JPH07140237A - Radio response system - Google Patents

Abstract

PURPOSE:To provide a radio response system which can select a responder to be interrogated even if plurality of responders are installed within a communications area. CONSTITUTION:An interrogator 1 has a control portion which generates interrogation signals for generating interrogation waves, a transmitting portion which transmits an interrogation wave (a) in response to the interrogation signal, and a receiving portion which receives response waves (b) to (d), and each responder 2 to 4 has an antenna which generates a reception signal when receiving the interrogation wave (a), a power source portion which generates power according to the reception signal, a control portion which starts operating on this power to generate a response signal, and a transmitting portion which transmits the response wave (b) to (d) from the antenna in response to the response signal. The control portion of the interrogator 1 varies the form of the interrogation signal depending on the responders 2 to 4, and the control portion of each responder 2 to 4 determines whether or not the interrogation wave (a) received by the antenna is directed to it, and generates the response signal (b) to (d) when determining that the interrogation wave (a) is directed to it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless response system for wirelessly checking the condition of a remote place.

[0002]

2. Description of the Related Art A wireless response system includes an interrogator that wirelessly transmits an inquiry wave for an inquiry, and a transponder that transmits a response wave to the interrogator in response to the inquiry wave. The transponder is installed in the communication area of the interrogator, and when receiving the interrogation wave from the interrogator, the transponder starts its operation by using the power of the interrogation wave and transmits the response wave to the interrogator.

With this wireless response system, the state of a remote installation place can be monitored without supplying power to the responder. Such a wireless response system is disclosed in Japanese Patent Application Laid-Open No. 4-147082.

[0004]

When the state of a plurality of places is monitored using this wireless response system, it is conceivable to install a plurality of responders in the communication area. However, when a plurality of transponders are installed, all the transponders in the communication area transmit the response wave to the interrogation wave from the interrogator, so that the interrogator side cannot select the transponder.

An object of the present invention is to eliminate the above drawbacks and to provide a radio response system which enables selection of the responders even if a plurality of responders are installed in the communication area.

[0006]

In order to achieve the object, the present invention provides an interrogator for transmitting an interrogation wave for inquiries and a reception signal when the interrogation wave is received. Based on the reception signal, The interrogator includes a plurality of transponders that transmit an interrogation wave, and the interrogator includes a controller that generates an interrogation signal for interrogation wave generation, and a transmitter that transmits the interrogation wave by the interrogation signal from the control unit. , A response unit that receives the response wave, and each responder includes an antenna that generates a reception signal when the interrogation wave is received, a power supply unit that generates power based on the reception signal from the antenna, and the power of the power supply unit. In a wireless response system that includes a control unit that starts an operation in to generate a response signal, and a transmission unit that transmits a response wave from an antenna using the response signal of the control unit, the control unit of the interrogator responds to the responder. Change the form of the question signal and The control unit of the vessel, the antenna receives a question wave is determined whether or not for its own device, for generating a response signal when found to own device for.

[0007]

With this configuration, when making an inquiry to the responder, the controller of the interrogator generates an inquiry signal. At this time, the control unit changes the form of the interrogation signal according to each responder. The transmission unit transmits the interrogation wave by the interrogation signal from the control unit.

The antenna of each transponder generates a reception signal when receiving the interrogation wave from the interrogator, and the power supply section generates electric power based on the reception signal. The control unit starts operation with the power of the power supply unit and generates a response signal. At this time, the control unit determines whether the interrogation wave received by the antenna is for the device itself, and generates a response signal when it is determined that the interrogation wave is for the device itself. The transmission unit transmits a response wave from the antenna to the interrogator by using the response signal from the control unit.

The receiver of the interrogator receives the response wave from the responder.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
It is a block diagram showing. This wireless response system includes an interrogator 1 that transmits an inquiry wave a for an inquiry, and responders 2, 3, and 4 that respectively transmit response waves b, c, and d to the interrogator 1 when the inquiry wave a is received. Equipped with. Transponder 2,
Reference numerals 3 and 4 are installed in different locations within the communication area of the interrogator 1 to monitor the status of the installation location.

As shown in FIG. 2, the interrogator 1 of the wireless response system includes a power supply unit 11, a control unit 12, and a RAM.
A (Random Access Memory) 13, a transmission circuit 14, an antenna 15, and a reception circuit 16 are provided. Control unit 12
Is a signal control circuit 12A and a CPU (Central Processi).
ng Unit) 12B and an amplifier circuit 12C. Further, the transmitting unit is composed of the transmitting circuit 14 and the antenna 15, and the receiving unit is composed of the antenna 15 and the receiving circuit 16.

The power supply unit 11 supplies DC power to the control section 12 to the transmission circuit 14 and the reception circuit 16.

The signal control circuit 12A of the control unit 12 has a CP
The U12B holds information for generating an inquiry signal and sending it to the amplifier circuit 12C.

When making an inquiry to the responders 2 to 4, the CPU 12B generates an inquiry signal for transmitting the inquiry wave a based on the information from the signal control circuit 12A, and sends the inquiry signal to the amplifier circuit 12C. At this time, when the responder 3 is selected, the CPU 12B sets the level of the inquiry signal to the responder 2 level.
Instruct to increase the level of the inquiry signal sent to. Similarly, when the responder 4 is selected, the level of the interrogation signal is instructed to be higher than that of the responder 3.

When the CPU 12B receives a reception signal from the reception circuit 16, it extracts data from the reception signal and sends it to the RAM 13.

The RAM 13 is a RAM for a data buffer.
And stores the data of the responders 2, 3, and 4 from the CPU 12B, respectively.

The amplifier circuit 12C is a circuit whose amplification degree changes according to an instruction from the CPU 12B. That is, the amplifier circuit 1
2C sends the inquiry signal from the CPU 12B to the CPU
Amplify based on instructions from 12B.

The transmission circuit 14 transmits the interrogation wave a from the antenna 15 in response to the interrogation signal from the amplifier circuit 12C.

The receiving circuit 16 generates received signals by the response waves b, c and d received by the antenna 15 and sends them to the CPU 12B.

The interrogator 1 has such a structure.

As shown in FIG. 3, the transponder 2 includes an antenna 21, a power supply section 22, a control section 23, and a transmission circuit 24 as a transmission section. The power supply unit 22 includes a rectifier circuit 22.
The control section 23 includes an amplitude determination circuit 23A, a ROM (Read Only Memory) 23B, and a CP.
U23C.

The rectifier circuit 22A of the power supply unit 22 rectifies the interrogation wave a received by the antenna 21, that is, the high frequency power.

The power supply circuit 22B converts the high frequency power rectified by the power supply unit 22 into DC power. Then, the DC power is supplied to the amplitude determination circuits 23A to 23C and the transmission circuit 24.

The ROM 23B stores in advance data relating to the place where the device is set. ROM23
B is the CPU 2 due to the DC power from the power supply circuit 22B.
The data can be read by 3C.

The amplitude determination circuit 23A starts operating with the DC power from the power supply circuit 22B, and the antenna 21 causes the interrogation wave a.
It is determined whether or not the level of the level of the received signal generated by receiving the signal is for the device itself. For this reason, the amplitude determination circuit 23A is set to the level of the signal corresponding to its own device, for example, and the amplitude determination circuit 23A compares this set value with the level of the received signal.

The CPU 23C starts operating with the DC power from the power supply circuit 22B, and the interrogation wave a is generated by the amplitude determining circuit 23A.
When it is determined to be for the own device, the data is read from the ROM 23B as a response signal according to the determination result.

The transmission circuit 24 transmits the response wave b modulated by the response signal from the CPU 23C from the antenna 21.

The transponder 2 has such a structure. The transponders 3 and 4 have the same configuration as the transponder 2.

Next, the operation of the first embodiment will be described.

When making an inquiry by selecting the responders 2, 3 and 4, the CPU 12B of the interrogator 1 generates an inquiry signal based on the control information of the signal control circuit 12A and sends it to the amplifier circuit 12C. At this time, the CPU 12B makes the level of the inquiry signal higher than that of the responder 2 when making an inquiry to the responder 3, and makes the level of the inquiry signal larger than that of the responder 3 when making an inquiry to the responder 4. Instruct the amplifier circuit 12C.

The amplifier circuit 12C amplifies the interrogation signal according to an instruction from the CPU 12B and sends the interrogation signal shown in FIG. At this time, of the interrogation signals, the interrogation signal of level A1 is for the transponder 2. Further, the interrogation signal of level A2 is for the transponder 3, and the interrogation signal of level A3 is for the transponder 4.

Upon receiving the interrogation signal from the amplifier circuit 12C, the transmission circuit 14 transmits the interrogation wave a from the antenna 15.

When the antenna 21 of the transponder 2 receives the interrogation wave a, the rectifier circuit 22A rectifies the high frequency power of the interrogation wave a, and the power supply circuit 22B converts the rectified high frequency power into DC power. The amplitude determination circuits 23A to 23C and the transmission circuit 24 operate with this DC power.

The amplitude determination circuit 23A determines whether or not the level of the received signal from the antenna 21 is for its own device. If it is determined to belong to its own device, CPU23C
When the inquiry signal ends, the data is read from the ROM 23B to generate a response signal, and the response signal is sent to the transmission circuit 24. The transmission circuit 24 receives the response wave b with this response signal.
To send.

Similar processing is performed in the responders 3 and 4. That is, when it is determined that the interrogation wave a is for the device itself, the responders 3 and 4 transmit the response waves c and d, respectively.

The receiving circuit 16 of the interrogator 1 has an antenna 15
Received signals are generated from the response waves b, c, and d received by and are sent to the control unit 11. The control unit 11 reads out the data of the transponders 2, 3 and 4 from the received signal and stores the data in the RAM 13, respectively.

As described above, in the first embodiment, since the responders are designated by the level of the interrogation signal, the interrogators 1 can select the transponders to be interrogated.

Since the responders 2, 3 and 4 transmit the response waves b, c and d after the interrogation wave a to the own device is completed, the response waves b, c and d can be prevented from interfering with each other. As a result,
The interrogator 1 can normally receive the data from the responders 2, 3, and 4.

In the first embodiment, the three transponders 2, 3 and 4 are installed in the communication area of the interrogator 1, but the present invention is not limited to this. At this time, the level of the interrogation signal may be increased according to the number of transponders installed.

[Embodiment 2] In Embodiment 2, the interrogator 1 of Embodiment 1 shown in FIG. 5 is used. Interrogator 1
A power supply unit 11, a RAM 13, a transmission circuit 14,
The antenna 15, the receiving circuit 16, and the control unit 17 are provided. The control unit 17 includes a signal control circuit 17A and a CPU 17
B and a time setting circuit 17C. Here, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The signal control circuit 17A of the control section 17 holds information for generating a burst interrogation signal of a length set for the transponders 2, 3 and 4.

The time setting circuit 17C specifies the burst length of the inquiry signal when making an inquiry. That is,
When the responder 2 is designated, the short burst is designated among the bursts for the responders 2, 3 and 4. When the responder 3 is designated, an intermediate burst is designated, and when the responder 4 is designated, a long burst is designated.

When the burst length is designated by the time setting circuit 17C, the CPU 17B generates a burst interrogation signal of the designated length based on the information from the signal control circuit 17A, and transmits this interrogation signal. Send to circuit 14. Also, C
When receiving the reception signal from the reception circuit 16, the PU 17B extracts data from the reception signal and sends it to the RAM 13.

The interrogator 1 has such a structure.

As shown in FIG. 6, the transponder 2 includes an antenna 21, a power supply section 22, a transmission circuit 24, and a control section 25. The control unit 25 includes a time determination circuit 25A and an RO
It is provided with an M25B and a CPU 25C. Here, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The time determination circuit 25A of the control unit 25 starts operating with the DC power from the power supply circuit 22B, and the antenna 2
1 determines whether the burst length of the received signal generated by receiving the interrogation wave a is for its own device. Therefore, the time determination circuit 25A reads the length of the received signal, and determines whether this length is a time peculiar to the own device.

The ROM 25B is the R of the transponder 2 of the first embodiment.
Same as OM23B.

The CPU 25C starts operating with the DC power from the power supply circuit 22B, and when the time determination circuit 25A determines that the interrogation wave a is for its own device, the ROM 2
Data is read from 5B and used as a response signal.

The transponder 2 has such a structure. The transponders 3 and 4 have the same configuration as the transponder 2.

Next, the operation of the second embodiment will be described.

When the responders 2, 3 and 4 are selected to make an inquiry, the time setting circuit 17C of the interrogator 1 is based on the control information of the signal control circuit 17A.
Specify a burst length specific to. CPU 17B
Based on the designation of the time setting circuit 17C, an inquiry signal is generated and sent to the transmission circuit 14.

In this case, when making an inquiry to the responder 3, the burst length of the inquiry signal is set longer than that of the responder 2. When making an inquiry to the responder 4, the burst length of the inquiry signal is set longer than that of the responder 3. For this reason, as shown in FIG. 7, the interrogation signal length B2 for the transponder 3 is equal to the interrogation signal length B1 of the transponder 2.
Further, the length B3 of the interrogation signal for the transponder 4 becomes longer than the length B2 of the interrogation signal for the transponder 3.

The interrogator 1 receives the interrogation wave a by this interrogation signal.
To send.

When the antenna 21 of the transponder 2 receives the interrogation wave a, the CPU 25C determines whether or not the burst length of the received signal is for its own device. When it is determined that the device is for its own device, the CPU 25C reads the data from the ROM 25B and sets it as a response signal when the inquiry signal ends. Then, the response signal is sent to the transmission circuit 24. The responder 2 transmits the response wave b with this response signal.

The same process is performed in the responders 3 and 4. That is, when it is determined that the interrogation wave a is for the device itself, the responders 3 and 4 transmit the response waves c and d, respectively.

The receiving circuit 16 of the interrogator 1 has an antenna 15
Received signals are respectively generated from the response waves b, c, d received by and are sent to the CPU 17B. The CPU 17B reads the data of the transponders 2, 3 and 4 from the received signal and stores the data in the RAM 13, respectively.

As described above, in the second embodiment, since the responders are designated by the burst length of the interrogation signal, the interrogators 1 can select the responders to be interrogated.

In the second embodiment, three transponders 2, 3 and 4 are installed in the communication area of the interrogator 1, but the present invention is not limited to this. At this time, the burst length of the inquiry signal may be changed according to the number of transponders installed.

[Third Embodiment] In the third embodiment, the interrogator 1 of the first embodiment shown in FIG. 8 is used. Interrogator 1
A power supply unit 11, a RAM 13, a transmission circuit 14,
The antenna 15, the receiving circuit 16, and the control unit 18 are provided. The control unit 18 includes a signal control circuit 18A and a CPU 18
B and an ID (Identification) code generator 18C. Here, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The signal control circuit 18A of the control section 18 holds information for generating an inquiry signal to which the ID code set for the responders 2, 3, 4 is added.

When making an inquiry, the ID code generator 18C generates an ID code according to the responders 2, 3 and 4. That is, when the responder 2 is designated, "1011" is generated as the ID code. When the responder 3 is designated, an ID code "0100" is generated,
When the responder 4 is designated, an ID code of "1101" is generated.

When the responder is designated, the CPU 18B
The ID code generator 18C generates an inquiry signal to which the generated ID code is added, and sends the inquiry signal to the transmission circuit 14. When the CPU 18B receives a reception signal from the reception circuit 16, the CPU 18B extracts data from the reception signal and outputs R
Send to AM13.

The interrogator 1 has such a structure.

As shown in FIG. 9, the transponder 2 includes an antenna 21, a power supply section 22, a transmission circuit 24, and a control section 26. The control unit 26 includes an ID code discriminator 26A,
The ROM 26B and the CPU 26C are provided. Here, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The ID code discriminator 26A of the control unit 26 is
The operation is started by the DC power from the power supply circuit 22B, and it is determined whether or not the ID code of the received signal generated by the antenna 21 receiving the interrogation wave a is for its own device.

The ROM 26B is the R of the transponder 2 of the first embodiment.
Same as OM23B.

The CPU 26C starts its operation with the DC power from the power supply circuit 22B, and when the ID code discriminator 26A discriminates that the interrogation wave a is for its own device, RO
Data is read from M26B and used as a response signal.

The transponder 2 has such a structure. The transponders 3 and 4 have the same configuration as the transponder 2.

Next, the operation of the third embodiment will be described.

When selecting the responders 2, 3 and 4 to make an inquiry, the ID code generator 18C of the interrogator 1 generates ID codes for all the responders 2, 3 and 4.
The CPU 18B generates an inquiry signal added with the ID code from the ID code generator 18C and sends it to the transmitting circuit 14. As shown in FIG. 10, this inquiry signal has an ID code “1011” added after the inquiry signal for the responder 2. Also, after the interrogation signal to the responder 3, the ID
The code "0100" is added, and the ID code "1101" is added after the interrogation signal to the responder 4.

The interrogator 1 transmits an interrogation wave a in response to this interrogation signal.

When the antenna 21 of the responder 2 receives the interrogation wave a, the ID code discriminator 26A discriminates whether or not the ID code of the received signal is for its own device. When the interrogation wave a is determined to be directed to the own device, the CPU 26C determines that the ID code following the interrogation signal for the own device is terminated,
Data is read from the ROM 26B and used as a response signal.
Then, the response signal is sent to the transmission circuit 24. The transponder 2 is
The response wave b is transmitted by this response signal.

Similar processing is performed in the transponders 3 and 4. That is, when it is determined that the interrogation wave a is for the device itself, the responders 3 and 4 transmit the response waves c and d, respectively.

The receiving circuit 16 of the interrogator 1 has an antenna 15
Received signals are generated from the response waves b, c, and d received by and are sent to the CPU 18B. The CPU 18B reads the data of the transponders 2, 3 and 4 from the received signal and stores the data in the RAM 13, respectively.

As described above, in the third embodiment, I is added to the inquiry signal.
Since D code is added and each responder is specified,
The responder can be selected on the interrogator 1 side.

In the third embodiment, three transponders 2, 3 and 4 are installed in the communication area of the interrogator 1, but the present invention is not limited to this. At this time, the number of ID codes to be added to the inquiry signal may be increased according to the number of transponders installed.

[0078]

As described above, according to the present invention, the control unit of the interrogator changes the form of the interrogation signal when the interrogation signal is generated, and the control unit of each responder responds to the received interrogation wave. It is determined whether or not it is for the own device, and a response signal is generated when it is determined to be for the own device. As a result, if the interrogator side decides the form of the interrogation signal, it is possible to specify the responder to inquire.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of an interrogator of the first embodiment.

FIG. 3 is a block diagram showing an example of a transponder of the first embodiment.

FIG. 4 is a waveform diagram of the first embodiment.

FIG. 5 is a block diagram showing an example of an interrogator according to a second embodiment.

FIG. 6 is a block diagram showing an example of a transponder according to a second embodiment.

FIG. 7 is a waveform diagram of the second embodiment.

FIG. 8 is a block diagram illustrating an example of an interrogator according to a third embodiment.

FIG. 9 is a block diagram showing an example of a transponder according to a third embodiment.

FIG. 10 is a waveform diagram of the third embodiment.

[Explanation of symbols]

 1 Interrogator 2 to 4 Responder a Interrogation wave b to d Response wave

Claims (4)

[Claims] 1. An interrogator that transmits an interrogation wave for inquiries, and a plurality of transponders that generate a reception signal when the interrogation wave is received and transmit a response wave to the interrogation device based on the reception signal. The interrogator includes a control unit that generates an interrogation signal for interrogation wave generation, a transmission unit that transmits the interrogation wave with the interrogation signal from the control unit, and a reception unit that receives the response wave, Each of the transponders receives an interrogation wave, an antenna that generates a reception signal, a power supply unit that generates electric power based on the reception signal from the antenna, and an electric power of the power supply unit to start an operation to generate a response signal. In a wireless response system that includes a control unit that generates and a transmission unit that transmits a response wave from the antenna with a response signal of the control unit, the control unit of the interrogator has a form of an interrogation signal according to the responder. Change each of the responders Control unit, a wireless response system interrogation wave the antenna has received, it is determined whether or not for its own device, characterized by generating a response signal when found to own device for. 2. The control unit of the interrogator changes the level of the interrogation signal in accordance with the responder, and the control unit of each responder determines whether the level of the interrogation wave received by the antenna is for its own device. The wireless response system according to claim 1, wherein the wireless response system generates a response signal when it is determined whether the device is for the device itself. 3. The control unit of the interrogator changes the burst length of the interrogation signal according to the responder, and the control unit of each responder controls the burst length of the interrogation wave received by the antenna. The wireless response system according to claim 1, wherein the wireless response system generates a response signal when it is determined that it is for the own device, and when it is determined to be for the own device. 4. The control unit of the interrogator adds identification information to the interrogation signal according to the responder, and the control unit of each responder uses the identification information of the interrogation wave received by the antenna as its own device. To determine if
The wireless response system according to claim 1, wherein a response signal is generated when it is determined that the device is for the own device.