JPH05333145A - Data carrier system - Google Patents

Abstract

PURPOSE:To prevent radio interference between a parent machine and a plurality of child machines by enabling the plurality of child machines to transmit response signals respectively in the different timing, and enabling the parent machine to communicate these with the child machines in reception order. CONSTITUTION:After a transmission part 2 of a parent machine 1 modulated serial signal output of a microcomputer part 4, it is converted into a light signal, and is transmitted. A reception part 3 is put in a receivable condition. Child machines 5 keep reception parts 6 in a parent machine 1 question receivable condition, and after a transmission part 7 modulated serial signal output of a microcomputer part 8, it is transmitted. After both the reception parts 3 and 6 demodulated the respectively received modulated signals, those are supplied to the computer parts 4 and 8. Now, when radio interference is caused due to responses of the plurality of child machines, the parent machine 1 outputs a signal of 'Information can not read due to radio interference.' In the case where radio interference information signal is received when communication between the mutual child machines 5 is impossible, the respective child machines 5 respond by delaying a time by a random hour or by a child machine proper hour. The parent machine 1 repeats this operation until information of the whole child machines 5 can be obtained, so that the radio interference can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data carrier system suitable for use in a system for communicating data between at least one master unit and a plurality of slave units.

[0002]

2. Description of the Related Art Conventionally, a wireless contactless mobile data carrier system has been used for management of an automated warehouse and management of vehicles and people. Many of these devices receive a base unit (also called an interrogator) having a function of emitting a radio wave into the air, receive a radio wave emitted from the base unit, modulate the received radio wave, and provide some information. Mixed in,
By combining with a child device (also called a responding device) having a function of transmitting to the parent device, information is transmitted and received while the parent device and the child device are relatively moving or stationary.

The information to be mixed on the slave unit side includes, for example, an ID code for identifying the slave unit in the master unit. In addition, most of the radio waves emitted from the base unit are currently widely used, but since the frequency is high and the radiated radio waves have directivity, the communication range between the base unit and the base unit is In addition to the relative distance between the mobile device and the mobile device, the directivity of the radio waves limits the range.

In general, the slave unit is designed to sequentially pass in front of the master unit, that is, within the communication range at a predetermined interval, and within the communication range, the mutual communication described above is performed. Be done. Then, the master unit receives the ID code from the slave unit to identify the slave unit that has entered the communication range.

[0005]

In the data carrier system described above, there is no particular problem when the slave unit faces the master unit within the communication range at a ratio of 1: 1. When a plurality of machines (n units) are combined, the master machine receives response information from a plurality of slave machines almost at the same time, causing interference and hindering information transmission. For this reason, when a person substitutes a card-type cordless handset for the name tag and checks the above-mentioned name tag at the time of entry and exit to identify the individual who owns the name tag, or with the commuter pass ticket still in the pocket. However, when attempting to realize a system such as an automatic ticket gate, there is a high possibility that multiple people will stand in the vicinity of the base unit, which causes interference and the problem that the information of the handset cannot be read normally. ..

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a data carrier system capable of preventing interference between a master unit and a slave unit even when there are a plurality of slave units in a communication area. Has a purpose.

[0007]

In order to solve the above-mentioned problems, according to the invention of claim 1, when the interrogation area of at least one interrogator and the interrogator is entered, the interrogator is And a plurality of responding devices that send response signals at different timings when interference occurs between the responding device and the interrogating device, the interrogating device corresponding to the received response signal among the plurality of responding devices. Characterized by communicating with things.

According to a second aspect of the present invention, in the data carrier system according to the first aspect, the plurality of responding devices are provided with a delay unit in which a unique delay time is set, and when the interference occurs. In addition, the response signal is transmitted after waiting the delay time.

According to a third aspect of the invention, in the data carrier system according to the first aspect, when the interference occurs, the plurality of response devices send response signals at timings randomly generated in each of them. It is characterized by

According to a fourth aspect of the present invention, when the interrogation occurs between the interrogation device and the plurality of response devices when the interrogation area between at least one interrogation device and the interrogation device is entered. , A plurality of responding devices each sending a response signal with a different carrier signal, and the interrogating device communicates with one of the plurality of responding devices corresponding to the received response signal. ..

According to a fifth aspect of the present invention, in the data carrier system according to the fourth aspect, the plurality of responding devices are provided with a delay unit in which a unique delay time is set, and when the interference occurs. In addition, after waiting for the delay time, response signals are transmitted with different carrier signals.

According to a sixth aspect of the present invention, in the data carrier system according to the fourth aspect, the plurality of responding devices are different from each other at random generation timings when the interference occurs. It is characterized in that a response signal is transmitted by a carrier signal.

[0013]

According to the first, second and third aspects of the present invention, the response device transmits a response signal to the interrogation device when it enters the area where communication with the interrogation device is possible. At this time, if a plurality of response devices enter the communicable area, interference occurs with the interrogation device. In this case, the response device retransmits the response signal at different timings, that is, after waiting for the delay time set in the delay unit or at random timings. The interrogation device communicates with the corresponding response device in the order in which the response signals are received.

According to the fourth aspect of the invention, the response device transmits a response signal to the interrogation device when the response device enters the communicable area with the interrogation device. At this time, if a plurality of response devices enter the communicable area, interference occurs with the interrogation device. In this case, the responding device retransmits the response signal with a different carrier signal. The interrogation device communicates with the corresponding response device in the order in which the response signals are received.

According to the fifth and sixth aspects of the invention, the response device transmits a response signal to the interrogation device when it enters the communicable area with the interrogation device. At this time, if a plurality of response devices enter the communicable area, interference occurs with the interrogation device. In this case, the response device retransmits the response signal after waiting for the delay time set in the delay unit or at random timing and with different carrier signals. The interrogation device communicates with the corresponding response device in the order in which the response signals are received.

[0016]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In this figure, the master device 1 is composed of an optical signal transmission unit (ultrasonic wave / electromagnetic wave) 2, a radio signal reception unit (oscillation detection unit) 3, and a microcomputer unit 4. The transmitter 2 modulates the serial signal output of the microcomputer 4 and then converts it into an optical signal for transmission. The receiving unit 3 is in a receivable state for the time required for communication.

The slave unit 5 comprises an optical signal receiving section 6, a radio wave modulated reflection signal transmitting section 7 and a microcomputer section 8. The receiving unit 6 is in a receivable state for the time required for communication. The transmitter 7 modulates the serial signal output of the microcomputer 8 and then applies a modulation signal to the radio wave modulation reflector. The receivers 3 and 6 of the master unit 1 and the slave unit 5 are
Together, the received modulated signal is demodulated and then supplied to the serial signal input terminals of the microcomputer units 4 and 8. A link is established between the microcomputer unit 4 in the parent device 1 and the microcomputer unit 8 in the child device 5 via the serial signal input / output circuits 9 and 10.

Although the figure shows a state in which one master unit and one slave unit are combined, in reality, a plurality of units (n units) are provided for one master unit. The child machine corresponds. Further, in the data carrier system of the present embodiment, unlike Ethernet and the like, a communication request is not made from the slave unit 5 side,
It is characterized in that communication is always started in response to a communication request from the base unit 1.

Two basic embodiments having the above-mentioned structure will be described. First, as the first embodiment, there is the following flow. When there is interference, base unit 1 outputs a signal that "interference cannot be performed to read information". Since this type of system cannot communicate with the other handset 5 and the other handset, each of the handset 5 receives a random time or a time unique to the handset when it receives a signal that the information cannot be read due to interference. , Delay and respond. The parent device 1 repeats the above operation until the information of all the child devices is obtained.

Next, as a second embodiment, there is the following flow. a. When there is interference, base unit 1 outputs a signal that "interference cannot be performed to read information". b. Each slave unit 5 has a unique ID code (identification code).
Is delayed (waiting) for a random time or a time peculiar to the slave unit, and then responds. c. The master unit 1 sequentially reads the unique ID code from the slave unit 5, or issues a line connection request signal only to the slave unit 5 which is read first. The line connection request signal has the ID code of the child device 5 read first. d. When the handset device 5 receives a line connection request signal for a device other than itself, the handset device 5 temporarily stops responding to the base device 1 for a certain period of time. Therefore, the master unit 1 can communicate only with the slave unit 5 that has matched the line connection request. e. By outputting the general response request from the master unit 1 again, the response of b is performed until the information of all slave units is obtained, and the process is repeated from c to d.

Next, the specific operation of the above-described first and second embodiments will be described with reference to the flow charts shown in FIGS. First, on the master side 1, in step SA1, when the slave 5 is within the communicable area, the transmitter 2 transmits a wake-up signal for notifying the slave 5 of the start of communication. Next, in step SA2, the system waits for "OK" + "code" reception.

On the other hand, on the side of each slave unit 5, step SB
In 1, the receiving unit 6 receives a wake-up signal from the master unit 1, branches the signal on the way, and inputs one to the interrupt input terminal and the other serial signal input terminal.
Next, in step SB2, when the interrupt signal is received, immediately the operation of the microcomputer section 8 in the STOP mode is started up to the RUN mode. Note that serial signal input is not accepted while the microcomputer unit 8 is initializing. Then, in step SB3, when the microcomputer unit 8 of the slave unit 5 enters the RUN mode and rises, the interrupt prohibition process (masking the interrupt input terminal) is immediately performed, and the process proceeds to step SB4. In step SB4, the microcomputer unit 8 of the child device 5 waits for a delay time having a random element after the initial processing. Next, step S
In B5, a unique "code No." preset in the slave unit is added to the reception ready ("OK") signal, and the transmitter unit 7 transmits the signal to the master unit.

The delay time having the above-mentioned random element is kept on standby because the wake-up signal is transmitted from one master unit to a plurality of slave units at the same time, in this system, only one channel is available. Since all the slaves inside receive the wakeup signal at the same time,
When there is no delay time or when the delay time is the same, a plurality of slave units send response signals almost at the same time, so that signal collision occurs and interference occurs. For this reason, the transmission signals of the slaves are individually delayed and transmitted, and the one in which the link is established first is preferentially communicated, and the other slaves are made to wait until the communication is completed. Then, the child device 5 proceeds to step SB6 and waits for reception.

On the side of the main unit 1, the response signal is received by the receiving unit 3 in step SA3, and it is determined in step SA4 whether or not the response signal is "OK" + "code No.". Then, if the result of the determination in step SA4 is "NO", the process returns to step SA1. Then, steps SA1 to SA4 are repeatedly executed until the determination result in step SA4 becomes “YES”.
The response signal received in step SA3 is "OK"
+ "Code No.", the determination result of step SA4 is "YES", and the process proceeds to step SA5. At Step SA5, it is judged whether or not the response signal is normally received. Here, if the content of the code is not normal,
The process proceeds to step SA6 and the code No. Is transmitted from the base unit 1 to the handset unit 5 so as to retransmit. This is the process when interference occurs due to a collision when receiving a code.
Then, in step SA7, the code reception is awaited.

On the other hand, when the receiving unit 6 receives the code retransmission request in step SB7, the handset 5 waits for a delay time having a random element in step SB8, and after waiting for a code No. in step SB9. The transmitter 7
Resend from. Then, in step SB10, the reception is awaited.

On the other hand, in the base unit 1, step SA
At 8, the receiving unit 6 receives the code retransmission from the slave unit 5. Then, in step SA9, it is determined whether or not the reception was successful. This is a judgment as to whether or not interference has occurred due to collision when the code is received. Step S
In the process of A6, when the slaves 5 that have received the retransmission request transmit using the same delay waiting time as that before the retransmission, the probability that a collision will occur again at the time of retransmission becomes extremely high. Therefore, the retransmission timing is delayed again by using the randomized delay waiting time value.

If the result of the determination in step SA9 is "NO", the process returns to step SA6 and again.
Request a code resend. Hereinafter, until the determination result in step SA9 is “YES”, steps SA6 to
Repeat SA9. Then, the above step SA
If the reception is normally performed in step 3 or the reception is normally performed in step SA8, the determination result in step SA5 or SA9 is "YES", and the process proceeds to step SA10. In step SA10, the code No. To specify the code No. from the master unit 1 to the slave unit 5. Is transmitted from the transmitter 2.

On the other hand, the slave unit 5 receives the communication designation code by the receiving unit 7 in step SB11. Then, in step SB12, it is determined whether or not the received communication designation code is the own code. If the received communication designation code is not the own code, the determination result in step SB12 is "NO", and the process proceeds to step SB13. In step SB13, the transmission is prohibited, and then the process proceeds to step SB14. And step SB
At 14, it is determined whether the waiting time has exceeded. A certain waiting time is provided so that when other slaves are communicating, if they are still in the communicable area, the communication signal of other slaves will wake up and prevent incorrect transmission. This is because the standby time is set appropriately when the system is designed.

If the waiting time is not over, the result of the determination in step SB14 is "N".
"O" and the process returns to step SB11. Then, until the own code is received or the own code is not received and the waiting time is exceeded, steps SB11 to SB11
SB14 is repeatedly executed. Step SB11
In the process of SB14, my code is not received,
If the standby time is exceeded, the result of the determination in step SB14 is "YES", and step SB20
Go to. In step SB20, a wakeup interrupt is permitted and the process proceeds to step SB21. In step SB21, the RUN mode is changed to the STOP mode, the process returns to step SB1 and waits for reception of the next wakeup signal from base unit 1.

On the other hand, in step SA10, when the communication designation code transmitted by the master unit 1 matches with its own code, the determination result in step SB12 is "YES".
Then, the process proceeds to step SB15. In other words, base unit 1
In the child device 5 in which the communication designation code transmitted by the user matches its own code, the determination result in step SB12 is "YE
S ”, and the process proceeds to step SB15.

Information is transmitted / received in step SA11 of the master unit 1 and in step SB15 of the slave unit 5. Next, on the base unit 1 side, step SA1
In 2, it is judged whether or not the communication is continued.
When the communication is continued, the determination result in step SA12 is "YES", and the process proceeds to step SA13. In step SA13, it is determined whether or not interference has occurred. Then, if interference has not occurred, the determination result in step SA13 is "NO", the flow returns to step SA11 to exchange information with the slave unit 5. And
While the communication with the handset 5 continues, and when there is no interference, the above steps SA11 to SA13 are repeatedly executed to sequentially exchange information.

On the other hand, if communication is interfered in steps SA11 to SA13, the determination result in step SA13 becomes "YES", and the process returns to step SA5.
Then, again, determine whether the communication (reception) is normal,
If not normal, proceed to steps SA6 to SA9,
Code N of handset 5 to communicate until communication becomes normal
o. Is transmitted, and the code No. from the child device 5 is transmitted. To receive. Then, when the communication (reception) is normally performed, the determination result in step SA5 or SA9 becomes "YES", the process proceeds to step SA10 and thereafter, and the information exchange is restarted. Then, the above step SA1
When communication is completed in steps 1 to SA13, step S
The determination result in A12 is “NO”, and step S
Go to A14. In step SA14, the communication end signal is transmitted from the transmitter 2.

At this time, when the handset unit 5 receives the communication end signal in step SB16, it proceeds to step SB17.
Go to. Then, in step SB17, a communication end confirmation signal is transmitted. On the other hand, in base unit 1, in step SA15, the communication end confirmation signal is received.
Then, in step SA16, it is determined whether or not the communication end confirmation signal is received. When the received signal is not the communication end confirmation signal, the determination result of step SA16 is "NO", the flow returns to step SA14, and the communication end signal is transmitted again. Hereinafter, steps SA14 to SA16 are repeatedly executed until the communication end confirmation signal from the handset 5 is received.

When the communication end confirmation signal from the handset 5 is received, the determination result in step SA16 is "Y".
ES ”, and proceeds to step SA17. Step SA
At 17, it is determined whether to communicate with the next child device 5. When communicating with the next child device 5, the determination result in step SA17 is "YES", and the process returns to step SA10.
Then, again, the code No. of the next slave unit 5 is displayed. And start exchanging information in the following steps. On the other hand, when communication with other slaves 5 is not made, that is, when communication with all slaves 5 in the communicable area is completed, the result of the determination in step SA17 is "NO", and the process ends. ..

To summarize the above, the master device 1 temporarily stores all the received codes and communicates in a fixed order (such as ascending or descending order of the received order). For example, A,
Code Nos. Of the three sets of cordless handsets B and C. Is "5", "6",
If the code is "7", the code number. Will communicate with the child machine of "5", communicate with "6", and after that, it will communicate with the child machine of "7", and so on.

Next, a third embodiment of the present invention will be described. Here, an example in which the present invention is applied to a conventional data carrier system will be described. First, the basic operation of the third embodiment is as follows. Third Example (General Example) I. The master unit is capable of discriminating signals of a plurality of carrier frequencies. II. If the handset interferes and cannot read the information, it changes the carrier frequency (at random timing) and retransmits.
(Or, change each carrier frequency to have a random value and retransmit.) III. When the communication is completed, the slave unit that has completed the communication stops the response for a certain period of time and opens the line for communication between the other slave unit and the master unit.

Next, a case where the processing of the above-described first to third embodiments is applied to a conventional system will be described with reference to FIG.
This will be described with reference to (a) and (b). Model A (Application Example of First to Third Embodiments) In FIG. 4A, in model A, the master device 20 includes a data processing unit 21, a question transmitting unit 22, a reading receiving unit 23, and a writing unit. It is composed of a transmission section 24 for use. The data processing section 21 judges whether the transmitted / received data is correct or not, and inputs / outputs predetermined data or the like from / to each of the transmitting / receiving sections according to the judgment. In addition, the question transmission unit 22 includes the data processing unit 21.
Data is superimposed on a predetermined carrier wave and transmitted from the antenna to the handset 30 side. The receiving unit for reading 23 demodulates after receiving the signal from the slave unit 30, and outputs the read data to the data processing unit 21. In addition, the writing transmission unit 24
Sends the writing data from the data processing unit 21 to the slave unit 30 side by superimposing the writing data on a predetermined carrier wave.

Next, the slave unit 30 is composed of a writing reception unit 31, an information storage unit 32, a delay unit 33, a modulation signal generation unit 34 and a modulation unit 35. The writing receiving unit 31 demodulates after receiving the signal transmitted from the writing transmitting unit 24 of the master device 20 described above, and the received data is the information storage unit 32.
Output to. The information storage unit 32 stores the data and outputs the data to the delay unit 33. Note that the write data is not always transmitted from the master device 20, but is transmitted as needed. Next, the delay unit 33
Has a predetermined delay time, and after delaying the data according to the delay time, the modulation signal generator 34
Output to. The modulation signal generation unit 34 generates a modulation signal according to the above data and outputs this to the modulation unit 35. The modulator 35 receives the radio wave transmitted from the inquiry transmitter 22 of the parent device 20, modulates the received radio wave according to the modulated signal, and transmits again from the antenna. Although the figure shows a state in which one master unit and one slave unit are combined, in reality, a plurality of units (n units) are provided for one master unit.
Correspond to the slave units, and the delay time of the delay unit 33 in each slave unit is different.

In the above-mentioned configuration, the master unit 20 transmits an unmodulated continuous wave or intermittent wave from the inquiry transmitting unit 22. This radio wave is received by the modulator 35 on the slave unit 30 side, modulated according to the modulation signal generated by the data stored in the information storage unit 32, and then transmitted again. At this time, when the reception radio waves interfere with each other on the side of the base unit 20, the communication transmitting inability signal for notifying that communication is impossible due to the interference is transmitted from the writing transmission unit 24. In this case, even if there are n slave units 30 for one master unit 20, the communication failure signal is issued from one master unit 20, so all the slave units within the communicable radio field intensity area. Thirty
An incommunicable signal is received at. When the handset 30 receives the communication disable signal, the handset 30 operates the respective delay units 33 to delay the modulation data output from the information storage unit 32, and the modulation signal generation unit 34. To delay the generation timing of the modulated signal. Therefore, the modulated radio waves transmitted from each slave unit 30 are received by the master unit 20 at different timings according to the delay time in the delay unit 33. The master device 20 exchanges data with the slave device 30 according to the order of reception.

In the above-described embodiment, the slave unit is provided with the delay unit 33 having a different delay time for each slave unit. However, in the modulation signal generation unit 34, the carrier frequency is changed for each slave unit. You can Further, in the above-described embodiment, the delay unit 33 has a different delay time for each child device, but the delay time may be randomly generated. In addition, at present, all the above processes may be performed by software. The carrier frequency is PLL
The setting of (Phase Locked Loop) may be set by a bit signal from the microcomputer.

Model B (Application Example of Second Embodiment) Next, a case where the processing of the third embodiment described above is applied to the system of model B will be described. FIG. 4B is a block diagram showing the configuration of the model B. In the figure, the same constituent elements as those of the model A shown in FIG. The modulation sweep unit 25 in the parent device 20 amplitude-modulates the data from the data processing unit 21 with the sweep signal, and transmits it from the antenna. Also,
The demodulation signal receiving unit 26 receives the radio wave from the slave unit 30, demodulates it, and outputs it to the data processing unit 21.

Next, the diode 36 in the slave unit 30
Detects the radio wave amplitude-modulated by the sweep signal from the base unit 20 and outputs it to the filter 37. Filter 37
Outputs the detected signal to the signal processing unit 38 after filtering the detected signal. The signal processing unit 38 operates the frequency resonance unit 39 at a timing specific to each child device. Frequency resonance unit 3
Reference numeral 9 generates a resonance coefficient according to the identification code (code) of each slave unit, and outputs this to the modulator 40. Modulator 40
Modulates the signal amplitude-modulated by the received sweep signal according to the resonance coefficient corresponding to the identification code, and then transmits the modulated signal to the master device 20. Although the figure shows a state in which one master unit and one slave unit are combined, in reality,
A plurality of (n) slave units correspond to one master unit, and the identification codes in each slave unit are different.

In the configuration described above, the electric wave amplitude-modulated by the sweep signal from the base unit 20 is transmitted from the modulation sweep unit 25. This radio wave is received by the modulator 40 on the slave unit 30 side and is supplied to the signal processor 38 via the diode 36 and the filter 37. In the signal processing unit 38, the frequency resonance unit 39 (randomly
Or) Operate at intervals specific to the slave unit. As a result, the modulator 40 modulates the received signal according to the resonance coefficient according to the identification code at intervals specific to the slave unit, and then transmits the signal to the master unit 20. Therefore, the modulated radio waves transmitted from each slave unit are transmitted to the master unit 20 at intervals specific to the slave unit.
To be received. The master device 20 exchanges data with the slave device 30 according to the order of reception.

In the above-described embodiment, the frequency resonance unit 39 is operated at different intervals for each slave unit.
You may make it operate | move at random intervals.

[0045]

As described above, according to the first, second and third aspects of the present invention, when the response device enters the area where communication with the interrogation device is possible, interference occurs with the interrogation device. Then, the responding device retransmits the response signal at different timings, that is, after waiting for the delay time set in the delay means, or at random timing, while the interrogator responds to the response signal Since communication is performed with the corresponding response device in the order of reception, there is an advantage that interference between the master unit and the slave unit can be prevented even if there are a plurality of slave units in the communicable area.

According to the fourth aspect of the present invention, when interference occurs between the answering device and the interrogating device when the answering device enters the area where the answering device can communicate with the interrogating device, the responding devices respond with different carrier signals. In response, the interrogating device communicates with the corresponding responding device in the order in which the response signals are received. Therefore, even if there are multiple slave units in the communicable area, The advantage is that interference between them can be prevented.

According to the fifth and sixth aspects of the invention, when interference occurs between the answering device and the interrogation device when the answering device enters the area where communication with the interrogation device is possible, the response device is set to the delay means. After waiting for the delay time, or at random timing, and with different carrier signals, the response signals are retransmitted. Since communication is performed, even if there are a plurality of slaves in the communicable area, there is an advantage that interference between the master and slaves can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a flowchart for explaining a specific operation of the first and second embodiments.

FIG. 3 is a flowchart for explaining a specific operation of the first and second embodiments.

FIG. 4A is a block diagram showing a configuration when the processing of the first to third embodiments is applied to a conventional model A system, and FIG. 4B is a block diagram of the first to third embodiments. It is a block diagram which shows the structure when the process of is applied to the system of the conventional model B.

[Explanation of symbols]

 1, 20 Parent Unit (Interrogation Device) 5, 30 Slave Unit (Response Device) 33 Delay Unit (Delaying Unit) 38 Signal Processing Unit

Claims (6)

[Claims] 1. A plurality of at least one interrogation device, and a plurality of interrogation devices, each of which outputs a response signal at a different timing when interference occurs between the interrogation device and the interrogation device when the interrogation area of the interrogation device is entered. Responding device, wherein the interrogating device communicates with one of the plurality of responding devices corresponding to the received response signal. 2. The plurality of response devices include a delay unit in which a delay time unique to each of them is set, and when the interference occurs, a response signal is transmitted after waiting the delay time. The data carrier system according to claim 1. 3. The data carrier system according to claim 1, wherein the plurality of responding devices send response signals at timings randomly generated in each case when the interference occurs. 4. At least one interrogator, and a carrier signal different from each other when interference occurs between the interrogator and the plurality of answering devices when entering a communication area between the interrogator and the interrogator. And a plurality of responding devices that send response signals according to the above, wherein the interrogating device communicates with one of the plurality of responding devices that corresponds to the received response signal. 5. The plurality of response devices include a delay unit in which a unique delay time is set for each, and when the interference occurs, response signals are different carrier signals after waiting the delay time. Data carrier system according to claim 4, characterized in that 6. The plurality of responding devices, when the interference occurs, send response signals with different carrier signals to each of them at a timing randomly generated in each of them. The described data carrier system.