JP4884741B2 - Wireless tag reader / writer - Google Patents

Description

The present invention relates to a non-contact access to can be read and / or write information radio tag reader / writer to the wireless tag.

  In recent years, contactless wireless tags have attracted attention as technologies relating to product identification and management that replace barcodes. The wireless tag is also called an IC tag, an ID tag, an RF tag, an electronic tag, a transponder, a data carrier, etc., receives an RF (Radio Frequency) signal and reads data recorded in an electronic circuit such as a semiconductor memory, Or it is a tag using RF-ID (Radio Frequency IDentification) technology which can write data. Recently, wireless tags that can be used semi-permanently without a power source have appeared due to the development of non-contact power transfer technology. A wireless tag reader / writer is used to read / write data from / to such a wireless tag.

  The wireless tag reader / writer includes a head unit that communicates with the wireless tag by non-contact communication and performs reading / writing, and a controller unit that controls the head unit. The wireless tag reader / writer is a transmission device that modulates and transmits a carrier wave as a baseband signal with a digital signal and receives a response signal from the wireless tag. The modulation based on the baseband signal of the carrier includes ASK (Amplitude Shift Keying) modulation for changing the amplitude of the carrier, FSK (Frequency Shift Keying) modulation for changing the frequency, and PSK (Phase Shift changing the phase). Keying) modulation.

On the other hand, the wireless tag is being standardized by the international standard ISO (International Organization for Standardization) / IEC15693. There are a plurality of types of wireless tags, and many comply with the international standard ISO15693. Such a tag compliant with ISO15693 manages the internal memory in units of blocks. The wireless tag reader / writer supports various commands related to wireless tag access for reading / writing with respect to a standardized wireless tag. For example, in the command defined in ISO 15693-3, the memory can be accessed in units of blocks.
Japanese Patent No. 2993008

  In such a wireless tag, the memory is managed on a block basis. In particular, in a wireless tag standardized by ISO15693, only updating in units of blocks is allowed. For this reason, the memory configuration in the tag needs to be performed in units of blocks. However, the number of bytes of memory constituting one block is not specified, and for example, one block includes a 4-byte wireless tag and an 8-byte wireless tag. For this reason, in order to realize access in units of blocks, it is necessary to describe and set a program in units of blocks while considering the number of bytes per block. was there. In addition, this configuration cannot cope with the difference in the number of bytes constituting one block of the wireless tag. Therefore, it is necessary to redesign the memory configuration for each wireless tag, which is extremely troublesome.

The present invention has been made in view of such a situation. A first object of the present invention is to provide a wireless tag reader / writer in which memory access to a wireless tag can be easily designed. Another object of the present invention is to provide a wireless tag reader / writer that can realize general-purpose memory access regardless of the type of the wireless tag.

  In order to achieve the above object, a first wireless tag reader / writer of the present invention includes a communication unit capable of transmitting and receiving a wireless signal to perform contactless communication with the wireless tag, and a wireless signal in the communication unit. A wireless tag reader / writer including a control circuit capable of controlling transmission and reception, a tag block size holding unit for registering the number of bytes constituting one block of a wireless tag memory to be used, and a wireless tag The instruction in byte unit of the program that defines the memory access processing in byte unit is converted into block unit according to the number of bytes per block registered in the tag block size holding unit, and from byte unit The result of the memory access processing performed by the control circuit according to the memory address converted into block units is converted from block units to byte units. And a size conversion unit that. Thus, while the user performs access design in units of bytes, the actual access is performed in units of blocks, so that the program design can be made extremely easy. In addition, since the size conversion unit can appropriately convert the byte unit to the block unit according to the number of bytes per block constituting the RFID tag memory, the versatility of the program is maintained, and the same regardless of the number of bytes. Access is possible.

  The second wireless tag reader / writer further includes a display unit capable of displaying the result of the memory access processing performed by the control circuit from the block unit to the byte unit and displaying the result in byte units. As a result, the user can design memory access by the program in units of bytes, and can display the access result in units of bytes, so that the program can be designed and operated without being aware of the tag block size of the wireless tag.

  Further, in the third wireless tag reader / writer, the tag block size holding unit records the tag head block number of the block constituting the wireless tag memory and the size of one block expressed in units of bytes. It is. Thereby, the tag block size of the wireless tag to be used can be stored in the existing tag information table, and the configuration can be simplified.

  Furthermore, the fourth wireless tag reader / writer is configured such that the tag block size holding unit can change the registered tag block size by the user. Thereby, even when a wireless tag having a different tag block size is used, the user can use this wireless tag only by changing the tag block size registered in the tag block size holding unit.

  Furthermore, in the fifth wireless tag reader / writer, the size conversion unit has registered in the tag block size holding unit the instruction in bytes for the program that defines the memory access processing to the wireless tag in bytes. According to the number of bytes per block, the control circuit executed the memory access process according to the first size conversion unit that converts the block unit and the memory address converted from the byte unit to the block unit by the first size conversion unit. The second size conversion unit converts the result from the block unit to the byte unit. In this way, by configuring the conversion unit that converts from byte units to block units and the conversion unit that converts block units into byte units again, both can be executed simultaneously.

  Furthermore, in the sixth wireless tag reader / writer, when the control circuit receives a memory read request for the wireless tag, the size conversion unit extracts all the blocks including the designated area designated in units of bytes. Are read out in units of blocks, and a designated indication area is read out in units of bytes in the read blocks, and is output as a result of a read request.

  Furthermore, in the seventh wireless tag reader / writer, when the control circuit receives a memory write request for the wireless tag, the size conversion unit extracts all blocks including the designated area specified in units of bytes. Are read out in units of blocks, the designated indication area is replaced in units of bytes, and the read block including the indication area after the replacement is written.

As described above , according to the wireless tag reader / writer of the present invention, the user can handle the memory in byte units and perform memory access without worrying about the size of the block constituting the wireless tag memory. It is easy to create, update, and modify programs. In addition, even if the block size differs depending on the wireless tag, conversion in byte units and block units is performed automatically, so it can be executed regardless of the tag block size of the wireless tag, increasing versatility. There is also an advantage that program change is unnecessary.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below are intended to illustrate the wireless tag reader / writer for embodying the technical idea of the present invention, the present invention does not specify the radio tag reader / writer to the following. Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

  In this specification, the connection between the RFID tag reader / writer and the computer, printer, external storage device and other peripheral devices for operation, control, input / output, display, and other processing connected thereto is, for example, IEEE 1394, RS -232x, RS-422, RS-423, RS-485, serial connection such as USB, parallel connection, or electrical connection via network such as 10BASE-T, 100BASE-TX, 1000BASE-T Do. The connection is not limited to a physical connection using a wire, but may be a wireless connection using a wireless LAN such as IEEE 802.1x or OFDM, radio waves such as Bluetooth, infrared rays, optical communication, or the like. Further, a memory card, a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like can be used as a recording medium for storing data of the wireless tag reader / writer or storing settings.

The wireless tag reader / writer is a device that can read and / or write a wireless tag, and is also called an interrogator, an interrogator, a controller, or the like.
(Embodiment 1)

1 is a perspective view showing a configuration of an RF-ID system 10 including a wireless tag reader / writer 100 according to Embodiment 1 of the present invention, FIG. 2 is a plan view of the wireless tag, and FIG. 3 is a wireless tag reader / writer. Block diagrams showing the configuration of 100 are respectively shown. The RF-ID system 10 in FIG. 1 manages the pallet W transported on the transport line by writing data to the wireless tag using the RF signal modulated with ASK or reading data in the wireless tag. System. The RF-ID system 10 includes a wireless tag 1, a reader / writer 2, a serial bus cable 3, and a control device 4.
(Wireless tag 1)

The wireless tag 1 receives an RF signal from the reader / writer 2 and generates electric power necessary for the operation, and writes received data into the memory or reads data from the memory based on the received data. . In this memory, UID (Unique ID) assigned at the time of manufacture is stored as identification information for identifying the wireless tag 1. Specifically, a manufacturer code, a product code, a serial number, and the like are stored as a UID. Therefore, the pallet W to which the wireless tag 1 is attached can be identified by reading the UID from the wireless tag 1. In addition, there are various types of wireless tags, and the commands that can be used differ mainly depending on the manufacturer. Wireless tag types include I / CODE SLI, MB89R116, MB89R118, Tag-itHFI, my-d, and the like.
(Reader / Writer 2)

Hereinafter, as one form of the wireless tag reader / writer 100, a reader / writer 2 that supports reading and writing of a plurality of types of wireless tags will be described. The reader / writer 2 performs an operation of transmitting an ASK modulation signal and receiving a response signal from the wireless tag 1. The reader / writer 2 is a wireless tag reader / writer based on the ISO15693 standard, and is a so-called proximity type (VICC: Vicinity) reader. Specifically, it is suitable for non-contact communication when the distance to the wireless tag is in the range of several centimeters to several tens of centimeters (for example, 70 cm). The reader / writer 2 is connected to the control device 4 via the serial bus cable 3. This reader / writer 2 is also called a head unit. On the other hand, the control device 4 is also called a controller unit, and is composed of a host computer, a PLC, and the like. Note that the head unit and the controller unit may be configured integrally as well as configured by separate members.
(Control device 4)

  The control device 4 instructs the reader / writer 2 to start communication with the wireless tag 1 and collects, accumulates, or displays data read from the wireless tag 1 by the reader / writer 2. The control device 4 instructs the start of communication at the timing when the pallet W on the transport line is located within the communication area of the reader / writer 2. As such a control device 4, an information processing terminal such as a PLC (Programmable Logic Controller) or a general-purpose personal computer is used.

Specifically, a read / write command is output from the control device 4 to the reader / writer 2 as a trigger signal for instructing the start of communication. Then, the reader / writer 2 starts transmitting a response request to the wireless tag 1 based on the read / write command. This response request is transmitted as an ASK-modulated RF signal, and is repeatedly transmitted until a response signal from the wireless tag 1 is received.
(Configuration of wireless tag 1)

  Details of the card-like wireless tag 1 shown in FIG. 1 are shown in a plan view of FIG. The wireless tag 1 includes a thin rectangular substrate 11, an antenna coil 12 spirally wired along each side of the substrate 11, and a semiconductor connected to the antenna coil 12 and disposed inside the antenna coil 12. It consists of a chip 13.

  The substrate 11 is made of, for example, a resin sheet having a thickness of 0.2 mm, and the antenna coil 12 is formed on the resin sheet by printing or etching. The semiconductor chip 13 includes a capacitor that forms a resonance circuit with the antenna coil 12, a demodulation circuit that demodulates the reception circuit, a processing circuit that processes reception data, and a semiconductor memory that stores UID and reception data. The response signal is output based on a response request from the reader / writer 2. Specifically, it is generated by reading data from the semiconductor memory based on the received data and encoding a subcarrier generated by load modulation of the RF signal.

  Next, a block diagram showing the configuration of the reader / writer 2 of FIG. 1 is shown in FIG. The reader / writer 2 includes an oscillation circuit 21, an amplification circuit 22, a modulation circuit 23, an LPF (low-pass filter) 24, an LC resonance circuit 25, an attenuator 26, a demodulation circuit 27, a binarization circuit 28, a control circuit 29, an external circuit An interface 30 and an encoding circuit 31 are provided.

  The oscillation circuit 21 is an RF signal generation circuit that generates an RF signal using a crystal oscillator. For example, a 13.56 MHz RF signal is generated and output as a carrier wave. The carrier wave is amplified by the amplifier circuit 22 and output to the modulation circuit 23.

  The modulation circuit 23 performs ASK modulation on the carrier wave after power amplification based on the baseband signal from the encoding circuit 31, and generates an ASK modulated signal. The modulation circuit 23 can switch between ASK modulation with a modulation factor of 100% and ASK modulation with a modulation factor of 10% so that communication can be performed even with different types of wireless tags. Further, in the ASK modulation with a modulation degree of 10%, in order to improve the communication performance for a wireless tag for a low modulation degree that designates a communication system with a modulation degree of 10%, the ASK modulation signal is within a range of 10% to 30%. The modulation degree can be switched.

  The encoding circuit 31 performs a process of encoding the data input from the control circuit 29 with a pulse position and generating a baseband signal.

  The harmonic component of the ASK modulated signal is removed by the LPF 24 and is output to the LC resonance circuit 25. The LC resonance circuit 25 is a resonance circuit including an antenna coil and a capacitor. The ASK conversion signal from the modulation circuit 23 is sent to the wireless tag 1 via the LC resonance circuit 25. The response signal from the wireless tag 1 is received by the LC resonance circuit 25. Thus, the LC resonance circuit 25 constitutes the communication unit 70. The received signal is attenuated by the attenuator 26 to a level that can be controlled by the demodulation circuit 27 at the subsequent stage.

  The demodulating circuit 27 demodulates the received signal after attenuation based on the carrier wave and the sub-carrier wave to generate a demodulated signal. The binarization circuit 28 is a comparator that binarizes the demodulated signal from the demodulation circuit 27 by threshold processing, and generates composite reception data.

  The control circuit 29 starts communication with the wireless tag 1 based on a trigger signal input from the control device 4 via the external interface 30, and performs control to switch the modulation degree based on the demodulated signal. Specifically, a response request for the wireless tag 1 is generated based on the read / write command from the control device 4 and is output to the encoding circuit 31, and the response signal is received from the wireless tag 1 based on the demodulated signal. And an operation of switching the modulation degree of the ASK modulation signal is performed.

Here, it is assumed that an operation for automatically setting parameters relating to communication with the wireless tag 1 is performed based on a control signal input from the control device 4. Specifically, the parameter table is read based on the automatic determination command from the control device 4, the reception command is generated based on the read parameter table, and is transmitted to the wireless tag 1. Communication parameters are set based on a response from the wireless tag 1 in response to this reception command.
(Parameter table)

  The parameter table is composed of communication parameters (data) relating to communication standards and communication methods, and a plurality of tables are stored in a memory such as an EEPROM according to the type of the wireless tag 1 to be communicated. The communication parameters include the degree of modulation in ASK modulation, the radio wave intensity at the time of RF signal transmission, the block size (access size) of the tag read from the wireless tag 1, the maximum size of received data, the reply timing, and the like. Here, there are 8 types depending on the combination of communication parameters, that is, whether the communication method is modulation degree 100% or 10%, the strength of the radio wave intensity, and the designation of the read size (8 bytes or 4 bytes) Are stored as a parameter table.

One such parameter table is read, and based on the read parameter table, a communication parameter is determined and an acceptance command is transmitted. The reception command is also called an Inventory command, and the reply data is data specifying the manufacturer code or product code of the wireless tag 1. If there is no response from the wireless tag 1, this acceptance command is retransmitted after changing the parameter table. If there is a response from the wireless tag 1 to the reception command, the type of the wireless tag 1 is determined based on the received data, and communication parameters are registered and set. That is, an appropriate communication parameter can be automatically set by sending an acceptance command to the wireless tag 1 to be communicated.
(Communication area)

  FIG. 4 shows an example of communication stability in the positional relationship between the wireless tag reader / writer and the pallet to which the wireless tag is attached. The stability of communication depends on the performance of the reader / writer, which is a wireless tag reader / writer, and installation conditions such as ambient noise, but generally has a distribution as shown in FIG. As shown in this figure, a stable communication area where communication can be performed stably and an unstable communication area where communication is unstable are formed around the wireless tag reader / writer. If a pallet with a wireless tag is transported on the line in the vicinity of the wireless tag reader / writer (upward in FIG. 4), stable communication is realized when the pallet is in the stable communication area. On the other hand, when the pallet is located on the unstable communication area or outside the stable communication area, stable communication cannot be performed. Under such circumstances, it has been difficult for the wireless tag reader to determine whether or not communication with the wireless tag is being performed stably.

In contrast, in the present embodiment, communication between the wireless tag reader / writer and the wireless tag is performed at intervals set in advance by the user, and terminal output and serial output are performed when the number of continuous successes exceeds a predetermined number. Notification that communication is possible. The user can stably communicate by setting the communicable detection time interval and the communicable coincidence number according to the use environment. Furthermore, since it is possible to detect that communication is possible by terminal input, it is possible to give an actual communication instruction according to this timing, and it is possible to realize more reliable and reliable communication. In particular, when a wireless tag is used in the FA field, it becomes an environment with a lot of noise. By setting an appropriate stability parameter according to the environment, the use of a wireless tag with stable communication and high reliability is realized. The
(Block Diagram)

  Hereinafter, a configuration for realizing the communicable detection will be described based on the block diagram of FIG. The wireless tag reader / writer shown in this figure includes a command input unit 41 as an input system 40, a tag type setting unit 42, a unique set value setting unit 43, and a stable parameter setting unit 47, and a command substitution unit as the control circuit 29. 44, a stability detection unit 48, and a size conversion unit 54, a command information holding unit 45 and a unique set value holding unit 46 as a storage unit 60, and a display unit 50. Furthermore, the communication part 70 which performs non-contact communication by radio | wireless with a wireless tag, the input terminal 49 for inputting the signal from the outside, and the output part 72 for outputting an output signal are also provided. As the communication unit 70, an antenna or the like capable of transmitting and receiving radio signals can be used.

  The command input unit 41 communicates with the control device 4, inputs a command related to access to the wireless tag, and sends it to the control circuit 29. The command input unit 41 corresponds to the external interface 30 in FIG.

  The tag type setting means 42 designates the type of wireless tag used manually or automatically. In the case of manual input, the type of the wireless tag used by the user is directly designated or selected from a plurality of options. In the case of automatic setting, the wireless tag reader / writer acquires and sets the type of the wireless tag as will be described later.

The unique setting value setting unit 43 can individually set setting parameter values related to command execution according to the type of the wireless tag. For example, a time for determining a processing result is set for a command in which a specified value of the completion time of processing executed by the command exceeds a predetermined value.
.

  The stability parameter setting unit 47 is an input means for the user to set the time interval and the number of times. That is, a predetermined command is transmitted to the wireless tag at a set time interval, and it is detected that the communication with the wireless tag has succeeded continuously for the set number of times, and the stability indicating the stability of communication is shown. Output the output. Further, the terminal output delay time of the stability detection unit 48 can be set from the stability parameter setting unit 47. The input system such as the unique set value setting unit 43 and the stable parameter setting unit 47 can be realized by an input device such as a keyboard, a mouse, a touch panel, and a console.

(Control circuit 29)
The control circuit 29 is constituted by a CPU or the like. The command replacement unit 44 replaces the input command input from the command input unit 41 with respect to a command that can be replaced with the selected arbitrary command and / or manufacturer setting command.

The stability detection unit 48 gives an instruction to transmit a predetermined command to the wireless tag at predetermined time intervals, detects that the communication of the command has succeeded more than a predetermined number of times, and performs communication. Outputs stable output indicating the stability of. For this reason, the stability detection unit 48 includes counting means such as a counter. For example, a success counter that counts the number of successful communications and a failure counter that counts the number of failures are provided. The stable output is output from the output unit.
(Size converter 54)

  The size conversion unit 54 gives an instruction in units of bytes of a program that prescribes memory access processing to the wireless tag in units of bytes according to the number of bytes per block registered in the tag block size holding unit 52. The control circuit 29 converts the result of executing the memory access processing from the block unit to the byte unit according to the memory address converted into the block unit and further converted from the byte unit into the block unit.

  In the access from the wireless tag reader / writer to the wireless tag, the size to be read and written is specified, and the access is performed with a unit of, for example, 8 bytes or 4 bytes as one block. As described above, the wireless tag defined in ISO 15693-3 performs memory management in units of blocks, but the number of bytes per block, that is, the tag block size is not defined and varies depending on the wireless tag. On the other hand, since the memory access is usually designed in units of bytes, the program is often designed in units of bytes. Therefore, when creating a memory access program, it is necessary to design the tag block size in correspondence with the byte unit. This conversion work is extremely complicated, and if the tag block size of the wireless tag is different, the design of the program needs to be changed accordingly, which is troublesome. Therefore, in the present embodiment, by providing a conversion unit that automatically converts the block unit and the byte unit according to the tag block size, the operation is performed in the unit of byte without making the user aware of the tag block size. Made it possible. As a result, the user can handle the memory in bytes without worrying about the tag block size.

  In the example of FIG. 5, one size conversion unit 54 performs conversion from byte unit to block unit to execute memory access, and converts the obtained result from block unit to byte unit to be displayed to the user. ing. However, the conversion unit that performs conversion from byte units to block units and the conversion unit that converts block units into byte units again may be configured as separate members. By using separate members, both conversions can be performed individually at high speed, but the configuration is complicated and the cost is increased.

(Storage unit 60)
The storage unit 60 can use a secondary storage medium such as a memory or a hard disk that can be electrically written and erased. Preferably, it comprises a ROM, RAM, EEPROM and / or FRAM for storing data. Data based on product information or the like can be stored in this memory.

The command information holding unit 45 holds arbitrary commands and / or manufacturer setting command information that can be used according to the type of the wireless tag used in advance. For the command information holding unit 45, a lookup table or a database can be used.
(Unique setting value holding unit 46)

The unique setting value holding unit 46 presets setting parameter values corresponding to the characteristics of the wireless tag corresponding to each command. The setting parameter value includes a completion time such as a write time-out time and a noise dead time (reception prohibition time) as described later. Further, the tag head block number, the tag block size, the number of tag blocks, and the like can be stored.
(Tag block size holding unit 52)

The number of bytes constituting one block of the memory of the used wireless tag, that is, the tag block size is registered in the tag block size holding unit 52. In addition, a block head number (tag head block number) included in the wireless tag memory can be registered in the tag block size holding unit 52. The tag block size holding unit 52 can be a dedicated table, but preferably the tag block size is stored in a tag information table storing various information related to the wireless tag, and can be used together as the tag block size holding unit 52. it can. In the example of FIG. 5, the unique setting value holding unit 46 storing the tag information table is used in combination with the tag block size holding unit 52. Since the tag information table is an existing member that is also used in the conventional wireless tag, the configuration can be simplified by using the tag information table. In addition, by enabling the user to set and change the tag information table, even when using wireless tags having different tag block sizes, it is possible to easily cope by changing only the tag information table. As a result, a wireless tag with a new specification can be introduced without rewriting the memory access program.
(Display unit 50)

In the display unit 50, the result of the memory access processing executed by the control circuit 29 is converted from the block unit to the byte unit by the size conversion unit 54 and displayed in byte units. As a result, the user can design memory access by the program in units of bytes, and can display the access result in units of bytes, so that the program can be designed and operated without being aware of the tag block size of the wireless tag. As the display unit 50, a display such as a CRT, a liquid crystal, or an organic EL can be used. Needless to say, it can also be used as a display unit for displaying the processing contents and processing results of the program.
(Memory conversion)

Next, a procedure for performing memory conversion from a byte unit to a block unit, and further from a block unit to a byte unit when the memory tag is actually accessed and processed by the memory conversion unit, based on the flowchart of FIG. explain. First, in step S101, the tag head block number is acquired from the tag information table, and in step S102, the tag block size is acquired from the tag information table. In step S103, the size converter 54 converts the byte unit into a block unit based on the acquired information. In step S104, processing is performed in units of blocks. Further, the user's instruction area is extracted from the data acquired as a result of the processing in step S105, returned to the byte unit by the size conversion unit 54, and the result is displayed on the display unit in byte unit in step S106, or the necessary output is output. Do.
(Memory read operation)

Hereinafter, as a specific operation using the wireless tag reader / writer, a procedure for performing a memory reading operation (reading) will be described with reference to FIG. In the reading operation, in response to the user's operation instruction, all blocks including the instruction area in byte units instructed by the user are read, and only the user instruction area is displayed on the display unit 50 as a processing result for the user. In the example of FIG. 7, an 8-byte wireless tag is used per block, and the user instructs an operation (read) of reading up to 10 bytes, that is, 13 bytes from the third byte from the top of the wireless tag memory. To do. Since the wireless tag reader / writer actually accesses the wireless tag in units of blocks, in this case, it is necessary to read 2 blocks from the head (0 block), that is, 8 bytes × 2 blocks = 16 bytes. Therefore, the size converter 54 converts the instruction to read 10 bytes from the third byte specified by the user into an instruction to read two blocks, and causes the control circuit 29 to execute the instruction. In this way, the corresponding block is read so as to include all the memory areas designated by the user. After the reading is completed, only the byte data (in this example, 3 to 13 bytes) corresponding to the user instruction area is extracted from the read data (in this example, 0 to 16 bytes), and the reading result Output as. In this way, the reading operation instructed in byte units is automatically converted into block units, and the read result is output again in byte units. As a result, the user can describe the memory access in units of blocks without being aware of the tag block size of the wireless tag to be used, and the access result can be obtained in units of bytes. Since the program is automatically converted and executed, the program can be designed very easily. In the present specification, the operation of extracting the data of the corresponding user instruction area from the block data read as described above is also referred to as re-conversion from the block unit to the byte unit.
(Memory write operation)

  Similarly, a procedure for performing a memory write operation (write) will be described with reference to FIG. In the case of a write operation, in response to a user operation instruction, all blocks including the instruction area in byte units specified by the user are read into the memory, and the part other than the user instruction area is left, and the user instruction is performed on the memory. Create and write data. In the example of FIG. 8, the wireless tag of 8 bytes per block is used as in FIG. 7, and the user writes 7 bytes from the 6th byte from the beginning of the wireless tag memory, that is, 13 bytes to predetermined write data. It is assumed that a writing operation (write) is instructed. Also in this case, in order to obtain a block including all 6 bytes to 13 bytes in the memory which is a work area, first, control is performed for 2 blocks from the top (0 block), that is, 8 bytes × 2 blocks = 16 bytes. The circuit 29 is once read. Next, among the data read into the memory, the designated area designated by the user, from 6 bytes to 13 bytes, is replaced with predetermined write data. In this way, the control circuit 29 performs an operation of rewriting all the two blocks after rewriting the designated area with the designated data in the two blocks including all the user designated areas. That is, the data for 2 blocks from 0 block is updated at once. As a result, the area designated by the user is updated to predetermined data. As described above, in the writing operation, the size conversion unit 54 reads the block including the target area once, rewrites the designated area as instructed, and performs writing in units of blocks. Convert to instruction. As a result, the user can write in units of blocks without being aware of the tag block size of the wireless tag to be used in the same manner as described above, and a program that defines free memory access without being limited by the memory size. Can be described. In addition, once a program is created, it can be easily changed. In particular, even tags having different tag block sizes can be used in the same manner by automatically performing size conversion by the size conversion unit 54, so that extremely flexible memory access of the wireless tag can be realized. In particular, the wireless tag standardized by ISO15693 stipulates that it can be accessed only in units of blocks, but even when such a wireless tag is used, according to this embodiment, data is updated in units of bytes. It is useful because it can.

The wireless tag reader / writer of the present invention can be applied to a reader / writer that reads information recorded on a wireless tag in a non-contact manner. For example, as an individual object recognition system called a data carrier system or the like, a wireless tag is attached to an article to identify the article. Examples of applications include machine tool tools in FA (Factory Automation), parts in factories, product management, article identification systems used in logistics systems, railway tickets, and supermarket price reading.

1 is a perspective view showing a configuration of an RF-ID system including a wireless tag reader / writer according to Embodiment 1 of the present invention. It is a top view of a wireless tag. It is a block diagram which shows the structure of a wireless tag reader / writer. It is explanatory drawing which shows an example of the stability of communication in the positional relationship of a wireless tag reader / writer and the pallet which attached | subjected the wireless tag. It is a block which shows the structure which performs the communicable detection of a wireless tag reader / writer. It is a flowchart which shows the procedure which performs size conversion. It is explanatory drawing explaining size conversion at the time of performing reading operation of the memory of a wireless tag. It is explanatory drawing explaining size conversion at the time of performing the write-in operation | movement of the memory of a wireless tag.

DESCRIPTION OF SYMBOLS 100 ... Wireless tag reader / writer 1 ... Wireless tag 2 ... Reader / writer 3 ... Serial bus cable 4 ... Control device 10 ... RF-ID system 11 ... Substrate 12 ... Antenna coil 13 ... Semiconductor chip 21 ... Oscillator circuit 22 ... Amplifier circuit 23 ... Modulation circuit 24 ... LPF
25 ... LC resonance circuit 26 ... Attenuator 27 ... Demodulation circuit 28 ... Binarization circuit 29 ... Control circuit 30 ... External interface 31 ... Coding circuit 40 ... Input system 41 ... Command input unit 42 ... Tag type setting means 43 ... Specific Setting value setting unit 44 ... Command replacement unit 45 ... Command information holding unit 46 ... Unique setting value holding unit 47 ... Stability parameter setting unit 48 ... Stability detection unit 49 ... Input terminal 50 ... Display unit 52 ... Tag block size holding unit 54 ... Size converter 60 ... Storage 70 ... Communicator 72 ... Output W ... Palette

Claims (7)

A communication unit capable of transmitting and receiving wireless signals to perform contactless communication with the wireless tag;
A control circuit capable of controlling transmission and reception of radio signals in the communication unit;
A wireless tag reader / writer comprising:
A tag block size holding unit for registering the number of bytes constituting one block of the memory of the wireless tag used;
An instruction in units of bytes of a program that prescribes memory access processing to the wireless tag in units of bytes, is converted into units of blocks according to the number of bytes per block registered in the tag block size holding unit,
Furthermore, according to the memory address converted from the byte unit to the block unit, a size conversion unit that converts the result of the memory access processing performed by the control circuit from the block unit to the byte unit,
A wireless tag reader / writer. The wireless tag reader / writer according to claim 1, further comprising:
A wireless tag reader / writer comprising: a display unit capable of displaying a result of the memory access processing performed by the control circuit from a block unit to a byte unit and displayed in byte units. The wireless tag reader / writer according to claim 1 or 2,
The tag block size holding unit is a tag information table in which a tag head block number and a block size expressed in units of bytes of a block constituting a radio tag memory are recorded. lighter. The wireless tag reader / writer according to any one of claims 1 to 3,
The wireless tag reader / writer, wherein the tag block size holding unit is configured so that a user can change a registered tag block size. The wireless tag reader / writer according to any one of claims 1 to 4,
The size converting unit
A program that defines memory access processing for a wireless tag in units of bytes, and that converts instructions in units of bytes into units of blocks according to the number of bytes per block registered in the tag block size holding unit. One size converter,
A second size conversion unit for converting the result of the memory access processing performed by the control circuit from the block unit to the byte unit according to the memory address converted from the byte unit to the block unit by the first size conversion unit;
A wireless tag reader / writer characterized by comprising: A wireless tag reader / writer according to any one of claims 1 to 5,
When the control circuit receives a memory read request for the wireless tag, the size conversion unit extracts all blocks including the designated area specified in bytes, and reads the blocks in blocks.
A wireless tag reader / writer configured to read a designated instruction area in units of bytes in the read block and output the result as a result of the read request. The wireless tag reader / writer according to any one of claims 1 to 6,
When the control circuit receives a memory write request for the wireless tag, the size conversion unit extracts all blocks including the designated area specified in bytes, and reads the blocks in blocks.
A wireless tag reader / writer configured to replace a designated indication area in units of bytes in a read block and write a read block including the indication area after replacement.

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