JP2010114632A - Wireless disaster prevention node - Google Patents

Abstract

An object of the present invention is to acquire a radio wave intensity and check a communication state without increasing a processing capability necessary for a control unit.
A radio reception repeater as a radio disaster prevention node receives and processes a radio signal including a phase correction signal at a telegram head position transmitted from a radio fire sensor as another node. The radio communication unit 22 of the radio reception repeater 12 receives a radio signal, demodulates the telegram signal, measures the radio wave intensity, and outputs a radio wave intensity signal. The CPU 20 functioning as a control unit acquires a radio wave intensity signal during reception of the phase correction signal in the wireless communication unit 22. For example, during reception of the phase correction signal, the CPU 20 transmits a radio wave intensity signal read command to the wireless communication unit 22 to acquire the radio wave intensity signal.
[Selection] Figure 2

Description

The present invention relates to a wireless disaster prevention node of a disaster prevention monitoring system that transmits an event signal wirelessly transmitted from a sensor node such as a wireless sensor to a receiver and issues an alarm.

  Conventionally, in a wireless disaster prevention monitoring system that monitors fires, multiple wireless fire detectors are installed in a warning area such as each floor of a building, and when a fire is detected by the wireless fire detector, a fire is detected. The radio signal shown is transmitted to a radio reception repeater installed on a floor basis.

  The radio receiver repeater is connected to the sensor line from the fire receiver. When a fire radio signal is received, a fire alarm signal is generated by flowing a alarm current between the sensor lines when the relay contact or switching element is turned on. Is sent to the receiver to issue a fire alarm.

According to such a wireless disaster prevention system, it is possible to eliminate the need for a sensor line for connecting the repeater installed on the floor of the building to the sensor, simplify the wiring work, and also require a place for the sensor to be installed. It can be determined accordingly.
JP-A-5-274580 JP 2001-290209 A

  By the way, in such a wireless disaster prevention monitoring system, it is necessary to confirm the certainty of communication between nodes. As one method for that purpose, there is a method of measuring the radio wave intensity during wireless communication between nodes.

  This is because the S / N ratio of the signal is deteriorated as the radio wave intensity is weakened, and the reliability of communication is deteriorated. Therefore, the reliability of communication can be confirmed by measuring the radio wave intensity. For example, if the acquired radio wave intensity exceeds a certain threshold, the communication state is “good”, and if it is below the threshold, the communication state is determined to be “bad”, and the determined communication state is displayed.

  However, during the wireless communication between nodes, if the process of acquiring the radio field strength signal, determining the communication status and displaying it, the processing burden on the control unit using the CPU increases, and the received message content is decoded. In order to secure this processing capability, it is necessary to increase the processing capability of the control unit, and there is a problem that the control unit becomes complicated and costs increase.

Here, during wireless communication, the control unit of the node using the CPU needs to perform a plurality of processes as follows.
(1) Acquisition of signal strength signal (2) Interpretation of received signal (3) Status display according to the content of received signal (4) Monitoring of input from receiver and control of output based on interpretation of received content In particular, high-speed and complicated processing is required for interpretation of a received signal.

  In general, the radio wave intensity signal is output as an analog signal or a digital signal from the wireless communication unit. In any case, a certain amount of processing is required to obtain the radio wave intensity signal, and this amount of processing is commensurate. High performance of the control unit is required.

  When the signal strength signal is output as an analog signal from the port of the wireless communication unit, the control unit acquires the signal strength signal using, for example, an AD conversion port of a microcomputer, and determines the reliability of communication based on the value. To do. Acquisition of a radio field intensity signal using this AD conversion port takes, for example, several tens of microseconds, and accordingly, it is necessary to improve the processing capability of interpreting the original telegram and outputting the result.

  When the radio wave intensity signal is output as a digital signal from the port of the wireless communication unit, a radio wave intensity signal read command is transmitted from the control unit to the wireless communication unit. When the radio communication unit receives the radio wave intensity signal read command, the radio communication unit transmits a digital signal indicating the radio wave intensity to the control unit. The time required to acquire the radio wave intensity signal is determined by the communication speed between the control unit and the wireless communication unit. The shorter the communication time, the less load is applied to the control unit. Ability is required.

An object of this invention is to provide the radio | wireless disaster prevention node which can acquire a radio field intensity and can confirm a communication state, without raising the processing capacity of a control part.

The present invention is a radio disaster prevention node that receives and processes a radio signal in which a phase correction signal is arranged at a message head position transmitted from another node.
A radio communication unit that receives a radio signal and demodulates a telegram signal, measures a radio wave intensity, and outputs a radio wave intensity signal;
A control unit that acquires a radio field intensity signal during reception of the phase correction signal in the wireless communication unit;
It is provided with.

  Here, during reception of the phase correction signal, the control unit transmits a radio wave intensity signal read command to the wireless communication unit to acquire the radio wave intensity signal.

  Also, the control unit may acquire the radio wave intensity signal output from the wireless communication unit by performing AD conversion during reception of the phase correction signal.

  While receiving the phase correction signal, the control unit compares the acquired radio wave intensity signal with a predetermined threshold to determine whether the reception is good or bad, and after acquiring and processing the telegram signal following the phase correction signal The reception status determined when the content of the message is specific is displayed on the status display section.

The other node is a sensor node that detects a fire and transmits a wireless signal, and the control unit receives a telegram signal demodulated from the wireless signal of the sensor node and determines when a fire is detected. A fire signal is relayed to the machine to alert.

According to the radio disaster prevention system of the present invention, the phase correction signal arranged as a preamble at the head position of the radio signal is a signal for preparation for reception in the radio communication unit, and during reception of the phase correction signal, the control unit Since there is no need to interpret the message, there is a relatively large processing capacity. By acquiring the radio field strength signal at this time, it is possible to acquire the radio field intensity signal without increasing the processing capacity of the control unit and Can be determined and displayed, and the reliability of communication can be confirmed.

  FIG. 1 is an explanatory view showing an embodiment of a wireless disaster prevention system according to the present invention. In FIG. 1, a P-type receiver 10 is installed as a fire detector on the first floor of a building 11 to be monitored. A power line 17 and a sensor line drawn from the P-type receiver are connected to each floor. A radio reception repeater 12 serving as a radio disaster prevention node of the invention is connected.

  A wireless sensor 16 that functions as a sensor node is installed on each floor of 1F to 3F. The wireless sensor 16 serving as a sensor node determines that a fire has occurred when the smoke concentration or temperature due to fire exceeds a predetermined threshold, and wirelessly transmits a fire event signal as a notification radio signal. The wireless reception repeater 12 receives the fire event signal transmitted from the wireless sensor 16, and causes the P-type receiver 10 to send an alarm current as a contact output to the sensor line 18, thereby generating a fire alarm. Send a signal.

  Further, in the wireless disaster prevention system of the present embodiment, the periodic notification event signal is periodically transmitted to monitor that the wireless sensor 16 is operating normally, that is, that it has not been taken away or the battery has run out. To send.

  In response to the transmission of the periodic notification event signal from the wireless sensor 16, the wireless reception repeater 12 resets and starts the timer corresponding to the node ID included in the periodic notification event signal. Is not received, the timer exceeds a certain time, and it is determined that the wireless sensor 16 is not operating normally, and the P-type receiver is notified of the failure.

  This failure occurrence notification notifies, for example, the occurrence of failure due to abnormal periodic notification by disconnecting the terminal resistance connected to the sensor line 18 from the P-type receiver 10 to create a pseudo disconnection state.

  Furthermore, for power supply to the radio reception repeater 12, for example, 24 VDC is supplied from the P-type receiver 10 through a dedicated power line 17. The wireless sensor 16 has a built-in battery such as an alkaline battery.

  FIG. 2 is a block diagram showing a first embodiment of the wireless reception repeater of FIG. In FIG. 2, the wireless reception repeater 12 includes a CPU 20 that functions as a control unit, a wireless communication unit 22, a wired communication unit 24, a status display unit 26, and a power supply circuit unit 28.

  The wireless communication unit 22 includes an antenna 30, a reception circuit unit 32, a radio wave intensity detection unit 34, and a serial interface 36. For example, in the case of Japan, the wireless communication unit 22 performs wireless communication according to the standard of a specific low-power wireless station in the 400 MHz band.

  The receiving circuit unit 32 receives the fire event signal or the periodic notification event signal transmitted from the wireless sensor 16 by the antenna 30, and demodulates the telegram data from the received signal. Along with the reception operation of the reception circuit unit 32, the radio wave intensity detection unit 34 outputs a radio wave intensity signal having a DC level corresponding to the radio wave intensity.

  Based on the read command from the CPU 20, the serial interface 36 serially transfers the message data demodulated by the receiving circuit unit 32 or the radio wave intensity signal detected by the radio wave intensity detector 34.

  The DC level radio wave intensity signal output from the radio wave intensity detector 34 is AD converted by the serial interface 36 and transferred as a digital signal. Of course, it may be converted into a digital signal and output to the serial interface 36 when it is output from the radio wave intensity detector 34.

  Here, the message format of the radio signal from the wireless sensor 16 received by the wireless communication unit 22 is as shown in FIG. In FIG. 3, in the message format, the phase correction data 42 is arranged at the head position that becomes the preamble of the radio signal, and the phase correction data 42 is “101010...”, For example, data of 24 bits length.

  The phase correction data 42 is demodulated by the reception circuit unit 32 provided in the wireless communication unit 22 of FIG. 2 and used to establish a reception preparation state. That is, the phase correction data 42 establishes the bit synchronization of the demodulation process in the receiving circuit unit 32 by repeating “101010.

  Following the phase correction data 42, communication control data 44, a transmission source identification code 46, data 48, and an error check code 50 are arranged. The communication control data 44 is data indicating the type of message, and represents the type of message such as a message indicating the sensor state and a message indicating a periodic report.

  The transmission source identification code 46 is an ID of a wireless sensor serving as a message transmission source. For example, when identification of a wireless sensor having a scale of 1 million is assumed, the transmission source identification code 46 is 50 to 60 bits long. The data 48 is information such as sensor output data such as smoke density and temperature detected by the wireless sensor 16. For example, a checksum is used as the error check code 50.

  Referring to FIG. 2 again, the CPU 20 functioning as a control unit is provided with a data processing unit 38 and a reception state determination unit 40 as functions realized by executing a program.

  The reception state determination unit 40 monitors the start of reception of the wireless signal in the wireless communication unit 22. When the reception start is determined, the reception state determination unit 40 transmits a radio field intensity read command to the wireless communication unit 22 to acquire the radio field intensity data. By comparing with a predetermined threshold, if the reception state is equal to or greater than the threshold, it is determined as “good”, and if it is below the threshold, it is determined as “bad”.

  Although the determination result by the reception state determination unit 40 is displayed on the state display unit 26, the processing of the reception state determination unit 40 is to receive the 24-bit phase correction data 42 arranged at the head of the wireless signal in the wireless communication unit 22. It is possible to operate only during the acquisition and processing up to the acquisition of the radio wave intensity data and the comparison judgment is possible, but the display of the judgment result may not be possible while receiving the phase correction signal. After receiving the signal, the signal is output to the state display unit 26 to display whether the reception state is “good” or “bad”.

  For example, when the transmission speed of the wireless signal from the wireless sensor 16 is 1200 bps, the reception time of the 24-bit phase correction signal is 20 milliseconds, and the reception is performed within the range not exceeding the reception time of this phase correction signal. The state determination unit 40 determines the communication state by acquiring the radio wave intensity signal and comparing the threshold value.

The reception state determination unit 40 displays the determined reception state on the state display unit 26 only when the content of the received message is a predetermined specific one. For example, the reception state determination unit 40 displays the determined reception state in the case of the following specific content.
(1) The reception status is displayed only when a communication test message is received.
(2) Change whether to display according to the transmission source information included in the message.

  As a result, the reception status is displayed for communication with a specific electronic message content or a specific transmission source, and a communication test or determination of the communication status with a specific wireless sensor can be performed appropriately and easily.

  The data processing unit 38 receives original telegram data received after the reception of the phase correction signal, that is, telegram data including the communication control data 44, the transmission source identification code 46, the data 48, and the error check code 56 in FIG. The serial data transfer i9l from the wireless communication unit 22 is received, each data is decoded, and, for example, when a fire event signal is discriminated based on the decoding result, the wired communication unit 24 detects it from the P-type receiver 10. A fire alarm signal is transmitted by causing an alarm current to flow through the instrument line 18 to display an alarm.

  In addition, when the periodic report abnormality is determined based on the periodic report signal, by creating a pseudo disconnection state by disconnecting the termination resistor connected to the termination of the sensor line 18 from the P-type receiver 10, A failure detection signal is sent to the P-type receiver 10 to display a failure display.

  FIG. 4 is a flowchart showing a reception process with reception intensity acquisition according to the embodiment of FIG. In FIG. 4, the reception state determination unit 40 of the CPU 20 transmits a status request command to the wireless communication unit 22 in step S1 and receives a status response. If a reception start response is discriminated in step S2 with respect to this status response, the process proceeds to step S3, and a radio wave intensity read command is transmitted.

  Here, the detection of the start of reception in the wireless communication unit 22 is judged as the start of reception when the radio field intensity detection unit 34 obtains a radio field intensity signal output of a predetermined value exceeding the noise level, and receives the status request command. Returns a start response.

  After transmitting the radio wave intensity reading command in step S3, it is determined whether or not radio wave intensity data is received in step S4. When the radio wave intensity data is received, it is compared with a predetermined threshold value in step S5. In step S6, the reception state is determined to be good.

  Subsequently, the data processing unit 38 obtains received data output by serial transfer from the wireless communication unit 22, that is, original telegram data. In step S8, the received data content is a specific content, for example, a test message or a specific transmission source. If there is, the data processing is performed by decoding the telegram data in step S9, and the reception good state determined by the reception state determination unit 40 in step S10 is performed on the state display unit 26 in step S10.

  The reception status “good” or “bad” in the status display unit 26 is indicated by a two-color display in which a green LED is lit when “good” and a red LED is lit when “bad”, or a single LED is displayed. Appropriate status display is performed, such as a display that lights with “good” and blinks with “bad”.

  On the other hand, if the radio wave intensity data falls below the threshold value in step S5, the reception state is determined to be “bad” in step S11. Subsequently, after the original message data is acquired by the data processing unit 38 in step S12, in this case, since reception is defective, the received data is discarded in step S13 and data processing is not performed. When the processing by the data processing unit 38 is completed, the reception state “defective” determined in step S11 is displayed on the state display unit 26 in step S14.

  FIG. 5 is a block diagram showing a second embodiment of the wireless reception repeater of FIG. 1. In this embodiment, a case where a radio wave intensity signal is output as an analog signal from the wireless communication unit 22 is taken as an example. taking it.

  In FIG. 5, the wireless reception repeater 12 includes a CPU 20, a wireless communication unit 22, a wired communication unit 24, a status display unit 26, and a power supply circuit unit 28 as in the first embodiment of FIG. 2. The radio communication unit 22 is provided with a receiving circuit unit 32 and a radio wave intensity detection unit 34, and the radio wave intensity signal detected by the radio wave intensity detection unit 34 is output from the radio wave intensity signal port 54 as an analog signal. The message data demodulated by the receiving circuit unit 32 is output from the data port 52 by serial bit transfer.

  In addition to the data processing unit 38 and the reception state determination unit 40, the CPU 20 is provided with a reception start detection unit 56 and an AD conversion unit 58. The reception start detection unit 56 receives the radio wave intensity signal from the radio wave intensity detection unit 34 provided in the wireless communication unit 22, and detects the reception start when the radio wave intensity signal exceeds a predetermined threshold level exceeding the noise level. Then, the AD conversion unit 58 is operated, and the radio wave intensity signal input at that time is converted into a digital signal and is read by the reception state determination unit 40.

  The reception state determination unit 40 compares the radio wave intensity signal acquired by the AD conversion unit 58 with a predetermined threshold, and determines that the reception state is “good” if the threshold is exceeded, and the reception state is “ After the data processing unit 38 completes the decryption and processing of the original telegram data, the status display unit 26 displays the reception status determination result.

  FIG. 6 is a flowchart showing a reception process with reception intensity acquisition according to the embodiment of FIG. In FIG. 6, the reception start detection unit 56 provided in the CPU 20 compares the radio wave intensity signal with a threshold value exceeding a predetermined noise in step S21. If the radio wave intensity signal exceeds the threshold value, the reception start detection unit 56 receives the radio wave intensity signal in step S22. In step S23, the AD conversion unit 58 is operated to read and convert the radio wave intensity signal by AD conversion.

  Thereby, the radio wave intensity signal can be read into the reception state determination unit 40 during reception of the phase correction data 42 shown in FIG. 3 arranged at the head of the radio signal. Subsequently, in step S24, it is determined whether or not the radio wave intensity data acquired by the reception state determination unit 40 is equal to or greater than a threshold value. If it is equal to or greater than the threshold value, the reception state is determined to be “good” in step S25, and the reception data is acquired in step S26. If the received data content is predetermined specific content in step S27, the process proceeds to step S28 to perform the processing based on the decryption of the original message data of the data processing unit 38 and the decryption result, and in step S29 after the completion “Good” is displayed as the reception state on the display unit 26.

  On the other hand, if the radio wave intensity data is below the threshold value in step S24, the reception state is determined to be “bad” in step S30, and the reception data is acquired by the data processing unit 38 in step S31. Since it is defective, the received data is discarded in step S32, and in step S33, the status display unit 26 displays that the reception status is “bad”.

  In the above embodiment, the radio reception repeater 12 is connected to the sensor line from the P-type receiver as a fire receiver, but the R-type receiver having a data transmission function is connected to the radio reception relay. The repeater 12 may be connected.

  In the above embodiment, the acquisition of the radio wave intensity signal and the determination of the communication state are performed during the reception of the phase correction signal arranged at the head of the radio signal, and then the normal message data reception process is completed. Later, the determined communication status is displayed on the status display unit 26. However, if the reception time of the phase correction signal can be sufficiently secured, the acquisition of the radio wave intensity signal, the determination, and the display of the determined communication status are phased. You may make it complete | finish during reception of a correction signal.

  Conversely, when the communication speed is fast and the reception time of the phase correction signal is short, only the acquisition of the radio wave intensity signal is executed while the phase correction signal is being received, and the determination and status display of the radio wave intensity signal is the original message data. It may be performed after the above process is completed.

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

Explanatory drawing which showed embodiment of the wireless disaster prevention system by this invention The block diagram which showed 1st Embodiment of the radio | wireless receiving repeater of FIG. Explanatory drawing which showed the message | telegram format of the radio signal received with the repeater for radio | wireless reception of FIG. The flowchart which showed the reception process with acquisition of the reception strength by embodiment of FIG. The block diagram which showed 2nd Embodiment of the radio | wireless receiving repeater of FIG. The flowchart which showed the reception process with acquisition of the reception strength by embodiment of FIG.

Explanation of symbols

10: P-type receiver 12: Repeaters 15-1 to 15-3 for wireless reception: Wireless controller 16: Wireless sensor 17: Power supply line 18: Sensor line 20: CPU
22: Wireless communication unit 32: Antenna 24: Wired communication unit 26: Status display unit 28: Power supply circuit unit 32: Reception circuit unit 34: Radio wave intensity measurement unit 36: Interface 37: Serial port 38: Data processing unit 40: Reception state Determination unit 42: phase correction data 52: data port 54: reception intensity signal port 56: reception start detection unit 58: AD conversion unit

Claims (5)

In a wireless disaster prevention node that receives and processes a radio signal in which a phase correction signal is arranged at the head position of a message transmitted from another node,
A radio communication unit that receives the radio signal and demodulates the telegram signal, and measures the radio field intensity and outputs the radio field intensity signal;
During reception of the phase correction signal in the wireless communication unit, a control unit for acquiring the radio field intensity signal;
A wireless disaster prevention node characterized by comprising:
The radio disaster prevention node according to claim 1, wherein the control unit acquires a radio wave intensity signal by transmitting a radio wave intensity signal read command to the radio communication unit during reception of a phase correction signal. Wireless disaster prevention node.
The wireless disaster prevention node according to claim 1, wherein the control unit acquires the radio wave intensity signal output from the wireless communication unit by performing AD conversion while receiving the phase correction signal. Disaster prevention node.
The wireless disaster prevention node according to claim 1, wherein the control unit compares the acquired radio wave intensity signal with a predetermined threshold during reception of the phase correction signal to determine whether the reception is good or bad. A wireless disaster prevention node, wherein after acquiring and processing a telegram signal following the phase correction signal, the determined reception state is displayed on a status display unit when the content of the telegram is specific.
In the wireless disaster prevention node according to claim 1,
The another node is a sensor node that detects a fire and transmits a radio signal;
When the control unit acquires a telegram signal demodulated from a radio signal of the sensor node and determines a fire, the control unit relays and transmits a fire signal to a receiver connected by a signal line. Wireless disaster prevention node.

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