Source: https://patents.google.com/patent/JP5027398B2/en
Timestamp: 2019-12-11 14:19:48
Document Index: 703963977

Matched Legal Cases: ['art 12', 'art 13', 'art 14', 'art 15', 'art 16', 'art 17', 'art 152']

JP5027398B2 - IC tag identification method - Google Patents
IC tag identification method Download PDF
JP5027398B2
JP5027398B2 JP2005280998A JP2005280998A JP5027398B2 JP 5027398 B2 JP5027398 B2 JP 5027398B2 JP 2005280998 A JP2005280998 A JP 2005280998A JP 2005280998 A JP2005280998 A JP 2005280998A JP 5027398 B2 JP5027398 B2 JP 5027398B2
JP2005280998A
JP2007094601A (en
2005-09-27 Application filed by ルネサスエレクトロニクス株式会社 filed Critical ルネサスエレクトロニクス株式会社
2005-09-27 Priority to JP2005280998A priority Critical patent/JP5027398B2/en
2007-04-12 Publication of JP2007094601A publication Critical patent/JP2007094601A/en
2012-09-19 Publication of JP5027398B2 publication Critical patent/JP5027398B2/en
The present invention relates to an IC tag, an IC tag control method, and an IC tag system, and more particularly, to an IC tag that performs wireless communication with a reader / writer, an IC tag control method, and an IC tag system.
In recent years, in logistics management at factories and article management at retail stores, a tag having an IC in which product specific information is written is pasted, the information is read with a wireless antenna, and the product is managed in real time. A technique relating to RFID (Radio Frequency IDentification) has attracted attention as means for automatically recognizing a product. Unlike a barcode or the like, RFID has an advantage that data can be read from a plurality of tags at once and data can be rewritten.
The above-described RFID IC tag (hereinafter referred to as an IC tag) performs data communication with a reader / writer to write and read data to and from a nonvolatile memory in the IC tag. The IC tag and the reader / writer communicate with each other by exchanging radio waves and data according to a predetermined communication protocol.
In RFID, a technique called anti-collision is used to enable communication between a reader / writer and a plurality of IC tags. In RFID, communication is performed by an IC tag responding to a reader / writer with respect to radio waves transmitted from the reader / writer. For this reason, when a plurality of IC tags exist within the communicable range of the reader / writer, signals are simultaneously transmitted from the plurality of IC tags to the reader / writer. In this case, the signals of a plurality of tags overlap in time, and the reader / writer cannot receive a correct signal. Such a phenomenon is called signal collision (collision), and a technique for avoiding this collision, identifying each IC tag and performing communication is anti-collision. In order to identify an IC tag, a tag ID (identification information unique to the IC tag) for uniquely identifying an IC tag called a unique ID is stored in the IC tag.
In order to access the anti-collision and IC tag memory, a tag ID read command for reading the tag ID from the IC tag, a read command for reading data stored in the IC tag, a write command for writing data to the IC tag, and the like are used. ing. When executing a command with an IC tag, command data indicating a command to be executed from the reader / writer to the IC tag is transmitted, and response data indicating a response as a command execution result is transmitted from the IC tag to the reader / writer. The
FIG. 8 shows a format of command data transmitted from the reader / writer to the IC tag. As shown in the figure, the command data includes a command ID field 801 and a data field 802. The command ID field 801 stores a command ID (command identifier) of a command executed by the IC tag. The data field 802 stores parameters necessary for command execution. For example, the command parameters include a tag ID of an IC tag to be executed, a read address, a write address, and write data. The data field 802 can be omitted depending on the command to be executed. When receiving the command data, the IC tag analyzes the command data and executes it based on the parameters of the data field.
The IC tag has a plurality of internal states (communication states), and operates while changing the state by executing a command or the like. For example, the internal state of the IC tag is held by a flag inside the IC tag. This flag includes a sleep flag and an isolate flag. The sleep flag is a flag indicating a SLEEP state in which the operation of the IC tag is temporarily interrupted. The isolate flag is a flag indicating that the reader / writer is in the ISOLATED state in which the tag ID is specified.
Each state is changed by a reset signal or command received from the reader / writer. As commands for changing the state of the IC tag, there are, for example, a SLEEP command for setting the IC tag in the SLEEP state, a WAKE command for releasing the SLEEP state of the IC tag, and an ISOLATE command for setting the IC tag in the ISOLATED state. . For example, when the IC tag receives a SLEEP command, it sets a sleep flag to set the internal state to the SLEEP state. When the IC tag receives the ISOLATE command, it sets the isolate flag to set the internal state to the ISOLATED state.
When receiving the command data, the IC tag performs a necessary operation based on the command parameter and the internal state of the IC tag. That is, the IC tag has a condition determination circuit inside, determines an execution condition for executing the command, and executes the command when the execution condition is satisfied. A command that is executed when a condition is matched is called a condition-matching command.
9 and 10 show command reception processing in a conventional IC tag. FIG. 9 shows an operation when a tag ID read command is received, and FIG. 10 shows an operation when a SLEEP command is received.
As shown in FIG. 9, when the IC tag receives the tag ID read command (S801), the IC tag determines whether or not the sleep flag held in the IC tag is 0 (S802). As a result of the determination, when the sleep flag is 0, that is, when the SLEEP state is released, tag ID read processing is performed (S803). When the sleep flag is not 0, that is, when the SLEEP state is set, the state is changed. No processing is performed, and the current state is maintained.
As shown in FIG. 10, when the IC tag receives the SLEEP command (S811), the IC tag refers to the parameter of the command, and whether or not the tag ID held internally is included in the designated tag ID range. Determination is made (S812). If the tag ID is included as a result of the determination, the sleep flag is set to 1 to enter the SLEEP state (S813). If the tag ID is not included, no processing such as state change is performed and the current state is maintained. To do.
FIG. 11 is a sequence showing a communication method of a conventional IC tag system. This sequence is an example in which the reader / writer communicates with the IC tags a and b existing in the communication area and specifies the tag IDs of the IC tags a and b by anti-collision.
First, the reader / writer transmits a reset signal to the IC tags a and b in order to reset the internal state of the IC tag existing in the communication area (S901). The IC tags a and b set the sleep flag to 1, The isolate flag is set to 0, and the internal state is set to the SLEEP state (S902). Next, the reader / writer transmits an INIT command to the IC tags a and b existing in the communication area (S903), and the IC tags a and b perform initial setting and the like (S904).
Next, the reader / writer performs anti-collision processing for identifying the IC tag in S905 and thereafter. First, the reader / writer transmits a WAKE command to the IC tags a and b (S905). Then, the IC tags a and b reset the sleep flag to 0 and cancel the internal SLEEP state (S906). Next, the reader / writer transmits a tag ID read command to the IC tags a and b (S907). Then, the IC tags a and b determine whether or not the sleep flag = 0 as shown in FIG. 9, acquire the tag ID held inside, and transmit the tag ID to the reader / writer as a response to the command ( S908).
Next, the reader / writer detects a collision of the received tag ID and transmits a SLEEP command to the IC tags a and b (S909). In this SLEEP command parameter, a tag ID range is set as a condition of an IC tag to be set in the SLEEP state. Then, it is determined whether the IC tags a and b are included in the range of the tag ID specified by the command parameter as shown in FIG. 10, and since the IC tag a is not included, no processing is performed. Since it is included, the sleep flag is set to 1 to enter the SLEEP state (S910). Next, the reader / writer transmits a tag ID read command to the IC tags a and b (S911). Then, the IC tags a and b determine whether or not the sleep flag = 0 as shown in FIG. 9. The IC tag b does not perform processing because the sleep flag = 1, and the IC tag a does not perform processing because the sleep flag = 0. The retained tag ID is acquired, and the tag ID is transmitted to the reader / writer as a response to the command (S912).
Next, since the collision between the tag IDs is avoided, the reader / writer identifies the tag ID of the IC tag a and transmits an ISOLATE command to the IC tags a and b (S913). Then, the IC tags a and b determine whether or not the sleep flag = 0, and the IC tag b does not perform processing because the sleep flag = 1, and the IC tag a sets the isolate flag to 1 because the sleep flag = 0. The ISOLATED state is set (S914).
Next, the reader / writer transmits a WAKE command to the IC tags a and b (S915). Then, the IC tags a and b reset the sleep flag to 0 and cancel the internal SLEEP state (S916). Next, the reader / writer transmits a SLEEP command to the IC tags a and b (S917). In this SLEEP command parameter, an isolate flag = 1 is set as a condition of an IC tag to be set in the SLEEP state. Then, the IC tags a and b determine whether the isolate flag = 1, the IC tag b does not perform processing because the isolate flag = 0, and the IC tag a sets the sleep flag to 1 because the isolate flag = 1. The SLEEP state is set (S918). Next, the reader / writer transmits a tag ID read command to the IC tags a and b (S919). Then, the IC tags a and b determine whether or not the sleep flag = 0 as shown in FIG. 9, and the IC tag a does not perform processing because the sleep flag = 1, and the IC tag b does not perform processing because the sleep flag = 0. The retained tag ID is acquired, and the tag ID is transmitted to the reader / writer as a response to the command (S920).
Next, since the collision between the tag IDs is avoided, the reader / writer identifies the tag ID of the IC tag b, and transmits an ISOLATE command to the IC tags a and b (S921). At this time, the IC tags a and b determine whether or not the sleep flag = 0, and the IC tag a does not perform processing because the sleep flag = 1, and the IC tag b sets the isolate flag to 1 because the sleep flag = 0. The ISOLATED state is set (S922). Next, the reader / writer transmits a WAKE command to the IC tags a and b (S923). Then, the IC tags a and b reset the sleep flag to 0 to cancel the internal SLEEP state (S924). Next, the reader / writer transmits a SLEEP command to the IC tags a and b (S925). In this SLEEP command parameter, an isolate flag = 1 is set as a condition of an IC tag to be set in the SLEEP state. Then, the IC tags a and b determine whether the isolate flag = 1, and the IC tags a and b set the sleep flag to 1 and set the SLEEP state because the isolate flag = 1 (S926). Thus, the anti-collision process is completed, a read command and a write command are transmitted to the IC tags a and b, and data is written to and read from the memories of the IC tags a and b.
Patent Document 1 is known as a conventional IC card system. In Patent Document 1, only an IC card that meets the conditions as shown in FIGS. 9 and 10 responds to the reader / writer.
JP 2004-38574 A
As described above, in the conventional IC tag system, it is necessary to transmit and receive a lot of command data and response data for the anti-collision processing until the tag ID of the IC tag is specified, and the processing takes time. This problem becomes more prominent as the number of IC tags increases.
Considering an example in which RFID is applied to a distribution system, the number of products (IC tags) that a reader / writer must recognize and process in one process is increasing due to recent mass distribution. In addition, when the tag is recognized and processed by a flow operation such as a belt conveyor, the flow speed of the belt conveyor itself is increasing. As described above, there is an increasing demand for processing more products faster, and it is important to increase the speed at which the reader / writer recognizes and processes tags.
An IC tag according to the present invention is an IC tag that executes command processing based on a received command, and includes an execution condition determination unit that determines an execution condition of the received command, and a case where the execution condition matches the execution condition. And a command execution unit that executes a second command process different from the first command process when the first command process is executed and does not match the execution condition. According to this IC tag, when one command is transmitted from the reader / writer, another process is executed by one IC tag and the other IC tag. Therefore, the communication sequence between the reader / writer and the IC tag can be reduced, and the communication time and the time required for executing the command can be reduced.
An IC tag control method according to the present invention is an IC tag control method that executes command processing based on a received command, wherein the IC tag determines an execution condition of the received command, and the execution condition The first command processing is executed when the two match, and the second command processing different from the first command processing is executed when the execution conditions do not match. According to this IC tag control method, one command is transmitted from the reader / writer so that one IC tag and another IC tag perform different processing. Therefore, the communication sequence between the reader / writer and the IC tag can be reduced, and the communication time and the time required for executing the command can be reduced.
An IC tag system according to the present invention is an IC tag system comprising a reader / writer and an IC tag that executes command processing based on a command received from the reader / writer, wherein the IC tag includes the reader / writer. An execution condition determination unit that determines an execution condition of a command received from a writer, and executes a first command process when the execution condition matches, and the first command process when the execution condition does not match A command execution unit that executes different second command processing. According to this IC tag system, when one command is transmitted from the reader / writer, another process is executed by one IC tag and the other IC tag. Therefore, the communication sequence between the reader / writer and the IC tag can be reduced, and the communication time and the time required for executing the command can be reduced.
According to the present invention, it is possible to provide an IC tag, an IC tag control method, and an IC tag system that can reduce the communication sequence between the reader / writer and the IC tag and reduce the communication time and the time required to execute a command.
First, an IC tag system according to Embodiment 1 of the present invention will be described. In the IC tag system according to the present embodiment, the first operation is performed when the IC tag that has received the predetermined command matches the execution condition of the command, and is different from the first operation when the execution condition does not match the execution condition. The second operation is performed. In particular, in the present embodiment, when the execution conditions match, the process of setting the internal state to the SLEEP state is executed, and when the execution conditions do not match, the process of reading the tag ID is executed.
Here, the configuration of the IC tag system according to the present embodiment will be described with reference to FIG. This IC tag system includes an IC tag 1 and a reader / writer 2 as shown in the figure. The IC tag system is a communication system in which the IC tag 1 and the reader / writer 2 perform wireless communication according to a predetermined communication protocol.
In the IC tag system, a plurality of IC tags 1 can be provided, and communication is possible between one reader / writer 2 and a plurality of IC tags 1 by an anti-collision function. In this example, two IC tags 1 of one reader / writer 2 and IC tags 1a and 1b are provided. Each IC tag 1 includes a semiconductor device 10 described later.
The reader / writer 2 is connected to, for example, a computer (not shown) so as to be communicable. In accordance with an instruction from the computer, the reader / writer 2 writes predetermined data to the storage circuit in the IC tag 1 or transfers the written data to the IC tag. Read from 1.
For example, when data is written to or read from the IC tag 1, when the distance between the reader / writer 2 and the IC tag 1 is reduced, the IC tag 1 receives the radio wave from the reader / writer 2 and rectifies the radio wave. To generate the power supply voltage. The reader / writer 2 transmits a command acquired from the computer to the IC tag 1, and the IC tag 1 receives this command and writes / reads data to / from the storage circuit in the IC tag 1.
Next, the configuration of the IC tag according to the present embodiment will be described with reference to FIG. As shown in the drawing, the IC tag 1 includes a semiconductor device 10 and an antenna 17, and the semiconductor device 10 and the antenna 17 are connected via an antenna terminal 18. The semiconductor device 10 includes a power supply voltage generation unit 11, a reception unit 12, a transmission unit 13, a clock generation unit 14, a control unit 15, and a storage unit 16.
The antenna 17 is an antenna that transmits and receives radio waves to and from the reader / writer 2, and has characteristics corresponding to the frequency of the radio waves transmitted by the reader / writer 2. The power supply voltage generation unit 11 rectifies the radio wave received by the antenna 17 and generates a power supply voltage based on the amplitude of the radio wave. This power supply voltage is supplied to the reception unit 12, the transmission unit 13, the clock generation unit 14, the control unit 15, the storage unit 16, and the like.
The receiving unit 12 demodulates the radio wave received by the antenna 17 and converts it into a demodulated signal. This demodulated signal is output to the clock generator 14 and the controller 15. The transmission unit 13 modulates a data signal including data to be generated and transmitted by the control unit 15 and converts it into a modulated signal. This modulated signal is transmitted as radio waves to the reader / writer 2 via the antenna 17.
The clock generation unit 14 extracts a frame pulse having a fixed period from the demodulated signal generated by the reception unit 12, and generates a clock signal based on the frame pulse. This clock signal is output to the control unit 15 and the like.
The storage unit 16 is a memory that stores data received from the reader / writer 2, and is, for example, a nonvolatile memory. The storage unit 16 stores data or outputs stored data according to the control of the control unit 15. The storage unit 16 may be an EEPROM (Electrically Erasable Programmable ROM), a flash memory, an FeRAM (Ferroelectric RAM), an MRAM (Magnetic RAM), an OUM (Ovonic Unified Memory), or the like as a nonvolatile memory. In addition, the storage unit 16 includes a booster circuit such as a charge pump, and when data is written, the booster circuit boosts the power supply voltage to a voltage necessary for writing.
Data is written to the storage unit 16 by a write command, and the written data is read by a read command. The storage unit 16 also stores a tag ID and an internal state. In order to increase the processing speed, a tag ID, an internal state, or the like may be stored in a register provided in the control unit 15.
The control unit 15 decodes the demodulated signal generated by the receiving unit 12 to extract and analyze a command, and writes to and reads from the storage unit 16 based on the command. The control unit 15 includes a command analysis unit 151 that analyzes the received command, and a command execution unit 152 that executes the analyzed command. When the command analysis unit 151 and the command execution unit 152 receive a predetermined command, the control unit 15 determines whether the command execution condition is satisfied, and executes different processing depending on whether the condition is satisfied or not. To do.
The command analysis unit 151 analyzes the format of the received command data, and acquires the command ID field and the contents of the data field included in the command data. Further, the command analysis unit 151 includes an execution condition determination unit 153 that determines a command execution condition in order to execute the command in the command ID field. For example, the execution condition includes an internal state of the IC tag and a tag ID specified by a parameter.
The command execution unit 152 executes the command analyzed by the command analysis unit 151. The command execution unit 152 executes the first command processing when the execution condition is satisfied, and differs from the first command processing when the execution condition is not satisfied, according to the determination result of the command analysis unit 151. The command processing is executed. For example, when the execution condition is an internal state condition, the command execution unit 152 performs the first command processing when the current internal state of the IC tag matches the execution condition of the received command, The second command processing is executed when the internal state of the command does not match the execution condition of the received command. When the execution condition is a tag ID condition, the command execution unit 152 executes the first command processing when the tag ID of the IC tag matches the tag ID specified by the received command, When the tag ID does not match the tag ID specified by the received command, the second command processing is executed.
For example, when the command analyzed by the command analysis unit 151 is a write command, the command execution unit 152 writes data to the storage unit 16 and transmits a response indicating command completion from the transmission unit 13. When the command analyzed by the command analysis unit 151 is a read command or a tag ID read command, the command execution unit 152 reads data or tag ID from the storage unit 16 and transmits the read data from the transmission unit 13.
Further, in the present embodiment, the tag ID read / SLEEP command is analyzed and executed. The tag ID read / SLEEP command is a command for causing the IC tag to execute either a tag ID read process for reading the tag ID or a SLEEP process for switching the internal state to the SLEEP state. For example, the tag ID read / SLEEP command is transmitted from the reader / writer in the format of FIG. 8, the identifier indicating the tag ID read / SLEEP command is set in the command ID field, and the tag of the IC tag to be set in the SLEEP state in the data field An ID is set.
The flowchart of FIG. 3 shows processing when the IC tag receives a tag ID read / SLEEP command.
First, the command analysis unit 151 analyzes the received command data and detects that the tag ID read / SLEEP command is received based on the command ID in the command ID field (S301).
Next, the command analysis unit 151 compares the tag ID range of the data field parameter with the tag ID stored in the storage unit 16, and the tag ID of the IC tag is included in the tag ID range specified by the command. It is determined whether or not (S302).
If it is determined in S302 that the tag ID is included, the command execution unit 152 sets the sleep flag to 1 and sets the sleep state (S303). If it is determined in S302 that the tag ID is not included, the command execution unit 152 executes a tag ID read process (S304). In the tag ID read process, the tag ID is acquired from the storage unit 16, and the acquired tag ID is transmitted from the transmission unit 13.
Next, a communication method of the IC tag system according to the present embodiment will be described using the sequence of FIG. FIG. 4 shows an example in which the reader / writer 2 communicates with the IC tags 1a and 1b existing in the communication area and sequentially specifies the tag IDs of the IC tags 1a and 1b by anti-collision.
First, the reader / writer 2 transmits a reset signal to the IC tags 1a and 1b in the communication area (S401). For example, after the IC tags 1a and 1b are arranged in the communication area of the reader / writer 2, the reader / writer 2 generates the power supply voltage and resets the frame pulse as the reset signal in order to reset it first. A signal including only (reference pulse) is generated and transmitted to the IC tag 1.
Next, the IC tags 1a and 1b receive the reset signal, set the sleep flag to 1, set the isolate flag to 0, and set the internal state to the SLEEP state (S402). At this time, in the IC tags 1a and 1b, the reset signal transmitted from the reader / writer 2 in S401 is input to the reception unit 12 and the power supply voltage generation unit 11 via the antenna 17, and is received by the power supply voltage generation unit 11. A power supply voltage corresponding to the received radio wave is generated. When the power supply voltage generated by the power supply voltage generation unit 11 becomes equal to or higher than the operating voltage of the semiconductor device 10, a reset signal is output from the power supply voltage generation unit 11 to the circuit such as the control unit 15 to initialize the internal state. Is called.
Next, the reader / writer 2 transmits an INIT command to the IC tags 1a and 1b in the communication area (S403). The INIT command is an initial setting command transmitted before the anti-collision process. For example, after a predetermined time has elapsed from S401, the reader / writer 2 transmits an INIT command to the IC tag 1. When receiving the INIT command, the IC tags 1a and 1b perform initial setting or the like (S404). Note that, here, a response is not transmitted from the IC tag to the INIT command or the WAKE command, but the response is not limited to this and may be transmitted. The reader / writer cannot recognize that an IC tag exists in the communication area before the start of communication. The reader / writer may recognize that the IC tag exists in the communication area by receiving the response of the INIT command or the WAKE command or the response of the tag ID read command from the IC tag.
Next, the reader / writer 2 performs anti-collision processing for specifying the IC tag 1 in S405 and thereafter. The anti-collision process is a process for sequentially specifying all IC tags in order to communicate with a plurality of IC tags.
First, the reader / writer 2 transmits a WAKE command to the IC tags 1a and 1b (S405). Then, the IC tags 1a and 1b reset the sleep flag to 0 in the command execution unit 152 to cancel the internal SLEEP state (S406).
Next, the reader / writer 2 transmits a tag ID read command to the IC tags 1a and 1b (S407). Then, the IC tags 1a and 1b determine whether or not the sleep flag = 0 in the command analysis unit 151, acquire the tag ID of the IC tag, and transmit the tag ID to the reader / writer 2 as a response to the command (S408). .
Next, the reader / writer 2 detects a collision of the received tag ID, and transmits a tag ID read / SLEEP command to the IC tags 1a and 1b (S409). In the data field of this command, a tag ID range is stored as a condition of the IC tag to be set in the SLEEP state. Then, as shown in FIG. 3, the IC tags 1a and 1b determine whether or not the tag ID of the IC tag is included in the tag ID range specified by the command parameter in the command analysis unit 151, and the IC tag 1b is included. Therefore, the command execution unit 152 sets the sleep flag to 1 to set the SLEEP state (S410), and since the IC tag 1a is not included, the command execution unit 152 obtains the tag ID and sends the tag ID as a response to the command. The data is transmitted to the writer 2 (S411).
For example, one of the two processes executed by the tag ID read / SLEEP command is a process that does not respond to the reader / writer. As a result, the reader / writer only needs to process one response, so there is no need to add complicated processing to process two responses simultaneously. In this example, one process is a process that responds with a tag ID, and the other process is a process that does not respond by switching (transitioning) the internal state of the IC tag.
Next, the reader / writer 2 specifies the tag ID of the IC tag 1a because the collision of the tag ID is avoided, and transmits an ISOLATE command to the IC tags 1a and 1b (S412). The IC tags 1a and 1b determine whether or not the sleep flag = 0 in the command analysis unit 151. Since the IC tag b has the sleep flag = 1, the command execution unit 152 does not perform processing, and the IC tag 1a has the sleep flag = Since it is 0, the command execution unit 152 sets the isolate flag to 1 to enter the ISOLATED state (S413).
Next, the reader / writer 2 transmits a WAKE command to the IC tags 1a and 1b (S413). Then, the IC tags 1a and 1b reset the sleep flag to 0 by the command execution unit 152 to cancel the internal SLEEP state (S415). Next, the reader / writer 2 transmits a SLEEP command to the IC tags 1a and 1b (S416). In this SLEEP command parameter, an isolate flag = 1 is set as a condition of an IC tag to be set in the SLEEP state. Then, the IC tags 1a and 1b determine whether or not the isolate flag = 1 in the command analysis unit 151. Since the IC tag b is the isolate flag = 0, the command execution unit 152 does not perform processing, and the IC tag a has the isolate flag = Since it is 1, the sleep flag is set to 1 by the command execution unit 152 and the SLEEP state is set (S417).
Next, the reader / writer 2 transmits a tag ID read command to the IC tags 1a and 1b (S418). The IC tags 1a and 1b determine whether or not the sleep flag = 0 in the command analysis unit 151. Since the IC tag 1a has the sleep flag = 1, the command execution unit 152 does not perform processing, and the IC tag 1b has the sleep flag = Since it is 0, the command execution unit 152 acquires the tag ID of the IC tag, and transmits the tag ID to the reader / writer as a response to the command (S419).
Next, the reader / writer 2 specifies the tag ID of the IC tag 1b because the collision of the tag ID is avoided, and transmits an ISOLATE command to the IC tags 1a and 1b (S420). The IC tags 1a and 1b determine whether or not the sleep flag = 0 in the command analysis unit 151. Since the IC tag 1a has the sleep flag = 1, the command execution unit 152 does not perform processing, and the IC tag 1b has the sleep flag = Since it is 0, the command execution unit 152 sets the isolate flag to 1 to enter the ISOLATED state (S421). Next, the reader / writer 2 transmits a WAKE command to the IC tags 1a and 1b (S422). Then, the IC tags 1a and 1b reset the sleep flag to 0 by the command execution unit 152 to cancel the internal SLEEP state (S423). Next, the reader / writer 2 transmits a SLEEP command to the IC tags 1a and 1b (S424). In this SLEEP command parameter, an isolate flag = 1 is set as a condition of an IC tag to be set in the SLEEP state. Then, the IC tags 1a and 1b determine whether the isolate flag = 1 in the command analysis unit 151. Since the isolate flag = 1 in the IC tags a and b, the sleep flag is set to 1 in the command execution unit 152 and the SLEEP state is set. (S425). Thus, the anti-collision process is completed, a read command and a write command are transmitted to the IC tags 1a and 1b, and data is written to and read from the memories of the IC tags 1a and 1b.
As described above, in the present embodiment, different processing is executed depending on whether the IC tag that has received the predetermined command matches the command condition or not. Accordingly, since the communication sequence can be reduced, the communication time between the reader / writer and the IC tag and the time required to execute the command can be reduced. For example, comparing the conventional example and the sequence of this embodiment, S909 to S912 in FIG. 11 correspond to S409 to S411 in FIG. 4 and the SLEEP command and the tag ID read command were transmitted twice. The command transmission can be reduced to one time by the tag ID read / SLEEP command.
In particular, the anti-collision process can be shortened by realizing the tag ID read process or the SLEEP process with a single command. In the IC tag system, when there are a plurality of IC tags, it is necessary to identify the IC tag, and the identification work (anti-collision process) takes time. This identification work takes time in proportion to the number of IC tags. Therefore, by shortening the anti-collision process, the entire communication process can be effectively shortened when there are a large number of IC tags.
Next, an IC tag system according to Embodiment 2 of the present invention will be described. In the present embodiment, in a command different from the above-described embodiment example, an IC tag executes a different operation depending on execution condition determination. In the present embodiment, when the execution conditions match, an ISOLETE process is executed that sets the internal state to the ISOLATED state, and when the execution conditions do not match, a process that sets the internal state to the WAKE process is executed.
The configuration of the IC tag system and the IC tag according to the present embodiment is the same as in FIG. 1 and FIG. In the present embodiment, in addition to the first embodiment, the ISOLATE / WAKE command is analyzed and executed. The ISOLATE / WAKE command is a command for causing the IC tag to execute either an ISOLATE process for switching the internal state to the ISOLATED state or a process for releasing the internal state from the SLEEP state. For example, the ISOLATE / WAKE command is transmitted from the reader / writer in the format of FIG. 8, the identifier indicating the ISOLATE / WAKE command is set in the command ID field, and the tag ID of the IC tag to be set in the ISOLATED state is set in the data field. The
The flowchart of FIG. 5 shows processing when the IC tag according to the present embodiment receives an ISOLATE / WAKE command.
First, the command analysis unit 151 analyzes the received command data, and detects that the ISOLATE / WAKE command is received based on the command ID in the command ID field (S501).
Next, the command analysis unit 151 compares the tag ID range of the data field parameter with the tag ID stored in the storage unit 16, and the tag ID of the IC tag is included in the tag ID range specified by the command. It is determined whether or not (S502).
If it is determined in S502 that the tag ID is included, the command execution unit 152 sets the isolate flag to 1 to enter the ISOLATED state (S503). If it is determined in S502 that the tag ID is not included, the command execution unit 152 resets the sleep flag to 0 and cancels the SLEEP state (S504).
Next, a communication method of the IC tag system according to the present embodiment will be described using the sequence of FIG. FIG. 6 is an example in which the tag IDs of the IC tags 1a and 1b are specified in order by anti-collision, as in FIG. In FIG. 6, S412 to S415 are replaced with S430 to S432, compared to FIG.
First, a reset signal and an INIT command are processed in S401 to S404, and an anti-collision process is performed in S405 and thereafter. In the anti-collision process, the tag ID collision is avoided and the tag ID of the IC tag 1a is specified by the WAKE command (S405), the tag ID read command (S407), and the tag ID read / SLEEP command (S409).
Next, the reader / writer 2 transmits an ISOLATE / WAKE command to the IC tags 1a and 1b (S430). Then, as shown in FIG. 5, the IC tags 1a and 1b determine whether or not the tag ID of the IC tag is included in the range of the tag ID specified by the command parameter in the command analysis unit 151, and the IC tag 1a is included. Therefore, the command execution unit 152 sets the isolate flag to 1 to set the ISOLATED state (S431), and since the IC tag 1b is not included, the command execution unit 152 resets the sleep flag to 0 and releases the SLEEP state (S432). . In this example, both of the two processes executed by the ISOLATE / WAKE command are processes that do not respond by switching the internal state of the IC tag.
Next, the IC tag 1b is specified by the SLEEP command (S416) and the tag ID read command (S418), and the IC tag 1b is in the ISOLATED state by the ISOLATE command (S420) (S421). Further, the IC tags 1a and 1b are brought into the SLEEP state by the WAKE command (S422) and the SLEEP command (S424) (S425).
As described above, in this embodiment, the communication sequence can be further reduced by the ISOLATE / WAKE command in addition to the tag ID / read command of the first embodiment, and the communication time between the reader / writer and the IC tag and the execution of the command can be reduced. Such time can be shortened. For example, comparing the sequence of the conventional example and this embodiment, S913 to S916 in FIG. 11 correspond to S430 to S432 in FIG. 6, and the ISOLATE command and the WAKE command were transmitted twice. -The WAKE command can reduce command transmission to one time. As a result, the anti-collision process can be further shortened.
Next, an IC tag system according to Embodiment 3 of the present invention will be described. In the present embodiment, when a plurality of IC tags are provided, different operations are executed by the determination of the execution condition in the IC tag. In this embodiment, a write process for writing data to the IC tag memory is executed when the execution conditions match, and a tag ID read process for reading the tag ID of the IC tag is executed when the conditions do not match.
The IC tag system according to the present embodiment has three IC tags 1a, 1b, and 1c. Other configurations of the IC tag system and the IC tag are the same as those in FIG. 1 and FIG.
Here, the communication method of the IC tag system according to the present embodiment will be described with reference to FIG. FIG. 7 shows an example in which the reader / writer 2 communicates with the IC tags 1a, 1b, and 1c existing in the communication area, specifies the tag IDs of the IC tags 1a, 1b, and 1c in order by anti-collision, and performs a write process. It is.
In the figure, S701, S702, and S703 are anti-collision processes for specifying the IC tags 1a, 1b, and 1c, respectively, and the details of the processes are the same as those in FIGS.
When the tag ID of the IC tag 1a is specified in S701, the IC tag 1a is in the ISOLATED state. Subsequently, anti-collision processing is performed in S702. At this time, the reader / writer 2 transmits a tag ID read / write command to the IC tags 1a, 1b, and 1c (S704). Then, the IC tags 1a, 1b, and 1c determine whether or not the tag ID of the IC tag corresponds to the tag ID specified by the command parameter. Since the IC tag 1a is applicable, write processing is executed and the command completion is returned to the reader / writer 2, and since the IC tags 1b and 1c are not applicable, the tag ID is acquired and returned to the reader / writer 2. Two processes executed by the tag ID read / write command are processes that respond to the reader / writer at different timings. Since the time required for processing is different in the IC tag between the write process and the read process, the time for receiving a response to the reader / writer is different, and the reader / writer can process both the write process and the read process response.
Similarly in S703, the reader / writer 2 transmits a tag ID read / write command to the IC tags 1b and 1c (S705), the IC tag 1b executes a write process, and the IC tag 1c executes a tag ID read process. Is done. After S703, a write command (S706) is transmitted to the IC tag 1c, and writing to the IC tag 1c is performed.
As described above, in this embodiment, tag ID read and data write can be executed with one command by a tag ID read / write command. As a result, the anti-collision process and the write process can be performed simultaneously in parallel, so that the communication sequence can be further reduced, and the communication time between the reader / writer and the IC tag and the time required for command execution can be reduced. .
Note that the two processes executed by one command are not limited to the above-described example, but may be other processes. For example, the command may be a combination of the WAKE command in S422 in FIG. 4 and the SLEEP command for the IC tag with the isolate flag = 1 in S424. In the above example, two different command processes are executed by one command, but a process selected from three or more command processes may be executed. For example, data writing, tag ID reading, sleep flag setting, etc. may be executed by one command.
In the above-described example, the passive IC tag having no power source is described. However, the present invention is not limited to this, and an active IC tag having a power source may be used.
It is a block diagram of the IC tag system concerning this invention. It is a block diagram which shows the structure of the IC tag concerning this invention. It is a flowchart which shows the command execution process of the IC tag concerning this invention. It is a sequence which shows the communication method of the IC tag system concerning this invention. It is a flowchart which shows the command execution process of the IC tag concerning this invention. It is a sequence which shows the communication method of the IC tag system concerning this invention. It is a figure which shows the communication method of the IC tag system concerning this invention. It is a figure which shows the format of the command data used with an IC tag system. It is a flowchart which shows the command execution process of the conventional IC tag. It is a flowchart which shows the command execution process of the conventional IC tag. It is a sequence which shows the communication method of the conventional IC tag system.
DESCRIPTION OF SYMBOLS 1 IC tag 2 Reader / writer 10 Semiconductor device 11 Power supply voltage generation part 12 Reception part 13 Transmission part 14 Clock generation part 15 Control part 16 Storage part 17 Antenna 18 Antenna terminal 151 Command analysis part 152 Command execution part
A first IC tag having a first storage circuit for storing a first tag ID and a first sleep flag, a second tag ID different from the first tag ID, and a second sleep flag; An IC tag identifying method for identifying the first and second IC tags by a reader / writer by anti-collision in a communication area including a second IC tag having a second storage circuit for storing
The reader / writer sends a first WAKE command,
In response to the reception of the first WAKE command, the first IC tag sets a first value indicating permission to transmit the tag ID of the IC tag to the first sleep flag,
The second IC tag sets the first value to the second sleep flag in response to receiving the first WAKE command,
After the first sleep flag and the second sleep flag are set in response to the first WAKE command, the reader / writer transmits a first tag ID read command,
The first IC tag transmits the first tag ID in response to receiving the first tag ID read command,
The second IC tag transmits the second tag ID in response to the reception of the first tag ID read command,
The reader / writer detects a collision between the first and second tag IDs transmitted from the first and second IC tags, and includes the second tag ID and the first tag ID. Send tag ID read / SLEEP command with no tag ID range as execution condition,
In response to receiving the tag ID read / SLEEP command, the first IC tag determines the execution condition of the tag ID read / SLEEP command, and transmits the first tag ID.
In response to reception of the tag ID read / SLEEP command, the second IC tag determines the execution condition of the tag ID read / SLEEP command, and indicates a second interruption of transmission of the tag ID of the IC tag. Set the value to the second sleep flag,
The reader-writer receives the first tag ID transmitted from the first IC tag according to the tag ID read-SLEEP command to identify the first IC tag within said communication area ,
The first storage circuit further stores a first isolate flag, and the second storage circuit further stores a second isolate flag,
The reader / writer sends a reset signal before sending the first WAKE command,
In response to receiving the reset signal, the first IC tag sets a third value indicating that the IC tag is not identified by the reader / writer in the first isolete flag,
In response to receiving the reset signal, the second IC tag sets the third value to the second isole flag,
The reader / writer receives the first tag ID transmitted from the first IC tag in response to the tag ID read / SLEEP command, and then transmits a first ISOLATE command.
The first IC tag determines the first sleep flag in response to reception of the first ISOLATE command, and indicates that the IC tag is identified by the reader / writer. Set the value to the first isolate flag,
After the first isolate flag is set in response to the first ISOLATE command, the reader / writer sends a second WAKE command,
The second IC tag sets the first value to the second sleep flag in response to receiving the second WAKE command,
After the second sleep flag is set in response to the second WAKE command, the reader / writer uses the first and second isolate flags as the fourth value as an execution condition. Send SLEEP command,
In response to receiving the SLEEP command, the first IC tag determines an execution condition of the SLEEP command, sets the second value in the first sleep flag,
After the first sleep flag is set in response to the SLEEP command, the reader / writer sends a second tag ID read command,
The second IC tag transmits the second tag ID in response to the reception of the second tag ID read command,
The reader / writer receives the second tag ID transmitted from the second IC tag in response to the second tag ID read command, and identifies the second IC tag in the communication area. And
The reader / writer receives the second tag ID transmitted from the second IC tag in response to the second tag ID read command, and then transmits a second ISOLATE command.
The second IC tag determines the second sleep flag in response to receiving the second ISOLATE command, and sets the fourth value in the second isolate flag.
IC tag identification method.
The reader / writer receives the first tag ID transmitted from the first IC tag in response to the tag ID read / SLEEP command, and then includes the first tag ID and the second tag ID. Send ISOLATE / WAKE command with tag ID range not including tag ID as execution condition,
The first IC tag is configured to determine an execution condition of the ISOLATE / WAKE command in response to reception of the ISOLATE / WAKE command, and to indicate that the IC tag is identified by the reader / writer. To the first isolate flag,
In response to receiving the ISOLATE / WAKE command, the second IC tag determines an execution condition of the ISOLATE / WAKE command, sets the first value to the second sleep flag,
After the first isolate flag and the second sleep flag are set according to the ISOLATE / WAKE command, the reader / writer has the first and second isolate flags having the fourth value. Send a SLEEP command with this as the execution condition,
After the first sleep flag is set in response to the SLEEP command, the reader / writer transmits a second tag ID read command,
The second IC tag transmits the second tag ID from the second IC tag in response to reception of the second tag ID read command,
After the second sleep flag is set in response to the second WAKE command, the reader / writer executes a tag ID range that includes the first tag ID and does not include the second tag ID. Send tag ID read / write command as a condition,
In response to reception of the tag ID read / write command, the first IC tag determines execution conditions of the tag ID read / write command, executes write processing, and a message indicating completion of the write processing Send
In response to receiving the tag ID read / write command, the second IC tag determines an execution condition of the tag ID read / write command, and transmits the second tag ID.
The reader / writer receives the second tag ID transmitted from the second IC tag in response to the tag ID read / write command, and identifies the second IC tag in the communication area. ,
The transmission timing of the message that the first IC tag transmits in response to the tag ID read / write command is the second tag that the second IC tag transmits in response to the tag ID read / write command. Different from the ID transmission timing,
The IC tag identification method according to claim 3 .
JP2005280998A 2005-09-27 2005-09-27 IC tag identification method Active JP5027398B2 (en)
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