JP2002259915A - Data carrier, reader/writer device, data carrier system and data carrier searching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute an ID searching process without trouble even if a data carrier carrying out an irregular operation is present when ID search is carried out in a detection area where plural data carriers are present. SOLUTION: When IDs of plural data carriers present in a response area are searched based on the IDs each comprising plural bits and assigned to every data carrier, this reader/writer device 10 executes processes for transmitting a response confirmation signal when at least one data carrier responses, and for transmitting a receiving non-confirming signal when no data carrier responses. A response is returned from a slave machine 30 according to a response request from the reader/writer device 10 when a corresponding search pattern is present, and the ID searching operation of the slave machine 30 is stopped when the receiving confirmation signal is not transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a data carrier, a reader / writer device, a data carrier system, and a data carrier search method.

[0002]

2. Description of the Related Art For example, in a data carrier system that performs processing such as gate management in a ticket gate of a station, etc., in principle, one data is stored in a search area of an interrogator (reader / writer device) for performing data search. Since there is only a carrier (child device), the data carrier that has entered the search area should always transmit its own ID to the interrogator.

However, for example, in order to use a data carrier system to manage inventory of a plurality of products placed on a shelf, a plurality of data carriers exist in a search area.

[0004]

When there is a data carrier that performs an irregular operation among the plurality of data carriers, confusion occurs in the ID search process.
Not only the total time of ID search becomes long, but also ID
In some cases, the search could not be performed.

The present invention has been made in view of the above problems, and when performing an ID search in a detection area where a plurality of data carriers exist, even if there is a data carrier that performs an irregular operation, the ID search process is confused. The purpose is to be able to run without.

[0006]

According to the present invention, there is provided a reader / writer device for retrieving a plurality of data carriers existing in a response area based on an ID composed of a plurality of bits assigned to each data carrier. A response request output means for outputting a response request signal to a data carrier whose search target bit in the ID of each data carrier has a predetermined search pattern; and a response signal receiving means for receiving a response signal from the data carrier When,
A reception acknowledgment signal transmitting means for transmitting a reception acknowledgment signal when a response is received from at least one of the plurality of data carriers; and a response from any one of the plurality of data carriers. When there is no reception confirmation signal transmission means for transmitting a reception non-confirmation signal. Another feature of the present invention is that, in response to the response from the response request output means, a response confirmation signal is transmitted when there is a response from the data carrier, and the search target is transmitted to the responded data carrier. It is characterized in that a signal for instructing carry of a bit is transmitted, and a signal for prohibiting an ID recognition operation in the sequence is transmitted to a data carrier that has not responded. Another feature of the present invention is that the search target bit is configured to carry two bits at a time, and that the search target bit includes four types of combinations of two-bit data. Features.

[0007] The data carrier of the present invention refers to its own ID in response to a response request from the reader / writer device.
D reference means, a response returning means for returning a response when a corresponding search pattern exists as a result of reference by the ID reference means, and the reader / writer device for a response returned by the response return means. And an ID search operation stopping means for stopping the ID search operation in the sequence when the reception confirmation signal is not transmitted from. According to another feature of the present invention, the ID search operation stopping means is configured to output a predetermined reception confirmation signal from the reader / writer device when the predetermined reception confirmation signal is not transmitted.
When data other than the reception confirmation signal or the reception non-confirmation signal is received, an error flag is set and the ID search operation in the sequence is stopped.

[0008] A data carrier system according to the present invention comprises any one of the reader / writer devices described above and any one of the data carriers described above.

According to the data carrier search method of the present invention, an ID composed of a plurality of bits assigned to each data carrier is provided.
A plurality of data carriers present in a response area based on the response request, wherein a response request signal is output to a data carrier whose search target bit in the ID of each data carrier has a predetermined search pattern. Processing, a response signal receiving process for receiving a response signal from the data carrier, and transmitting a reception acknowledgment signal for transmitting a reception acknowledgment signal when a response is received from at least one of the plurality of data carriers. The reader / writer device performs a process and, when there is no response from any of the plurality of data carriers, a process of transmitting an unacknowledged signal for transmitting an unacknowledged signal, from the reader / writer device. ID reference processing for referring to its own ID in response to a response request of A response returning process for returning a response when a search pattern to be executed exists, and a sequence for responding to the response returned by the response returning process when no reception confirmation signal is transmitted from the reader / writer device. And the ID carrier is stopped by the data carrier.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a data carrier, a reader / writer device, a data carrier system, and a data carrier search method according to the present embodiment will be described with reference to the drawings. First, an anti-collision operation will be described before describing the embodiment of the present embodiment.

FIG. 2 is a diagram showing an example of operation timing of anti-collision performed in the data carrier system of the present embodiment. In the following embodiments, a data carrier is referred to as a “child device” and a reader / writer device is referred to as an interrogator.

FIG. 2 shows an example of the operation timing of the anti-collision according to the present embodiment. In this example, four response periods are provided for every two bits of the ID code.

At the time of the anti-collision operation, first, a response request data ID indicating the ID search mode is transmitted from the interrogator, followed by four response periods T1 to T
4 is provided, and blank data of 8 bits is transmitted for each response period.

Each response period includes a T1 period for searching for “HH”, a T2 period for searching for “HL”,
It is divided into a T3 period for searching for “LH” and a T4 period for searching for “LL”.

An interrogator transmits a response confirmation signal during the first four bits of the 8-bit blank data (response confirmation is made by setting a specific bit of the four bits to "H" or "L"). ), Each slave unit references its own ID with the search target bit.

Each of the slave units, from the period of T1 to the period of T4,
The comparison is performed in the order of the periods, and if the comparison result is the corresponding bit pattern, a response is returned during the latter four bits in the search period.

The interrogator performs an ID search in the order from the T1 period to the T4 period. When there is a response, the interrogator does not perform a search with a subsequent search pattern, but proceeds to a next 2-bit search. Then, a response acknowledgment signal is transmitted in the first half of the next 8-bit blank signal in the response period in which the response has been received, and the slave is notified of the transition to the next 2 bits.

On the other hand, an instruction to stop the response is given to the child device that did not respond. The above basic operation is described in
Since the invention is almost the same as the invention described in Japanese Patent No. 6623, the detailed description is omitted.

If there is no response confirmation signal from the interrogator during the first 4-bit period, the slave sets the following pattern (for example, when "HH" was searched, "HL" is searched)
, And refers to the search target bit of its own ID.

FIG. 1 is a block diagram showing a schematic functional configuration of a data carrier system of the present invention. As shown in FIG. 1, the data carrier system according to the present embodiment includes:
An interrogator (reader / writer device) 10 and a slave (data carrier) 30 are provided.

The interrogator 10 includes a communication unit 101, a response request output unit 102, a response signal reception unit 103, a reception confirmation signal transmission unit 104, a reception non-confirmation signal transmission unit 105, and the like. In addition, the child device 30 is
1, an ID reference means 302, a response returning means 303, an ID search operation stopping means 304, and the like.

The communication means 101 transmits and receives communication with the child device 30, and has a function of supplying operating power to the child device 30 as described later. The response request output means 102 outputs a response request signal to a data carrier whose search target bit in the ID of each slave 30 has a predetermined search pattern.

The response signal receiving means 103 is connected to the slave 30
Receiving the response signal transmitted from. In addition, the reception confirmation signal transmitting unit 104 is configured to
When a response is received from at least one of the slaves 30, a response confirmation signal is transmitted.
When there is no response from any of the plurality of slave units 30, a reception unconfirmed signal is transmitted.

The communication means 301 in the slave unit 30
Has a function of communicating with the communication means 101 of the interrogator 10 to exchange data and to receive power used by the slave 30 from the interrogator 10. ID reference means 302 refers to its own ID in response to a response request from interrogator 10. The response returning means 303 returns a response when the ID search means 302 finds that the corresponding search pattern exists. ID search operation stopping means 3
In the step 04, when the interrogator 10 does not transmit a reception confirmation signal in response to the response returned by the response returning unit 303, the interrogator 10 stops participating in the ID search operation in that sequence.

FIG. 4 is a block diagram showing a specific configuration example of the data carrier system. In FIG. 4, an interrogator 10 includes an oscillation circuit 11 for generating a basic signal of a carrier wave,
A frequency dividing circuit 12 for generating a first carrier by dividing the basic signal from the oscillation circuit 11 by different frequency dividing ratios, a frequency dividing circuit 13 for generating a second carrier, a first carrier and a second carrier. And a selection circuit 15 for selecting and outputting one carrier wave from the carrier waves, an output amplifier 16, a first tuning circuit 17 and a second tuning circuit 18. Further, the interrogator 10 has an internal processing circuit 19 for generating a transmission signal and the tuning circuit 1
A demodulation circuit 20 for processing and demodulating the signals received at 7 and 18 is provided.

With such a configuration, the interrogator 10 controls the selection operation of the selection circuit 15 based on the transmission signal generated by the internal processing circuit 19, and performs FSK modulation on the carrier.
The first tuning circuit 17 includes an antenna coil L1 and a tuning capacitor C1, and the second tuning circuit 18 includes an antenna coil L2 and a tuning capacitor C2. The first tuning circuit 17 and the second tuning circuit 18 are connected in parallel as shown in FIG. In addition, a capacitor C3 for adjusting the tuning circuits 17, 18 is connected in series with the second tuning circuit 18.

The slave unit 30 includes a transmission / reception coil 31, a tuning capacitor 32 connected in parallel to the transmission / reception coil 31,
It is composed of a rectifier circuit 33, a demodulation circuit 34 for performing FSK demodulation, an internal processing circuit 35, a transmission modulation circuit 36, and a transmission load transistor 37.

The internal processing circuit 35, like a general signal processing circuit, includes a CPU 35a, a RAM 35b, a ROM 35c storing programs and the like, and an electrically rewritable E.
An EPROM 35d and an interface 35e are provided.

The oscillation circuit 11 of the interrogator 10 is, for example, 4M
Generate a reference signal in Hz. This reference signal is supplied to the first frequency dividing circuit 12 and the second frequency dividing circuit 13 and is divided by the first frequency dividing circuit 12 into 1/32 (125 KH).
z) is obtained, and a signal (117.6470588 KHz) divided by 1/34 is obtained from the second frequency dividing circuit 13.

When the internal processing circuit 19 instructs the transmission of data of the logical value "H", the output of the first frequency dividing circuit 12 is selected by the selecting circuit 15 and a signal of 125 KHz is supplied to the output amplifier 16 to output the signal. To the tuning circuits 17 and 18 on the other hand,
When the internal processing circuit 19 instructs the transmission of the data of the logical value “L”, the output of the second frequency dividing circuit 13 is selected by the selecting circuit 15 and the signal of 117.6470588 KHz is transmitted to the output amplifier 16. To the tuning circuits 17 and 18

On the other hand, the slave 30 transmits data by ASK modulation. Hereinafter, the operation of the child device 30 will be described. Cordless handset 30
Is used by converting a carrier wave received by a tuning circuit composed of a transmitting / receiving coil 31 and a tuning capacitor 32 into a direct current by a diode and a smoothing capacitor (not shown) of the rectifier circuit 33.

When data is transmitted from the slave unit 30 to the interrogator 10, data generated by the CPU 35a inside the internal processing circuit 35 is transmitted to the modulation circuit 36 via the interface 35e, and is output to the output of the modulation circuit 36. In response, the transmission load transistor 37 is turned on / off. Then, the current flowing through the transmission / reception coil 31 changes according to the on / off operation of the transmission load transistor 37, and the strength of the electromagnetic coupling between the transmission / reception coil 31 and the antenna coil L1 changes.

The demodulation circuit 20 of the interrogator 10 demodulates a change in voltage generated at both ends of the antenna coil 17. Specifically, 125 KH output from the first frequency dividing circuit 12
A change in the amplitude of the signal z is detected to demodulate data from the slave unit 30. Actually, a demodulation operation is performed on a 125 KHz signal output from the first frequency dividing circuit 12 by detecting a change in the amplitude and phase of the sub-band signal sent from the data carrier with a band-pass filter. .

FIG. 8 is a flowchart illustrating the anti-collision operation of the data carrier system according to the present embodiment. The interrogator 10 transmits a multi-ID recognition command (Step S201). Subsequently, a waiting time set in advance is prepared as a preparation period for starting the data transfer between the interrogator 10 and the slave 30 (step S202). As an initialization operation during this waiting time, a counter (not shown) is set to “1” so that the search target starts from the first two bits.

The interrogator 10 transmits an 8-bit blank signal following transmission of the ID recognition command (step S20).
3) Yes. The 8-bit period T1 is a period in which the child device 30 having the ID “HH” responds as the first response period as described above.

If the 12th bit and the 2nd bit of the ID of the slave unit 30 are "HH", the slave unit 30 returns a response signal in the period of 4 bits after the 5th bit in the blank signal of the 8-bit period T1. Specifically, the coupling relationship between the coils 31 and 17 is changed by turning on the transistor 37 in the modulation circuit 36 of FIG. 4 and modulating the signal of 125 KHz representing the blank data from the interrogator 10. The change is detected by the demodulation circuit 20 (step S20).
4).

When the interrogator 10 detects the response from the slave unit 30, the process proceeds to step S204a, and transmits the first acknowledgment signal "ACK-A". Upon receiving the first acknowledgment signal "ACK-A", the slave 30 that has returned the response carries the counter up by two bits and prepares for the next search. on the other hand,
The child device that has not returned a response stops responding (step S
206).

Next, the process proceeds to step S214 to shift to 2-bit search. The interrogator 10 determines whether or not the search has been completed up to the last bit. The counter of the machine 10 is carried (Step S215), and thereafter, the process returns to Step S203, and the above-described processing is repeated.

If no response signal is returned from any of the slaves 30 as a result of the determination in step S204, the process proceeds to step S204b, where the interrogator 10 transmits a first unacknowledged signal "NACK-A". I do. Step S2 above
The processing from 01 to S204b is performed in FIG.
This is shown as a first search flow A.

Next, the interrogator 10 transmits an 8-bit blank signal following the first unacknowledged signal "NACK-A" (step S205). The 8-bit period T2 is a period in which a slave having an ID of “HL” responds as a second response period.

The slave 30 having "HL" in the first and second bits in its own ID returns a response signal in a period of four bits after the fifth bit of the blank signal. This is the first 8+
It is the fifth and subsequent bits. Thereafter, similarly, step S207
a, S208, S214, S215, and step S
Return to 203.

On the other hand, if the result of determination in step S207 is that no response signal has returned from any of the slaves 30, the process proceeds to step S207b, where the interrogator 10 transmits a second unacknowledged signal "ACK-B". I do. Step S20 above
The processing from 5 to S207b is shown as a second search flow B in FIG.

Next, the interrogator 10 transmits an 8-bit blank signal following the second unacknowledged signal "ACK-B" (step S209). The 8-bit period T3 is a period in which a slave having an ID of “LH” responds as a third response period.

The slave 30 having "LH" in the first and second bits in its own ID returns a response signal in a period of four bits after the fifth bit of the blank signal (step S210). This is the first 16 + 5th and subsequent bits when viewed from the ID calling mode signal. Thereafter, similarly, the process proceeds to steps S210a, 211, 214, and 215, and returns to step S203.

On the other hand, as a result of the determination in step S210, if no response signal returns from any of the slaves 30, the process proceeds to step S210b, where the interrogator 10 transmits the third unacknowledged signal "ACK-C". I do. Step S20 above
The processes from 9 to S210b are shown as a third search flow C in FIG.

Next, the interrogator 10 transmits an 8-bit blank signal subsequent to the third unacknowledged signal "ACK-C" (step S212). The 8-bit period T4 is a period in which a slave having an ID of “LL” responds as a fourth response period.

The slave 30 having "LL" in the first and second bits in its own ID returns a response signal in a period of four bits after the fifth bit of the blank signal. This is the first 24
It becomes the + 5th bit or later.

Thereafter, in step S213a, the fourth
Is transmitted, and it is determined in step S214 whether the search has been completed up to the last bit. If the result of this determination is that the search has been completed up to the last bit, the process proceeds to step S216, where the ID of the child device 30 for which the search has been completed is specified, and a response prohibition command for the child device 30 is transmitted.

On the other hand, as a result of the determination in step S213, if no response signal returns from any of the slaves 30, the process proceeds to step S213b, where the interrogator 10 transmits the fourth unacknowledged signal "ACK-D". I do. Step S21 above
The processes from 2 to S213b are shown as a fourth search flow D in FIG.

In step S217, it is determined whether there is a retry. If the result of this determination is that there is a retry, the flow returns to step S203 to search again for the same two bits. If the result of determination in step S217 is that there is no retry, the multi-ID recognition operation is stopped.

Here, a specific example will be described with reference to FIG. In the following example, the first child device 3 is used as the child device 30.
0-1 (ID: HHHL ...), second child device 30-2
(ID: LH ...), the third slave unit 30-3 (ID: H
The operation will be described using a case where three slave units (HLH...) Are stored on a shelf.

The interrogator 10 transmits 8-bit blank data following the response request data ID indicating the ID search mode. The first slave unit 30-1 and the second slave unit 30- that have received the response request data ID from the interrogator 10
Second, the third slave unit 30-3 checks the first and second bits of its own ID, and when it is “HH”, transmits the response signal in the fourth bit period after the fifth bit of the blank signal.

In the example of FIG. 3, the first slave unit 30-1 and the second slave unit 30-1
Since the first two bits of the ID of the child device 30-3 are "HH", the two child devices return a response. On the other hand, since the first two bits of the ID of the second slave unit 30-2 are "LH", no response is returned.

If there is a response from at least one handset (the interrogator 10 cannot recognize how many handsets 30 have received a response), the interrogator 10 performs the first reception confirmation. Transmit the signal “ACK-A”. When receiving the first acknowledgment signal "ACK-A", the slave unit carries a counter in its own when it has returned a response, and sets a target to be compared with the next blank signal period. The ID is set to 3 bits or 4 bits. On the other hand, the child device that has not returned a response is in a response stop state and waits until the next response request data ID is sent.

In the example of FIG. 3, since there is a response from the first slave unit 30-1 and the third slave unit 30-3 during the period T1 for searching for "HH", the interrogator 10 performs the next search. T is the period
In the first 4-bit period of 1 ', the first acknowledgment signal "AC
KA ”and the search for the next two bits is started. if,
When there is no slave unit having the ID pattern of “HH” in the first two bits, the interrogator 10 transmits a first unacknowledged signal “NACK-A”.

Next, as a T2 period, a blank signal of 8 bits is transmitted, and the first two bits of "HL" I
It waits for a response from the slave unit having the D pattern, and if there is no response, further transmits a blank signal of 8 bits as a T3 period, and transmits a response from the slave unit having the LH ID pattern in the first two bits. If no response is received, an 8-bit blank signal is further transmitted as a T4 period, and a response from a slave having an ID pattern of "LL" in the first two bits is waited.

This time, since there was a response during the T1 period,
Move to the third and fourth bit search. Since the first acknowledgment signal “ACK-A” is transmitted in the first four bits of the T1 ′ period, each child device has a search target bit of ID = 3.
It is possible to know that the search has been started for the bit 4 and the bit 4.

In the T1 'period, the first and third slave units 30-1 and 30-3 have IDs of "HH" in the third and fourth bits.
There is no response because there is no pattern. Interrogator 10
Subsequently, an 8-bit blank signal is transmitted as a T2 period.

The first slave unit 30-1 outputs the third bit and the fourth bit.
Since the bit has an “HL” ID pattern in the bit,
A response is returned during the period, and the third slave unit 30-3 has no response because it does not have the ID pattern of “HL” in the third and fourth bits.

In the case of this example, since there was a response from the first slave unit 30-1, the interrogator 10 does not proceed to the search in the T3 period of the third and fourth bits to be searched. Go to the 6th and 6th bit. The interrogator 10 transmits the third acknowledgment signal “ACK-C” using the first four bits of the T1 ″ period.
Send

The first slave unit 30-1 carries the counter and sets the next comparison target to the 5-bit and 6-bit IDs. On the other hand, the third slave unit 30-3 that has not returned a response is in a response stop state, and waits until the next response request data ID is sent.

As described above, since two of the three units have stopped responding, the first slave unit 30-1 thereafter detects the detection period T1, T2 corresponding to the pattern of every two bits until the last bit of the ID. A response is detected at T2, T3, and T4, and the first child device 3
The ID of 0-1 can be determined. The first slave unit 30-1, for which the determination has been completed, stops responding, and the subsequent processing is the second step.
The IDs of the slave units 30-2 and 30-3 are detected by the same method as described above.

Next, a countermeasure against offset which is a main part of the data carrier system of the present embodiment will be described. Figure 5
FIG. 7 shows an example of an algorithm that enables the interrogator 10 to normally perform the ID search of the slave 30 even when the carrier offset exists. When the slave 30 replies, if there is no carrier cancellation, the interrogator 10 can perform normal reception.
There is no problem when the slave 30 does not reply.

If the handset 30 responds, the interrogator 10 cannot receive the signal if there is a carrier offset. Therefore, information as to whether or not the handset 30 itself is a response to the response request is stored. Carrier cancellation is detected by comparing presence / absence information as to whether or not there is a reply.

When the carrier cancellation is detected, a carrier cancellation flag is set. Subsequently, as shown in FIGS. 5 to 7, even if the sequence is interrupted or the sequence is performed to the end, the flag indicating that the sequence has been completed normally is not set, so that the next multi-data carrier ID is set. The read sequence should be executable. The details will be described below.

The interrogator 10 transmits a multi-ID recognition command (step S101). Interrogator 10 and handset 3
A waiting time set in advance is prepared as a preparation period for starting data transfer of 0. During this waiting time, as an initialization operation, a counter (not shown) is set to "1" so that the search target starts from the first two bits (step S10).
2).

The slave 30 checks the carrier canceling flag (step S103), and if the carrier canceling flag is not set, proceeds to step S105. If the carrier offset flag has been set, the process proceeds to step S104, and a countermeasure for carrier offset is implemented. Thereafter, the carrier offset flag is reset, and the process proceeds to step S105 for re-search.

In step S105, the interrogator 10
Transmits an instruction to the slave 30 such that the slave at the “HH” level in which the search target bit of the ID code is assigned in the first response period returns a response (transmission of blank data).

Next, the process proceeds to step S106, where
Is determined. If the result of this determination is that at least one child device has responded, the flow proceeds to step S107.

If the result of determination in step S106 is that no slave unit 30 has returned a response, step S1
Proceeding to 18, the response reception signal transmitted by the interrogator 10 is determined. If the result of this determination is that the response received signal transmitted by the interrogator 10 is the first unacknowledged signal “NACK-A”, a search for a second response period (block B shown by a dotted line in FIG. 5) Proceed to). That is, the child device 30 whose search target bit is at the “HL” level transmits an instruction to return a response in the latter half of the second response period (transmission of blank data) (step S105b).

If the result of the determination in step S118 is that the response received signal transmitted by the interrogator 10 is a signal other than the first unacknowledged signal "NACK-A", the flow advances to step S122 to set an error flag. Set, then
Proceeding to step S123, the multi-ID recognition operation of the child device 30 in which the error has occurred is stopped.

In step S107, it is determined whether interrogator 10 has received a reception confirmation signal from child device 30 or not.
If the first acknowledgment signal "ACK-A" has been received, the acknowledgment signal is transmitted in the first half of the next response period (step S108), and the process proceeds to step S111 to carry the ID bit. . When the interrogator 10 cannot confirm the response, the interrogator 10 determines that there is no response from any of the slaves 30, and proceeds to step S105b of block B.

The handset 30 to which it has responded determines that carrier cancellation has occurred because the response confirmation signal has not been sent even though it has responded, and sets a carrier cancellation flag in the RAM 35b. (Step S110). Since the interrogator 10 does not know at this point that the carrier offset flag of the slave unit 30 is set, the interrogator 10 proceeds to the entrance of the next block indicated by B in FIG. 5 and continues for the second response period (second block). B), the search is continued for the third response period (third block C) and the fourth response period (fourth block D), but it is found that the correct ID has not been finally detected in step S114. Then, the process returns to step S101 via step S115.

Similarly, step S10 of block B
5b, 106b, 107b, 108b, 109b, 11
0b, an “HL” level search is performed, and the third block C
Perform a search at the “LH” level, and perform a search at the “LL” level in the fourth block D. In step S111, I
It is determined whether the search has been performed up to the last bit of the number of bits assigned as D. If the search has not been performed up to the last bit, carry is performed in step S112, and the above-described processing in step S105 and subsequent steps are repeated. .

By performing the above processing, the search for one slave unit 30 is completed.
(Step S113), and if there is a response from the child device 30, it is determined that the ID is a correct ID, and the child device searched in order to end the present sequence is not subjected to the subsequent multi-ID search. The response is prohibited (step S116).

On the other hand, if there is no response from any of the slaves to the response confirmation signal, it is determined that a collision has occurred, the searched ID is discarded, and the search is started again (step S115). Specifically, the process returns to step S103 after discarding the ID. At this time, a countermeasure for carrier cancellation is performed in steps S103 and S104. Subsequent to step S106, the process is repeated until there is no response from all the slaves 30 (step S117).

Next, a method for countermeasures for carrier cancellation will be described. If the carrier offset flag is set,
Take measures against carrier offset by the following method. One method is to use a 1-bit random number generation circuit existing in the slave 30 itself to determine whether the slave 30 transmits or not depending on whether 1 bit is “0” or “1”. To determine.
Thus, the slave 30 that has caused carrier cancellation stops transmission with a certain probability, thereby making it possible to avoid carrier cancellation.

Another method is to use the 1-bit random number generation circuit of the handset 30 itself for the handset 30 to use the "1" level as the phase at the time of transmission, or to use "0" which is 180 ° out of phase. Decide what level to use. This method can be avoided by changing the phase, since the carrier cancellation occurs in the slave 30 transmitting the opposite phase.

[0079]

According to the present invention, as described above, according to the present invention, while a plurality of data carriers are being searched, the operation of the irregularly operated data carriers can be stopped. When performing an ID search in a detection area where there is an error, it is possible to prevent the ID search process from being confused by a data carrier that performs an irregular operation, and to reduce the total processing time required for the ID search.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a data carrier system of the present invention.

FIG. 2 is a diagram illustrating an example of an operation timing of anti-collision according to the present embodiment.

FIG. 3 is a diagram showing a specific example of communication between an interrogator and a slave.

FIG. 4 is a block diagram illustrating a specific configuration example of a data carrier system.

FIG. 5 is a flowchart illustrating an example of an algorithm in which an interrogator performs an ID search for a slave unit.

FIG. 6 is a flowchart illustrating details of the flowchart in FIG. 5;

FIG. 7 is a flowchart illustrating details of the flowchart in FIG. 5;

FIG. 8 is a flowchart of an anti-collision operation of the data carrier system according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Interrogator 101 Communication means 102 Response request output means 103 Response signal receiving means 104 Reception confirmation signal transmission means 105 Unrecognized signal transmission means 30 Handset 301 Communication means 302 ID reference means 303 Response return means 304 ID search operation stop means

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[Procedure amendment]

[Submission date] December 11, 2001 (2001.12.
11)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

According to the present invention, there is provided a reader / writer device for retrieving a plurality of data carriers existing in a response area based on an ID composed of a plurality of bits assigned to each data carrier. A response request output means for outputting a response request signal to a data carrier whose search target bit in the ID of each data carrier has a predetermined search pattern; and a response signal receiving means for receiving a response signal from the data carrier When,
A reception acknowledgment signal transmitting means for transmitting a reception acknowledgment signal when a response is received from at least one of the plurality of data carriers; and a response from any one of the plurality of data carriers. When there is no reception confirmation signal transmission means for transmitting a reception non-confirmation signal. Another feature of the present invention is that, in response to the response from the response request output means, a response confirmation signal is transmitted when there is a response from the data carrier, and the search target is transmitted to the responded data carrier. It is characterized in that a signal for instructing carry of a bit is transmitted, and a signal for prohibiting an ID recognition operation in the sequence is transmitted to a data carrier that has not responded. Another feature of the present invention is that the search target bit is configured to carry two bits at a time, and that the search target bit includes four types of combinations of two-bit data. Features. Another feature of the present invention is that the reception acknowledgment signal from the reader / writer device and the reception acknowledgment signal are four types of different signals composed of a combination of search target 2-bit data. I have.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007] The data carrier of the present invention refers to its own ID in response to a response request from the reader / writer device.
D reference means, a response returning means for returning a response when a corresponding search pattern exists as a result of the reference by the ID reference means, and the reader / writer device for the response returned by the response return means. And an ID search operation stopping means for stopping the ID search operation in the sequence when the reception confirmation signal is not transmitted from. According to another feature of the present invention, the ID search operation stopping means is configured to output a predetermined reception confirmation signal from the reader / writer device when the predetermined reception confirmation signal is not transmitted.
When data other than the reception confirmation signal or the reception non-confirmation signal is received, an error flag is set and the ID search operation in the sequence is stopped. Other features of the present invention include:
When a signal different from the expected acknowledgment signal or unacknowledged signal is received on the data carrier,
The data carrier is characterized by entering a search routine.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction contents]

On the other hand, as a result of the determination in step S207, if no response signal returns from any of the slaves 30, the process proceeds to step S207b, where the interrogator 10 transmits the second unacknowledged signal " NACK-B ". I do. Step S2 above
The processing from 05 to step S207b is performed in FIG.
This is shown as a second search flow B.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

Next, the interrogator 10 transmits an 8-bit blank signal following the second unacknowledged signal " NACK-B " (step S209). The 8-bit period T3 is a period in which a slave having an ID of “LH” responds as a third response period.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

On the other hand, as a result of the determination in step S210, if no response signal returns from any of the slaves 30, the process proceeds to step S210b, where the interrogator 10 transmits the third unacknowledged signal " NACK-C ". I do. Step S2 above
The processing from 09 to step S210b is performed in FIG.
This is shown as a third search flow C.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction contents]

Next, the interrogator 10 transmits an 8-bit blank signal following the third unacknowledged signal " NACK-C " (step S212). The 8-bit period T4 is a period in which a slave having an ID of “LL” responds as a fourth response period.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0049

[Correction method] Change

[Correction contents]

On the other hand, if the result of determination in step S 213 is that no response signal returns from any of the slaves 30, the process proceeds to step S 213 b, where the interrogator 10 transmits a fourth unacknowledged signal “ NACK-D ”. I do. Step S2 above
The processing from 12 to step S213b is performed in FIG.
This is shown as a fourth search flow D.

Continuing on the front page (72) Inventor Yoshikazu Sugawara 1-16-2 Kotobashi, Sumida-ku, Tokyo Jacqueline 47 Building 5F Yoshikawa RF System Tokyo Head Office F-term (reference) 5B035 BB09 CA23 5B058 CA15 CA23 5K012 AB05 AB12 AB18 AB19 AC01 AC11 BA03 BA07

Claims (7)

[Claims] 1. A reader / writer device for searching for a plurality of data carriers present in a response area based on an ID consisting of a plurality of bits assigned to each data carrier, wherein a search target bit in the ID of each data carrier is Response request output means for outputting a response request signal to a data carrier having a predetermined search pattern; response signal receiving means for receiving a response signal from the data carrier; and at least one of the plurality of data carriers A reception acknowledgment signal transmitting means for transmitting a reception acknowledgment signal when there is a response from the data carrier; and transmitting a reception non-acknowledgment signal when no response is received from any of the plurality of data carriers. A reader / writer device comprising: an unacknowledged signal transmission unit. 2. In response to a response from the response request output means,
When a response is received from the data carrier, a response acknowledgment signal is transmitted, a signal instructing the carry of the search target bit is transmitted to the responded data carrier, and the sequence is transmitted to the data carrier that did not respond. 2. The reader / writer device according to claim 1, wherein a signal for prohibiting an ID recognition operation is transmitted. 3. The data processing apparatus according to claim 2, wherein the search target bits are carried by two bits at a time, and are composed of four kinds of combinations of 2-bit data. Reader / writer device. 4. An ID reference means for referring to its own ID in response to a response request from a reader / writer device, and a response is returned if a corresponding search pattern exists as a result of reference by the ID reference means. Response returning means; and ID search operation stopping means for stopping an ID search operation in the sequence when a reception confirmation signal is not transmitted from the reader / writer device in response to the response returned by the response return means. A data carrier comprising: 5. The ID search operation stopping means, when a predetermined reception confirmation signal is not transmitted from the reader / writer device, and when data other than any of the reception confirmation signal and the reception non-confirmation signal is received. 5. The data carrier according to claim 4, wherein an error flag is set to stop the ID search operation in the sequence. 6. A data carrier system comprising: the reader / writer device according to claim 1; and the data carrier according to claim 4 or 5. 7. A method for searching for a plurality of data carriers present in a response area based on an ID consisting of a plurality of bits assigned to each data carrier, wherein a search target bit in the ID of each data carrier is a predetermined search. A response request output process of outputting a response request signal to a data carrier having a pattern, a response signal receiving process of receiving a response signal from the data carrier, and a response signal receiving process of at least one of the plurality of data carriers. A reception acknowledgment signal transmission process for transmitting a reception acknowledgment signal when there is a response, and a reception acknowledgment signal for transmitting a reception acknowledgment signal when there is no response from any of the plurality of data carriers The reader / writer performs transmission processing, and responds to a response request from the reader / writer. First, an ID reference process for referring to its own ID, a response return process for returning a response if a corresponding search pattern exists as a result of the ID reference process, and a response returned by the response return process. If no acknowledgment signal is transmitted from the reader / writer device,
A data carrier search method, wherein the data carrier performs an ID search operation stop process for stopping the D search operation.