JP3497527B2 - Data carrier communication control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a specific area of an internal memory.
Identification data is written in advance in the
Returns the data of this specific area at the start of force reception
Data writing and reading are possible
Of non-contact data carrier communication control method
It is. [0002] 2. Description of the Related Art General data carriers and access heads
The operation of communication with the host will be described with reference to FIG. First, the internal structure
However, the access head 13 is connected to the host computer.
(Hereinafter simply abbreviated as host) 5
From host interface unit 6 and host 5
Various operations to be performed on the data carrier 28 based on the content
Controls command selection and transmission / reception procedures for this command.
The communication control unit 7 that controls
Send a series of command blocks including send data
Command transmission buffer 8 and data corresponding to each command.
Receiving the response data block from the carrier 28
Response buffer 9, based on the contents of transmission data,
Modulator 11 for modulating a signal, demodulation for demodulating a received signal
Section 12, power supply to data carrier 28 and operation
A clock generator 10 for generating a lock carrier signal;
Transmits the transmission signal and carrier signal from modulation section 11
And the antenna coil L1 that receives the response signal
It is composed of The data carrier 28 is provided with the access
The contactless communication with the antenna coil L1 of the head 13 is controlled.
Antenna coil L2, and this antenna coil L2
Whether the received carrier signal is a capacitor and a diode
Rectified by a rectifier circuit consisting of
Rectifier / constant voltage unit 25 that monitors its power supply voltage and
If the voltage is lower than the voltage level, the reset signal S21 is output.
The power supply voltage detection unit 23 detects a change from the antenna coil L2.
The demodulation signal is demodulated, and the code transmitted from the access head 13 is demodulated.
Demodulation that converts a command block into a series of digital data
Unit 27 modulates response data to access head 13
Modulating section 26, as a specific area including the ID code for identification, A
TR (Answer-to-reset) data area 2
Memory 22 as a data storage unit containing 1
To the memory 22 based on a command from the head 13
Write or read data and access
And a control unit 24 for responding to the
You. Now, as an initial state, the access head 1
3 continuously outputs a carrier signal from the antenna coil L1.
Data carrier 28 is still in range
There is no such thing. In this state, the data carrier 28
Enters the communication possible area with the access head 12 and
As the antenna coils L1 and L2 of the user approach each other,
And the data carrier 28 is
Rectifier / constant voltage
The output of the DC voltage from the unit 25 is started. However,
Immediately after the start of reception of the rear signal, the antenna coil L2
Is the distance between the access head 13 and the antenna coil L1.
However, since it is still far away,
The voltage level of the body is low, and the
This capacitor is not fully charged.
Is output from the data carrier 28.
Is not at an operable level and the power supply voltage detection unit 23
Remain the reset signal S21 output. this
At this time, the control unit 24 is in a hardware reset state.
Does not work. Data carrier 28 has access
As it approaches the network 13, the signal of the received carrier signal is
Signal level increases, and the rectification and constant voltage section
25 capacitors are fully charged, and data carrier 2
8 reaches an operable voltage level, the power supply voltage detection
The output of the reset signal S21 from the output unit 23 stops, and
The hardware reset of the control unit 24 is released. [0005] The control unit 24 performs a hardware reset.
Is released, the ATR in the memory 22 is first
The data in the data area 21 is read out and modulated by the modulation unit 26
After that, with ATR data via antenna coil L2
To the access head 13. Then the control
The unit 24 receives a command block transmitted from the access head 12.
Waits for lock reception, and thereafter, based on each command
To read data from the memory 22 or
Write and respond to the access head 13.
No, repeat this. The access head 13 has an antenna core.
ATR from the data carrier 28 through IL L1
Receives the data and demodulates it in the demodulation unit 12 to receive a response buffer.
After being temporarily stored in the host 9, the communication control unit 7
Sent to the host 5 via the interface unit 6.
The host 5 receives the ATR data,
To know that the data carrier 28 has arrived
The processing contents corresponding to the contents of the ATR data are
To the interface unit 6. This host-in
The interface unit 6 is controlled by an instruction from the host 5.
The other area of the memory 22 of the data carrier 28
Read data or write data
The command is divided into individual command execution levels and
Execute each command according to the specified processing procedure.
Command. In the communication control unit 7, the host interface
ー According to the command contents instructed from the face unit 6,
Sends a command block containing data etc. to the next stage command
The antenna coil is formed in the buffer 8 through the modulation unit 11.
From L1. In the data carrier 28, the antenna
This command block is received by the Nakoi L2, and
After demodulation by the control unit 27, the control unit 24 responds to the command contents.
Write or read data to / from the memory 22
And the execution result as a response data block.
And reply. In the access head 13, this data
The response block from the carrier 28 is stored in the ATR data
After the same operation as when receiving data, the host interface
To the base unit 6. This operation from the host 5
All commands executed according to the specified processing contents are executed.
Until the application is completed, the same procedure is performed, and then the host
The result is notified from the interface unit 6 to the host 5.
You. Based on the result, the host 5 displays a predetermined message,
The operation will be performed. [0007] The access head 13 and the data
Of the system consisting of the data carrier 28 and the host 5
The work will be explained in an easy-to-understand manner using specific operation examples.
First, this system can be used, for example, to enter a gate on a specific site.
It shall be used for exit management. Access head 13
And host 5 are installed on the gate side,
The carrier 28 is assumed to be carried by the visitors. Day
Freepass for a specific period
Tickets and coupons that can be entered up to the specified number of times.
The identification code of the bill type is stored in the memory of the data carrier 28.
22 is written in the ATR data area 21.
And In addition, the free pass ticket is a date indicating the expiration date.
Data other than the memory 22 other than the ATR data area 21
The coupon is written on the remaining area.
It is assumed that the usage count data is written in the same area. Ma
In addition, the ATR data area 21 manages and collects admission personnel.
Totals for each data carrier.
ID code for user identification which is different
Shall be rare. Admission is possible as the specification of Host 5
Announcement of no and gate ticket type, opening and closing of gate door
Operation shall be performed. For reference, the above operation
FIG. 3 illustrates an actual use state based on an example.
did. In FIG. 3A, the user carries the data carrier 28
A person is within the communication area with the antenna coil L1.
Followed by a person with another data carrier 28a
It shows the appearance of trying to enter. FIG.
3 (a), communicable area of antenna coil L1
And the positional relationship between the data carriers 28 and 28a
I have. Now, a person approaches the gate to enter
Say The access head installed on the gate side
Of the data carrier 28 to the antenna coil L1 of the
When the antenna coil L2 approaches and reaches the communicable area,
The power supply voltage detector 23 of the data carrier 28 is reset
The output of the signal S21 stops, and the hardware
Reset is released. Then, the ATR data area 21
Is read out, and the modulating unit 26 and the antenna coil L2 are read out.
To the access head 13 as ATR data
Reply. In the access head 13, the antenna coil L
1 to receive the ATR data,
Receive buffer 9, communication control unit 7, and host interface
The data is sent to the host 5 via the face unit 6. Host 5
By receiving the ATR data, the data
A When you know that 28 has entered,
Data contents, i.e., user identification ID code and ticket type
Check the code. Here, the data carrier 28 that has just entered
If the was a free pass ticket for a specific period, the host
5 judges it from the ticket type code,
To inform the expiration date of the data carrier 28
Instruct The host head of the access head 13
The interface unit 6 receives the instruction and receives the instruction via the communication control unit 7.
To execute the read command, and the data carrier 2
8 is written with data indicating the expiration date of the memory 22.
The reading of the data of the area is performed. Command transmission
The antenna coil L1 via the buffer 8 and the modulation unit 11
This command block sent from the
At the rear 28, the antenna coil L2 and the demodulation unit 27
The data is decoded by the control unit 24 through the
Reads data of area and responds to access head 13
I do. In the access head 13, the response data block
Receive the host and host interface
Extract only necessary data from response data in step 6
And sent to the host 5. In this way,
The host 5 knows the expiration date of the data carrier 28,
If it is determined that it is possible to pass,
Announce that it is possible and open the gate door.
And Next, the incoming data carrier 28 is located.
Assume that the ticket is a coupon that can be entered up to a certain number of times. ATR de
After receiving the data, the host 5
3 for the remaining number of uses of the data carrier 28
Instruct them to inform. Same as above for free pass ticket
And the host interface of the access head 13
The communication unit 6 receives the instruction and reads it out via the communication control unit 7.
Executing a command, the memory of the data carrier 28
Data indicating the number of remaining uses of
The data of the area to be read is read. Where the free path
The difference from the coupon is that the remaining number of uses of the coupon is one point.
That is, it must be reduced. That is,
The host interface unit 6 sends a read command
After execution, execute the write command
Remaining usage count data in the memory 22 of the data carrier
Data to one point less data
U. Remaining usage count read by read command
Using the data as the previous value, subtract 1 point from this previous value
Write the new value as new remaining usage count data.
A command block is formed and sent to the data carrier 28.
I believe. In the data carrier 28,
Sent to a certain area as a command block,
Write the new remaining usage count data and
Is returned to the access head 13. Said e
The read / write operation is performed by the
When both commands have been executed, the read command
From the response data block by the command
The numerical data is extracted and sent to the host 5. The host
5 indicates that the remaining number of uses of the data carrier 28 is zero.
If you decide that you can pass,
Announcing that it is possible to enter and the gate door
Will open. [0011] SUMMARY OF THE INVENTION Conventional data carriers
In the communication operation between the access head 13 and the
Seth head 13 communicates with a data carrier 28,
In other words, while executing the command, other data
If the carrier 28a enters the communicable area,
There are a plurality of data carriers 28, 28a in the area
Will be. In such a state, the access head 13
If you execute the write command, it already exists
Rewrite data in memory to data carrier 28
At the same time as another data carry-in
In the same way, writing data in memory
You will replace it. That is, the data that comes in later
Data already existing in the memory of the carrier 28a.
The data of the data carrier 28 is written.
For example, in the above operation example, in some cases,
The remaining number of uses of a few tickets may become zero,
-The remaining number of times the coupon is used
Data is written and becomes meaningless data.
Problems such as data being destroyed over time
Will occur. An object of the present invention is to solve the above problems.
The data in the internal memory of the data carrier is not prepared
A reliable data cache that will not be overwritten
It is intended to provide a rear communication control method. [0013] This object is achieved according to the present invention.
This can be achieved by the following configuration. sand
That is, while receiving power from the antenna due to non-contact
Data communication and write data to internal memory
And reading means, and individual identification IDs
The internal memory where ATR data including a code is stored.
Molly and reception of power supplied from the antenna
By detecting the start, the A of the internal memory
A data carrier having ATR means for returning TR data.
Rear, the antenna responsible for communication with the data carrier,
And a data transmission / reception circuit.
Of ATR data returned by the carrier ATR means
ATR reception start detecting means for detecting the start of communication,
ATR data storage means for storing and holding the ATR data,
The ATR data from the data carrier to the AT
After storing and holding the R data storage means,
Before sending a command to the carrier,New ATR
Received dataTimeThe ATR data storage operator
The currently communicating data carrier already stored in the stage
ATR data and the newly received ATR data
Are compared for at least the ID code.
ATR data comparator that detects whether or not
Stage, the comparison result in the ATR data comparing means is not
If it is, another data carrier can communicate with the antenna.
Is determined to have entered the active area, and the subsequent data
Communication control means to stop data write operation to rear
Communicable area
Of the same data for multiple data carriers
Prevents writing and internal memory of other data carriers
Not to overwrite the data of
You. [0014] Embodiments of the present invention will be described below with reference to the drawings.
I do. FIG. 1 is a functional block diagram illustrating the present invention.
The data carrier 28 and the host 5 are described in the conventional example.
Is the same as In the access head 13,
Functional unit that controls the basic communication operation with data carrier 28
Minute, that is, the host interface that controls communication with the host 5.
Data based on instructions from the face unit 6 and the host 5
Selection of various commands to the carrier 28 and this command
Communication control unit 7 for controlling a command transmission / reception procedure,
A series of commands including transmission data depending on the command contents
Command transmission buffer 8 for transmitting blocks, each command
Response data block from data carrier corresponding to
Response buffer 9 for receiving the
Modulating section 11 that modulates a received carrier signal
Power supply to demodulation unit 12 and data carrier 28 for demodulation
And clock for generating carrier signal for operation clock
Transmission signal and carrier from generation section 10 and modulation section 11
An antenna that transmits a signal and receives a response signal
Each part of the coil L1 is also the same as that described in the conventional example.
It is. The access head 13 implements the present invention.
ATR match detector 1 is added as a function to
ing. The ATR match detection unit 1
Of the demodulation unit 12 based on the ATR detection state signal S2 of FIG.
Monitor the response received signal from the
Data reception start and the ATR detection
Depending on the state of the state signal S2, the ATR storage signal S3 or
Is an ATR reception that outputs one of the ATR comparison signals S8
Upon receiving the start detection unit 4 and the ATR storage signal S3,
The ATR data temporarily stored in the reception buffer 9 is recorded.
ATR data storage unit 3 for storing the ATR comparison signal
In response to S8, the contents of the ATR data storage unit 3 and the current
The new reception temporarily stored in the response reception buffer 9
Compare the contents of the received ATR data,
ATR data inconsistency is detected if they do not match.
ATR data comparison that outputs matching signal S7 to communication control unit 7
2 and the proximity of the data carrier 28
Of ATR data returned in response to
If another data carrier enters while communicating with carrier 28
Detection of newly returned ATR data
Comparison with the first ATR data already stored
Now. Next, the operation of this embodiment will be described. First,
The data carrier 28 still communicates with the access head 13.
It is assumed that it is not within the receivable range. In this state, access
The communication control unit 7 of the head 13 outputs the ATR detection state signal S2
Is output as an initial state.
Reply to 4 due to proximity of data carrier 28
Monitoring the start of ATR data reception
Outputs ATR storage signal S3 after detection of R data reception
Instruct Here, the data carrier 28 accesses
The ATR data enters the area where communication with the head 13 is possible,
If it is returned, the access head 13
The signal is demodulated by the demodulation unit 12 through the coil L1. The AT
The R reception start detection unit 4 detects the change in the demodulated signal.
Detects as reception start detection signal S1 and stores ATR data
The signal S3 is output. In the ATR data storage unit 3,
Receiving ATR data storage signal S3 and receiving
After the completion of accumulation in the communication buffer 9, the contents are transferred to the transfer data S4.
And stored internally. After demodulation by the demodulation unit 12,
ATR data temporarily stored in the response receiving buffer 9
Indicates that the communication control unit 7 and the host-in
It is sent to the host 5 via the interface 6. here,
The communication control unit 7 outputs the ATR state detection signal S2 initially.
From the initial state to the command communication state, and
Command communication with the data carrier 28 to the output unit 4
Monitoring the start of reception of new ATR data on the way, and
Outputs ATR comparison signal S8 after detecting ATR data reception
To do so. The subsequent operations are performed as described in the conventional example.
The processing content corresponding to the content of the received ATR data is
From the host interface unit 6
Is divided and executed. In the communication control unit 7
Receives the instruction to execute each command, the next command
The command block formed in the transmission buffer 8 is transmitted.
Before that, the ATR data comparison unit 2
ATR data mismatch signal S7 output from
You. The ATR data mismatch signal S7 has not been output.
The command block is sent as is.
As described in the conventional example, the response from the data carrier 28 is performed.
After receiving the response, the host 5 is notified. However, later
As described above, the ATR data mismatch signal S7 is output.
If so, subsequent transmissions of the command block
The host 5 is stopped and notified to that effect. The received ATR data is stored in the host.
5 to the host interface unit 6
A command execution instruction is issued by the communication control unit 7.
Until the command block transmission starts, other data
Data carrier 28a enters the communicable range, and A
The case where the reply of TR is performed will be described. The other data
ATR data transmission from carrier 28a is optional
Other than the timing expected when executing the command
Then, the response is detected, that is, the demodulation signal is changed by the demodulation unit 12.
The ATR state detection signal S2 is
ATR reception start detection unit 4 that is input as the communication state
Captures this change and outputs an ATR comparison signal S8.
You. In the ATR data comparison unit 2, the ATR comparison signal S
8, the received data is sent to the response reception buffer.
9 After the storage is completed, its contents, that is,
ATR data newly received from the data carrier
And stored in the ATR data storage unit 3.
Compare the contents of ATR data of existing data carriers,
If they do not match, the communication control unit 7
An R data mismatch signal S7 is output. Then, the communication
The control unit 7 transmits the command block as described above.
Notifying the host 5 to that effect and displaying an error
Is performed, and the processing for the data carrier 28 is interrupted.
Will be. Here, of the newly received ATR data,
The contents are the contents of the existing ATR data
If they are the same, A
TR data mismatch signal S7 is not output and command block
Transmission of commands and subsequent command execution operations are as usual.
Will be done. This is the newly received ATR data.
Data is not due to the proximity of other data carriers.
And the existing data carrier 28 itself
Out of the communicable area with the head 13 and reenter the same area
That the ATR data was re-replyed
Because it can be considered. Incidentally, as can be easily understood from the above description.
In addition, ATR data is different for each data carrier.
Content. Because of this, data carriers
At least 28 ATR data areas 21 in the memory 22
ID code for identification is written in part or all
Need to be. ATR data of the access head 13
In the data comparison unit 2, all ATR data contents are
Alternatively, only the identification ID code may be used. As described above, when a new command is
ATR reception detection operation and ATR data
The data comparison operation is performed by each command block to the data carrier 28.
Performed before starting lock transmission and for other data carriers
The command is not executed. In particular,
Rewrite the contents of the memory 22 of the data carrier 28
Command, such as when executing a write command
Mistakenly writes the memory contents of another data carrier.
It is necessary so that it is not replaced. The access head 13 and the data
Of the system consisting of the data carrier 28 and the host 5
Based on the specific operation example used in the conventional example,
This is explained clearly with reference to a flowchart. Ma
And check the system configuration again.
It is used for gate entry / exit management to a specific site, and
Access head 13 and host 5 are installed on the gate side,
The data carrier 28 is assumed to be carried by the visitors.
You. As the type of the data carrier 28, the
-Two types of pass tickets and coupons that can be entered up to the specified number of times
The identification codes of both ticket types are stored in the data carrier 28
Written to the ATR data area 21 in the memory 22
It is assumed that In addition, free pass tickets have an expiration date
Data in the memory 2 other than the ATR data area 21
2 is written in the other area, and the coupon
Used number of times data is written to the same area.
You. The ATR data area 21 contains individual data.
There are also user identification ID codes that are different for each carrier.
It is assumed that it has been written in advance. Host 5 specifications
Announcement of admission and gate pass ticket type,
It is assumed that the gate door is opened and closed. In FIG. 2, steps 100 to 105 mainly include
Detection of data carrier entry and storage of ATR data,
The transmission to the host is performed.
Divergence, 115-116 or 107-1 for each ticket type
After proceeding with each of the fourteen processing steps, steps 117-118
The processing at the host is performed and the next data from step 101 is processed.
This is repeated from the detection of the entrance of the carrier. In the decision step 101, the data carrier 28
Of ATR data returned due to proximity
Is monitored to see if any
If there is no rear 28, this determination step 101 is repeated.
Have been. Now, a person approaches the gate to enter
Say Data carrier 28 is access head 1
3 is within the communicable area and ATR data reply is opened.
The process is started, and the detection proceeds to the next step. Process
At 102, when a series of ATR data is received,
In the meantime, this is temporarily stored and stored and held in step 103.
You. In step 104, the temporarily stored ATR data
Is sent to the host 5, and in step 105, an instruction from the host 5 is sent.
And a processing method in a judging step 106 according to the contents of the instruction.
Is selected and branched. The data carrier that received the signal now
Assuming that 28 is a free pass ticket, step 115 and subsequent steps
Is executed. In step 115, the data carrier 28 is
And the read command block is transmitted, and
By receiving the response from the data carrier 28 at 6,
Data indicating the expiration date of the memory 22 is written.
The data of the area to be read is read. Here, the process
Before the execution of 115, another data carrier
If you enter the area where communication with the
There will be two data carriers in
The command executed for the carrier is readout.
The data content of the memory is not rewritten.
The data in the memory of the data carrier
It does not destroy the data. Therefore, the read command
Is executed, a new ATR data reception start detection
And comparison with stored ATR data.
The ATR match detection operation need not be performed. This
In the case of, the response by the read command
Responses are sent from the rear at the same time,
Cannot be demodulated normally by the access head.
Eventually, communication error will occur and error processing will be performed
However, this error processing method will be described in the present application.
The content is omitted because it is not particularly required. In the case of a coupon,
As a result of the selection of the processing method, steps 107 and subsequent steps are executed.
You. Steps 107 and 108 include steps 115 and 1 described above.
As in step 16, transmission of the read command block and response
An answer is received. However, it is read because it is a coupon
The data is the remaining number of uses. In decision step 109,
Detects the start of reception of new ATR data and detects
If not, steps 113 and 114 are performed for the data carrier.
To write command execution. In step 113,
A write command is issued along with the data to be written.
Transmitted as a command block, and
After rewriting the contents of the memory 22, the data carry
The response from a is received at step 114. Now, we have another data carrier
The same place, despite people approaching and there are still previous ones
Suppose you stood in a place. The data carrier of the previous person
Is within the communication area with the
A new ATR data is returned because
Communication begins. In decision step 109, this new AT
Detecting that the reception of the R data has begun;
Receives a series of ATR data at
Temporarily store and store in step 103 in step 111
ATR data is compared with the contents of the ATR data. Both ATR
The data comparison operation is performed by the user in a series of ATR data.
This is performed on the contents of the ID code for identification.
ATR data returned from another data carrier
Therefore, in the determination step 112,
And the data carrier in steps 113 and 114
Write command is not executed, and
The host informs the host. In the above description, the newly returned ATR data
Described as coming from another data carrier
However, the person in front of the gate now moves back and forth,
Carrier is temporarily out of the communication area with the access head.
Move out of the area and return to the same area again
Means that the data carrier is interrupted and re-
Reset due to power interruption / resupply at the start of communication
Later, the same data is returned to return ATR data again.
Start of ATR reception of a carrier is detected.
You. In this case, in the judgment step 109,
Detecting the start of receiving new ATR data of
Received a series of ATR data and temporarily stored
And the AT stored in step 103 in step 111
Performs comparison with the contents of R data,
The content of the user identification ID code to be compared is naturally
However, since they are exactly the same,
Are regarded as coincidence, and thereafter, steps 113 and 11 are performed as usual.
4 when the write command to the data carrier is executed.
Will be carried out. The execution of the command for the data carrier is
When all is completed, the result is usually returned to the host in step 117.
Is notified and at step 118 the gate toll ticket type and
Announcement that admission is possible and opening the gate door
Will be. However, during the command execution, other data
Data carrier is detected and ATR data
If the results of the comparisons do not match,
Writing to data carrier by 113, 114
The command is not executed, and the process proceeds to step 117 to the host.
After being informed, at step 118, another data
Processing has become impossible due to the
And announce that they will re-enter
Call for attention. Of course, the data carrier 28
Gate door until command execution is completed successfully
Does not open. [0031] As is apparent from the above description, the present invention
According to, The data carrier enters
Using dynamically returned ATR data,A data cache
New ATR data during command execution for rear
When the ATR data is detected, the ATR data is received.
Along with the ATR data already stored and held
Are compared and the contents of both ATR data do not match.
If other data carriers enter the coverage area,
CameQuickly detect thatFor subsequent data carriers
The execution of the write command to
Data to be written to the data carrier
And writes the data to another data carrier
Since it will not be destroyed by rewriting,
Eliminate weak points due to communication by contactAnd
In addition, the data carrier responds to the ID collation function and the collation result.
Has a function to restrict writing to the same memory
Not even cheap systems,Reliable data key
To provide communication control methods for
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram showing a configuration of the present invention. FIG. 2 is a flowchart showing a flow of an operation of the configuration shown in FIG. FIG. 3 is a diagram illustrating an actual use state based on the operation example described in the embodiment of the present invention. FIG. 4 is a functional block diagram showing a configuration of a conventional example. [Description of Signs] 1 ATR coincidence detection unit 2 ATR data comparison unit 3 ATR data storage unit 4 ATR reception start detection unit 13 Access head 21 ATR data area 22 in memory 22 Internal memory 28 for data carrier Data carrier

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiromitsu Arai 2-1-224 Himonya, Meguro-ku, Tokyo Japan Olivetti Co., Ltd. (72) Inventor Katsutoshi Tanaka 2-1-224 Himonya, Meguro-ku, Tokyo Sun Olivetti Co., Ltd. (56) References JP-A-4-288696 (JP, A) JP-A-2-226389 (JP, A) JP-A-5-143870 (JP, A) JP-A-3-273378 ( JP, A) JP-A-62-220387 (JP, A) JP-A-6-187515 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06K 17/00 G06K 19/07 H04B 7/24-7/26 H04L 29/08 H04Q 7/00-7/38

Claims (1)

(57) [Claim 1] Means for performing data communication while receiving power from an antenna in a non-contact manner to write and read data to and from an internal memory, and an ID code for individual identification An ATR that returns the ATR data in the internal memory by detecting the start of reception of power supplied from the antenna and the internal memory storing ATR data including
ATR reception start detecting means for detecting the start of reception of ATR data returned by the ATR means of the data carrier, comprising: a data carrier having means for communicating with the data carrier; ATR data storage means for storing and holding the received ATR data, before from the data carrier
The ATR data is stored and held in the ATR data storage means.
After sending a command to the data carrier.
Before you trust, when the newly carried out the reception of the ATR data
It is whether the the ATR data storage means already ATR data of the data carriers in the communication current that is stored and held, and ATR data received the newly performs a comparison for at least ID codes, they match ATR data comparing means for detecting whether or not the ATR data comparing means does not agree with each other, it is determined that another data carrier has entered the communicable area with the antenna, and a subsequent data carrier is determined. And an access head comprising communication control means for stopping the data write operation of the data carrier. Data carrier communication control system characterized in that data is not rewritten .