JP2015060567A - Communication control device, communication control method, and communication control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To write data to a tag at high speed using an appropriate writing command at a time of writing data to the tag.SOLUTION: A communication control device 3 exerting control to write data to a tag A includes: a table storage unit 21 that stores the writing time reflecting the actual measurement time for writing data to the tag A and a frequency of errors that occur when the data is written to the tag A for each of different commands; a command determination unit 14 that determines a command used when the data is written to the tag A on the basis of the writing time and the error frequency; and a reader-writer device control unit 18 that exerts control to write the data to the tag A using the command determined by the command determination unit 14.

Description

  The present invention relates to a communication control device, a communication control method, and a communication control program.

  A technique is known in which a RFID (Radio Frequency Identification) tag (hereinafter referred to as a tag) and a reader / writer device perform non-contact wireless communication. When the reader / writer device communicates with the tag, the reader / writer device can write data to the tag, and the reader / writer device can read data from the tag. In communication between a reader / writer device and a tag, a technique for reducing the read / write error of the tag has been proposed (for example, see Patent Document 1).

JP 2006-245951 A

  When writing data to the tag from the reader / writer device, a write command is used. As the write command, writing in block units and writing in word units are known. Therefore, the reader / writer device writes data to the tag using any one of the block unit and word unit write commands.

  When writing data from the reader / writer device to the tag, it is desirable that the data is written at high speed. Therefore, it is preferable that the reader / writer device selects a write command that can be written at a high speed between block unit writing and word unit writing.

  However, depending on various conditions such as the size and position of data to be written from the reader / writer device to the tag, the type of tag, and the compatibility between the reader / writer device and the tag, the write command for writing data at high speed changes. Under certain conditions, block-wise writing is faster than word-wise writing, and under other conditions, word-wise writing is faster than block-wise writing.

  Also, depending on the compatibility between the type of write command and the tag, a write error may occur when data is written to the tag. When a write error occurs, the write is retried, and the write speed is reduced due to the retry.

  In one aspect, the present invention has an object of writing data at high speed using an appropriate write command when writing data to a tag.

  In one proposal, a communication control apparatus that performs control of writing data to a tag, the write time reflecting the actual measurement time when writing the data to the tag and the frequency of errors that occur when writing the data to the tag Are stored for each different command, based on the write time and the error frequency, a command determination unit that determines the command when writing the data to the tag, and the command determination unit A control unit that controls to write the data to the tag using the determined command.

  Further, in another proposal, a communication control method for performing control to write data to a tag, wherein a write time reflecting an actual measurement time when writing the data to the tag and a time to write the data to the tag Based on the write time and the error frequency of the storage unit that stores the error frequency that occurs for each different command, the command for writing the data to the tag is determined, and the determined command is And control to write the data to the tag.

  In another plan, the communication control program has different writing time reflecting the actual measurement time when writing data to the tag and error frequency generated when writing the data to the tag to the computer. Based on the writing time and the error frequency of the storage unit that stores for each command, the command for writing the data to the tag is determined, and the data is stored in the tag using the determined command. The control is performed to write the data.

  When writing information to the tag, data can be written at high speed using an appropriate write command.

It is a block diagram which shows an example of the whole structure of a system. It is a figure which shows an example of the hardware constitutions of a communication control apparatus. It is a figure explaining an example of block unit writing. It is a figure which shows an example of the table memorize | stored in a table memory | storage part. It is FIG. (1) explaining an example which calculates a performance predicted value. It is FIG. (2) explaining an example which calculates a performance predicted value. It is a flowchart which shows an example of starting processing. It is a flowchart which shows an example of a tag search process. It is a flowchart (the 1) which shows an example of tag writing processing. It is a flowchart (the 2) which shows an example of a tag writing process. It is a flowchart which shows an example of an end process.

  Hereinafter, embodiments will be described with reference to the drawings. In the embodiment, an example is shown in which the reader / writer device performs contactless wireless communication with a tag. The reader / writer device only needs to have a function of writing data to the tag (write function). In the embodiment, a function of reading data from the tag (read function) is not essential. Therefore, as a device that performs contactless wireless communication with a tag, a device that has only a function of writing data may be used.

  FIG. 1 shows an example of a system 1 according to the embodiment. The system 1 is not limited to the example of FIG. The system 1 includes an information processing device 2, a communication control device 3, reader / writer devices 4A to 4C, and a tag A. The communication control device 3 is not limited to the configuration shown in FIG. Also, the number of reader / writer devices 4A to 4C (collectively referred to as reader / writer devices 4) is not limited to three.

  The information processing apparatus 2 is a personal computer, for example. In the information processing apparatus 2, an application (software) is operating. Under the control of the application, predetermined data is written to the tag. For this reason, the information processing device 2 and the communication control device 3 are connected to be communicable.

  The communication control device 3 includes an information input / output unit 11, a device activation control unit 12, a tag search unit 13, a command determination unit 14, a command processing unit 15, a tag read unit 16, a reader / writer device determination unit 17, and a reader / writer device control unit 18. A performance measurement unit 19, an error frequency detection unit 20, a table storage unit 21, a memory 22, and a table management unit 23. In FIG. 1, the reader / writer device is indicated as “R / W device”.

  The information input / output unit 11 communicates with the application of the information processing device 2. The information input / output unit 11 inputs data to be written to the tag and various information from an application. The information input / output unit 11 outputs predetermined information to the application.

  The device activation control unit 12 performs activation control of the reader / writer devices 4A to 4C. The application instructs the communication control device 3 about the reader / writer device that communicates with the tag depending on which tag the data is written to. The device activation control unit 12 activates (opens) the reader / writer device corresponding to the tag for writing data.

  The tag search unit 13 performs control to search for tags. For the tag search, for example, a tag identifier is used. As the tag identifier, for example, TID (Tag Identifier), EPC (Electronic Product Code), or the like is used.

  The command determination unit 14 determines a command for writing to the tag. In the embodiment, data is written to the tag using one of two types of write commands. There are two types of write commands: word unit writing and block unit writing. However, the types of write commands are not limited to two.

  The command processing unit 15 performs various processes for writing data to the tag using the write command determined by the command determination unit 14. The tag read unit 16 performs processing for reading data from the tag. As described above, in the embodiment, it is not essential to read data from the tag, and therefore the tag read unit 16 is not an essential element.

  The reader / writer device determination unit 17 determines which of the reader / writer devices 4 </ b> A to 4 </ b> C is to be activated based on a command from the application of the information processing device 2. In the embodiment, the reader / writer device 4A is activated to show an example of writing data to the tag A.

  The reader / writer device control unit 18 controls the reader / writer devices 4A to 4C. The reader / writer device control unit 18 performs control so that the reader / writer device 4A determined by the reader / writer device determination unit 17 is activated. Based on this control, the reader / writer device 4A starts activation. The reader / writer device control unit 18 is also referred to as a control unit.

  The performance measurement unit 19 measures the communication performance when the reader / writer devices 4A to 4C write data to the corresponding tags. Here, the time required for the reader / writer devices 4A to 4C to write data to the corresponding tag is measured as the communication performance.

  The error frequency detection unit 20 detects the frequency of write errors when the reader / writer devices 4A to 4C write information to the corresponding tags. When the reader / writer devices 4A to 4C write data to the tag, a write error may occur. The error frequency detection unit 20 detects the frequency of write errors.

  The table storage unit 21 stores a table as shown in FIG. In this table, the writing time measured by the performance measuring unit 19 and the error frequency detected by the error frequency detecting unit 20 are reflected. The table storage unit 21 is also simply referred to as a storage unit.

  The memory 22 temporarily stores the table read from the table storage unit 21. Then, the table management unit 23 updates each data in the table, and the updated table is stored in the table storage unit 21. When the command determination unit 14 determines a command, the command determination unit 14 refers to the table read to the memory 22 and determines the command.

  In the embodiment, the table stored in the table storage unit 21 is read into the memory 22, but the memory 22 is not an essential element. When the contents of the table are changed, the table in the table storage unit 21 is directly updated. When the command determination unit 14 determines a command, the table stored in the table storage unit 21 is directly referred to. Also good.

  The table management unit 23 manages the table storage unit 21 and the memory 22. The table management unit 23 reads the table from the table storage unit 21 to the memory 22. In addition, the table management unit 23 changes the contents of the table read to the memory 22. Then, the table management unit 23 stores the table read into the memory 22 in the table storage unit 21.

  Next, the reader / writer devices 4A to 4C will be described. The reader / writer devices 4A to 4C perform contactless wireless communication with the corresponding tags. In the example shown in FIG. 1, the reader / writer device 4A and the tag A are communicating.

  The reader / writer device 4A communicates with the tag A existing in a predetermined range. Since the range in which the reader / writer device 4A can perform wireless communication is a short distance, if the tag A is out of the range in which the reader / writer device 4A can perform wireless communication, a writing error occurs.

  The tag may be referred to as an RFID tag, an IC tag, a non-contact IC card, a non-contact IC chip, or the like. The reader / writer device 4A can perform wireless communication with the tag A to write data. Although not shown in FIG. 1, the same applies to the tag B corresponding to the reader / writer device 4B and the tag C corresponding to the reader / writer device 4C.

  Next, referring to FIG. 2, the hardware configuration of the communication control device 3 will be described. As shown in FIG. 2, a processor 31, a RAM (Random Access Memory) 32, a ROM (Read Only Memory) 33, a storage device 34, a communication interface 35, and an input / output device 36 are connected to the bus 30.

  The processor 31 is an arbitrary processing circuit such as a CPU (Central Processing Unit). The processor 31 executes a program expanded in the RAM 32. The ROM 33 is a non-volatile storage device that stores programs developed in the RAM 32. The program expanded in the RAM 32 may be stored in the storage device 34. As an example of the storage device 34, a portable recording medium, a semiconductor memory, a hard disk drive, or the like can be applied. The storage device 34 is also referred to as an auxiliary storage device.

  The RAM 32, the ROM 33, and the storage device 34 are all examples of a tangible storage medium that can be read by a computer. These tangible storage media are not temporary media such as signal carriers.

  As an example, the device activation control unit 12, the tag search unit 13, the command determination unit 14, the command processing unit 15, the tag read unit 16, the reader / writer device determination unit 17, the reader / writer device control unit 18, the performance measurement unit 19, and the error frequency detection The unit 20 and the table management unit 23 may be realized by the processor 31.

  The information input / output unit 11 may be realized by the input / output device 36. The memory 22 may be realized by the RAM 32. Communication between the reader / writer device controller 18 and the reader / writer devices 4A to 4C may be realized by the communication interface 35.

  Next, the write command will be described. As described above, the write commands of the embodiment include two types of write commands: block unit writing and word unit writing. In the embodiment, two types of write commands are illustrated, but other types of write commands may be used.

  First, the tag memory space will be described. An area (memory space) in which information can be stored in the tag is mainly divided into a user area and a system area. The system area stores information related to the tag system.

  On the other hand, arbitrary data can be written in the user area. The user area is divided into a predetermined number of blocks. Each block has a predetermined amount of data. For example, 2 kilobytes of user area and 8 bytes of data can be stored in each block.

  The reader / writer device can write data in units of blocks or words in the user area of the tag. In many cases, writing in blocks can write data to a tag at a higher speed than writing in words. Therefore, it is often preferable to use writing in block units.

  However, writing in word units may be faster than writing in block units. This will be described with reference to FIG. In FIG. 3, “tag” indicates a user area of the tag. The tag area is divided into a plurality of blocks. FIG. 3 shows a block number “5” and a block number “6”. Each block has an 8-byte storage area.

  FIG. 3 shows “block unit write 1” as an example when the write command designates block unit write. The writing block is assumed to be 8 bytes like the block in the user area, and the block number “5” of the tag and the writing block are in the same position. For example, the tag address designated by the writing block may coincide with the start address of the block number “5” of the tag.

  In this case, since the tag block number “5” and the writing block are at the same position (for example, the same start address), the writing block can be written to the tag block number “5” by one writing. it can.

  On the other hand, FIG. 3 shows “block unit writing 2” as another example when the write command designates block unit writing. The write block is assumed to be 8 bytes as in “Block unit write 1”.

  However, “block unit writing 2” is different from “block unit writing 1”, and the block writing position is different. In “block unit writing 2”, block unit writing is performed from the middle of the storage area of the block number “5” of the tag. Since the block to be written to the tag is 8 bytes, all data cannot be written only by the storage area of the tag block number “5”.

  In the example of FIG. 3, it is assumed that 4-byte data can be written in the storage area of the block number “5” of the tag. Since the amount of data written to the tag is 8 bytes, the remaining 4 bytes of data are written to the storage area of the tag block number “6”.

  Therefore, in the case of “block unit writing 2” in FIG. 3, the block unit writing of data is performed across the block number “5” and the block number “6” of the tag storage area. For this reason, block unit writing is performed on different block numbers in the tag storage area, so the writing speed is reduced.

  As described above, as a write command, writing in units of blocks is often faster than writing in units of words. However, as described above, when writing in block units is performed on different block numbers in the tag storage area, writing in word units may be faster than writing in block units.

  Therefore, there are cases where the word command writing is selected as the write command so that the tag can be written at a high speed, and the case where the block writing is selected can be written to the tag at a high speed. is there.

  Next, a table stored in the table storage unit 21 will be described with reference to FIG. An example of the table is shown in FIG. The table format and items are not limited to the example shown in FIG.

  The items in the table of FIG. 4 will be described. The reader / writer device type (R / W device type in FIG. 4) indicates the type of the reader / writer device. Here, the reader / writer device 4A is indicated as “device A”, and the reader / writer device 4B is indicated as “device B”. Although not shown, there is “device C” corresponding to the reader / writer device 4C as the reader / writer device type.

  The RFID tag type indicates a tag identifier (TID) that identifies a tag that performs contactless wireless communication for each reader / writer device 4. FIG. 4 shows the details of the data in the table for the tag having the tag identifier “0x00112233”. Although not shown, the same applies to tags other than “0x2334455”.

  As shown in FIG. 4, command operations are roughly classified into word writing and block unit writing. Word writing includes “Word write maximum size” and “Word write performance”. The block unit writing includes “Block Write availability”, “Block size”, “Block cross availability”, and “Block write performance”.

  First, word writing will be described. “Word write maximum size” is information related to the maximum writable size when writing a word to the tag. In the example of FIG. 4, “128 Word” is set. That is, when word writing is performed, data of a maximum of “128 words” can be written with one write command.

  In the example of “Word write performance” in FIG. 4, the initial value performance, the learning value performance, the error frequency, the error count, and the write count are shown for write sizes of 1 Word, 2 Word, 4 Word, 8 Word, 16 Word, and 32 Word. Although not shown in the example of the table of FIG. 4, the initial value performance, the learning value performance, the error frequency, the error count, and the write count may be provided for 64 Word and 128 Word.

  The “performance” of the initial value performance indicates the time required for the reader / writer device to write data to the tag. That is, the data writing time is represented by an index called “performance”. The index indicating “performance” is not limited to the above time.

  The initial value performance is the initial value of the above time. As for the initial value performance, before the system 1 is actually operated, the performance measuring unit 19 may measure the time for the reader / writer device to write data to the tag, and the result may be stored as the initial value performance. Further, the initial value performance may be stored based on the specifications of the reader / writer device and the tag.

  The learned value performance is a time in which the performance measuring unit 19 measures the time required for the reader / writer device to write to the tag after operating the system 1 and reflects the result. The learning value performance is also referred to as a writing time reflecting the actual measurement time when writing data.

  For example, each time the reader / writer device writes to a tag, the average value of the above time may be calculated, and the calculated average time may be used as the learning value performance. Further, each time the reader / writer device writes to the tag with respect to the initial value performance, the difference between the time measured by the performance measuring unit 19 and the time of the initial value performance is calculated, and the calculation result may be used as the learning value performance. .

  The error frequency indicates the frequency with which an error occurs when the reader / writer device writes data to the tag. The error frequency may be indicated by the ratio of the number of times an error has occurred to the number of times the reader / writer device has written data to the tag. The error frequency may be indicated by the total number of errors that have occurred since the system 1 was operated.

  Next, block unit writing will be described. In the example of the table in FIG. 4, “Blockwrite availability”, “Block size”, “Block spanability”, and “Block write performance” are provided.

  “Blockwrite availability” indicates whether or not block unit writing is possible. Depending on the tag, there is a case where block unit writing cannot be performed. In this case, “block write enable / disable” is disabled. In the example of the table of FIG. 4, when “Block write enable / disable” is disabled, block unit writing cannot be performed. For this reason, a write command in units of words is selected as the write command.

  “Block size” indicates the size of the block written by the write command. In the example of FIG. 4, it is 8 Word. Therefore, the tag is written with 8 words as one block.

  “Blockability” indicates whether or not writing can be performed across a plurality of blocks in the tag storage area. For example, in “block unit writing 2” shown in FIG. 3, the reader / writer device writes to the tag across the block number “5” and the block number “6” in the tag storage area.

  At this time, if “Block Crossability” is “No”, it is not possible to perform writing such as “Block Unit Write 2” shown in FIG. Therefore, when “Blockability” is “No”, the block of data to be written is divided and block unit writing is performed.

  The “Block write performance” is the same as the “Word write performance”. That is, it has items of size, initial value performance, learning value performance, error count, and write count. The content of each item is the same as the content of the “word writing performance” item.

  In the example of the table in FIG. 4, “Word writing performance” of 16 words and 32 words is “impossible”. This is because “block straddleability” in the example of the table of FIG. 4 is “no” and “block size” is 8 Word.

  In other words, for a size where the “Block size” exceeds 8 Words, the block of the tag storage area is straddled, and therefore, 8 Word blocks cannot be written at once. Therefore, the 8-word block is divided into two blocks for writing.

  Referring to an example of the table shown in FIG. 4, the initial value performance and the learning value performance are different values. This is because when the reader / writer device writes to the tag, the performance measuring unit 19 actually measures the time required for writing and reflects the result as the learning value performance.

  That is, every time the reader / writer device writes to the tag, the time required for writing is learned as performance. Then, by reflecting the learned performance, the learning value performance when the system 1 is actually operated can be stored in the table.

  The time measured by the performance measuring unit 19 may be reflected in the table at any timing. That is, every time the reader / writer device writes to the tag once, instead of reflecting the actually measured time on the table, for example, when one of the two times of writing is performed. The performance measuring unit 19 may perform actual measurement. Then, the actually measured time may be reflected in the table at a rate of one writing with respect to two writings.

  The error frequency detection unit 20 detects the number of times the reader / writer device has written to the tag. Further, the error frequency detection unit 20 detects the number of times an error has occurred when the reader / writer device writes to the tag. Therefore, the error frequency detection unit 20 stores the ratio of the number of occurrences of the error to the number of times the reader / writer device has written to the tag as an operator and an error frequency in the table.

  The above table is referred to by the command determination unit 14 when writing to the tag from the reader / writer device. The command determination unit 14 determines a write command as described above. That is, the command determination unit 14 determines either a word unit write command or a block unit write command.

  When the command determination unit 14 refers to a table stored in the table storage unit 21, the table management unit 23 reads the table into the memory 22. Assume that the read table is the table shown in FIG.

  The command determination unit 14 determines whether to use a word unit write command or a block unit write command based on the learned value performance and the error frequency. The command determination unit 14 selects a write command having a higher learned value performance (less time required for writing to the tag) and a lower error frequency.

  For example, in the example table shown in FIG. 4, the command determination unit 14 refers to the table read into the memory 22 when writing data of a size of 4 words. In the example table shown in FIG. 4, the learning value performance is “200 ms” and the error frequency is “10%” for the size of four words written in units of words. On the other hand, the learning value performance is “160 ms” and the error frequency is “10%” for the size of 4 words for writing in block units.

  Therefore, the error frequency is the same between the word unit writing and the block unit writing. In this case, it is determined by learning value performance whether to select writing in word units or writing in block units.

  The learning value performance for writing in word units is “200 ms”, whereas the learning value performance for writing in block units is “160 ms”. Therefore, writing in units of blocks has higher performance as a write command. That is, data can be written to the tag A at a higher speed by writing in units of blocks. Therefore, the command determination unit 14 selects writing in block units as a write command.

  Therefore, the command determination unit 14 selects a write command that has better learning value performance (can be written at high speed) and has a lower error frequency. In addition, when the learning value performance is the same between the block unit writing and the word unit writing, the command determination unit 14 selects the write command with the lower error frequency, and performs the block unit writing and the word unit writing. If the error frequency is the same, the write command with the better learning value performance is selected.

  Next, determination of a write command using the performance prediction value will be described. The performance prediction value is a value reflecting the error frequency in the learning value performance. In the above-described example, the write command having the better learning value performance and the lower error frequency is selected between the block unit writing and the word unit writing.

  In addition, when the learning value performance is the same between the block unit writing and the word unit writing, the write command with the lower error frequency is selected. Similarly, when the error frequency is the same, the write command with the better learning value performance is selected.

  However, when the write command is determined, the learning value performance is excellent, but when the error frequency is high, and when the error frequency is low but the learning value performance is not excellent, the command determination unit 14 simply The write command cannot be determined.

  As described above, the learning value performance indicates the time required for the reader / writer device to write data to the tag as performance. The error frequency is a ratio of the number of error occurrences to the number of times the reader apparatus writes information to the tag. Therefore, the learning value performance and the error frequency cannot be simply compared.

  Therefore, in the embodiment, a write command is determined using a performance prediction value reflecting the error frequency in the learning value performance. FIG. 5 is a diagram illustrating the performance prediction value. The command determination unit 14 acquires values of error frequency and learned value performance from the table read out to the memory 22.

  In the example of FIG. 5, the write position is 8 words. In the embodiment, as described above, the block of the tag storage area is 8 words. Therefore, information can be written to the tag by writing once in block units.

  Referring to the example of FIG. 5, the learning value performance of writing in units of words (shown as “performance” in FIG. 5) is “250 ms”, and the learning value performance of writing in units of blocks is “205 ms”. Therefore, if only the learning value performance is used as a reference, the write command is selected to be written in block units.

  On the other hand, referring to the example of FIG. 5, the error frequency of writing in units of words is “10%”, and the error frequency of writing in units of blocks is “15%”. Therefore, on the basis of only the error frequency, the write command is selected to be written in units of words.

  The command determination unit 14 selects an appropriate write command based on the learning value performance and the error frequency. Therefore, if only the values of the learning value performance and the error frequency are used as a reference, the word unit writing and the block unit writing are performed. It is not possible to judge which one is to be determined.

  Therefore, the command determination unit 14 calculates a performance predicted value using the numerical values of the table read out to the memory 22, and determines a write command based on the calculated performance predicted value. Hereinafter, the performance prediction value will be described.

  As an example in which the command determination unit 14 calculates the performance prediction value, the number of retries until the writing to the tag becomes normal at a predetermined rate (the number of retries until the predetermined success rate is reached) is calculated. In order to calculate the number of retries, the command determination unit 14 reads out the error frequency corresponding to the size written in the tag from the table read out to the memory 22.

  The command determination unit 14 calculates the number of retries for both block unit writing and word unit writing. In the example of FIG. 5, since the write size is 8 words, the command determination unit 14 has a size “ The error frequency corresponding to “8 words” is read out.

  In the example of FIG. 5, the error frequency is “n”. The word-by-word writing error frequency n is “10%” based on the table read into the memory 22. On the other hand, the writing error frequency n in units of blocks is “15%” based on the table read to the memory 22.

  In the example of FIG. 5, the number of retries until writing to the tag reaches a success rate of “99%” is calculated. This “99%” is “x: probability of normal writing” shown as an example in FIG.

The command determination unit 14 calculates the number of retries for each of the word-unit writing and the block-unit writing using the error frequency n and the normal writing probability x. The calculated number of retries is as follows.
Retry count = (log (1-x)) / log ((1 / (1-n) -1) / (1 / (1-n)))) (Equation 1)

  The command determination unit 14 calculates the number of retries for each of the word-unit writing and the block-unit writing based on Equation 1 above. As a result, as in the example shown in FIG. 5, the number of retries until “99%” is normal (shown as “number of times until 99% is normal” in FIG. 5) is “ “2000 times” and “2427 times” for writing in block units.

  The number of retries is the number of retries until writing to the tag reaches a success rate of “99%”. The number of retries is multiplied by the learning value performance “t”. As described above, the learning value performance indicates the time required for writing to the tag each time the reader / writer device writes to the tag. The command determination unit 14 refers to the table read into the memory 22 and acquires the learning value performance “t” for each of “Word write performance” and “Block write performance”.

  The learning value performance corresponding to “8 words” of “Word write performance” is “250 ms”. The learning value performance corresponding to “8 words” of “Block write performance” is “205 ms”.

The command determination unit 14 multiplies the learned value performance “t” acquired from the table by the number of retries described above, and obtains a predicted performance value “y”. Therefore, the predicted performance value “y” is expressed by the following equation 2.
Performance prediction value y = number of retries × learning value performance “t” (Equation 2)

  As described above, the learning value performance in word unit writing is “250 ms”. The number of retries in word unit writing is “2000 times”. Therefore, the command determination unit 14 calculates the performance predicted value “y” based on Equation 2. That is, the command determination unit 14 performs an operation “2000 × 250 ms = 500 s”. “500 s” obtained as a result of the calculation becomes a performance predicted value “y” in writing in units of words.

  Further, the learning value performance in writing in block units is “205 ms”. The number of retries in writing in block units is “2427”. Therefore, the command determination unit 14 calculates the performance predicted value “y” based on Equation 2. That is, the command determination unit 14 performs the calculation “2427 × 205 s = 497.535 s”. Here, the numbers after the decimal point are rounded off, and “497.535 s” is set to “498 s”. “498s” obtained as a result of the calculation becomes a performance predicted value “y” in writing in units of blocks.

  The command determination unit 14 compares the performance prediction value “y” in word unit writing with the performance prediction value “y” in block unit writing. In the embodiment, the performance prediction value “y” is superior in writing in block units. That is, the write performance prediction value “y = 498 s” for each block is shorter than the write performance prediction value “y = 500 s” for each word.

Therefore, the command determination unit 14 determines writing in units of blocks with a better performance predicted value “y” as command writing. In order to obtain this performance predicted value “y”, the description has been made using Expression 1 and Expression 2. However, when Expression 1 and Expression 2 are combined, the following Expression 3 is obtained.
y = (log (1-x)) / log ((1 / (1-n) -1) / (1 / (1-n)))) * t (Equation 3)

  The performance prediction value “y” is a time obtained by adding the number of retries until a predetermined success rate is achieved to the time required for the reader / writer device to write information to the tag (learning value performance). Since the number of retries is obtained from the error frequency “n”, the performance prediction value “y” is a time reflecting both the learning value performance and the error frequency. That is, the predicted performance value “y” is the time required for the reader / writer device to write information to the tag before writing is performed at a predetermined success rate.

  Therefore, even when the learning value performance is excellent but the error frequency is high, and when the error frequency is low but the learning value performance is not excellent, the command determination unit 14 writes based on the performance prediction value “y”. The command can be determined.

  Next, the determination of the write command will be described based on the predicted performance value “y” using another example of FIG. In this example, the write position is 4 words. Therefore, in the case of writing in units of words, the reader / writer device can write to the tag once, but in the case of writing in units of blocks, writing is performed by dividing a block of data.

  That is, similarly to the example shown in FIG. 3, when writing an 8-word block starting from 4 words in the tag storage area, block-unit writing is performed in two steps. For this reason, in the example shown in FIG. 6, illustration is performed separately for the first time and the second time.

  In the case of writing in word units, the error frequency “n” is “10%”. Therefore, the command determination unit 14 calculates the number of retries using Equation 1. As a result, the number of retries is “2000”. The learning value performance corresponding to 8 words in the table is “250 ms”.

  Therefore, the predicted performance value of writing in word units is “y” becomes “y = 2000 × 250 ms = 500 s”. The command determination unit 14 calculates a write performance prediction value “y = 500 s” in units of words.

  Next, in the case of writing in units of blocks, the reader / writer device writes to the tag in four words every two times. Therefore, the command determination unit 14 acquires learning value performance corresponding to 4 Word of “Block write performance”. The acquired learning value performance is “160 ms”. Further, the command determination unit 14 acquires an error frequency corresponding to 4 Word of “Block write performance”. The acquired error frequency is “10%”.

  The command determination unit 14 calculates the number of retries. Here, calculation of the number of retries for two times is performed. The retry count for two times is “2773”. In addition, the learning value performance for two times is “160 ms × 2 = 320 ms”. Therefore, the write performance prediction value “y” in units of blocks is “y = 2773 × 320 ms = 887 s”.

  Accordingly, the command determining unit 14 determines writing in units of words with an excellent performance predicted value “y” as a write command. In the example of FIG. 5, the command unit writing performance prediction value “y” is excellent, and therefore the command determination unit 14 determines command unit writing as a write command. On the other hand, in the example of FIG. 6, since the performance prediction value “y” for writing in units of words is excellent, the command determination unit 14 determines writing in units of words as a write command.

  Next, the operation will be described using a flowchart. FIG. 7 shows an example of a flow for starting the reader / writer device. First, an application running on the information processing apparatus 2 issues an instruction to write predetermined data to the tag (step S1).

  In the embodiment, data is written to tag A, but data may be written to tag B or tag C. An application that operates on the information processing apparatus 2 is a block for writing information to which tag (in this case, tag A) that specifies data to be written, the amount of data to be written to the storage area of the tag A, and data writing. An instruction about information such as a number and a writing position is issued.

  An application that operates on the information processing device 2 outputs an instruction including the above-described information to the information input / output unit 11 of the communication control device 3. When the information input / output unit 11 inputs an instruction from the application, the table management unit 23 reads the table from the table storage unit 21 and stores it in the memory (step S2). Note that step S2 may be performed at an arbitrary timing as long as it is before a tag writing process described later.

  The instruction output from the application of the information processing apparatus 2 includes information for specifying a tag for writing data. In the embodiment, it is assumed that the tag A is specified. The tag A corresponds to the reader / writer device 4A.

  The device activation control unit 12 performs control to activate the tag A. Since the tag A is specified, the reader / writer device determination unit 17 determines the reader / writer device 4A corresponding to the tag A. Then, the reader / writer device control unit 18 activates (opens) the reader / writer device 4A (step S3). Thus, the activation process is completed.

  Next, tag search processing shown in FIG. 8 is performed. The tag search unit 13 controls the reader / writer device control unit 18 to cause the reader / writer device 4A to search for the tag A (step S4). The reader / writer device 4A has a predetermined communication range, and it is determined whether or not the tag A is found within the communication range (step S5).

  If tag A is not found (No in step S5), the process ends. In this case, information indicating that the tag A was not found may be notified to the application of the information processing apparatus 2. In this case, the data instructed by the application is not written to the tag A from the reader / writer device 4A.

  On the other hand, when the tag A is found (Yes in step S5), a tag identifier is transmitted from the tag A to the reader / writer device 4A (step S6). The reader / writer device 4A notifies the tag search unit 13 of the communication control device 3 that the tag identifier has been received from the tag A. Then, the tag search unit 13 notifies the tag identifier of the tag A to the application of the information processing device 2 via the information input / output unit 11.

  Thus, the application recognizes that the tag A that can communicate with the reader / writer device 4A is found. Thus, the reader / writer device 4A can write data to the tag A. That is, the reader / writer device 4A is ready to write data to the tag A.

  Next, tag writing processing will be described with reference to FIGS. 9A and 9B. When the reader / writer device 4A writes data to the tag A, there are two write commands: word unit write and block unit write. Accordingly, the reader / writer device 4A performs non-contact wireless communication with the tag A by determining which of the two write commands is used.

  Therefore, the command determination unit 14 refers to the table read to the memory 22 (step S11). Then, the command determination unit 14 determines whether or not block writing (block unit writing) is possible (step S12).

  An example of the table is shown in FIG. 4, but there is an item “Blockwrite availability” in the table of FIG. 4. If this item is "No" (No in step S12), writing in units of blocks cannot be performed. Accordingly, the command determination unit 14 determines to write data to the tag A using word unit writing. Accordingly, in this case, the process proceeds to step S15 described later.

  On the other hand, if the item “Block write enabled / disabled” is “enabled” (Yes in step S12), both block unit writing and word unit writing are possible. At this time, the command processing unit 15 calculates the performance predicted value separately for writing in units of blocks and writing in units of words (step S13).

  When writing in units of blocks, the command processing unit 15 determines the number of times of writing to the tag A and the tag based on the position and size information instructed by the application, information on whether or not the table read into the memory 22 can be blocked. The size when data is written once to A is calculated.

  When writing in units of words, the command processing unit 15 calculates the number of times of writing to the tag A instructed by the application, the size when data is written once to the tag A, and the like.

  As described above, when it is determined No in step S12, the command determination unit 14 determines which one of block-unit writing and word-unit writing is used. In order to make this determination, as described above, the command determination unit 14 calculates the performance predicted value “y”. The predicted performance value “y” is calculated for both writing in units of words and writing in units of blocks.

  When the performance predicted value “y” for writing in units of words is superior to the performance predicted value “y” for writing in units of blocks, the command determining unit 14 determines to write in units of words as a write command. To do.

  On the other hand, if the performance prediction value “y” for block-unit writing is superior to the performance prediction value “y” for word-unit writing, the command determination unit 14 writes the block unit as a write command. To decide.

  As a result, the command determination unit 14 selects a write command to be used when writing data to the tag A (step S14). When the command determining unit 14 selects writing in units of blocks, the process proceeds to “B” in FIG. 9A. The process “B” in FIG. 9A will be described later.

  On the other hand, when the command determining unit 14 selects writing in units of words, the reader / writer device 4A writes data in units of words to the tag A (step S15). Thereby, the data instructed by the application is written in the predetermined area of the tag A.

  When the reader / writer device 4A writes data to the tag A in units of words, the table management unit 23 writes to the tag A in the “Word write performance” of the table read to the memory 22. The number of writes corresponding to the size of the data is incremented (step S16).

  The reader / writer device 4A writes data to the tag A. At this time, data writing may be performed normally, but may not be performed normally. Therefore, the reader / writer device 4A determines whether or not data has been normally written to the tag A (step S17).

  When the writing from the reader / writer device 4A to the tag A is not normally performed (No in step S17), the table management unit 23 increments the number of errors (step S18). The table read to the memory 22 has an item of the number of times of writing, and the table management unit 23 reads the number of times of writing corresponding to the size of writing in units of words.

  Then, the table management unit 23 calculates the ratio of the number of errors to the read number of writes. As a result, the error frequency of the size corresponding to writing in word units is updated (step S19).

  The table management unit 23 stores the updated error frequency in an error frequency of a size corresponding to writing in units of words. Thereby, the error frequency of the table read to the memory 22 is updated based on the actual measurement.

  If writing from the reader / writer device 4A to the tag A is not normal, writing (retry) is performed again. There is a predetermined upper limit for the number of retries (the number of retries). It is determined whether or not the number of retries has reached a predetermined upper limit (step S20). When the number of retries reaches a predetermined upper limit, abnormal termination processing is performed. On the other hand, when the number of retries has not reached the predetermined upper limit value, the process proceeds to step S15.

  In step S17, when the writing from the reader / writer device 4A to the tag A is normally performed, the performance measuring unit 19 measures the time during which the reader / writer device 4A writes data to the tag A as the performance (step S21). ).

  The table management unit 23 reflects the time actually measured by the performance measurement unit 19 in the learning value performance. Thereby, the learning value performance is updated (step S22). Then, the learning value performance corresponding to the “Word write performance” in the table is updated. Thereby, the learning value performance of the table read to the memory 22 is updated based on the actual measurement.

  Depending on the designation of the application, there is a case where not all data can be written to the tag A by one writing in units of words. Therefore, the command processing unit 15 determines whether or not data for the size specified by the application has been written to the tag A (step S23).

  When data of the size specified by the application is written to the tag A (Yes in step S23), the processing ends normally. On the other hand, when all the data of the size specified by the application has not been written to the tag A, the process proceeds to step S15 (“A” in FIG. 9A).

  As described above, the processing when word unit writing is selected in step S14 is performed. Next, processing when block unit writing is selected will be described with reference to FIG. 9B.

  When writing in units of blocks is selected, the reader / writer device 4A writes data in units of blocks to the tag A (step S31). Then, the table management unit 23 increments the number of times of writing corresponding to the size of the data written to the tag A among the “Block writing performance” of the table read to the memory 22 (step S32).

  As described above, when the reader / writer device 4A writes data to the tag A, writing may not be performed normally. Therefore, the reader / writer device 4A determines whether or not data has been normally written to the tag A (step S33).

  When the writing from the reader / writer device 4A to the tag A is not normally performed (No in step S33), the table management unit 23 increments the number of errors (step S34). As described above, when writing from the reader / writer device 4A to the tag A is not normal, a retry is performed. It is determined whether the number of retries has reached the upper limit (step S35).

  When the number of retries reaches a predetermined upper limit, abnormal termination processing is performed. On the other hand, when the number of retries does not reach the predetermined upper limit value, it is determined whether the write command with a low error frequency is a block-unit write or a word-unit write (step S36).

  The determination in step S36 means that the writing from the reader / writer device 4A to the tag A in step S33 is not normal. Therefore, the command determination unit 14 refers to the table read to the memory 22. Then, the command determination unit 14 refers to the error frequency corresponding to the size designated by the application.

  At this time, if the error frequency of writing in word units is less, the process proceeds to step S15 in FIG. 9A. That is, in writing in units of blocks, an error occurs and the frequency of errors is greater in writing in units of blocks than in writing in units of words, and therefore writing in units of words is selected. On the other hand, if it is determined in step S36 that the error frequency of writing in units of blocks is smaller, the process proceeds to step S31.

  In step S33, when the writing from the reader / writer device 4A to the tag A is normally performed, the performance measuring unit 19 measures the time during which the reader / writer device 4A writes data to the tag A as the performance (step S37). ).

  The table management unit 23 updates the learning value performance by reflecting the time actually measured by the performance measurement unit 19 (step S38). Then, the learning value performance corresponding to the “Block write performance” in the table is updated. Thereby, the learning value performance of the table read to the memory 22 is updated based on the actual measurement.

  As described above, depending on the designation of the application, there is a case where not all data can be written to the tag A by one writing in block units. Therefore, the command processing unit 15 determines whether or not data for the size specified by the application has been written to the tag A (step S39).

  When data of the size specified by the application is written to the tag A (Yes in step S39), the processing ends normally. On the other hand, when all data of the size specified by the application is not written in the tag A, the process proceeds to step S31 (“C” in FIG. 9B).

  The above is the tag writing process. After the reader / writer device 4A writes predetermined data to the tag A, it is necessary to end the writing process. The process for that is shown in FIG. First, the application of the information processing device 2 issues an end instruction to the communication control device 3 (step S41).

  Based on this instruction, the table management unit 23 of the communication control device 3 stores the table read in the memory 22 in the table storage unit 21. At this time, the table stored in the table storage unit 21 is updated by the various processes described above. Accordingly, the updated table is stored in the table storage unit 21 (step S42).

  Then, the reader / writer device control unit 18 stops (closes) the reader / writer device 4A designated by the application (step S43). As a result, the reader / writer device 4A stops the activation state and does not communicate with the tag A. Thus, the end process is completed.

  Therefore, in the embodiment, when the reader / writer device writes predetermined data to the tag, an appropriate write command is selected from the block unit write command and the word unit write command based on the learning value performance and the error frequency. Selected. This improves the performance when the reader / writer device writes data to the tag.

  Then, the time that reflects the actual measurement time when the reader / writer device writes data to the tag is used as the learning value performance, and an appropriate write command is selected based on the performance prediction value that reflects the error frequency in the learning value performance. Yes.

  By setting the error frequency to the number of retries until writing becomes normal at a predetermined rate, a performance prediction value can be obtained by multiplying the learning value performance and the number of retries. That is, the error frequency can be reflected in the learning value performance. Therefore, it is possible to select an appropriate write command based on the performance prediction value that comprehensively considers both the learning value performance and the number of retries.

  In the above, the command determination unit 14 selects an appropriate write command based on the predicted performance value. For example, even if the performance prediction value is slightly different between the word unit writing and the block unit writing, the write command having the better performance prediction value is selected.

  Here, when only one of the word unit writing and the block unit writing always has an excellent performance prediction value, the other write command is selected even if the difference in the performance prediction value is small. Never happen. As a result, the learning value performance and error frequency of the write command that is not selected are not actually measured. For this reason, the reliability of the learning value performance and error frequency value of the write command which is not selected is lowered.

  Therefore, the command determination unit 14 may select a write command with a poor performance prediction value at a predetermined rate. For example, even if the performance prediction value of the write command for each block is always excellent, data may be written to the tag A with the write command for each word at a rate of about once every 10 times.

  Further, the command determination unit 14 determines whether to write the write command in units of words or in units of blocks based on the performance prediction value. As described above, the performance prediction value “y” needs to be subjected to a predetermined calculation.

  Therefore, the command determination unit 14 reads the learning value performance and the error frequency corresponding to the write size of the table shown as an example in FIG. 4 for each of the word unit write and the block unit write. The command determination unit 14 may refer to the learned value performance and the error frequency and select a write command if there is a write command having an excellent learned value performance and a low error frequency.

  That is, a write command that has excellent learning value performance and low error frequency is an appropriate write command. In this case, the command determination unit 14 can determine an appropriate write command without calculating the performance prediction value “y”. For this reason, the processing time for calculating the performance prediction value “y” can be reduced.

  When the learning value performance is excellent but the error frequency is high, or when the error frequency is low but the learning value performance is not excellent, the command determination unit 14 calculates the performance prediction value “y” and appropriately The correct command may be determined.

  In the embodiment, the table is premised on having both the learning value performance and the error frequency. However, when the table has only one of them, the other is used. An appropriate write command may be determined.

  Although the disclosed embodiments and their advantages have been described in detail, those skilled in the art can make various modifications, additions and omissions without departing from the scope of the present invention as explicitly set forth in the claims. Let's go.

DESCRIPTION OF SYMBOLS 1 System 2 Information processing apparatus 3 Communication control apparatus 4 Reader / writer apparatus 11 Information input / output part 12 Apparatus start-up control part 13 Tag search part 14 Command determination part 15 Command processing part 16 Tag read part 17 Reader / writer apparatus determination part 18 Reader / writer apparatus control Unit 19 Performance measurement unit 20 Error detection unit 21 Table storage unit 22 Memory 23 Table management unit 30 Bus 31 Processor 32 RAM
33 ROM
34 Storage Device 35 Communication Interface 36 Input / Output Device

Claims (8)

A communication control device that controls writing data into a tag,
A storage unit that stores a writing time that reflects an actual measurement time when writing the data to the tag and an error frequency that occurs when writing the data to the tag for each different command;
A command determination unit that determines the command when writing the data to the tag based on the write time and the error frequency;
A control unit that performs control to write the data to the tag using the command determined by the command determination unit;
A communication control device comprising: The command determination unit determines the command based on a performance prediction value reflecting the error frequency in the write time;
The communication control device according to claim 1. The command determination unit reflects the number of retries for writing the data to the tag until the predetermined success rate is reflected in the write time as the error frequency.
The communication control apparatus according to claim 2. When the success rate is x, the error frequency is n, and the write time is t, the predicted performance value y is
y = (log (1-x)) / log ((1 / (1-n) -1) / (1 / (1-n)))) * t
Is,
The communication control apparatus according to claim 2. The command determination unit determines to write to the tag using the command when there is a command with a short writing time and a low error frequency, and otherwise, the performance prediction value Determining the command based on:
The communication control apparatus according to claim 3 or 4. The command determination unit determines to use the command whose performance prediction value is not excellent at a predetermined rate,
The communication control apparatus according to any one of claims 1 to 4. A communication control method for performing control of writing data to a tag,
The write time and error frequency of the storage unit that stores the write time reflecting the actual measurement time when writing the data to the tag and the error frequency generated when writing the data to the tag for each different command And determining the command when writing the data to the tag,
Using the determined command to control to write the data to the tag;
Communication control method. On the computer,
The writing time reflecting the actual measurement time when writing data to the tag and the error frequency that occurs when writing the data to the tag are stored in the writing time and error frequency of the storage unit for each different command. Based on the command to write the data to the tag,
Using the determined command to control to write the data to the tag;
A communication control program that executes processing.

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