response signals SN1 to SN16 that respond to the request signal within the reception sections R1 to R16.

  The total response section T2 is a section in which the reception unit 23 receives the response signals SN1 to SN16 in which each of the slave units B1 to B16 responds to the request signal transmitted from the base unit 20 in the communication section C1. The processing unit 271 determines reception intervals R1 to R16 for receiving the response signals SN1 to SN16 transmitted from the respective slave units B1 to B16 in the entire response interval T2 based on the waiting times W1 to W16. The processing unit 271 identifies the child devices B1 to B16 that are the transmission sources of the received response signals SN1 to SN16 based on the reception sections R1 to R16, respectively. Moreover, the process part 271 recognizes the data contained in response signal SN1-SN16 from subunit | mobile_unit B1-B16.

  The configuration and operation of the slave units B1 to B16 (slave unit 10) will be described.

  The subunit | mobile_unit 10 is provided with the transmission circuit 15, the receiving circuit 16, the control part 19, the memory | storage part 17, and the detection part 13 as shown in FIG. Moreover, the subunit | mobile_unit 10 is provided with the diode bridge (DB) 11, the power supply circuit 12, and the alerting | reporting part 14. FIG. The subunit | mobile_unit 10 is connected to a pair of electric wire 51,52.

  The receiving circuit 16 receives a signal based on a change in voltage between the pair of electric wires 51 and 52. The reception circuit 16 receives the request signal transmitted from the transmission unit 24 of the parent device 20 and outputs the reception result to the control unit 19.

  The transmission circuit 15 has a function of drawing a current flowing through the pair of electric wires 51 and 52 and a function of stopping the drawing of the current. When the current flowing through the pair of electric wires 51 and 52 changes, the voltage between the pair of electric wires 51 and 52 changes due to the voltage drop at the resistor 22 of the parent device 20. The transmission circuit 15 changes the voltage level of the pair of electric wires 51 and 52 in three stages, thereby transmitting a signal for notifying the parent device 20 of a non-reporting state, a fire report, and an interlocking report. Note that the voltage levels of the pair of electric wires 51 and 52 that are changed by the transmission circuit 15 are not limited to three levels, as long as at least a fire report can be notified.

  The diode bridge 11 includes a pair of input terminals to which the pair of electric wires 51 and 52 are electrically connected, and a pair of output terminals. The power supply circuit 12, the transmission circuit 15, and the reception circuit 16 are electrically connected to the output terminal of the diode bridge 11, respectively.

  Details of the operations of the plurality of slave units B1 to B16 will be described with reference to FIG.

  Each of the plurality of slave units B1 to B16 starts timing when the synchronization signal SY11 is received. The subunit | mobile_unit B1-B16 times with the timer which counts a clock, for example. The subunit | mobile_unit B1-B16 is measuring the waiting time W1-W16, after receiving the synchronizing signal SY11. Each of the plurality of slave units B1 to B16 changes the voltage between the pair of electric wires 51 and 52 in the response sections S1 to S16 after the waiting times W1 to W16 have elapsed after receiving the synchronization signal SY11. SN1 to SN16 are transmitted.

  Response section S1-S16 is defined for every subunit | mobile_unit B1-B16. The start timings of the response sections S1 to S16 are the time points when the waiting times W1 to W16 have elapsed since the reception circuit 16 received the synchronization signal SY1. That is, the response sections S1 to S16 are determined based on the waiting times W1 to W16, respectively. Moreover, response area S1-S16 is an area where the control part 19 transmits response signal SN1-SN16, respectively. In other words, the control unit 19 causes the transmission circuit 15 to transmit the response signals SN1 to SN16 within the response sections S1 to S16 determined based on the waiting times W1 to W16.

  The length of the waiting time W1 of the slave unit B1 is equal to the length of the communication section C1. For example, the waiting time W2 is a length obtained by adding a certain time interval T5 to the waiting time W1. For example, the waiting time W3 is a length obtained by adding a certain time interval T5 to the waiting time W2. That is, the lengths of the respective waiting times W1 to W16 corresponding to the plurality of slave units B1 to B16 are different at a constant time interval T5. In other words, the lengths of the reception intervals R1 to R16 are each equal to a certain time interval T5.

  The control unit 19 is configured by a microcomputer, for example, and realizes a desired function by executing a program stored in the memory. The program may be previously written in the memory, stored in a recording medium such as a memory card, or provided through an electric communication line such as the Internet.

  The control unit 19 controls the transmission circuit 15, the reception circuit 16, the storage unit 17, and the notification unit 14. The control unit 19 acquires data included in the request signal from the reception result of the reception circuit 16. The control unit 19 causes the transmission circuit 15 to transmit response signals SN1 to SN16 that respond to the request signal in the response sections S1 to S16.

  Each control part 19 of cordless handset B1-B16 transmits two signals, response signal SN1-SN16, and alerting signal A1-A16 from the transmission circuit 15 in response area S1-S16. Response signals SN1 to SN16 are signals including data that responds to a request signal from parent device 20. The notification signals A1 to A16 are a signal for notifying the parent machine 20 of a non-reporting state, a fire report, or a linked report. The interlocking report is a signal for interlocking the other device 30 (see FIG. 2) connected to the master unit 20 with the fire detection operation of the slave unit 10.

  The lengths of the response sections S1 to S16 in the present embodiment are shorter than the lengths of the reception sections R1 to R16 determined by the parent device 20, respectively. Each control unit 19 of the slave units B1 to B16 defines a guard section G1 between the start timing of the reception sections R1 to R16 and the start timing of the response sections S1 to S16. Moreover, each control part 19 of subunit | mobile_unit B1-B16 has each defined the guard area G2 between the end timing of response area S1-S16, and the end timing of receiving area R1-R16. Accordingly, the combined length of the guard interval G1, the response interval S1, and the guard interval G2 is equal to the length of the reception interval R1. The control unit 19 does not transmit a signal from the transmission circuit 15 in the guard sections G1 and G2. The guard sections G1 and G2 are provided so that the plurality of slave units B1 to B16 are difficult to transmit signals simultaneously.

  The control unit 19 is in a state (operating state) of operating in the normal mode from the start timing of reception of the synchronization signal SY1 (synchronization signal SY11) to the end timing of reception of the synchronization signal SY11. From the time when the reception end timing of the synchronization signal SY11 is reached to the time when the reception timing of the next synchronization signal SY1 (synchronization signal SY12) is reached, the control unit 19 starts from the “normal mode” which is a normal operation state. Also operates in “standby mode” with reduced power consumption. In the “standby mode”, the control unit 19 enters a standby state in which power consumption is suppressed as compared with a normal operation state. In addition, the control unit 19 in the standby state suppresses power consumption by stopping the other functions except the time counting function and the function of returning from the standby state to the normal state. When the control unit 19 of each of the slave units B1 to B16 shifts to the standby state, it resets the counter of the timer and measures the time, and returns from the standby state to the normal state before reaching the start timing of the reception sections R1 to R16. And each control part 19 of cordless handset B1-B16 makes response signal SN1-SN16 and alerting | reporting signal A1-A16 transmit from the transmission circuit 15 when the start timing of response area S1-S16 is reached. That is, the control unit 19 is in an operating state during a period in which the synchronization signal SY1 is received, and is in a standby state in a period in which the synchronization signal SY1 is not received.

  The power supply circuit 12 includes a capacitor that is charged with power supplied from the pair of electric wires 51 and 52. The power supply circuit 12 supplies power necessary for realizing the functions of the transmission circuit 15, the reception circuit 16, the control unit 19, the storage unit 17, and the detection unit 13.

  The alerting | reporting part 14 has a buzzer, LED, etc., for example, and is comprised so that it may alert | report the generation | occurrence | production of a fire around. The operation of the notification unit 14 is controlled by the control unit 19.

  The memory | storage part 17 is comprised by EEPROM (Electrically Erasable Programmable Read-Only Memory), for example. The storage unit 17 stores identification information unique to the child devices B1 to B16. The unique identification information is information for the parent device 20 to identify each of the plurality of child devices 10, and is information that does not overlap. The storage unit 17 stores a determination condition for the control unit 19 to determine whether to transmit a fire report from the transmission circuit 15 or to transmit a linked report. The determination condition is, for example, a threshold set for the output of the detection unit 13 or the number of samplings.

  The control unit 19 periodically reads the detection value of the detection unit 13 and determines whether or not a fire has occurred by referring to the determination conditions in the storage unit 17. The control unit 19 selects a signal (a fire report, a linked report, a signal notifying a non-reported state) to be transmitted to the base unit 20 based on the detection value of the detection unit 13 and the determination condition thereof, and a transmission circuit 15 is transmitted.

  The other device 30 (see FIG. 2) is electrically connected to the parent device 20. The other device 30 is, for example, a fire prevention facility such as a fire prevention facility such as a fire door or smoke exhaust facility, an emergency broadcast facility, an external transfer device, or a sprinkler. When the master unit 20 receives the interlocking report from the slave unit 10, the master unit 20 transmits a signal for interlocking the other device 30 to the other device 30.

  The interlocking unit 28 outputs a signal for interlocking the other device 30 to the other device 30. The operation of the interlocking unit 28 is controlled by the processing unit 271. For example, when identifying the link information, the processing unit 271 causes the link unit 28 to output a signal for causing the other device 30 to link with the slave unit 10.

  The standby power supply 29 is configured by a storage battery, for example. The standby power supply 29 is configured to have a capacity of power for operating the automatic fire alarm system 1 for a certain time even during a power failure.

  The display unit 25 includes, for example, an LED (Light Emitting Diode), a liquid crystal display, or an organic electroluminescence display. The operation of the display unit 25 is controlled by the processing unit 271. The processing unit 271 changes the display content of the display unit 25 according to the content of the signal received from the pair of electric wires 51 and 52. The display unit 25 displays, for example, the occurrence of a fire in the apartment house 60 and the floor (floor) where the fire occurred.

  The operation unit 26 includes, for example, a push button switch or a touch panel type display. For example, the operation unit 26 is configured to cause the processing unit 271 to stop the fire notification operation, stop the abnormality detection operation of the slave unit 10, and the like.

  Next, detailed operations related to communication between the parent device 20 and the child device 10 will be described with reference to FIG.

  The transmission control unit 274 of the parent device 20 causes the transmission unit 24 to periodically transmit the synchronization signal SY1 to the pair of electric wires 51 and 52. The processing unit 271 determines the communication period C1 after the transmission control unit 274 transmits the synchronization signal SY1 from the transmission unit 24, and measures the elapsed time from the start timing of the communication period C1. The transmission control unit 274 causes the transmission unit 24 to transmit request signals for the plurality of slave units 10 in the communication section C1. When reaching the end timing of the communication section C1, the processing unit 271 determines the entire response section T2. In all response intervals T2, reception intervals R1 to R16 (time slots) divided into a plurality of times in the time axis direction are set.

  The transmission control unit 274 of the parent device 20 transmits the synchronization signal SY1 (synchronization signal SY11) from the transmission unit 24 and starts measuring time. When the measured time reaches the predetermined time T1, the transmission control unit 274 causes the transmission unit 24 to transmit the synchronization signal SY1 (synchronization signal SY12). The transmission control unit 274 transmits the synchronization signal SY1 every time the measured time reaches the predetermined time T1. The transmission control unit 274 transmits the request signal from the transmission unit 24 in the communication section C1 after transmitting the synchronization signal SY11.

  When the reception circuit 16 receives the synchronization signal SY11, each control unit 19 of the slave units B1 to B16 subsequently receives the request signal transmitted in the communication section C1. Each control unit 19 of the slave units B1 to B16 transmits the response signals SN1 to SN16 corresponding to the request data included in the request signal received in the communication section C1 in the response sections S1 to S16 to which each slave unit 10 corresponds. Transmission is performed from the receiving circuit 16. Hereinafter, each operation | movement of the subunit | mobile_unit B1, B2, B16 in all the response area T2 is demonstrated. In addition, since operation | movement of subunit | mobile_unit B3-B15 is the same as that of subunit | mobile_unit B2, description of the operation | movement is abbreviate | omitted.

  The control unit 19 of the child device B1 starts measuring time when the receiving circuit 16 receives the synchronization signal SY11. The control unit 19 does not transmit a signal from the transmission circuit 15 in the guard section G1. The control unit 19 starts measuring the response section S1 when the end timing of the guard section G1 is reached. The control unit 19 causes the transmission circuit 15 to transmit the response signal SN1 and the notification signal A1 in the response section S1.

  The control unit 19 of the child device B1 causes the transmission circuit 15 to transmit the response signal SN1 corresponding to the request signal from the parent device 20 received in the communication section C1 in the response section S1. The control unit 19 of the slave unit B1 transmits the notification signal A1 from the transmission circuit 15 after transmitting the response signal SN1 from the transmission circuit 15. Based on the data included in the notification signal A1, the processing unit 271 of the parent device 20 identifies whether the child device B1 is in a non-reporting state, a fire reporting state, or a linked reporting state.

  The control part 19 of the subunit | mobile_unit B1 transfers to a standby state, when the end timing of response area S1 is reached. When the control unit 19 shifts to the standby state, the timer 19 resets the counter of the timer and measures the time, and returns from the standby state to the normal state before reaching the start timing of the reception section R1. Then, the control unit 19 causes the transmission circuit 15 to transmit the response signal SN1 and the notification signal A1 when the start timing of the response section S1 is reached. The same applies to the operation of each of the control units 19 of the slave units B2 to B16 returning from the standby state to the normal state.

  When reaching the end timing of the communication section C1, the control unit 19 of the slave unit B2 shifts to a standby state. Then, it returns to the normal state before reaching the start timing of the receiving section R2. The control unit 19 of the child device B2 causes the transmission circuit 15 to transmit the response signal SN2 and the notification signal A2 when the end timing of the guard interval G1 of the reception interval R2 is reached. When reaching the end timing of the response section S2, the control unit 19 shifts from the normal state to the standby state.

  When reaching the end timing of the communication section C1, the control unit 19 of the slave unit B16 shifts to a standby state. Then, the state returns to the normal state before reaching the start timing of the reception section R16. The control unit 19 of the child device B16 causes the transmission circuit 15 to transmit the response signal SN16 and the notification signal A16 when the end timing of the guard interval G1 of the reception interval R16 is reached. When reaching the end timing of the response section S16, the control unit 19 of the slave unit B16 is continuously in an operating state in order to receive the request signal included in the synchronization signal SY12 and the communication section C1. When reaching the end timing of the communication section C1, the control unit 19 of the slave unit B16 shifts to a standby state.

  In FIG. 3, as an example, every time the transmission circuit 15 of the slave unit B1 transmits the response signal SN1, the transmission unit 24 of the master unit 20 transmits the synchronization signal SY1 (synchronization signals SY11, SY12). Although the case is shown, it is not limited to this example. The processing unit 271 of the parent device 20 may determine the predetermined time T1 so that the transmission signal 15 of the child devices B1 to B16 transmits the synchronization signal SY1 each time the response signals SN1 to SN16 are transmitted a plurality of times. That is, the entire response section T2 in the predetermined time T1 may be determined twice or more. For example, the synchronization signal SY1, the communication interval C1, and the multiple response intervals T2 may be periodically determined in this order. In other words, the length of the predetermined time T1 may be equal to or longer than the total length of the reception sections R1 to R16 corresponding to the number of handset B1 to B16. As an example, the length of the predetermined time T1 may be determined to be n times (n is an integer of 2 or more) the total length of the communication section C1 and the total response section T2. As the length of the predetermined time T1 is increased, the number of transmissions of the synchronization signal SY1 per unit time decreases. Since the transmission time of the synchronization signal SY1 occupying the communication time between the parent device 20 and the child device 10 is reduced, the communication time from the child device 10 can be relatively increased, and signals from all the child devices 10 can be shortened. Thus, the master unit 20 can receive the data efficiently.

  The control part 19 of the subunit | mobile_unit 10 measures waiting time W1-W16 after receiving the synchronizing signal SY11, and has determined the start timing and end timing of response area S1-S16. When the control unit 19 counts with a timer, if the accuracy of the oscillation circuit that outputs a clock to the timer is low, the start timing of the response sections S1 to S16 for the reception sections R1 to R16 as the length of the predetermined time T1 increases. In some cases, the deviation of the end timing becomes large. As a comparative example, a description will be given of a case where the accuracy of an oscillation circuit that outputs a clock to the timer when the control unit 19 uses a timer is low.

  When the accuracy of the oscillation circuit that outputs a clock to the timer of the control unit 19 of the comparative example is low, the start timing and end timing of the response sections S1 to S16 with respect to the reception sections R1 to R16 as the length of the predetermined time T1 increases. The deviation may be large. When the difference between the start timing and the end timing of the response sections S1 to S16 with respect to the reception sections R1 to R16 becomes large, it is conceivable that the two slave units 10 transmit response signals at the same time (signal collision). In this case, the processing unit 271 of the parent device 20 may not correctly identify the response signal and the notification signal.

  As a method of reducing the above-described deviation, the accuracy of the timer oscillation circuit of the control unit 19 of the comparative example is increased, the lengths of the guard sections G1 and G2 are set longer, or the length of the predetermined time T1 is set shorter. A method is conceivable.

  By increasing the accuracy of the timer oscillation circuit of the control unit 19 of the comparative example (increasing clock accuracy), it is possible to reduce the deviation of the response intervals S1 to S16 with respect to the reception intervals R1 to R16. Increasing the accuracy increases the power consumption of the oscillation circuit. As an example, the power consumption of the slave unit 10 in this embodiment is several hundred μA or less, but the power consumption of the oscillation circuit that outputs a high-accuracy clock is several mA, and the power consumption of the slave unit 10 is reduced. However, it is difficult to increase the accuracy of the clock of the oscillation circuit.

  In addition, by setting the lengths of the guard sections G1 and G2 of the comparative example to be long, the response sections S1 to S16 can be accommodated in the reception sections R1 to R16, respectively, even if the above-described deviation increases. The length of time T1 increases. In this case, the length of the predetermined time T1 becomes longer as the number of the child devices 10 connected to the parent device 20 increases. When the length of the predetermined time T1 is increased, for example, when the child device B1 detects the occurrence of a fire other than the response section S1, the waiting time until reaching the start timing of the response section S1 is increased. That is, the time required from the time when the child device B1 detects the occurrence of a fire to the time when the fire information is transmitted to the parent device 20 may increase.

  By shortening the length of the predetermined time T1 of the comparative example, it is possible to reduce the shift in synchronization timing between the parent device 20 and each child device 10. However, if the length of the predetermined time T1 is set short with respect to the number of slave units 10, the length of the response section S1 of each slave unit 10 is shortened. If the length of the response section S1 is short, there may be a case where the handset B1 cannot transmit the response signal SN1 and the notification signal A1. FIG. 4A is a diagram for explaining the communication state of the slave units B1 to B16 in the present embodiment, and FIG. 4B is a diagram for explaining the communication state of the slave units B1 to B16 according to the comparative example. In the comparative example, the predetermined time Tx1 that is the transmission interval of the synchronization signal SY1 is set to a length shorter than the predetermined time T1. In the comparative example, the length of each of the response sections S1 to S16 is set to be shorter than that of the present embodiment. The subunit | mobile_unit B1-B16 in a comparative example transmits alerting signal Ax1-Ax16 of the length shorter than alerting signal A1-A16. As the lengths of the notification signals Ax1 to Ax16 become shorter, there is a higher possibility that the base unit 20 may or may not recognize the received notification signals Ax1 to Ax16. Further, when the length of the response signals SN1 to SN16 is shortened, there is a high possibility that the base unit 20 erroneously recognizes or cannot recognize the data included in the received response signals SN1 to SN16. Therefore, the length of the predetermined time T1 needs to be set to a length including the response sections S1 to S16 that allow the base unit 20 to correctly receive the response signals SN1 to SN16 and the notification signals A1 to A16.

  By the way, an operation in which the processing unit 271 of the parent device 20 determines the predetermined time T1 will be described. For example, the processing unit 271 performs test communication with each control unit 19 of the slave units B1 to B16 in a state where the operation mode is set to the test mode. The test mode of the processing unit 271 is an operation mode for setting the predetermined time T1, unlike the normal mode for notifying the occurrence of a fire. That is, the processing unit 271 alternatively selects a normal mode in which a notification operation is performed when the receiving unit 23 receives a fire report and a test mode. As an example, when the operation unit 26 performs an operation mode switching operation, the processing unit 271 switches between the normal mode and the test mode. In the normal mode, when the reception unit 23 receives the fire report transmitted from the transmission circuit 15 of the slave unit 10, the processing unit 271 performs a notification operation for notifying the occurrence of a fire. In the test mode, the transmission control unit 274 causes the transmission unit 24 to transmit a test signal. In the test mode, the reception control unit 273 causes the reception unit 23 to receive the test response signal transmitted from the transmission circuit 15 of each slave unit 10.

  Hereinafter, operations of the parent device 20 and the child device 10 in the test mode will be described. For example, the transmission control unit 274 transmits a test signal from the transmission unit 24 in the communication section C1. The reception control unit 273 causes the reception unit 23 to receive the test response signals from the slave units B1 to B16 in each of the reception sections R1 to R16. The reception control unit 273 determines whether the data included in the test response signal received by the reception unit 23 is correct. The determination method is, for example, cyclic redundancy check or parity check.

  The processing unit 271 sets the first test time TT1 to the predetermined time T1, and causes the transmission unit 24 to transmit the synchronization signal SY1 and the test signal multiple times. The processing unit 271 causes the transmission unit 24 to transmit a test signal. When the reception control unit 273 determines that the data included in the test response signals of all the slave units 10 received by the reception unit 23 is correct, the processing unit 271 adds the second test time TT2 to the predetermined time T1. Then, the test signal is transmitted from the transmission unit 24 as a new predetermined time T1. When the reception control unit 273 determines that the data included in the test response signals of all the slave units 10 received by the reception unit 23 is correct, the processing unit 271 adds the second test time TT2 to the predetermined time T1. This time is set as a new predetermined time T1. Then, the processing unit 271 repeatedly executes the transmission of the test signal from the transmission unit 24. The value of the predetermined time T1 increases as the number of times the reception control unit 273 determines that the data included in the test response signals of all the slave units 10 received by the reception unit 23 is correct. Assume that the reception control unit 273 determines that the reception unit 23 has not correctly received the data included in the test response signal from at least one slave unit 10. In this case, the processing unit 271 sets the predetermined time T1 determined in the previous (or earlier) test mode as the predetermined time T1 in the normal mode. Then, the processing unit 271 shifts from the test mode to the normal mode. That is, the processing unit 271 transmits the synchronization signal SY1 from the transmission unit 24 to correctly receive the data included in the response signals SN1 to SN16 and the notification signals A1 to A16, and sets the length of the longest period to the length of the predetermined time T1. Determined by Thereby, before the reception control unit 273 cannot correctly identify the data included in the response signals SN1 to SN16 and the notification signals A1 to A16, the transmission control unit 274 transmits the synchronization signal SY1. Accordingly, without increasing the accuracy of the oscillation circuit of the timer of the control unit 19, increasing the length of the guard sections G1 and G2, or setting the length of the predetermined time T1 short, the slave units B1 to B16 The response signals SN1 to SN16 can be made difficult to interfere.

  As described above, the base unit 20 in the present embodiment transmits a signal to the plurality of slave units B1 to B16 (slave unit 10) electrically connected to the pair of electric wires 51 and 52 to which a voltage is applied. It is a master unit of the automatic fire notification system 1. Base device 20 includes transmission unit 24, transmission control unit 274, reception unit 23, and reception control unit 273. The transmission unit 24 is electrically connected to the pair of electric wires 51 and 52, changes the voltage between the pair of electric wires 51 and 52, and transmits signals to the plurality of slave units 10. The transmission control unit 274 controls the transmission unit 24 and causes the transmission unit 24 to transmit the synchronization signal SY1 every time the predetermined time T1 elapses. The receiving unit 23 is electrically connected to the pair of electric wires 51 and 52 and receives signals from the plurality of slave units 10 based on a change in voltage between the pair of electric wires 51 and 52. The reception control unit 273 controls the reception unit 23. The plurality of slave units B1 to B16 (slave unit 10) change the voltage between the pair of electric wires 51 and 52 after the waiting time W1 to W16 has elapsed after receiving the synchronization signal SY1, and send the response signals SN1 to SN16. Send. The lengths of the waiting times W1 to W16 are different for each of the plurality of child devices B1 to B16. The reception control unit 273 receives the response signals SN1 to SN16 from each of the plurality of slave units B1 to B16 (slave unit 10), after the waiting time W1 to W16 has elapsed since the transmission unit 24 transmitted the synchronization signal SY1. Are received by the receiver 23 in the receiving sections R1 to R16. The predetermined time T1 is a length of time during which the response signals SN1 to SN16 are within the receiving sections R1 to R16.

  According to the above configuration, the predetermined time T1 is a length of time during which the response signals SN1 to SN16 are within the reception sections R1 to R16, so that the response signals SN1 to SN16 are unlikely to protrude from the corresponding reception sections R1 to R16. ing. Each of the plurality of slave units 10 measures the waiting time W1 to W16 after receiving the synchronization signal SY1 transmitted from the transmission unit 24 every time the predetermined time T1 elapses, and the response signal after the waiting time W1 to W16 elapses. SN1 to SN16 are transmitted. Therefore, even if the start timing for transmitting the response signals SN1 to SN16 is deviated from the time of receiving the previous synchronization signal SY1, the plurality of slave units 10 receive the synchronization signal SY1 and thereby respond to the synchronization signal SY1. The start timing deviation can be corrected. In other words, the base unit 20 of the automatic fire notification system 1 can make it difficult to interfere with the response signals SN1 to SN16 transmitted from the plurality of slave units 10.

  The processing unit 271 of the base unit 20 of the automatic fire notification system 1 in the present embodiment has two operation modes, a normal mode and a test mode, and determines a predetermined time T1 in the test mode. The processing unit 271 determines the longest predetermined time T1 when the reception control unit 273 determines that the reception unit 23 has correctly received the data included in the response signals SN1 to SN16 and the notification signals A1 to A16 in the test mode. Therefore, even if the start timing shift of the response sections S1 to S16 with respect to the reception sections R1 to R16 increases, the start timing shift of the response signals SN1 to SN16 is corrected each time the predetermined time T1 elapses. Therefore, base unit 20 can make it difficult to interfere with response signals SN1 to SN16 transmitted from a plurality of handset units 10. In addition, since the number of transmissions of the synchronization signal SY1 per unit time is reduced, the communication time from the child device 10 in the time in which the parent device 20 and the child device 10 communicate can be relatively increased. The base unit 20 can efficiently receive the signal from the slave unit 10 in a short time.

  The processing unit 271 of the parent device 20 in the present embodiment performs test communication with the child devices B1 to B16 in a state where the operation mode is set to the test mode. The processing unit 271 in the test mode repeatedly performs test communication with the control unit 19 of the slave units B1 to B16 to increase the length of the predetermined time T1 stepwise. The processing unit 271 determines the longest predetermined time T1 when the receiving unit 23 can correctly receive the data included in the response signals SN1 to SN16 and the notification signals A1 to A16, and stops increasing the length of the predetermined time T1. . Thereby, even when the accuracy of the oscillation circuit of each slave unit 10 is relatively low, the response signals SN1 to SN1 transmitted from the plurality of slave units 10 while suppressing the number of transmissions of the synchronization signal SY1 per unit time. SN16 can be made difficult to interfere.

  In the base unit 20 of the present embodiment, the length of the predetermined time T1 is preferably equal to or longer than the total length of the reception sections R1 to R16 for the number of the handset B1 to B16 (slave unit 10).

  According to the above configuration, the predetermined time T1 (that is, the transmission interval of the synchronization signal SY1) is determined to be longer than the time required for the slave units B1 to B16 to transmit the response signals SN1 to SN16. The number of hits of the synchronization signal SY1 is reduced. Since the communication time from the child device 10 occupying the time for the communication between the parent device 20 and the child device 10 can be relatively increased, signals from all the child devices 10 can be efficiently transmitted in a short time. It can be received.

  The automatic fire notification system 1 of the present embodiment includes the above-described parent device 20 and the child devices B1 to B16 (child device 10). The slave units B1 to B16 (slave unit 10) are connected to the pair of electric wires 51 and 52, and change the voltage between the pair of electric wires 51 and 52 after waiting time W1 to W16 has elapsed after receiving the synchronization signal SY1. The response signals SN1 to SN16 are transmitted.

  According to the above configuration, since the automatic fire notification system 1 includes the above-described master unit 20, it is possible to correct a shift in start timing for transmitting the response signals SN1 to SN16 of the slave units B1 to B16. In other words, the automatic fire notification system 1 can make it difficult to interfere with the response signals SN1 to SN16 transmitted from the plurality of slave units B1 to B16.

  The slave units B1 to B16 (slave unit 10) of the present embodiment are used in the automatic fire notification system 1.

  According to the said structure, subunit | mobile_unit B1-B16 (child unit 10) can correct | amend the shift | offset | difference of the start timing which transmits response signal SN1-SN16 based on the synchronizing signal SY1 which the main | base station 20 transmitted. In other words, the plurality of slave units B1 to B16 (slave unit 10) in the automatic fire notification system 1 can transmit the response signals SN1 to SN16 that are difficult to interfere.

  The subunit | mobile_unit B1-B16 of the automatic fire alerting | reporting system 1 in this embodiment transmits response signal SN1-SN16 and alerting | reporting signal A1-A16 within response area S1-S16 corresponding to each of receiving area R1-R16. Therefore, the response signals SN1 to SN16 and the notification signals A1 to A16 are all transmitted in a state in which they are difficult to protrude from the reception sections R1 to R16.

  In the slave unit 10 of the present embodiment, the operation state (normal mode in the present embodiment) is in a period in which the synchronization signal SY1 is received, and in a period in which the synchronization signal SY1 is not received, a standby state in which power consumption is suppressed compared to the operation state ( In this embodiment, it is preferable to be in a standby mode.

  According to the above configuration, the slave unit 10 can enter a standby state in which the power consumption is lower than the operation state in a period in which the synchronization signal SY1 is not transmitted from the transmission unit 24, and thus suppresses power consumption of the slave unit 10. be able to.

  In addition, although waiting time W1-W16 in this embodiment is defined based on the specific identification information of the subunit | mobile_unit 10, it is not limited to this example, It is defined for every some subunit | mobile_unit 10 by an appropriate method. It only has to be. That is, the waiting times W1 to W16 may be determined so that the plurality of slave units 10 do not transmit signals simultaneously.

  The information regarding the length of the waiting times W1 to W16 is not limited to being stored in a recording medium such as a memory, and may be set using, for example, a dip switch.

  In the present embodiment, the predetermined time T1 is determined by the processing unit 271;

  In the present embodiment, the processing unit 271 starts counting the predetermined time T1 at the transmission start timing of the synchronization signal SY1, but the timing start timing of the predetermined time T1 is the same as the transmission start timing of the synchronization signal SY1. It is not meant to be limited. For example, the processing unit 271 may start measuring the predetermined time T1 when a slight time has elapsed from the transmission start timing of the synchronization signal SY1. The slight time is a time that allows each of the plurality of slave units 10 to recognize that the received signal is the synchronization signal SY1 based on the data included in the received signal. Further, the start timing of measuring the predetermined time T1 may be the end of transmission of the synchronization signal SY1, that is, the start timing of the communication section C1.

  Although the control part 19 of the subunit | mobile_unit 10 in this embodiment has defined guard area G1, G2, at least one of guard area G1, G2 may be abbreviate | omitted.

  As an example, the control units 19 of the plurality of slave units 10 in the present embodiment are in a standby state except for the period in which the receiving circuit 16 receives the synchronization signal SY1 and the request signal for the communication section C1, but this example It is not limited to. For example, the control part 19 may be comprised so that it can select alternatively the case where it will be in a standby state during the period of the communication area C1, and the case where it will be in an operation state.

  The processing unit 271, the reception control unit 273, and the transmission control unit 274 in the present embodiment are realized by one control unit 27, but are not limited to this configuration. The processing unit 271, the reception control unit 273, and the transmission control unit 274 may each be realized by a separately prepared microcomputer, a calculation IC (Integrated Circuit), or the like.

  In the present embodiment, the slave unit 10 stores identification information in the memory of the control unit 19. However, the present invention is not limited to this configuration, and the identification information is set using, for example, a dip switch provided in the slave unit 10. May be.

  In the present embodiment, each of the master unit 20 and the slave unit 10 changes the voltage between the pair of electric wires 51 and 52 by changing the current value of the current flowing through the pair of electric wires 51 and 52, and transmits a signal. However, it is not limited to this example. For example, each of the master unit 20 and the slave unit 10 may transmit a signal by directly changing the voltage between the pair of electric wires 51 and 52.

  In the automatic fire alarm system 1 of the present embodiment, a pair of electric wires 51 made up of two sets of electric wires 51 as well as a pair of electric wires made up of two sets of electric wires used in a conventional P-type automatic fire alarm system. , 52 are used. Therefore, when introducing the automatic fire alarm system 1 of the present embodiment into an apartment house or the like where the conventional P-type automatic fire alarm system is used, a pair of conventional electric wires is not laid. Electric wires are available. Realizing the automatic fire alarm system 1 by replacing the master unit of the conventional P-type automatic fire alarm system with the master unit 20 and replacing the slave unit of the conventional P-type automatic fire alarm system with the slave unit 10 Is also possible.

(Modification of Embodiment 1)
Although the control part 19 of the subunit | mobile_unit 10 of this embodiment has provided the guard sections G1 and G2, respectively before and behind a response section, you may abbreviate | omit the guard sections G1 and G2. Hereinafter, an example in which the guard sections G1 and G2 are omitted will be described as a modification of the present embodiment. FIG. 5 is a diagram for explaining the communication state of the parent device 20 and the child device 10 according to this modification.

  In this modification, each reception section R21 to R36 defined by the parent device 20 is set to the same length as the response sections S1 to S16 of the corresponding slave devices B1 to B16. In other words, the reception intervals R21 to R36 are equal to the intervals when the guard interval G1 and the guard interval G2 are excluded from each of the reception intervals R1 to R16 in the first embodiment. Therefore, the end timings in the reception intervals R21 to R35 and the start timings of the next adjacent reception intervals R22 to R36 are determined at the same time.

  Each of the reception sections R21 to R36 has a shorter length than the reception sections R1 to R16 in the first embodiment. Therefore, the length of all response intervals T21 including all reception intervals R21 to R36 can be set shorter than all response intervals T2 in the first embodiment. When the total response section T21 is shortened, the time from the time when the synchronization signal SY1 is received to the start timing of each of the response sections S1 to S16 is shortened, so that the deviation of the start timing of each of the response sections S1 to S16 is reduced.

  By the way, if the start timings of the response sections S1 to S16 are shifted, there may be a case where adjacent response sections slightly overlap each other in time. When two signals overlap so that the voltage value between the pair of electric wires 51 and 52 becomes large, the voltage value becomes larger than the voltage value at the time of transmitting a normal signal. The processing unit 271 of the base unit 20 regards as a noise when the voltage value of the pair of electric wires 51 and 52 exceeds the upper limit of the predetermined value in the vicinity of the start timing and the end timing of the reception sections R21 to R36. It is distinguished from the signals SN1 to SN16. The predetermined value of the voltage value referred to here is a value obtained by adding a margin to the voltage value generated in the pair of electric wires 51 and 52 when one slave unit 10 transmits a response signal. If the response interval S1 and the response interval S2 are slightly overlapped, the voltage fluctuation range of the pair of electric wires 51 and 52 is increased for a moment compared to the case where the response interval S1 and the response interval S2 are not overlapped.

  Base unit 20 regards the voltage signal having a large fluctuation range as noise. When the time at which the response signals SN1 and SN2 are simultaneously transmitted is shorter than the transmission time of 1 bit transmitted in the response section S1 and the response section S2, the base unit 20 transmits the noise and the response signals SN1 to SN16. It can be received in a distinguishing manner.

  In addition, when two signals overlap so that the voltage value between the pair of electric wires 51 and 52 becomes small, the voltage value becomes smaller than the voltage value at the time of transmitting a normal signal. The processing unit 271 of the base unit 20 considers it as noise when the voltage value of the pair of electric wires 51 and 52 is below the lower limit of the predetermined value in each of the vicinity of the start timing and the end timing of the reception sections R21 to R36. It can be distinguished from the signals SN1 to SN16.

  In the test mode, base unit 20 determines a predetermined time T11 so that the overlapping time between adjacent response sections is shorter than the 1-bit transmission time in response signals SN1 to SN16. In the test mode, the operation of the base unit 20 for determining the predetermined time T11 is the same as the case where the predetermined time T1 is replaced with the predetermined time T11 in the test mode of the first embodiment, and thus description thereof is omitted.

  The predetermined time T11 is a time from the transmission timing of the synchronization signal SY1 to the end timing of the reception section R36, and is equal to the transmission interval of the synchronization signal SY1. FIG. 5 shows an example in which the predetermined time T11 is set to a length obtained by combining the synchronization signal SY1, the communication section C1, and the entire response section T21. The predetermined time T11 may be set to a length obtained by combining the length of an integral multiple of 2 or more of all response intervals T21, the length of the synchronization signal SY1, and the length of the communication interval C1. The transmission control unit 274 may cause the transmission unit 24 to transmit the synchronization signal SY12 after the reception control unit 273 receives a plurality of response signals SN1 to SN16 from each of the child devices B1 to B16. Since the number of transmissions of the synchronization signal SY1 per unit time can be reduced and the ratio of the response signals SN1 to SN16 from the slave unit 10 to the signals transmitted to the pair of electric wires 51 and 52 can be increased, the master unit 20 Can communicate with all the slave units 10 in a short time.

  As described above, in the base unit 20 of the present modification, the lengths of the waiting times W1 to W16 of the plurality of slave units B1 to B16 (slave unit 10) are different at a certain time interval T5, and received. The length of the sections R21 to R36 is preferably equal to the constant time interval T5.

  According to the above configuration, since the lengths of the reception intervals R21 to R36 are equal to the certain time interval T5, the lengths of the reception intervals R21 to R36 are the same as the response intervals S1 to S16. Since the lengths of the reception sections R21 to R36 are the minimum lengths that can be accommodated in the response sections S1 to S16, the total length of the reception sections R21 to R36 (all response sections T21) can be minimized. As the total length of the reception sections R21 to R36 is shorter, the start timing shift of the response sections S1 to S16 of the slave unit 10 tends to be smaller. Therefore, the master unit 20 is a synchronization signal for correcting the shift. The transmission interval (predetermined time T11) of SY1 can be set large. Since the ratio of the response signals SN1 to SN16 from the child device 10 in the signals transmitted to the pair of electric wires 51 and 52 can be increased, the parent device 20 communicates with all the child devices 10 in a short time. be able to.

  The base unit 20 in this modification is regarded as noise when the voltage value of the pair of electric wires 51 and 52 exceeds a predetermined value in the vicinity of the start timing and end timing of the reception sections R21 to R36, and the response signals SN1 to SN1. It is distinguished from SN16. Therefore, base unit 20 can distinguish between the last bit of the response signal and the first bit of the response signal that overlaps with the last bit, and can therefore receive response signals SN1 to SN16 separately.

  In the present modification, the case where the response signals SN1 and SN2 are simultaneously transmitted is shorter than the time required to transmit one bit of data included in the response signals SN1 and SN2, but this is an example. It is not limited to examples. The time when response signals SN1 and SN2 are simultaneously transmitted may be shorter than the time required for transmitting a plurality of bits of data included in response signals SN1 and SN2. For example, the processing unit 271 of the parent device 20 has a multi-bit (for example, 2 bits) error detection and correction function for received data. In this case, the processing unit 271 can identify data included in the response signals SN1 to SN16 even when a plurality of bits (2 bits) of data included in the response signals SN1 and SN2 are not correctly received. In this case, the processing unit 271 can set the predetermined time T11 to be longer.

(Embodiment 2)
As shown in FIG. 6, the base unit 20 b in the present embodiment communicates with the slave unit 10 connected to at least one pair of electric wires 51 and 52 when connected to a plurality of pairs of electric wires. Is configured to do. FIG. 6 is a diagram illustrating a schematic configuration of the automatic fire notification system 1b in the present embodiment. The base unit 20b has the same configuration as the base unit 20 in the first embodiment. In addition, about the structure similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the present embodiment, the transmission unit 24 (see FIG. 1) and the reception unit 23 (see FIG. 1) are connected to four sets of communication paths using a pair of electric wires as one set of communication paths. That is, the base unit 20b is connected to one set of communication paths (a pair of electric wires 51 and 52) and three sets of communication paths (a pair of electric wires 53 and 54). Four slave units 10 (slave units B1 to B4) are connected to the pair of electric wires 51 and 52. Four sets of slave units 70 are connected to the three pairs of electric wires 53 and 54 for each set, and a total of 12 slave units 70 (units E1 to E12) are connected. When detecting the occurrence of the fire, the slave unit 70 short-circuits between the pair of electric wires 53 and 54 and notifies the master unit 20b of the occurrence of the fire. The subunit | mobile_unit 70 differs from the subunit | mobile_unit 10 in the point which does not have a function which transmits a response signal with respect to the request signal from the main | base station 20b. That is, in the automatic fire notification system 1b, the slave unit 10 that can transmit a response signal to the request signal from the master unit 20b and the slave unit that does not have a function of transmitting a response signal to the request signal from the master unit 20b. Each of the devices 70 is connected to the parent device 20b.

  Each of the pair of electric wires 53 and 54 is connected to a terminating resistor 41 at an end opposite to the end to which the master unit 20b is connected. The master unit 20b can detect the disconnection of the pair of electric wires 53 and 54 by measuring the current value of the current flowing between the pair of electric wires 53 and 54. Note that the termination resistor 41 is not an essential component and may be omitted.

  The transmission control unit 274 (see FIG. 1) of the base unit 20b transmits a synchronization signal SY1 and a request signal in the communication section C1 to the pair of electric wires 51 and 52 and the three pairs of electric wires 53 and 54, respectively. Is transmitted from the transmission unit 24. The control units 19 (see FIG. 1) of the slave units B1 to B4 transmit response signals SN1 to SN4 corresponding to the request signals from the transmission circuit 15, respectively. The reception control unit 273 (see FIG. 1) receives the response signals SN1 to SN4 transmitted to the pair of electric wires 51 and 52 in the reception sections R1 to R4 by the reception unit 23. The processing unit 271 (see FIG. 1) of the parent device 20b recognizes that the child devices B1 to B4 are connected to the pair of electric wires 51 and 52. On the other hand, since the subunit | mobile_unit E1-E12 does not transmit the response signal with respect to a request signal, the process part 271 judges that the subunit | mobile_unit 10 is not connected to a pair of electric wire 53,54.

  It is assumed that the transmission control unit 274 determines that the child device 10 is connected to the pair of electric wires 51 and 52. In this case, the synchronization signal SY1 (synchronization signal SY12) is transmitted from the transmission unit 24 to the pair of electric wires 51 when a predetermined time T1 has elapsed since the transmission control unit 274 has transmitted the synchronization signal SY1 (synchronization signal SY11) from the transmission unit 24. 52. Thereafter, the transmission control unit 274 sends the synchronization signal SY1 from the transmission unit 24 to the pair of electric wires 51 and 52 every time a predetermined time T1 has elapsed since the transmission control unit 274 transmitted the synchronization signal SY1 from the transmission unit 24. Let On the other hand, the transmission control unit 274 does not cause the transmission unit 24 to transmit the synchronization signal SY1 to the three pairs of electric wires 53 and 54 to which the slave unit 10 is not connected. That is, even when the child device 10 and the child device 70 are connected, the parent device 20b can communicate with the child device 10 individually by transmitting the synchronization signal SY1. Master device 20b can make it difficult to interfere with response signals SN1 to SN4 transmitted from a plurality of slave devices B1 to B4 (slave device 10).

  As described above, the transmission unit 24 and the reception unit 23 in the present embodiment are connected to a plurality of sets (four sets in the present embodiment) of a pair of wires 51 and 52 as a set of communication channels. ing. The transmission control unit 274 transmits the synchronization signal SY1 from the transmission unit 24 to at least one set of communication paths (a pair of electric wires 51 and 52 in the present embodiment) to which the plurality of child devices B1 to B4 (child devices 10) are connected. Let

  According to the above configuration, when the slave units B1 to B4 (slave unit 10) are connected to at least one set of communication paths (the pair of electric wires 51 and 52), the master unit 20b transmits the synchronization signal SY1 to the communication path. Send. Master device 20b can make it difficult to interfere with response signals SN1 to SN4 transmitted from a plurality of slave devices B1 to B4 (slave device 10).

  Even if the parent device 20b is connected to the child devices B1 to B4 (child device 10) and the child device 70 that does not have a function of transmitting a response signal to the request signal from the parent device 20b, The synchronization signal SY11 can be transmitted to the slave units B1 to B4, and the response signals SN1 to SN4 can be received. Therefore, even if the subunit | mobile_unit 10 and the subunit | mobile_unit 70 are each connected, the main | base station 20b can correct | amend the start timing shift of response area S1-S4 with respect to receiving area R1-R4. In other words, the base unit 20b can make it difficult to interfere with the response signals SN1 to SN4 transmitted from the plurality of handset B1 to B4 (slave unit 10).

(Embodiment 3)
The master 20c and the automatic fire alarm system 1c using the master 20c will be described with reference to FIGS. 7 and 8A to 8C. As shown in FIG. 7, the base unit 20 c in the present embodiment includes a comparison unit 272. Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

  The reception sections R41 to R56 in the present embodiment correspond to the reception sections R1 to R16 in the first embodiment, respectively. Base unit 20c further includes a comparison unit 272 that compares the respective start timings in reception sections R41 to R56 with the reception timings of response signals SN1 to SN16 corresponding to reception sections R41 to R56. The processing unit 271 determines the predetermined time T1 based on the comparison result of the comparison unit 272.

  The comparison unit 272 compares the time difference D1 between the start timing of the reception intervals R41 to R56 and the reception timing of the response signals SN1 to SN16 corresponding to the reception intervals R41 to R56 with a reference value. The reference value in the present embodiment is the length of the guard section G1. The comparison unit 272 outputs the comparison result to the processing unit 271. The comparison unit 272 is realized by the control unit 27 reading and executing a program from the memory. Note that the program for realizing the comparison unit 272 may be previously written in a memory, stored in a recording medium such as a memory card, or provided through an electric communication line such as the Internet. May be.

  FIG. 8A, FIG. 8B, and FIG. 8C are diagrams for explaining an operation in which the parent device 20c and the child device B2 (child device 10) communicate with each other. 8A, FIG. 8B, and FIG. 8C respectively show a reception section R42 that is determined when the parent device 20c transmits the synchronization signal SY1, and a response signal SN2 that the child device B2 transmits in response to the synchronization signal SY1. . The start timing of the reception section R42 is determined when the waiting time W2 elapses from the time when the transmission control unit 274 ends the transmission of the synchronization signal SY11. In addition, since the operation | movement which each of subunit | mobile_unit B1, B3-B16 and the main | base station 20c communicate is the same as the operation | movement which the main | base station 20c and the subunit | mobile_unit B2 communicate, description is abbreviate | omitted.

  FIG. 8A shows a case where it is not necessary to correct the deviation of the start timing for transmitting the response signal SN2 in the response section S2. The start timing for transmitting the response signal SN2 (start timing of the response section S2) is almost the same as the end timing of the guard section G1. Further, the guard section G1 and the guard section G2 in FIG. 8A have substantially the same length. The transmission control unit 274 of the parent device 20c determines the reception interval R420 when a predetermined time T1 has elapsed from the start timing at which the synchronization signal SY1 is transmitted from the transmission unit 24.

  The control unit 19 of the child device B2 causes the transmission circuit 15 to transmit the response signal SN2 when the start timing for transmitting the response signal SN2 from the transmission circuit 15 (start timing of the response section S2) is reached. The comparison unit 272 measures a time difference D1 from the time when the start timing of the reception section R42 is reached to the time when the response signal SN2 is received. In the present embodiment, the time difference D1 is obtained based on the number of clocks counted by the timer. In FIG. 8A, the time difference D1 is almost the same length as the guard interval G1. When the processing unit 271 determines that the time difference D1 is substantially the same length as the guard interval G1, the processing unit 271 does not change the predetermined time T1. The transmission control unit 274 causes the transmission unit 24 to transmit the synchronization signal SY12 when a predetermined time T1 has elapsed from the time when the synchronization signal SY11 is transmitted from the transmission unit 24.

  FIG. 8B shows an example in which the start timing of the response section S2 determined by the control unit 19 of the slave unit B2 is shifted so as to be earlier than the start timing of the reception section R42. The reception timing of the response signal SN2 (start timing of the response section S2) is earlier than the end timing of the guard section G1. A case where the oscillation cycle of the oscillation circuit in the control unit 19 of the slave unit B2 is slightly shortened can be considered. The time difference D1 in FIG. 8B is shorter than the time difference D1 in FIG. 8A. If the transmission control unit 274 transmits the synchronization signal SY12 from the transmission unit 24 when the predetermined time T1 has elapsed after the transmission of the synchronization signal SY11, the time difference D1 may be further shortened.

  When the comparison unit 272 outputs a comparison result in which the length of the time difference D1 is shorter than the length of the guard interval G1 to the processing unit 271, the processing unit 271 is based on the determination result of the comparison unit 272 and is longer than the predetermined time T1. It is determined at a long predetermined time T43. For example, the processing unit 271 sets the time obtained by subtracting the length of the time difference D1 from the length of the guard section G1 to the predetermined time T1 as the predetermined time T43, and sets the predetermined time T43 as the new predetermined time T1. In other words, the processing unit 271 determines a predetermined time T43 obtained by adding the length of a section where the response section S1 and the guard section G1 overlap with the predetermined time T1 as a new predetermined time T1. The transmission control unit 274 causes the transmission unit 24 to transmit the synchronization signal SY21 when a predetermined time T43 has elapsed since the transmission of the synchronization signal SY11 was started. The reception control unit 273 determines the reception section R421 when a predetermined time T1 has elapsed from the time when transmission of the synchronization signal SY11 is started. That is, the reception control unit 273 determines the time when the waiting time W2 further elapses from the time when the predetermined time T1 elapses as the start timing of the reception section R421. On the other hand, the transmission timing of the response signal SN2 (start timing of the response section S2) is determined based on the time when the synchronization signal SY12 is transmitted (the time when the predetermined time T43 has elapsed from the time when the synchronization signal SY11 is transmitted). Accordingly, the reception timing of the response signal SN2 with respect to the start timing of the reception section R421 (start timing of the response section S2) is delayed. That is, the transmission timing of the response signal SN2 approaching the start timing of the reception section R42 (start timing of the response section S2) is corrected to a timing close to the end timing of the guard section G1.

  FIG. 8C shows an example in which the transmission timing of the response signal SN2 determined by the control unit 19 of the child device B2 (start timing of the response section S2) is deviated from the start timing of the reception section R42. Yes. A case where the oscillation cycle of the oscillation circuit in the control unit 19 of the slave unit B2 is slightly longer can be considered. The transmission timing of the response signal SN2 (start timing of the response section S2) is later than the end timing of the guard section G1. The time difference D1 in FIG. 8B is longer than the time difference D1 in FIG. 8A. If the transmission control unit 274 transmits the synchronization signal SY12 from the transmission unit 24 when the predetermined time T1 has elapsed after the transmission of the synchronization signal SY11, the time difference D1 may be further increased.

  When the comparison unit 272 outputs a comparison result in which the length of the time difference D1 is longer than the length of the guard section G1 to the processing unit 271, the processing unit 271 is based on the determination result of the comparison unit 272 and is longer than the predetermined time T1. It is determined at a short predetermined time T44. For example, the processing unit 271 subtracts the time obtained by subtracting the length of the guard section G1 from the length of the time difference D1 from the predetermined time T1 as the predetermined time T44, and sets the predetermined time T44 as a new predetermined time T1. In other words, the processing unit 271 subtracts the length of the interval between the end timing of the guard interval G1 and the start timing of the response interval S1 from the predetermined time T1 as the predetermined time T44, and sets the predetermined time T44 as a new predetermined time T1. Determine as The transmission control unit 274 causes the transmission unit 24 to transmit the synchronization signal SY31 when a predetermined time T44 has elapsed since the transmission of the synchronization signal SY11 was started. The reception control unit 273 determines the reception section R431 when a predetermined time T1 has elapsed from the time when transmission of the synchronization signal SY11 is started. That is, the reception control unit 273 determines the time when the waiting time W2 further elapses from the time when the predetermined time T1 elapses as the start timing of the reception section R431. On the other hand, the transmission timing of the response signal SN2 (start timing of the response section S2) is determined based on the time when the synchronization signal SY31 is transmitted (the time when the predetermined time T44 has elapsed from the time when the synchronization signal SY11 is transmitted). Therefore, the reception timing of the response signal SN2 with respect to the start timing of the reception section R431 (start timing of the response section S2) is advanced. That is, the transmission timing of the response signal SN2 that has approached the end timing of the reception section R42 (start timing of the response section S2) is corrected to a timing that is close to the end timing of the guard section G1.

  The processing unit 271 of the parent device 20c changes the length of the predetermined time T1 according to the comparison result of the comparison unit 272. The processing unit 271 can correct a shift in the reception timing of the response signals SN1 to SN16 from the slave unit 10 with respect to the reception sections R41 to R56 (start timing of the response sections S1 to S16) in the normal mode. Therefore, base unit 20c can make it difficult to interfere with response signals SN1 to SN16 transmitted from a plurality of slave units B1 to B16.

  As described above, base unit 20c in the present embodiment compares time difference D1 between the start timing of reception sections R41 to R56 and the reception timing of response signals SN1 to SN16 corresponding to reception sections R41 to R56 with a reference value. Further, a comparison unit 272 is provided. When the time difference D1 is larger than the reference value (the length of the guard section G1 in the present embodiment), the length of the predetermined time T1 is shortened (in the present embodiment, the predetermined time T1 is set to the length of the predetermined time T44). Will be changed as follows.

  According to the above configuration, the processing unit 271 changes the length of the predetermined time T1 according to the comparison result of the comparison unit 272. Even if the start timing at which the slave unit 10 transmits the response signals SN1 to SN16 is delayed with respect to the start timing of the reception sections R41 to R56, the delay is caused by changing the length of the predetermined time T1 to be short. Is corrected. In addition, the processing unit 271 has the length of the predetermined time T1 even if the start timing at which the handset 10 transmits the response signals SN1 to SN16 is advanced (becomes earlier) than the start timing of the reception sections R41 to R56. By changing so as to become longer, the advance is corrected. Therefore, base unit 20c can make it difficult to interfere with response signals SN1 to SN16 transmitted from a plurality of slave units B1 to B16.

  In the present embodiment, the length of the guard section G1 is used as a reference value for the time difference D1, but the present invention is not limited to this configuration. The reference value may be a value stored in a recording medium such as a memory, or a value set in a dip switch or the like. The reference value for the time difference D1 may be determined based on, for example, the time difference from when the processing unit 271 transmits a request signal from the transmission unit 24 to when the response unit receives the response signal. The processing unit 271 performs, for example, transmission of a request signal and reception of a response signal once or a plurality of times, and an average value of a time difference from when the request signal is transmitted from the transmission unit 24 until the reception unit 23 receives the response signal A reference value for the time difference D1 may be determined based on the above.

  The comparison unit 272 in the present embodiment compares the time difference D1 between the reception section R42 and the response section S2 every time the response signal SN2 is received once, but is not limited to this example. For example, the comparison unit 272 may compare the time difference D1 between the reception interval R42 and the response interval S2 every time the response signal SN2 is received n times (n is an integer of 2 or more).

  The comparison unit 272 in the present embodiment has described the operation of the comparison unit 272 for the reception intervals R42, R421, R431 and the response interval S2, but is not limited to this operation. The comparison unit 272 may count the time difference D1 for each of the reception intervals R1 to R16 and the response intervals S1 to S16 in the first embodiment. In that case, you may change the length of predetermined time T1 based on the largest time difference D1 in the start timing of response area S1-S16.

  The comparison unit 272 may measure the time difference between the end timing of the reception section R42 and the reception end timing of the response signal SN2. That is, the comparison unit 272 may have an appropriate configuration that can measure the shift in the reception timing of the response signals SN1 to SN16 with respect to the reception sections R1 to R16.

  In the first embodiment and its modified examples and the second and third embodiments, the processing unit 271 changes the length of the predetermined time T1 (predetermined time T11). However, the present invention is not limited to this configuration. You may change the length of predetermined time T1 (predetermined time T11) by running a program. In addition, for example, a microcomputer other than the microcomputer constituting the control unit 27 and an arithmetic IC may be configured to change the length of the predetermined time T1 (predetermined time T11).

  The first embodiment, the modification of the first embodiment, and the second and third embodiments can be combined. For example, the base unit 20b of the second embodiment includes the comparison unit 272, and determines the predetermined time T1 and the reception sections R1 to R4 in the same manner as in the first embodiment, and communicates with the slave units B1 to B4. It may be configured.

(Embodiment 4)
A base unit and an automatic fire notification system using the same according to the present embodiment will be described with reference to FIGS. 9A and 9B. In addition, since the structure of the main | base station and automatic fire alerting | reporting system in this embodiment is the same as that of Embodiment 3, the same code | symbol is attached | subjected to the same component and description is abbreviate | omitted.

  The parent device in the present embodiment differs from the third embodiment in the operations of the processing unit 271 (see FIG. 7) and the comparison unit 272 (see FIG. 7). Note that reception sections R61 to R76 described below correspond to the reception sections R1 to R16 in the first embodiment, respectively.

  The processing unit 271 alternatively selects the full response mode or the divided response mode. The processing unit 271 in the full response mode receives response signals SN1 to SN16 from each of the 16 slave units B1 to B16 (slave unit 10) (see FIGS. 2 and 7) by the reception unit 23 (see FIG. 7). The reception control unit 273 (see FIG. 7) is controlled so that As shown in FIG. 9A, the processing unit 271 in the all response mode defines 16 reception sections R61 to R76.

  As an example, as illustrated in FIG. 9B, the processing unit 271 in the divided response mode transmits a synchronization signal SY1 (synchronization signal SY51) and a request signal H51, and includes eight slave units B1 to B8 (a group of children). Response signals SN1 to SN8 transmitted from each of the devices) are received by the receiver 23. The processing unit 271 in the divided response mode transmits the synchronization signal SY51 (synchronization signal SY52) when the predetermined time T51 has elapsed since the transmission of the synchronization signal SY51. Then, the processing unit 271 transmits a request signal H52 to cause the reception unit 23 (see FIG. 7) to receive response signals SN9 to SN16 from each of the other eight slave units B9 to B16 (a group of slave units). . That is, the processing unit 271 in the divided response mode divides the 16 slave units B1 to B16 into two groups, and sends the response signals transmitted from the eight slave units 10 included in each group to the reception unit 23. Receive. The master unit in the divided response mode in this embodiment transmits a synchronization signal SY1 (synchronization signals SY51 and SY52) every time a predetermined time T51 in which response signals can be received from the eight slave units 10 has elapsed. In the divided response mode, since the transmission interval of the synchronization signal SY1 is shorter than in the full response mode, the slave units B1 to B16 correct the deviation of the transmission timing of the response signals SN1 to SN16 with respect to the start timing of the divided reception sections R511 to R518. Increases frequency. Therefore, a shift in transmission timing of the response signals SN1 to SN16 with respect to the start timing of the divided reception sections R511 to R518 is suppressed. In other words, the base unit of the automatic fire notification system according to the present embodiment can make it difficult for the response signals SN1 to SN16 transmitted from the plurality of handset units 10 to interfere with each other.

  Hereinafter, details of operations of the processing unit 271 and the comparison unit 272 will be described.

  The processing unit 271 controls the transmission control unit 274 (see FIG. 7) to transmit the synchronization signal SY1 (synchronization signal SY11) from the transmission unit 24 (see FIG. 7) in a state where the full response mode is selected as the operation mode. To do. The processing unit 271 controls the transmission control unit 274 to transmit the request signal H1 from the transmission unit 24 in the communication section C1. The request signal H1 includes data that causes all 16 slave devices B1 to B16 to transmit response signals SN1 to SN16, respectively.

  For example, the comparison unit 272 measures the start timing of the reception interval R70 and the reception timing of the response signal SN10 corresponding to the reception interval R70, and the time difference between the start timing of the reception interval R70 and the reception timing of the response signal SN10. Find D1. The comparison unit 272 compares the absolute value K1 of the difference between the time difference D1 and the first reference value F1 with the second reference value F2, and outputs the comparison result to the processing unit 271. As an example, each of the first reference value F1 and the second reference value F2 is set to a half length of the guard section G1.

  When the comparison result that the absolute value K1 of the difference between the time difference D1 and the first reference value F1 is greater than or equal to the second reference value F2 is input from the comparison unit 272, the processing unit 271 selects the divided response mode as the operation mode. . Hereinafter, an example in which the reception timing of the response signal SN10 is shifted so as to be earlier than the end timing of the guard interval G1 as illustrated in FIG. 9A will be described.

  Since the reception timing of the response signal SN10 is earlier than the end timing of the guard interval G1, the time difference D1 is shorter than half the length of the guard interval G1.

  The comparison unit 272 calculates an absolute value K1 of the difference between the time difference D1 and the first reference value F1. The absolute value K1 (the absolute value of the difference between the length of the guard section G1 and the length of the time difference D1) is larger than half of the length of the guard section G1. The comparison unit 272 outputs to the processing unit 271 a comparison result in which the absolute value K1 of the difference between the time difference D1 and the first reference value F1 is greater than or equal to the second reference value F2. The processing unit 271 selects the divided response mode as the operation mode based on the comparison result output from the comparison unit 272. Details of the operation of the processing unit 271 in the divided response mode will be described below.

  The processing unit 271 transmits the synchronization signal SY1 (synchronization signal SY51) in the divided response mode after a predetermined time T1 has elapsed after the synchronization signal SY1 (synchronization signal SY11) is transmitted from the transmission unit 24 in the full response mode. The transmission control unit 274 is controlled so that the transmission is started. The processing unit 271 controls the transmission control unit 274 to transmit the request signal H51 from the transmission unit 24 as illustrated in FIG. 9B in the communication section C1 after the synchronization signal SY1 (synchronization signal SY51). The request signal H51 includes data that causes the plurality of slave units B1 to B8 to transmit the response signals SN1 to SN8. In other words, the request signal H51 is a group included in one group among a plurality of slave units B1 to B16 (slave units 10) divided into two groups each consisting of eight slave units 10. The data which makes the cordless handset B1-B8 transmit response signals SN1-SN8 is included.

  The processing unit 271 determines the entire response section T22 after transmitting the request signal H51 in the communication section C1. The entire response section T22 in the divided response mode includes divided reception sections R511 to R518 for receiving the response signals SN1 to SN8. The divided reception sections R511 to R518 correspond to the reception sections R1 to R8 in the first embodiment, respectively. In the divided reception sections R511 to R518, the response sections S1 to S8 are accommodated, respectively. Guard sections G1 and G2 are provided before and after each of the response sections S1 to S8. The divided reception sections R511 to R518 are different from the reception sections R1 to R16 in the entire response section T2 in that the divided reception sections R511 to R518 are reception sections having the number of sections corresponding to the number of slave units 10 specified by the request signals H51 and H52. In other words, in the first embodiment, the receiving sections R1 to R16 in the entire response section T2 are composed of the receiving sections having the number of sections corresponding to the number of the slave units 10, but the entire response section T22 in the present embodiment is the request signal H51, The length of the section changes according to the number of handset 10 designated by H52.

  The processing unit 271 that has selected the division response mode changes the length of the predetermined time T1 to be shorter. The processing unit 271 changes the transmission interval of the synchronization signal SY1 from the predetermined time T1 to the predetermined time T51 shorter than the predetermined time T1 according to the number of the slave units 10 specified by the request signals H51 and H52. In the present embodiment, the number of slave units 10 specified by the request signals H51 and H52 is eight. The predetermined time T51 is a length obtained by combining the length of the synchronization signal SY1, the length W511 of the communication section C1, and the total response section T22. In other words, the predetermined time T51 is a length of time during which the response signals SN1 to SN8 are within the divided reception sections R511 to R518. The processing unit 271 controls the reception control unit 273 to cause the reception unit 23 to receive the response signals SN1 to SN8 and the notification signals A1 to A8 in the divided reception sections R511 to R518, respectively.

  When the receiving circuit 16 (see FIG. 7) of the group of slave units B1 to B8 receives the request signal H51, the control unit 19 (see FIG. 7) of the group of slave units B1 to B8 counts the divided waiting times W511 to W518. To start. On the other hand, the control unit 19 of the group of slave units B9 to B16 does not transmit the response signals SN9 to SN16 from the transmission circuit 15 in response to reception of the request signal H51, and therefore does not measure the division waiting time.

  The control units 19 of the group of slave units B1 to B8 receive the response signals SN1 to SN8 after the division waiting times W511 to W518 have elapsed after receiving the synchronization signal SY1 (synchronization signal SY51), respectively (see FIG. 7). ) The lengths of the divided waiting times W511 to W518 are different for each group of slave devices B1 to B8. The division waiting times W511 to W518 are determined according to the number of slave units 10 specified by the data included in the request signals H51 and H52. In the present embodiment, the request signals H51 and H52 designate eight different slave units 10, and eight divided waiting times W511 to W518 are the memory of the master unit and the storage of the slave unit 10 in the present embodiment. Each of them is stored in the unit 17 (see FIG. 7).

  The reception control unit 273 causes the reception unit 23 to receive the response signals SN1 to SN8 transmitted from the transmission circuits 15 of the group of slave units B1 to B8 in the divided reception sections R511 to R518.

  The processing unit 271 transmits the synchronization signal SY1 (synchronization signal SY52) when a predetermined time T51 has elapsed since the transmission of the synchronization signal SY1. The processing unit 271 controls the transmission control unit 274 to cause the transmission unit 24 to transmit a request signal H52 for designating the slave units B9 to B16 in the communication section C1 after transmitting the synchronization signal SY1 (synchronization signal SY52). The request signal H52 includes data that causes the plurality of slave units B9 to B16 to transmit the response signals SN9 to SN16. In other words, the request signal H52 is a group of slave units B9 to B16 included in a group different from the group of slave units B1 to B8 specified by the request signal H51 among the plurality of slave units B1 to B16 (slave unit 10). The data for transmitting the response signals SN9 to SN16 from the transmission circuit 15 is included. The processing unit 271 controls the reception control unit 273 to cause the reception unit 23 to receive the response signals SN9 to SN16 and the notification signals A9 to A16 in the divided reception sections R511 to R518, respectively.

  When the receiving circuit 16 of the group of slave units B9 to B16 receives the request signal H52, the control unit 19 of the group of slave units B9 to B16 starts measuring the divided waiting times W511 to W518. On the other hand, the control unit 19 of the group of slave units B1 to B8 does not transmit the response signals SN1 to SN8 from the transmission circuit 15 in response to the reception of the request signal H52, and therefore does not measure the division waiting time.

  The control unit 19 of the group of slave units B9 to B16 causes the transmission circuit 15 to transmit the response signals SN9 to SN16 after the division waiting times W511 to W518 have elapsed. That is, the transmission circuits 15 of the slave units B9 to B16 transmit the response signals SN9 to SN16 in the divided reception sections R511 to R518, respectively.

  The reception control unit 273 causes the reception unit 23 to receive the response signals SN9 to SN16 from each of the group of child devices B9 to B16 in the divided reception sections R511 to R518.

  The processing unit 271 changes one selected group cyclically each time the synchronization signal SY1 (synchronization signals SY51, SY52) is transmitted from the transmission unit 24. In the present embodiment, the processing unit 271 alternately selects groups that specify the slave units B1 to B8 and groups that specify the slave units B9 to B16. That is, the processing unit 271 controls the transmission control unit 274 so that the request signal H51 and the request signal H52 are alternately transmitted from the transmission unit 24 in the communication period C1 every time the synchronization signal SY1 (synchronization signals SY51 and SY52) is transmitted. To do.

  In the present embodiment, the example in which the reception timing of the response signal SN10 is shifted so as to be earlier than the end timing of the guard interval G1 has been described, but is shifted so as to be later than the end timing of the guard interval G1. May be. Since the comparison unit 272 calculates the absolute value of the difference between the time difference D1 and the first reference value F1, the comparison result is obtained in both cases where the timing is earlier or later than the end timing of the guard interval G1. Can be output. Therefore, the processing unit 271 increases the transmission frequency of the synchronization signal SY1 by shortening the length of the predetermined time T1 even when the reception timing of the response signal SN10 is shifted so as to be later than the end timing of the guard interval G1. Is possible.

  As described above, the base unit of the automatic fire notification system according to the present embodiment includes the comparison unit 272 and the processing unit 271. The processing unit 271 controls the transmission control unit 274 to transmit the request signals H51 and H52 from the transmission unit 24 each time the synchronization signal SY1 is transmitted from the transmission unit 24, and changes the length of the predetermined time T1. The request signals H51 and H52 are response signals SN1 to SN16 to a group of slave units included in one group selected by the processing unit 271 among the plurality of slave units B1 to B16 (slave units 10) divided into a plurality of groups. Including data to be sent. In this embodiment, it is divided into two groups of slave units B1 to B8 and slave units B9 to B16. The processing unit 271 alternatively selects the full response mode or the divided response mode. The full response mode is a mode in which the reception unit 23 receives the response signals SN1 to SN16 from each of the plurality of slave units B1 to B16 (slave unit 10). The division response mode is a mode in which the reception unit 23 receives response signals (response signals SN1 to SN8 or response signals SN9 to SN16) from each of a group of slave devices (slave devices B1 to B8 or slave devices B9 to B16). is there. The comparison unit 272 includes a time difference D1 between the start timing of the reception interval (reception interval R70 in this embodiment) and the reception timing of the response signal (response signal SN10 in this embodiment) corresponding to the reception interval, and the first reference value F1. Is compared with the second reference value F2. The processing unit 271 selects the divided response mode when the absolute value of the difference between the time difference D1 and the first reference value F1 is equal to or greater than the second reference value F2. The processing unit 271 that has selected the division response mode controls the transmission control unit 274 to transmit the request signals H51 and H52 from the transmission unit 24, and changes the length of the predetermined time T1 to be short. The processing unit 271 changes one selected group cyclically every time the synchronization signal SY1 is transmitted from the transmission unit 24. The group of slave units (slave units B1 to B8 or slave units B9 to B16) receive response signals (response signals SN1 to SN8 or response signals SN9 to SN9) after the division waiting times W511 to W518 have elapsed after receiving the synchronization signal SY1. SN16). The lengths of the divided waiting times W511 to W518 are different for each group of child devices (child devices B1 to B8 or child devices B9 to B16). The reception control unit 273 divides response signals (response signals SN1 to SN8 or response signals SN9 to SN16) from each of a group of slave devices (slave devices B1 to B8 or slave devices B9 to B16) into divided reception sections R511 to R518. The receiving unit 23 receives the signal. The division reception sections R511 to R518 are reception sections after the division waiting times W511 to W518 have elapsed since the transmission unit 24 transmitted the synchronization signal SY1. The predetermined time T51 is a length of time during which the response signals (response signals SN1 to SN8 or response signals SN9 to SN16) fall within the divided reception sections R511 to R518.

  According to the above configuration, the processing unit 271 of the parent device in the present embodiment selects the division response mode when the absolute value of the difference between the time difference D1 and the first reference value F1 is equal to or greater than the second reference value F2. The predetermined time T51 in the divided response mode is set shorter than the predetermined time T1 in the full response mode. The processing unit 271 in the divided response mode transmits the synchronization signal SY1 (synchronization signals SY51 and SY52) every time the predetermined time T51 elapses. In the divided response mode, the transmission interval of the synchronization signal SY1 is shorter than in the full response mode. Therefore, the frequency with which the slave units B1 to B8 (or the slave units B9 to B16) correct the deviation of the transmission timing of the response signals SN1 to SN8 (or the response signals SN9 to SN16) with respect to the start timing of the divided reception sections R511 to R518 increases. . The processing unit 271 changes one selected group cyclically each time the synchronization signal SY1 (synchronization signals SY51, SY52) is transmitted from the transmission unit 24. Therefore, the processing unit 271 can cause the response signals SN1 to SN16 to be transmitted from all the plurality of slave units B1 to B16 even in the divided response mode. Therefore, the transmission timing shift of the response signals SN1 to SN8 (or the response signals SN9 to SN16) is suppressed with respect to the start timing of the divided reception sections R511 to R518. In other words, the base unit of the automatic fire notification system according to the present embodiment can make it difficult for the response signals SN1 to SN16 transmitted from the plurality of handset units 10 to interfere with each other.

  In this embodiment, the operation of the processing unit 271 that divides the 16 slave units 10 into two groups is described. However, the processing unit 271 is configured to further divide the two groups into a plurality of groups. May be. For example, when the absolute value of the difference between the time difference D1 and the first reference value F1 is equal to or greater than the second reference value F2 in one reception interval within the entire response interval T22, the processing unit 271 includes eight slave units. 10 may be further divided into four units, and the 16 slave units 10 may be divided into four groups. In this case, the predetermined time T51 is set to be short so as to be half the length. Moreover, the process part 271 is not limited to dividing each group into the half of the number of the original subunit | mobile_unit 10, You may divide into an appropriate number of groups. In this case, the master unit and the slave unit 10 in the present embodiment may be configured to determine the division waiting time according to the data of the number of slave units 10 included in the request signal. Moreover, the process part 271 may determine so that the number of the subunit | mobile_units 10 of a group of each group may become substantially equal, and may determine the number of each group arbitrarily.

  In the present embodiment, the comparison unit 272 obtains the time difference D1, but the comparison unit 272 is not limited to obtaining the time difference D1. For example, the processing unit 271 may obtain the time difference D1. In addition, for example, a calculation unit for obtaining the time difference D1 may be separately provided.

  In the present embodiment, the comparison unit 272 operates based on the time difference D1 from the reception timing of the response signal SN10 corresponding to the reception interval R70. However, the time difference D1 varies between the reception interval R70 and the response signal SN10. It is not limited to being based. The comparison unit 272 may use a time difference D1 between the start timing of an arbitrary response section and the reception timing of the response signal corresponding thereto. In addition, as an example, the comparison unit 272 may use the time difference D1 of each of a plurality of arbitrary slave units. In that case, for example, the comparison unit 272 may newly set the average value of the plurality of time differences D1 as the time difference D1, or may set the time difference D1 having the largest value among the plurality of time differences D1.

  In this embodiment, the division waiting times W511 to W518 corresponding to the request signals H51 and H52 are stored in the memory of the parent device and the storage unit 17 of the child device 10 in this embodiment, respectively, but this configuration is limited. Not. The division waiting times W511 to W518 corresponding to the request signals H51 and H52 are, for example, based on the data included in the request signals H51 and H52, and the master unit and the slave unit 10 according to the present embodiment each execute a program and wait for division. Times W511 to W518 may be obtained.

  The processing unit 271 of the present embodiment is applicable to the first embodiment and the second embodiment excluding the modification example.

1, 1b, 1c Automatic fire alarm system 10, B1 to B16 Slave unit 20, 20b, 20c Master unit 23 Receiver 24 Transmitter 51, 52 A pair of wires (communication path)
53, 54 A pair of wires (communication path)
272 Comparison unit 273 Reception control unit 274 Transmission control unit D1 Time difference H1, H51, H52 Request signal R1-R16, R21-R36 Reception period R41-R56, R61-R76, R421, R431 Reception period SN1-SN16 Response signal SY1, SY11 , SY12, SY51, SY52 Sync signal T1, T11, T43, T44, T51 Predetermined time T5 Fixed time interval W1-W16 Wait time W511-W518 Divided wait time R511-R518 Divided reception section

Claims (10)

A base unit of an automatic fire alarm system for transmitting a signal to a plurality of slave units electrically connected to a pair of electric wires to which a voltage is applied,
A transmitter that is electrically connected to the pair of electric wires, changes a voltage between the pair of electric wires, and transmits signals to the plurality of slave units;
A transmission control unit for controlling the transmission unit and transmitting a synchronization signal from the transmission unit every time a predetermined time elapses;
A receiving unit that is electrically connected to the pair of electric wires and receives signals from the plurality of slave units based on a change in voltage between the pair of electric wires;
A reception control unit for controlling the reception unit ;
A processing unit that obtains data included in the signal from an output of the receiving unit;
With
The plurality of slave units change the voltage between the pair of wires after a waiting time has elapsed since receiving the synchronization signal, and send a response signal.
The length of the waiting time is different for each of the plurality of slave units,
The reception control unit causes the reception unit to receive the response signal from each of the plurality of slave units in a reception period after the waiting time has elapsed since the transmission unit transmits the synchronization signal,
The predetermined time is Ri time der the length of the response signal falls within the receiving section,
The lengths of the waiting times of the plurality of slave units are different at regular time intervals,
The length of the reception interval is equal to the certain time interval,
The processing unit regards as noise when the voltage value of the pair of electric wires exceeds the upper limit of a predetermined value or lower than the lower limit of the predetermined value in each of the vicinity of the start timing and the end timing of the reception section, Distinguish it from the signal,
The master unit of the automatic fire alarm system. The length of the predetermined time, the master unit of the automatic fire alarm system according to claim 1, wherein the at plural slave unit number worth the reception period summed over the length of. A comparison unit that compares a time difference between the start timing of the reception interval and the reception timing of the response signal corresponding to the reception interval with a reference value;
The base unit of the automatic fire alarm system according to claim 1 or 2 , wherein when the time difference is larger than the reference value, the length of the predetermined time is changed. A comparison unit;
A processing unit that controls the transmission control unit to transmit a request signal from the transmission unit each time the synchronization signal is transmitted from the transmission unit, and changes the length of the predetermined time, and
The request signal includes data for transmitting a response signal to a group of slave units included in one group selected by the processing unit among the plurality of slave units divided into a plurality of groups,
The processing unit is configured to cause the reception unit to receive the response signal from each of the plurality of slave units, and a divided response to cause the reception unit to receive the response signal from each of the group of slave units. Select the mode and
The comparison unit compares a second reference value with an absolute value of a difference between a time difference between a start timing of the reception interval and a reception timing of the response signal corresponding to the reception interval and a first reference value;
The processing unit selects the division response mode when the absolute value of the difference is equal to or greater than the second reference value, and controls the transmission control unit to transmit the request signal from the transmission unit; and The length of the predetermined time is changed short, and the selected one group is cyclically changed every time the synchronization signal is transmitted from the transmission unit,
The group of slave units transmits the response signal after a division waiting time has elapsed since receiving the synchronization signal,
The length of the division waiting time is different for each group of slave units,
The reception control unit receives the response signal from each of the group of slave units to the reception unit in a divided reception section after the division waiting time has elapsed since the transmission unit transmitted the synchronization signal. Let
The base unit of the automatic fire notification system according to claim 1 or 2 , wherein the predetermined time is a length of time during which the response signal fits in the divided reception section. A plurality of sets of the communication paths are connected to the transmission section and the reception section, with the pair of wires as a set of communication paths,
The transmission control unit causes the transmission unit to transmit the synchronization signal to at least one set of the communication paths to which the plurality of slave units are connected. The transmission unit according to any one of claims 1 to 4 , The main fire alarm system. The parent machine according to any one of claims 1 to 5 ,
A plurality of slave units connected to the pair of electric wires and transmitting the response signal by changing a voltage between the pair of electric wires after the waiting time has elapsed after receiving the synchronization signal. Automatic fire alarm system. It is used for the automatic fire alarm system of Claim 6. The subunit | mobile_unit of the automatic fire alarm system characterized by the above-mentioned. During the period of receiving the synchronization signal, it is in an operating state,
The slave unit of the automatic fire alarm system according to claim 7 , wherein in a period in which the synchronization signal is not received, a standby state in which power consumption is suppressed as compared with the operation state is set. A base unit of an automatic fire alarm system for transmitting a signal to a plurality of slave units electrically connected to a pair of electric wires to which a voltage is applied,
A transmitter that is electrically connected to the pair of electric wires, changes a voltage between the pair of electric wires, and transmits signals to the plurality of slave units;
A transmission control unit for controlling the transmission unit and transmitting a synchronization signal from the transmission unit every time a predetermined time elapses;
A receiving unit that is electrically connected to the pair of electric wires and receives signals from the plurality of slave units based on a change in voltage between the pair of electric wires;
A reception control unit for controlling the reception unit,
The plurality of slave units change the voltage between the pair of wires after a waiting time has elapsed since receiving the synchronization signal, and send a response signal.
The length of the waiting time is different for each of the plurality of slave units,
The reception control unit causes the reception unit to receive the response signal from each of the plurality of slave units in a reception period after the waiting time has elapsed since the transmission unit transmits the synchronization signal,
The predetermined time is a length of time during which the response signal fits in the reception section,
A comparison unit that compares a time difference between the start timing of the reception interval and the reception timing of the response signal corresponding to the reception interval with a reference value;
When the time difference is larger than the reference value, the length of the predetermined time is changed so as to be shortened. A base unit of an automatic fire alarm system for transmitting a signal to a plurality of slave units electrically connected to a pair of electric wires to which a voltage is applied,
A transmitter that is electrically connected to the pair of electric wires, changes a voltage between the pair of electric wires, and transmits signals to the plurality of slave units;
A transmission control unit for controlling the transmission unit and transmitting a synchronization signal from the transmission unit every time a predetermined time elapses;
A receiving unit that is electrically connected to the pair of electric wires and receives signals from the plurality of slave units based on a change in voltage between the pair of electric wires;
A reception control unit for controlling the reception unit,
The plurality of slave units change the voltage between the pair of wires after a waiting time has elapsed since receiving the synchronization signal, and send a response signal.
The length of the waiting time is different for each of the plurality of slave units,
The reception control unit causes the reception unit to receive the response signal from each of the plurality of slave units in a reception period after the waiting time has elapsed since the transmission unit transmits the synchronization signal,
The predetermined time is a length of time during which the response signal fits in the reception section,
A comparison unit;
A processing unit that controls the transmission control unit to transmit a request signal from the transmission unit each time the synchronization signal is transmitted from the transmission unit, and changes the length of the predetermined time, and
The request signal includes data for transmitting a response signal to a group of slave units included in one group selected by the processing unit among the plurality of slave units divided into a plurality of groups,
The processing unit is configured to cause the reception unit to receive the response signal from each of the plurality of slave units, and a divided response to cause the reception unit to receive the response signal from each of the group of slave units. Select the mode and
The comparison unit compares a second reference value with an absolute value of a difference between a time difference between a start timing of the reception interval and a reception timing of the response signal corresponding to the reception interval and a first reference value;
The processing unit selects the division response mode when the absolute value of the difference is equal to or greater than the second reference value, and controls the transmission control unit to transmit the request signal from the transmission unit; and The length of the predetermined time is changed short, and the selected one group is cyclically changed every time the synchronization signal is transmitted from the transmission unit,
The group of slave units transmits the response signal after a division waiting time has elapsed since receiving the synchronization signal,
The length of the division waiting time is different for each group of slave units,
The reception control unit receives the response signal from each of the group of slave units to the reception unit in a divided reception section after the division waiting time has elapsed since the transmission unit transmitted the synchronization signal. Let
The base unit of an automatic fire alarm system, wherein the predetermined time is a length of time during which the response signal fits in the divided reception section.

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