JP2840367B2 - Wireless alarm system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wireless alarm system for monitoring an abnormality such as a fire.

[Prior art] Conventionally, in order to monitor a fire at a building site such as a building, a child device directly attached with a fire detector is arranged on a ceiling side of a guard area, and when a fire signal is obtained from the fire detector. A wireless alarm system has been proposed which wirelessly transmits an abnormality detection signal together with a slave unit address to a master unit to notify an abnormality. Note that the slave unit has a built-in battery power source, and can be freely installed at a required place.

In such a wireless alarm system, for example, eight frequency channels corresponding to the maximum number of communicable slave units of eight are assigned to the master unit. Carrier sense is performed to determine whether or not the channel is empty. If the first channel is not used, it is selected as an empty channel. Next, the slave unit is switched to the transmission state, and the abnormality detection signal is transmitted to the master unit together with the slave unit address using the first channel selected by the carrier sense. As for the transmission of the abnormality detection signal from the slave unit, continuous transmission is performed while a fire signal is obtained, for example, repeating a transmission period of 8 seconds and a pause period of 2 seconds.

If the first channel is used by another slave in the first carrier sense, the second channel is switched to perform the carrier sense, and the carrier sense by the channel switching is sequentially repeated until an empty channel is found.

On the other hand, in the parent device, the same eight frequency channels as those of the child device are allocated, and the carrier sense of the eight channels is always performed in sequence. When a carrier is detected, the reception state of the detection channel is fixed and transmitted from the child device. The abnormality detection signal is received, and an abnormal state is identified and displayed to give an alarm.

[Problems to be Solved by the Invention] However, in such a conventional wireless alarm system, carrier detection for searching for an empty channel for transmission when an abnormality is detected is performed in order from the first channel. For example, in a case where a plurality of slaves are operated at a time at the time of a test and an abnormality detection signal is transmitted at a time, carrier sensing from the first channel is started in all slaves. Due to the signal collision, it takes time to select an empty channel in a specific slave unit, and there is a problem that it takes too much time until the reception and display of the abnormality detection signal is finally completed in the master unit.

The present invention has been made in view of such a conventional problem. Even when a plurality of slaves transmit an abnormality detection signal at the same time, all the slave information is not conscious of the waiting time on the master side. An object of the present invention is to provide a wireless alarm system capable of promptly receiving and displaying.

[Means for Solving the Problems] In order to achieve this object, the present invention is configured as follows. The reference numerals of the drawings of the embodiments are also shown.

First, according to the present invention, each of the plurality of slave units 12-1 to 12-n connected to the detector 10 for detecting an abnormality such as a fire matches the maximum number of slave units that can communicate with the master unit 14, for example, eight units. The number of frequency channels CH1 to CH8 is allocated, and when any abnormality is detected, first, the slave unit 12 is set to the receiving state, carrier sense is performed, and an empty channel not used by another slave unit is selected. A wireless type that switches to the transmission state and transmits an abnormality detection signal to the master unit 14 together with the slave unit address by continuously repeating a fixed transmission period and a pause period using the selected empty channel to alert the abnormal state. For alarm systems.

According to the present invention with respect to such a wireless alarm system, in each of the slave units 12-1 to 12-n, a channel for first performing carrier sense according to the set address of the slave unit is provided for each slave unit. In this embodiment, a channel setting means 18 for automatically setting a different channel setting is provided.

[Operation] According to the wireless alarm system of the present invention having such a configuration, a plurality of slave units operate and transmit an abnormality detection signal because the channel for performing carrier sensing differs for each slave unit first. In this case, signal collision does not occur, and the abnormality detection signal can be transmitted to the master unit with one carrier sense, and the reception display on the master unit can be performed quickly without being aware of the waiting time.
When the slave unit address is set, a channel for performing carrier sense is automatically set first, and a channel setting operation for starting carrier sense and a switch for channel setting are not required.

Embodiment FIG. 1 is a system configuration diagram showing an overall configuration of the present invention.

In FIG. 1, 12-1, 12-2,..., 12-n are slave units, each of which is connected to a fire detector 10 and receives a fire detection signal from the fire detector 10. An abnormality detection signal is transmitted from the antenna 22 to the parent device 14 together with the child device address. In this embodiment, a maximum of eight slave units 12-1 to 12-8 can be provided as a group for the master unit 14.

Each of the slave units 12-1 to 12-n has a maximum number of slave units that can communicate with the master unit 14, for example, eight frequency channels corresponding to eight units, for example, eight frequency channels CH1 to C in a 429 MHz band.
H8 is assigned.

In the transmission operation of the slaves 12-1 to 12-n, when an abnormality is detected, first, a reception state is set to check whether or not the channel frequency to be transmitted is being used by another slave. Carrier sense is performed, and after confirming that it is not being used by another slave unit by carrier sense, it is switched to the transmission state, and a fixed transmission period of 8 seconds and a pause period of 2 seconds using the selected empty channel. While the fire detection signal is being obtained by repeating the above, the abnormality detection signal is continuously transmitted to the master unit 14 together with the slave unit address.

In the transmission operation of the slave units 12-1 to 12-n according to the present invention, the channel for performing the carrier sense first is made different for each slave unit. The setting of a different channel for each slave unit that performs carrier sense first is as follows:
Channel setting can be automatically performed based on the address set by an address setting switch such as a dip switch provided in each of the slave units 12-1 to 12-n.

FIG. 2 is an embodiment configuration diagram showing one embodiment of the slave unit of the present invention.

In FIG. 2, reference numeral 24 denotes a CPU, which includes a transmission control unit 26 by a program control function and a channel setting unit 18 for automatically setting a channel for performing carrier sensing first based on address setting information.

Reference numeral 28 denotes a fire receiving circuit in which the fire detector 10 is connected via the power / signal line 100. When the fire detector 10 generates an alarm, a fire signal is received via the power / signal line 100, and the fire receiving signal is received. Output to CPU 24 and start-up circuit 30. Upon receiving the fire reception output, the startup circuit 30 turns on the power supply control circuit 32, supplies the power supply voltage from the battery power supply 25 to the CPU 24, starts power-on, and causes the transmission control unit 26 to perform a fire detection signal transmission operation. .

36 is a periodic notification circuit, which provides a periodic notification output to the CPU 24 and the start-up circuit 30 by a timer, for example, once every 9 hours,
When the power supply control circuit 32 is turned on, the CPU 24 performs a power-on start to transmit a periodic notification.

Reference numeral 16 denotes an address setting circuit, for example, a dip switch or the like is used, and the address setting circuit 16 uses one address unit and a plurality of child devices, for example, a group address and a child device in which up to eight child devices are grouped. An individual address that is set individually for each is set.

The address information of the address setting circuit 16 is given to the transmission control unit 26 as a slave unit address, and is also given to the channel setting unit 18 as information for automatically establishing the first channel for carrier sensing.

FIG. 3 shows a channel setting unit 1 provided in the CPU 24 of FIG.
FIG. 8 is a diagram showing an embodiment of the present invention in more detail.

In FIG. 3, the channel setting unit 18 includes an address pointer 18-1 and a conversion table 18-2. The address pointer 18-1 stores the address setting information set by the address setting circuit 16, that is, the slave unit address. The conversion table 18-2 stores channel information CH1 to CB8 indicating channels for which carrier sensing is performed first, corresponding to slave unit addresses (group addresses and individual addresses) A1 to A8.

Therefore, when a different address is set for each slave in the slave address setting circuit 16, this address setting information is stored in the address pointer 18-1 and the address pointer 18-1 is set.
The corresponding channel information is read out by accessing the conversion table 18-2 using the storage address of -1 and the transmission control unit
For 26, the channel for performing carrier sense first can be automatically set.

Referring to FIG. 2 again, the nonvolatile memory 35 is connected to the CPU 24. The non-volatile memory 35 is, for example, an EEPROM, and stores a call identification signal (ID code) transmitted first, which is approved by the Minister of Posts and Telecommunications. In a specific low power radio station according to the Radio Law, it is required to transmit a call identification signal at the beginning of transmission.

Further, a delay time setting counter 34 is connected to the CPU 24, and based on the count value of the delay time setting counter 34, the delay time of the slave unit when an abnormality is detected is set.

FIG. 4 is a block diagram of an embodiment showing the delay time setting counter 34 and the delay time setting means on the CPU 24 side.

In FIG. 4, first, the delay time setting counter 34 always receives power supply from the battery power supply 25, and performs a clock counting operation.
For example, the clock counting operation that occurs once every two seconds is sequentially repeated, and specifically, a binary 3-bit count output (b2 b
A counter circuit producing 1 b0) is used.

An information table 39 is provided on the CPU 24 side, and the information table 39 stores a pseudo-randomized numerical sequence of delay times as shown in the figure. In this embodiment, the numerical sequence of the delay time is 0.2 seconds at address 000 and 0.2 seconds at address 001.
0.0 seconds,... Stored at address 111 for 0.8 seconds. The delay time setting counter 34 counts the clock and generates a binary 3-bit output (b2 b1 b0), and supplies this counter output to the delay time setting unit 37 in the CPU 24. The delay time setting unit 37 outputs a 3-bit output (b2 b) of the delay time setting counter 34 at the timing when the CPU 24 is powered on by fire detection.
1 b0) is read and this counter output is stored in the information table 39
The read access is executed as the address pointer of, and the delay time at the address corresponding to the numerical series counter output is read out and set as the delay time used for carrier sense at that time.

Referring to FIG. 2 again, a transmission / reception circuit unit is provided on the left side of the CPU 24.

In this transmission / reception circuit section, reference numeral 40 denotes a synthesizer circuit, and a PLL circuit 42 and a VCO (voltage controlled oscillator) 44
An L oscillation circuit is configured to output the oscillation output of the VCO 44 via the amplifier 46. The oscillation frequency of VCO44 is set to CP for PLL circuit 42.
It can be changed freely by the division ratio data set from U24. Therefore, at the time of the first carrier sense, the CPU 24 sets the frequency division ratio data so as to oscillate the local oscillation frequency required for the carrier sense reception operation of the channel frequency to be transmitted. When an empty channel is selected by carrier sense, frequency division ratio data is set so as to oscillate the carrier frequency of the next selected empty channel. Of course, the channel for performing the first carrier sense is automatically set to a different channel for each slave unit by the channel setting unit 18 based on the address setting information.

The output of the synthesizer circuit 40 is supplied to a transmission circuit 50 or a high-frequency amplification / mixing circuit 54 on the reception side via a signal switch 48. The output of the transmitting circuit 50 is provided to the antenna 22 via the antenna switch 52. The other end of the antenna switch 52 is input to the high frequency amplification / mixing circuit 54. The high frequency amplifying / mixing circuit 54 converts the frequency of the received signal according to the local oscillation frequency of the channel for which carrier sense is to be performed from the synthesizer circuit 40 at the time of carrier sensing and converts the received signal to an intermediate frequency amplifying / mixing circuit 56 as an intermediate frequency fi signal. Output.
Specifically, for example, the transmission frequency f of the channel CH1
Assuming that t1 = 429.175 MHz and the intermediate frequency from the high-frequency amplification / mixing circuit 54 is fi = 21.7 MHz, the synthesizer circuit 40 at the time of carrier sense of the channel CH1 has the local oscillation frequency fr
1 = 407.475 MHz is oscillated and output to the high frequency amplification / mixing circuit 54.

The intermediate frequency amplification / mixing circuit 56 performs frequency conversion into a 455 KHz frequency signal using a local oscillator that performs fixed frequency oscillation. The method of performing frequency conversion twice by the high frequency amplification / mixing circuit 54 and the intermediate frequency amplification / mixing circuit 56 is known as a double superheterodyne method.

The output of the intermediate frequency amplification / mixing circuit 56 is a carrier detection circuit
58 and the modem 60. The carrier detection circuit 58 determines the received signal based on a threshold based on the white nozzle level when there is no carrier, and provides a detection output of the presence or absence of the carrier to the CPU 24.

The MSK modem 60 has a function of converting 1200 Hz and 1800 Hz reception frequency signals into data bits 1 and 0, respectively, and a function of converting data bits 1, 0 from the CPU 24 into 1200 Hz and 1800 Hz frequency signals. The frequency signal converted from the bit is applied to VCO 44 of synthesizer circuit 40 to perform MSK modulation of the carrier frequency.

Reference numeral 62 denotes a power supply switching circuit which controls on / off of power supply to the transmission circuit unit and power supply to the reception circuit unit under the control of the CPU 24. That is, the power supply to the receiving circuit unit is turned on at the time of carrier sense, and when an empty channel is selected by the carrier sense, the power supply to the receiving circuit unit is turned off, and then the power supply to the transmitting circuit unit is turned on.

The signal switch 48 and the antenna switch 52 are provided with a power switch circuit.
Switching is performed so that the circuit section that has been activated by receiving the power supply from 62 is enabled. That is, in this embodiment, the reception mode and the transmission mode are switched by turning on and off the power supply.

FIG. 5 is a timing chart showing a continuous transmission operation when a fire is detected in the slave unit embodiment of FIG.

In FIG. 5, when a fire is detected, first, the receiving state is entered, the first carrier sense is performed from the automatically set channel to select an empty channel, and after selection, the state is switched to the transmitting state, and a transmission period of T1 = 8 seconds, After performing the operation of transmitting the fire detection signal to the parent device, the operation is paused for T2 = 2 seconds, and thereafter, this operation is repeated. In the transmission period of T1 = 8 seconds, the call identification code is transmitted first. This call identification code has the format configuration shown in FIG. When the transmission of the call identification code is completed, the transmission of the mark and the transmission code is alternately repeated a plurality of times as shown in FIG. The mark is data in which all 1s are continuous, while the information code is composed of, for example, four frames 1 to 4 shown in FIG.

In FIG. 7, the first start bit 0 and the last stop bit 1 of frames 1 to 4 are provided for frame synchronization. An 8-bit data area is provided following the start bit 0. In frame 1, a group address (upper address for extension) is transmitted. In frame 2, an individual address and a group address (lower) are transmitted.
, An alarm signal is sent, and in frame 4, a horizontal parity bit is sent. The horizontal parity bits of the frame 4 are set such that the sum of the same bit positions of the frames 1 to 3 becomes an odd number, for example. Subsequent to the 8-bit data area, a parity bit for each frame is provided.

Next, the transmission operation in the slave unit of FIG. 2 will be described with reference to the flowchart of FIG.

Now, if the fire detector 10 issues an alarm, the fire receiving circuit
The start-up circuit 30 operates by the reception output of 28, the power supply control circuit is turned on, the battery power supply 25 supplies power to the CPU 24,
The operation flow of FIG. 8 is executed by the 24 power-on start.

In FIG. 8, first, an initialization process is performed in step S1 (hereinafter, "step" is omitted), and in the next S2, the call identification code and the slave unit address (the upper group address, the lower group address, Group address and individual address). Next, the process proceeds to S3, where it is checked whether or not the transmission is continuous. When a fire is detected, the process proceeds to S4 because of continuous transmission. On the other hand, at the time of power-on start based on the periodic notification output from the periodic notification circuit 36, since the transmission is not continuous, the process proceeds to S5, and a fixed delay time is set.

In the process of S4 in the case of continuous transmission, as shown in FIG. 4, when the CPU 24 is powered on, the count output (b2 b
1b0) is read into the delay time setting unit 37, and the numerical output of the delay time in the information table 39 is accessed using the count output as an address pointer, and the corresponding delay time is read and set.

Next, proceeding to S6, the first channel for performing carrier sense corresponding to the slave unit address is set. That is, as shown in FIG. 3, the address setting information read in S2 is stored in the address pointer 18-1, and a conversion table based on the address setting information of the address pointer 18-1 is stored.
In the access of 18-2, for example, if the address is A1, the channel CH is first used as channel information for performing carrier sense.
1 is set.

Next, proceeding to S7, the local oscillation frequency of the reception channel corresponding to the transmission channel set in S6 is set in the PLL circuit 42 for carrier sensing.

Next, proceeding to S8, the power supply to the receiving circuit unit is turned on to activate the operation, and whether the power supply to the receiving circuit unit has already been turned on in S9, that is, the power supply to the first receiving circuit after the power-on start. It is checked whether it is the first time, and if it is the first time, the process goes to S10 to wait for 300 ms to stabilize the operation of the receiving circuit unit, and then goes to S11.

In S11, check the presence or absence of carrier detection,
If there is no carrier detection, the process proceeds to S14 and waits for the elapse of the delay time, and the processes of S11 and S14 are repeated until the delay time is reached. When it is determined that the carrier detection is not performed over the delay time, the process proceeds to S15, and after the receiving circuit unit is turned off,
The division ratio data for oscillating the transmission frequency of the selected channel without the carrier is set in the PLL circuit 42, and in S16, the power supply to the transmission circuit unit is turned on to be in an operation state.

Next, the call identification code is transmitted first in S17, and then the mark and the transmission code are transmitted sequentially in S18. When you finish sending
At S19, the transmission counter A is incremented by one, and at S20
In step S2, it is checked whether or not A = n times, for example, n = 75 times, has been transmitted.
After a pause of 2 seconds by the timer in step 1, the process proceeds to step S22 to check whether a fire signal is being received. If the fire signal is being received, the process returns to S2 and repeats the same transmission operation. If the fire signal has been cut off, the process proceeds to S23 to perform a power-off process for cutting off the power supply to the CPU 24.

On the other hand, if a carrier is detected in the carrier detection in S11, the process proceeds to S12 and checks whether or not the carrier detection continues for a predetermined time or more. If the carrier detection has been continued for a predetermined time or more, the process proceeds to S13, the frequency division ratio data for oscillating the local oscillation frequency is set in the PLL circuit 42 for carrier sensing of the next reception channel, and the process returns to S9.
The carrier sensing process for the next channel is started, and carrier sensing by channel switching is repeated until an empty channel is found.

FIG. 9 is an embodiment configuration diagram showing one embodiment of the parent device of the present invention.

In FIG. 9, the main unit 14 is provided with a CPU 64,
The reception control unit 72 is configured by the program control of the CPU 64, and an address setting circuit 68 using a dip switch or the like is connected to the CPU 64. The address setting circuit 68 sets all of the plurality of slave unit addresses.

Antenna 94 as receiving circuit for CPU 64, receiving circuit
76, an MSK modem 78 and a synthesizer circuit 80 are provided. The transmission circuit section of this master unit has substantially the same configuration as that of the slave unit transmission / reception circuit shown in FIG. 2 except for the transmission side.

The reception control unit 72 of the CPU 64 sets the frequency division ratio data to the synthesizer circuit 80 to set the channels CH1 to C
The local oscillation frequency of H8 is sequentially switched and supplied to the receiving circuit 76, and the carrier sense of the channels CH1 to CH8 is repeatedly performed. When the carrier sense output is obtained from the receiving circuit 76, the switching of the frequency division ratio data set switching to the synthesizer circuit 80 is stopped to set a fixed receiving state, and the received signal obtained in this receiving state is converted into a data bit by the MSK modem 78. Convert and import to CPU64. The reception control unit 72 that has received the reception data first performs address collation. That is, it is checked whether or not the group address included in the received data matches the group address of the master unit. Are sequentially checked to see if they match any of the individual addresses, and if they match any of the individual addresses, the received data is decoded. The decoding of the received data is performed by decoding the data area of the frame 3 shown in FIG. Display.
Of course, a fire indicator light (not shown) is turned on, and an alarm buzzer sounds. Further, when the receiver 84 is connected via the transmission line 82, the receiver 84
Fire alarms can be issued on the side.

In such a receiving operation of the parent device 14, on the child device side of the present invention, for example, when a plurality of child devices operate simultaneously at the time of a test or the like, a channel for performing carrier sense first is a child device address. Is automatically set to be a different channel based on the channel, the selection of empty channels in all slave units is completed by one carrier sense, and test signals are transmitted simultaneously using different channels. . For this reason,
In the base unit 14, a carrier sense output is obtained from the receiving circuit unit 76 in each carrier sense of the channels CH1 to CH8, and address matching, data analysis, and test display are performed by receiving the received data, and the next channel is received. The switching operation is performed continuously. Since the processing time of the carrier sense, address collation, and data analysis for one receiving terminal is on the order of milliseconds, even if eight channels are continuously processed, transmission is performed from all the slaves without being aware of the reception waiting time. Information can be received and displayed.

In the above-described embodiment, the case where the fire detector is connected to the slave unit is taken as an example. In addition, a suitable abnormality detector such as a gas leak detector or an intruder detector may be used. May be connected.

[Effects of the Invention] As described above, according to the present invention, since a channel for performing carrier sense differs first for each slave, a plurality of slaves operate and transmit an abnormality detection signal at once. Signal collision does not occur, and each slave unit can send an abnormality detection signal to the master unit with one carrier sense, and the reception display on the master unit can be quickly performed without being aware of waiting time, testing It is possible to efficiently perform reception display such as time.

In addition, when the slave unit address is set, the channel for performing carrier sense is automatically set first, and the slave unit configuration can be simplified simply because the channel setting operation for starting carrier sense and the switch for channel setting are not required. can do.

[Brief description of the drawings]

FIG. 1 is a block diagram of a system according to the present invention; FIG. 2 is a block diagram of an embodiment of a slave unit of the present invention; FIG. 3 is a block diagram of an embodiment of a channel setting circuit for performing carrier sense at the beginning of the present invention; FIG. 5 is a diagram showing a configuration of an embodiment of a delay time setting circuit unit according to the present invention; FIG. 5 is a transmission timing chart of a slave unit of the present invention; FIG. 6 is a format diagram of a call identification code transmitted from the slave unit of the present invention; FIG. 7 is a diagram showing a format configuration of a transmission code transmitted from the slave unit of the present invention; FIG. 8 is an operation flow chart showing a slave unit transmitting operation of the present invention. FIG. 9 is a block diagram of an embodiment of the parent device of the present invention. In the figure, 10: fire detector 12, 12-1 to 12-n: slave 14: master 16, 68: address setting circuit 18: channel setting section 18-1: address pointer 18-2: conversion table 20: Delay time setting unit 22, 94: Antenna 24, 64: CPU 25: Battery power 26: Transmission control unit 28: Fire receiving circuit circuit 30: Startup circuit 32: Power supply control circuit 34: Delay time setting counter 35: Non-volatile memory (EEPROM 36: Periodical notification circuit 37: Delay time setting section 39: Information table 40, 80: Synthesizer circuit 42: PLL circuit 44: VCO 46: Amplifier 48: Signal switch 50: Transmission circuit 52: Antenna switch 54: High frequency amplification / Mixing circuit 56: Intermediate frequency amplification / Mixing circuit 58: Carrier detection circuit 60,78: MSK modem 62: Power supply switching circuit 76: Reception circuit 72: Reception controller 74: Individual display 75: Display circuit 84: Receiver 86 : Transfer circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G08B 25/10 H04Q 9/00 311

Claims (1)

(57) [Claims] A plurality of slave units connected to a detector for detecting an abnormality such as a fire are assigned frequency channels of the same number as the maximum number of slave units capable of communicating with the master unit, and an abnormality of one of the slave units is detected. Sometimes, first, carrier sense is performed as a reception state to select an idle channel that is not used by another slave, and then the slave is switched to the transmission state, and a fixed transmission period and a pause are performed using the selected idle channel. In a wireless alarm system that sends an abnormality detection signal together with the slave unit address to the master unit by repeating the period and alerts the user of an abnormal state, each of the slave units firstly responds to the set address of the slave unit. A wireless alarm system provided with channel setting means for automatically setting a channel for performing carrier sensing to be different for each slave unit.