JPS6129580B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data collection method, and more specifically, a method for collecting data from each terminal station at a base station using a wireless channel between one base station and a plurality of terminal stations. This relates to data collection methods.

In general, this type of data collection method uses a polling mode in which the base station constantly controls each terminal station and collects data from each terminal station one by one, and the other There are two types of methods: those using an interrupt mode in which data is sent to the base station by interrupting the base station itself, and the base station then collects data. In conventional data collection systems, when collecting various data from a large number of terminal stations using one wireless channel, as the number of terminal stations increases, the frequency collection method using polling mode allows specific terminal stations to collect data. This has the disadvantage that the time interval between when the terminal station sends out the data and when the same terminal station sends out the next data is long, and even if data that needs to be sent urgently arises, it will not be possible to send it out for a considerable period of time. On the other hand, in the data collection method using interrupt mode, as the number of data transmissions from the terminal station increases, the number of times that the transmission data from each terminal station is sent simultaneously increases, and the wireless communication between the base station and each terminal station increases. This has the disadvantage that it becomes difficult to make a good connection. One possible measure to eliminate these drawbacks is to increase the number of wireless channels, but increasing the number of wireless channels is extremely difficult in these days when radio waves are becoming increasingly congested. There is a need for a method that eliminates these drawbacks.

In addition, in the conventional polling/contention communication method, when there is simultaneous transmission from multiple terminal devices during contention, wasted time occurs due to the overhead. It is known that a transmission timing is given to a transmission timing (for example, Japanese Patent Application Laid-Open No. 51-23008). However, this method has the disadvantage that the number of transmissions and the amount of information to be transmitted increase as the transmission timing is determined by polling. Furthermore, there is a problem in that simply using the polling/contention communication method alone does not provide quick response and quickness of communication.

Furthermore, instead of uniformly polling all terminal stations at a predetermined period, terminal stations that should transmit data and terminal stations that do not need data transmission are divided into groups for each period, and the terminal stations that do not need data transmission are simply called " A method is known in which the polling cycle is shortened by simply transmitting "no data" to avoid wasted time (for example, Japanese Patent Application Laid-Open No. 17606/1983). However, this method also has a problem in that it is not possible to obtain the quick response of communication based only on the polling method. Furthermore, since the above-mentioned "data present" group and "data absent" group change from time to time, there is a problem in that it takes time to classify them into groups.

In addition, it is composed of one coaxial cable forming a signal transmission path, a relatively simple transmission control device and a plurality of terminal devices connected to this signal transmission path,
In order to enable arbitrary communication between devices connected to the signal transmission path, the transmission control device and the terminal device are connected by three types of wires: a signal transmission path, a request signal transmission line, and a permission signal transmission line, and the terminal device is set in polling mode. In addition to this, a data transmission system is known that also uses a preferred mode higher than the polling mode (for example, Japanese Patent Laid-Open No. 56804/1983). Since this method uses a preferred mode, it enables highly responsive communication, but when considering data communication from all terminal devices, sufficient communication efficiency cannot necessarily be obtained. have. In addition, in this method, each terminal device using the preferred mode and the transmission control device must be connected with three lines: a signal transmission line, a request signal transmission line, and a permission signal transmission line. , these transmission lines must be installed in proportion to the number of terminal devices, making the configuration complex. Furthermore, since priority control between preferred devices is performed by the transmission control device,
There is a problem in that the load on the transmission control device increases.

Therefore, an object of the present invention is to provide a data collection method that can quickly collect information from each terminal station without requiring an increase in the number of wireless channels. A feature of the present invention for achieving the above object is that all terminal stations are divided into two or more groups, and the base station collects data using polling mode for some of the divided terminal station groups, and collects data from the remaining terminal stations. The purpose is to collect data from all terminal stations by collecting data from a terminal station group in interrupt mode.

Hereinafter, the system of the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a schematic block diagram of a wireless communication system to which a data collection method according to the present invention is applied. This wireless communication system 1 is a wireless communication system for establishing a disaster prevention information system for a predetermined area when various disasters occur or are likely to occur in the area. . This relatively wide area (for example, a special district unit) is divided into predetermined areas as appropriate, and a plurality of terminal stations 2 ₁ , 2 ₂ are arranged corresponding to each divided area.
_2N , and a base station 3 for controlling these terminal stations ₂₁ to _2N . The base station 3 is for collecting various types of disaster-related information from each terminal station and also giving appropriate instructions to _each terminal station _.
Frequency ₁ is used for communication from the base station 3 to the terminal station, and frequency ₂ is used for communication from each terminal station to the base station 3. When a terminal station communicates with a base station in this way, each terminal station uses the same frequency, but each terminal station transmits independently, causing interference and causing the base station to be unable to perform its functions. In order to avoid a situation in which the terminal station is unable to fulfill its requirements and to enable each terminal station to transmit necessary information to the base station under the control of the base station 3, each terminal station is provided with an identifiable predetermined A calling code is defined.
This call code is a so-called address code. Furthermore, each terminal station is divided into a plurality of terminal station groups according to a predetermined point, and each of the plurality of terminal stations belonging to each group displays the group to which it belongs in addition to the individual call code. A group call code is provided for this purpose. As will be described in detail later, the base station can use the individual calling code to call one or more terminal stations individually using the group calling code, and can also call all terminal stations belonging to a desired group all at once. is now possible.

As shown in Fig. 2, the transmission format of the transmission signal from the base station 3 includes a digital signal B for bit synchronization, a digital signal F for frame synchronization, a calling code ID of the terminal station on the other side to which the signal should be sent, and the terminal station side. It consists of a command signal C and data D for controlling various devices according to the judgment of the base station. The signal formed in this way is FM modulated in the transmitting/receiving device 3a of the base station 3, and has a frequency of ₁
The signal is transmitted as a radio wave from the antenna 3C to all terminal stations. The call code ID consists of a mode signal E consisting of 2-bit data and two individual call modes ID ₁ and ID _2. When the mode signal E is "00", it is the simultaneous call mode for all terminal stations,
“01” indicates a call to the terminal station included in individual call codes ID ₁ to ID ₂ , “10” indicates ID ₁ and ID ₂ indicate the group call code to be called, and “11” indicates a call to the terminal station included in the individual call code ID 1 to ID 2.
ID ₁ and ID ₂ are defined to indicate two call codes.

Figure 3 shows the format of the transmission signal sent from each terminal station to the base station, and this transmission format consists of digital signal B for bit synchronization, digital signal F for frame synchronization, It consists of code IDC and data D.

In FIG. 4, the terminal station ₂₁ is shown in a block diagram. Terminal station 2 ₁ includes a receiver 4 tuned to frequency ₁ and a receiver ₂ tuned to frequency 2 to detect the presence or absence of a transmission signal from another terminal station.
8, and the transmitted radio wave ₁ from the base station 3 inputted from the transmitting/receiving antenna 5 is transmitted to the antenna duplexer 2.
9 is input to the receiving section 4. On the other hand, the transmitted radio waves ₂ from other terminal stations are transmitted to the antenna duplexer 29.
The signal is extracted separately from the transmitted radio wave ₁ , and is input to the receiving section 28 via the antenna switch 6, which is normally switched to the receiving section 28 side as shown in the figure. Each receiving section 4, 28 converts input received radio waves into FM
Detection is performed and outputs detection signals S ₁ and S ₁ ', respectively.
The detected signal S ₁ from the receiver 4 is input to the amplifier 7 and at the same time to the reception register 8.
The reception register 8 stores each frame ID, command signal C, and data D based on the frame synchronization digital signal F and the bit synchronization digital signal B included in the transmission signal. The stored contents of the reception register 8 are transferred to the input/output signal controller 9. First, the call code ID is decoded in the input/output signal controller 9, and it is determined whether the received packet is addressed to the local station or not. That is, it is determined whether or not the own station is being called. If the calling address stored in the reception register 8 is for calling the own station, the input/output signal controller 9
The command signal C transferred to the terminal station is decoded, and various circuits, etc. in this terminal station are controlled according to the command signal C and data D. That is, when the received calling code matches the calling code of the local station, the input/output signal controller 9 sends a decoding signal _S2 for the command signal C to the reception control circuit 10, and this decoding signal
Based on S ₂ , the reception control circuit 10 outputs an operation command signal S 3 to the amplifier 7 for switching the amplification degree of the amplifier 7 from zero to a predetermined value, and also outputs the activation command signal S ₃ to the startup circuit 11 . It outputs an operation command signal _S4 to bring the device into the normal operating state. In this way, when the input/output signal controller 9 determines that the own station is being called, the amplifier 7 and the starting circuit 11 are activated by the operation command signals _S3 and _S4 , respectively. The detected signal S ₁ is amplified by the amplifier 7 and then power amplified by the power amplifier 12 . On the other hand, the activation circuit 11 connects the output from the power amplifier 12 to the speaker circuit 14, so that the audio signal from the base station can be transmitted as an information signal to the operator of this terminal station. Starting circuit 1
1 is connected to a first buzzer 15 and a second buzzer 18, and when a digital signal is sent to the own station, the first and second buzzers 15,
18 are activated together, and when an audio signal is sent to the base station, only the first buzzer 15 is activated to inform the operator that the base station has received information from the base station, and the information is digitally transmitted. It is possible to inform whether the signal is a signal or an audio signal. The notification by the buzzer may be performed using a single buzzer such that the type of signal is identified based on the strength of the sound.
Further, the activation circuit 11 activates the microphone circuit 16 when the base station 3 requests its own station to transmit some information by voice, and the microphone circuit 16 is activated. A display 13 is controlled to notify the operator of this by flashing a lamp. Of the data signal D from the reception register 8 input to the input/output signal controller 9, the digital information is displayed on the display unit 19 after it is confirmed that it is being transmitted to the own station.
Digitally displayed. In order to display this digital information in normal characters, etc. in an easy-to-understand manner, a code decoder (not shown) is used. It is also possible to configure the system so that the contents of the digital information can be displayed separately.

If the base station receives a general information request command in which a transmission request signal for placing the terminal station in a transmitting state is inserted into the command signal in order to request some kind of response from the terminal station, this The transmission request signal is decoded by the input/output signal controller 9, and a transmission activation signal _S20 is output to activate the transmission activation circuit 21, and the output signal _S21 causes the transmission control circuit 22 to
_S8 is output, and the transmitter 17 is placed in a transmitting state.
The transmitting state thus established can be configured to return to the receiving state after a predetermined period of time by a transmission stop command signal from the base or by an appropriate means such as a timer.

The transmitter 17 transmits the signal as described above in response to a command from the base station.
In addition to activating the transmission command signal _S5 from the input/output signal controller 9, so that the terminal station can interrupt transmission to the base station when an item to be transmitted occurs at the terminal station. An interrupt transmission activation circuit 20 is provided which starts operation accordingly. FIG. 5 shows the interrupt transmission activation circuit 20 in a circuit diagram. In Fig. 5, Tr ₁ to
Tr ₃ is a transistor, R ₁ to R ₃ are resistors, VR ₁ to VR ₃ are variable resistors, C ₁ to C ₃ are capacitors,
RL is a relay coil, SW ₁ and SW ₂ are relay coils
A switch that opens and closes in response to RL being energized, _A1 is an inverter, _A2 is a NAND circuit, _SW3 ,
SW ₄ is an input switch that opens and closes in response to the transmission command signal S ₅ , BA is a voltage source to keep the output of inverter A ₁ at "0" when switch SW ₃ is open, and OR is an OR circuit. It is. In the interrupt transmission activation circuit 20, when the transmission command signal _S5 is not input, the switch _SW3 is open;
Since switch SW ₄ that interlocks with switch SW ₃ is closed, the potential of voltage source BA is supplied to the input of inverter A ₁ , the output of inverter A ₁ is approximately at ground potential, and relay coil RL is This circuit 20 is in a de-energized state and the switches SW ₁ and SW ₂ are switched as shown by the solid lines, so this circuit 20 is in a non-operating state. When the transmission command signal _S5 is input, the switch
Since SW ₃ is closed and switch SW ₄ is opened, the output signal from the OR circuit OR is input to the input of inverter A ₁ . Since the detection signals S ₁ and S' ₁ are input to each input of the OR circuit OR, the levels of both detection signals S ₁ and S' ₁ are both below a predetermined position, that is, neither of the transmitted radio waves ₁ and ₂ The output of the OR circuit OR becomes "0" only when there is no radio wave, and the output of the OR circuit OR becomes "1" when at least one of the transmitted radio waves ₁ and ₂ is emitted.

Therefore, if the base station 3 is emitting a transmission signal of frequency ₁ or another terminal station is emitting a transmission signal of frequency ₂ , the output of the OR circuit OR is "1", so the inverter A The output of _{Tr 1} is approximately at ground potential, turning off the transistor Tr ₁ , and the relay coil RL is not energized, so the switches SW ₁ and SW ₂ remain in the state shown, and therefore the transistor Tr 1 is turned off. The collector potential of Tr ₁ is approximately the same potential as the power supply +B, and the multivibrator circuit 40 mainly composed of transistors Tr ₂ and Tr ₃ has its ground side open, so both inputs of the NAND circuit A ₂ are The level becomes high, and the output of NAND circuit _A2 is kept at approximately ground potential. However, when transmission from the base station 3 and other terminal stations 2 ₂ , 2 ₃ , ... is stopped,
Since the output of the OR circuit OR becomes "0", the output of the inverter _A1 becomes high level, the transistor _Tr1 turns on, and the relay coil RL is energized, so each switch _SW1 , _SW2 is indicated by the dotted line in the figure. It can be switched as shown. When switch SW ₁ is switched in this way, capacitor C ₁ , which was charged to the polarity shown in the figure with the current from power supply +B when switch SW ₁ was connected as shown in the solid line, is charged via variable resistor VR ₁ . Current begins to flow through the base circuit of transistor Tr ₁ , keeping transistor Tr ₁ in the on state. This holding time by capacitor C ₁ is determined by a time constant that depends on the value of capacitor C ₁ and the value of variable resistor VR ₁ . Referring to FIGS. 6a and 6b, when the output of inverter _A1 becomes high level at time t= _t1 , the relay circuit including relay coil RL operates at time t= _t2 with a time delay of Δt. , thereafter, this time constant continues to maintain the energized state of the relay coil. Therefore, during the period from time _t2 to time _t3 , the collector of transistor _Tr1 is at a low level. On the other hand, at the same time, the switch
Since SW ₂ is switched as shown by the dotted line, the multivibrator circuit 40 starts to operate, and the transistor
_The potential of _{the collector of Tr 3 is} as shown in _{FIG .} During the period from t3 to time _t3 , a transmission control signal _S7 as shown in FIG. 6d is output from the output of the NAND circuit _A2 . The high level period T ₁ and the low level period T ₂ of the output S ₆ can be appropriately determined by adjusting the values of the variable resistors VR ₂ and VR ₃ , respectively. As can be seen from the above description, this interrupt transmission activation circuit ₂₀ generates an intermittent signal as shown in FIG. outputs a transmission control signal _S7 of the form. Therefore, even if this terminal station needs to transmit and a transmission command signal _S5 for interrupt transmission is issued, the base station 3
The transmission control signal SG is generated only when the emission of transmission radio waves by terminal station ₁ is stopped and there are no transmission radio waves from other terminal stations, and this signal _S7 is intermittent. However, the detection signal S' ₁ from the receiving section 28 is not input to the interrupt transmission starting circuit 20, and the operation of this circuit 20 is controlled using only the level of the detection signal S _{' 1} from the receiving section 4, and other terminals It may be configured such that it responds only to the presence or absence of radio waves transmitted from the base station 3, regardless of the presence or absence of radio waves transmitted from the base station.In this case, the chances of interruption will increase.

Returning to FIG. 4, the transmission control signal _S7 generated as described above is input to the transmission control circuit 22, and the transmission activation signal S is outputted from the transmission control circuit ₂₂ based on this transmission control signal S7. ₈ is applied to the transmitter 17 and the antenna switch 6, and the transmitter 17 is activated and the antenna 5 is switched to the transmitter side only during the period when the signal shown in FIG. 6d is at a high level. At this time, the digital information stored in the transmission register 23 is input to the modulation input 17a of the transmission section by the function of the transmission control circuit, but the stored contents are based on the digital information specified by the command signal from the base station. This is digital information input by the operator using the numeric keypad device 24. This digital information, together with the frame synchronization signal and the calling code of this terminal station, is converted into a packet as shown in FIG. 3 and stored in the transmission register 23 in advance. In the illustrated embodiment, this packet α has a length of 1/3 of one transmission period T ₁ , and the same packet is repeatedly transmitted 3 times during period T ₁ .
times are sent to the base station. However, it goes without saying that the configuration may be such that any number of packets can be sent during this period _T1 . An ETX code is attached to the end of this transmitted data to indicate that the data has ended.
The ETX code is decoded within the transmission control circuit 22,
Based on this decoding result, the transmitting state is automatically switched to the receiving state. When the base station confirms reception of this transmission signal, it sends out a predetermined confirmation code with the calling code of this terminal station attached.
Therefore, when this terminal station becomes in the receiving state during the next period _T2 , this terminal station confirms that it is being called and decodes this confirmation code as described above. In this way, the transmission command signal _S5 is canceled and unnecessary transmissions are not performed thereafter.

On the other hand, if the request from the base station 3 is a voice response, a command signal to that effect is decoded by the input/output signal controller 9, and the activation circuit 1
1 puts the microphone circuit 16 into the operating state, a continuous transmission command signal S ₉ is sent out instead of the transmission command signal S ₅ , and the transmission control circuit 22 amplifies the contents of the transmission register 23 by the amplifier 25 . Applying the output from the microphone circuit 16 to the modulation input 17a via the amplifier 25 and the transmission control circuit 22,
Signal S ₈ is continuously outputted by signal S ₉ and desired information is transmitted back to the base station in the form of voice. Therefore, from the base station 3 to the terminal station 2 ₁ , it is transmitted at the frequency ₁ , and at the same time from the terminal station 2 ₁ to the base station 3
Two-way communication is possible because the signals are transmitted on _two frequencies.

Further, the input/output controller 9 receives an output from a sensor 26 such as a device for measuring the water level of a river or other automatic measuring device, and the output signal from the sensor 26 is inputted to the input/output controller 9. It can be sent to the base station as a digital signal in the same way as the signal. Therefore, if a command signal to transmit the output signal from the sensor 26 is included in the transmission signal from the base station side, the input/output signal controller 9 transmits the output signal from the sensor 26 to the transmission register 23. At the same time, the contents of the transmission register 23 are transmitted at the predetermined timing as described above. That is, by preparing various automatic measuring devices as the sensors 26 and connecting them to the input/output signal controller 9, the base station can easily obtain desired information on a predetermined area. In this case, if the sensor outputs highly urgent information (for example, information to notify that the water level of a river has become extremely dangerous), it will be automatically activated at the terminal station. Based on this judgment, it is best to configure the system so that the interrupt transmission activation circuit 20 is automatically activated even without polling from the base station, so that this highly urgent information can be automatically transmitted by interrupt transmission. desirable.

As mentioned above, in this communication system, the terminal station basically receives information from the base station, and only when the base station deems it necessary, sends the terminal station to the transmitting state by a command signal from the base station, and transmits the required digital data. Or, audio data is transmitted toward the base station to ensure orderly communication between the base station and the terminal station, but if a serious and emergency situation occurs on the terminal station side, The above-mentioned interrupt transmission activation circuit 20 is used so that the terminal station can call the base station without causing confusion in the communication operations of the base station. When the terminal station issues a request to communicate with the base station, by pressing an interrupt transmission button (not shown) included in the numeric keypad device 24, the transmission command signal _S5 is forcibly output. When the switch SW ₃ shown in FIG. 5 is closed and the switch SW ₄ is opened, the call code of the local station and predetermined code information requesting communication are stored in the transmission register 23, as described above. The contents stored in the transmission register 23 are then transmitted to the base station. In this case too,
The same applies to automatically stopping emergency transmission from the terminal station by returning a confirmation code after confirmation at the base station. If there are multiple terminal stations for which you want to perform this interrupt transmission, if each terminal station interrupts at the same time after a predetermined period of time has elapsed after transmission from the base station has stopped, the terminal station that issued the interrupt will Since the transmitted waves are all duplicated and cannot be distinguished by the base station, by changing the timing indicated by time _t2 in Figure 6 for each terminal station, each terminal station transmits at different timings, and the terminal station It is now possible for the base station to easily identify the transmitted waves. When a large number of such interrupt transmissions are received from terminal stations, the base station appropriately judges which of these interrupt transmissions are considered to be of low importance, and forces the transmission state of the corresponding terminal station. It can be stopped automatically. This forced transmission stop operation may be performed, for example, by sending back a confirmation code from the base station to the terminal station, as described above.

When an emergency situation such as an earthquake occurs in the area under the control of the base station 3, in order to appropriately deal with the emergency situation, the base station 3 receives necessary information from each terminal station, such as the presence or absence of a fire, and sends it to the base station. It is necessary to collect data at station 3 within a short period of time. Therefore, in this system, all terminal stations are divided into several groups, and the base station collects data from each terminal station in each group by collecting data using polling mode and interrupt mode. It's summery.

Therefore, the terminal station ₂₁ includes a modulation detection unit 50 that detects whether the received radio wave ₁ of the frequency ₁ is modulated, and a modulation detection unit 50 that detects whether the radio wave of the frequency ₁ is transmitted from the base station 3. It has a carrier wave detection section 51 for detecting the carrier wave, and an interrupt permission command detection section 52 connected to the receiving register 8 for detecting the interrupt permission command addressed to the own station inserted into the received radio wave of frequency ₁ . Detection units 50, 51,
52 outputs the determination results in each as a binary signal. That is, the detection signal from the modulation detection section 50
S ₅₀ becomes “1” only when the received wave ₁ is modulated, and the detection signal from the carrier wave detection unit 51
S ₅₁ becomes "1" only when receiving wave ₁ is being transmitted, and detection signal S ₅₂ from interrupt permission command detection section 52 becomes "1" only when receiving wave ₁ has an interrupt permission command signal inserted. It becomes "1". These detection signals S ₅₀ to S ₅₂ and the interrupt output from the transmission register 23 become "1" if there is information to be transmitted by the interrupt, and become "0" if there is no information to be transmitted. Include request signal S ₅₃
is input to the logic discrimination circuit 53. The logic discrimination circuit 53 consists of inverters 54 to 57, NOR circuits 57, 58, and an AND circuit 59, and when the received wave is not modulated, an interrupt enable command is given, and there is an interrupt element. It outputs a first activation control signal S ₅₄ that becomes "1" only when there is an interrupt request and a second activation control signal S ₅₅ that becomes "1" only when there is an interrupt request and _one wave is not transmitted.
Both activation control signals S ₅₄ and S ₅₅ are sent to the interrupt transmission activation circuit 20
When either signal becomes "1", the interrupt transmission activation circuit 20 is activated. Although only the terminal station 2 ₁ has been explained above, other terminal stations 2 ₂ ,
2 ₃ ,...2 _N are similarly configured.

Next, a method will be described in which, when an emergency situation occurs, the base station 3 obtains necessary information from terminal stations within its coverage area in a short time using the system of the present invention.

When an emergency situation occurs and the base station 3 wants to collect various information from the terminal station, that is, when there is a request to perform scanning within a short period of time, the base station 3 continuously transmits _one wave. This keeps each terminal station in a state where transmission is prohibited. Next, the base station 3 collects data from terminal stations in a predetermined group of terminal stations in a polling mode. For example, if terminal stations No. 0001 to No. 0100 are considered as one terminal station group, the contents stored in each transmission register 23 for each terminal station constituting this terminal station group _are It is transmitted to the base station 3 by waves. The time required for this polling operation for each station is approximately 1 minute per 100 terminal stations. In this way No.0001
After polling of terminal stations from No. 0100 to No. 0100 is completed, next, polling of other terminal stations (for example No. 2000 to No.
An interrupt permission code is given to all 1,600 terminal stations at once. This is executed by using a call code ID specifying these terminal station groups as a call code and inserting an interrupt permission command into the command signal C. Since the detection signal S ₅₂ of these terminal stations becomes "1", when the transmission of the interrupt permission command is completed and _one wave becomes unmodulated and the signal S ₅₀ becomes "1", the transmission register 23 If the interrupt request signal _S53 is output, the first activation control signal _S54 is set to "1" by the function of the logic discrimination circuit 53.
Then, the interrupt transmission activation circuit 20 is activated. Such an operation is performed for each of the 400 terminal stations in this terminal station group, and among these terminal stations, stations that have an interrupt request interrupt the base station 3 all at once. Since this interrupt operation is basically as described above, a similar explanation will be omitted here again. The time given to this interrupt operation is set to 10 seconds in total, and each terminal station receives the interrupt permission command, decodes that _{the first} wave is unmodulated, and then issues the interrupt after a predetermined time tx. Start. This predetermined time tx is set to a different time for each of these 400 terminal stations to prevent interference as much as possible. If modulation is applied to _one wave before the above predetermined time tx has elapsed, the terminal station will cancel the interruption in advance, and the predetermined time tx will elapse after _{the first} wave becomes unmodulated again. Interrupt later.

Once the 10 second period mentioned above has elapsed, base station 3
transmits a register clear code for clearing the contents of each transmission register 23 to these 400 terminal stations, and causes these terminal stations to cancel interrupts. Therefore, while transmitting the register clear code,
Since _one wave is modulated, no interrupts can be made from the terminal stations of the group. In this case, it is also possible to send an interrupt prohibition code to each of these terminal stations to temporarily stop the interrupt before the predetermined 10 second period has elapsed. In this case, the interrupt operation is simply stopped, and the contents stored in the transmission register 23 are not erased.

When the predetermined interrupt mode period ends in this manner, the base station 3 again selects a predetermined group of terminal stations (No.
Data is collected from terminal stations (No. 200 to No. 300) by polling mode, and then from another group of terminal stations (No. 1200 to No. 1200).
1599) in interrupt mode. In this way, the polling mode period and the interrupt mode period are set alternately for each terminal station group,
By collecting information from a group of terminal stations blocked in advance for each period, information can be collected in an extremely short time. In the above example of running this for 2000 terminal stations, from No.0001
For terminal stations up to No. 400, data is collected in polling mode every 100 stations, and from No. 401 to No.
For up to 2000 terminal stations, data is collected in interrupt mode every 400 stations, so in the end, the data is 60 x 4 +
Information can be collected from all terminal stations in 10×4=280 [seconds], that is, 4 minutes and 40 seconds. In the above, the interrupt mode time is set to 10 seconds for 400 stations, but it is not limited to 10 seconds and can be increased or decreased as appropriate depending on the circumstances. Further, if information is still insufficient even after collecting information for the 2000 terminal stations as described above, the information may be collected again using the same method. Furthermore, in the above embodiment, a case has been described in which all terminal stations are divided into two terminal station groups, and data collection is performed by alternately performing data collection in polling mode and data collection in interrupt mode. The invention is not limited to such an information collection method, but for example, terminal stations No. 0001 to No. 400,
Divided into two terminal station groups consisting of terminal stations No. 401 to No. 2000, data collection is performed for one terminal station group in polling mode, and then an interrupt is sent to the other terminal station group. Data collection may be performed depending on the mode.

Here, the method of grouping the terminal stations is to monitor the data transmission rate from the terminal stations in the interrupt mode at the base station, and to monitor the transmission data that is transmitted by interrupt within a predetermined time when the number of interrupts is large. If it is not possible to judge the number of terminal stations in one terminal station group,
On the other hand, if the number of interruptions is small, the number of terminal stations in one terminal station group may be increased to 400 or less. This allows for extremely highly efficient data collection. It becomes possible to do this.

Furthermore, in the above embodiment, when data is collected from a terminal station using the interrupt mode, the interrupt mode period is limited to 10 seconds; If it is not possible to process all of the data, data collection may be performed again in interrupt mode for the terminal station group.

In this way, polling mode and interrupt mode are used together when collecting data from each terminal station, so in the event of an emergency, various information from each terminal station can be transmitted to the base station extremely quickly. Therefore, useful information can be accurately grasped at the base station in the early stages after an earthquake, fire, etc. occurs, before the damage spreads. Therefore, it is extremely effective for local disaster prevention, since it is possible to take extremely effective and appropriate treatment for disasters that require appropriate treatment at the initial stage.

As described above, according to the present invention, all the terminal stations are divided into two or more groups by using both the polling mode and the interrupt mode, and the base station sends data to some of the divided terminal station groups using the polling mode. This system collects data from all terminal stations by setting the remaining terminal station groups to interrupt mode and collecting data from all terminal stations.Moreover, simultaneous transmission from multiple terminal stations is possible. This method allows data to be collected from each terminal station to the base station while avoiding this, and has the effect that various information from each terminal station can be collected to the base station extremely quickly.

Further, according to the present invention, the data can be collected using only two wireless channels regardless of the number of terminal stations, and the number of wireless channels can be reduced.

Furthermore, in the present invention, the base station monitors the data transmission rate from terminal stations in interrupt mode, groups terminal stations, and collects data in polling mode and interrupt mode in group units, which is extremely effective. This has the effect of making it possible to collect data highly efficiently and in accordance with the situation.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram schematically showing the communication system of the present invention, FIG. 2 is a diagram showing the transmission format of a transmission signal from the base station in FIG. 1, and FIG. 4 is a block diagram of the terminal station in FIG. 1, and FIG. 5 is a circuit diagram of the interrupt transmission activation circuit in FIG. 4.
6a to 6d are waveform diagrams for explaining the circuit of FIG. 5. FIG. 1... Wireless communication system, 2 ₁ , 2 ₂ ,... 2 _N ...
Terminal station, 3... Base station, 4... Receiving section, 9... Input/output signal controller, 17... Transmitting section, 20... Interrupt transmission starting circuit, 50... Modulation detecting section, 51... Carrier wave detecting section, 5
2...Interrupt permission command detection unit, 53...Logic discrimination circuit, _S1 , _S'1 ...detection signal, _S2 ...decoding signal, _S3 ...operation command signal, _S4 ...operation command signal, _S5 ...transmission command Signal, S ₇ … Transmission control signal, S ₈ … Transmission activation signal, S ₉ …
Continuous transmission command signal, _S50 , _S51 , _S52 ...detection signal,
_S53 ...interrupt request signal, _S54 ...first activation control signal,
S ₅₅ ...Second activation control signal.

Claims (1)

[Claims] 1. A receiving section, each of which is assigned a corresponding identification code and responds to first and second frequencies, and a transmitter that transmits information including the corresponding identification code by the second frequency. a base station that transmits information including a corresponding identification code on a first frequency and receives information in response to a second frequency; A data collection method in which a base station controls wireless connections between a base station and a plurality of terminal stations and collects data from the plurality of terminal stations to the base station, wherein the transmission control unit of each terminal station controls the wireless connection between the base station and a plurality of terminal stations, When activating the transmitter in response to a polling mode from a base station received by the base station and activating the transmitter in response to an interrupt mode from the base station, either the base station or another terminal station If there is no transmission from the first group, the transmitter is configured to operate, and the plurality of terminal stations are divided into a plurality of groups, and in the polling mode from the base station, the terminal stations of the first group sequentially send the required information to the base station. data collection, characterized in that after the polling mode, the terminal station to which the information should be transmitted among the terminal stations in another group transmits the required information to the base station in the interrupt mode. method.