CN112639716A

CN112639716A - Reader/writer, method for controlling reader/writer, and program

Info

Publication number: CN112639716A
Application number: CN201980057264.1A
Authority: CN
Inventors: 肥塚八寻
Original assignee: Omron Corp
Current assignee: Omron Corp
Priority date: 2018-10-30
Filing date: 2019-09-18
Publication date: 2021-04-09
Anticipated expiration: 2039-09-18
Also published as: CN112639716B; WO2020090269A1; DE112019005456T5; JP2020071612A; JP7155879B2

Abstract

The invention suppresses cost increase and increases the capacity of information managed by an RF tag. The reader/writer includes: an RF tag identification unit (21) that identifies a predetermined plurality of RF tags (40) as target RF tags (40); and a memory processing unit (22) that integrates the memories included in the plurality of target RF tags (40) and performs memory processing of at least one of reading and writing as one virtual memory space.

Description

Reader/writer, method for controlling reader/writer, and program

Technical Field

The present invention relates to a reader writer (reader writer) that reads and writes data from and to a Radio Frequency (RF) tag, and a method and a program for controlling the reader writer.

Background

Conventionally, in order to perform solid state management at a manufacturing site or a distribution site, the following reader/writer is known: data is read from or written to an RF tag attached to an individual, and is exchanged with an industrial control device such as a Programmable Logic Controller (hereinafter, abbreviated as "PLC").

In order to improve the reliability of wireless communication, there is a technique for performing abnormality detection by adding a Cyclic Redundancy Code (CRC) to data from an RF tag (see, for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent publication "Japanese patent No. 3007926 (registration of 12.3.1999)"

Disclosure of Invention

Problems to be solved by the invention

In recent years, however, the volume of information used for individual management at a production site has increased. However, the memory capacity of the RF tag is generally small, and there is a problem that the memory capacity of the RF tag is insufficient for a necessary data capacity. On the other hand, an RF tag having a large memory capacity has a problem of high unit price, resulting in an increase in cost.

An object of an embodiment of the present invention is to realize the following technique: the increase of cost can be suppressed, and the capacity of information which can be managed by the RF tag can be increased.

Means for solving the problems

In order to solve the above problem, a reader/writer according to an embodiment of the present invention performs at least one of reading and writing of data with an RF tag by wireless communication, and includes: an RF tag identification unit that identifies a predetermined plurality of RF tags as target RF tags; and a memory processing unit that integrates the memories included in the plurality of target RF tags, and performs memory processing of at least one of reading and writing as one virtual memory space.

Further, in order to solve the above problem, a control method of a reader/writer according to an embodiment of the present invention includes the steps of: determining a prescribed plurality of RF tags as object RF tags; and a memory process of integrating memories included in the plurality of target RF tags and performing at least one of reading and writing as one virtual memory space.

In order to solve the above problem, a program according to an embodiment of the present invention causes the reader/writer to operate and causes a computer to function as the RF tag determination unit and the memory processing unit.

ADVANTAGEOUS EFFECTS OF INVENTION

According to an embodiment of the present invention, the capacity of information that can be managed by the RF tag can be increased while suppressing an increase in cost.

Drawings

Fig. 1 is a block diagram showing a main part configuration of a reader/writer according to an embodiment.

Fig. 2 is a diagram schematically showing a system environment in which a reader/writer is used.

Fig. 3(a) and (b) are block diagrams showing the configuration of a system using a reader/writer.

Fig. 4 is a diagram showing an example of data flow between the reader/writer and the RF tag.

Fig. 5 is a flowchart showing specific example 1 of the flow of the read processing by the reader/writer.

Fig. 6 is a flowchart showing specific example 2 of the flow of the read processing by the reader/writer.

Fig. 7 is a diagram showing an example of data flow among the PLC, the reader/writer, and the RF tag.

Fig. 8 is a flowchart showing an application example of the flow of the read processing by the reader/writer.

Detailed Description

Hereinafter, an embodiment (hereinafter also referred to as "the present embodiment") according to one aspect of the present invention will be described with reference to the drawings.

Application example § 1

First, an example of a scenario to which the present invention is applied will be described with reference to fig. 1 and 2. Fig. 1 is a block diagram showing a main part configuration of a reader/writer 10 according to the present embodiment. Fig. 2 is a diagram schematically showing a system environment in which the reader/writer 10 according to the present embodiment is used.

As shown in fig. 2, an RF tag 40 may be used, for example, in order to individually manage items such as parts and products in a production site. The RF tag 40 is used by attaching a predetermined plurality of, three in the present embodiment (

RF tags

40A, 40B, and 40C) to one pallet (pallet)100 on which a workpiece 101 such as a component or a product is placed.

As shown in fig. 1, the reader/writer 10 includes an antenna 35 that performs wireless communication with each of the plurality of RF tags 40(40A, 40B, and 40C), and performs at least one of reading and writing of data with a predetermined plurality of RF tags 40(40A, 40B, and 40C) in a mutual communication area via the antenna 35. When at least one of reading and writing data from and to the predetermined plurality of RF tags 40 is performed, the reader/writer 10 integrates the memories included in the respective predetermined plurality of RF tags 40 to perform memory processing as one virtual memory space.

In this way, since the reader/writer 10 performs memory processing as one virtual memory space by integrating the memories of the respective predetermined RF tags 40, the memory capacity can be increased virtually even if the memory capacity of each RF tag 40 is as small as, for example, 2 KB. Therefore, even if the amount of information required for individual management of articles such as parts and products increases, the information can be distributed among a predetermined plurality of RF tags 40 and at least one of read and write can be performed.

Construction example 2

Hereinafter, the configuration of the reader/writer 10 according to the embodiment of the present invention will be described in detail with reference to fig. 1 to 3. Fig. 1 is a block diagram showing a main part structure of a reader/writer 10. Fig. 2 is a diagram schematically showing a system environment in which the reader/writer 10 is used. Fig. 3(a) and (b) are block diagrams showing the configuration of a system using the reader/writer 10.

[ Structure of reader/writer 10 ]

As shown in fig. 1, the reader/writer 10 performs at least one of reading and writing of data with the RF tag 40 by wireless communication. The reader/writer 10 is used as an input device of a plc (programmable Logic controller)50 which is a higher-level device.

The reader/writer 10 includes an upper communication control unit 11, an RF communication control unit 20, a storage unit 30, and an antenna 35.

The upper communication control unit 11 controls communication with the PLC 50. The upper communication control unit 11 performs wireless communication with the PLC 50 or wired communication via a bus or a network. The upper communication control unit 11 can exchange data with the PLC 50 at a high speed of several microseconds to several milliseconds per byte.

The reader/writer 10 communicates with the PLC 50 under the control of the upper communication control unit 11, and receives a command of at least one of reading and writing data from and to the RF tag 40 from the PLC 50 via the upper communication control unit 11.

The antenna 35 enables wireless communication with a prescribed plurality of RF tags 40. The antenna 35 transmits an electromagnetic wave including a command signal to the predetermined plurality of RF tags 40 and receives a response signal from the predetermined plurality of RF tags 40 in response to the command, based on the control of the RF communication control unit 20.

The RF communication control unit 20 performs at least one of reading and writing of data with a predetermined plurality of RF tags 40 via the antenna 35. The RF communication control unit 20 may be an arithmetic unit having a function of comprehensively controlling each unit of the reader/writer 10. The RF communication control Unit 20 may control each Unit of the reader/writer 10 by executing a program stored in one or more memories (e.g., a Random Access Memory (RAM), a Read Only Memory (ROM), or the like) by one or more processors (e.g., a Central Processing Unit (CPU)) or the like.

The RF communication control unit 20 interprets the command received from the PLC 50 by the function of the upper communication control unit 11. The commands received from the PLC 50 include a write command for designating data writing to the RF tag 40 and a read command for designating data reading from the RF tag 40. The write command and the read command include data related to the data exchange size between the PLC 50 and the reader/writer 10.

The PLC 50 does not need to recognize the number of RF tags 40 that the reader/writer 10 communicates with in order to read or write data in accordance with one command. As will be described later in detail, the RF communication control unit 20 performs a process of reading or writing data to the memory of each of the predetermined plurality of RF tags 40 according to the capacity of the data to be read or written.

The RF communication control unit 20 converts data included in the write command received from the PLC 50 into data that can be written to the RF tag 40. The RF communication control unit 20 converts data such as octal Code, hexadecimal Code, and sixty-four Code included in the write command received from the PLC 50 into data of American Standard Code for Information exchange (ASCII Code), for example.

The RF communication control unit 20 converts data read out from the RF tag 40 into data that can be transferred to the PLC 50 in response to a read command received from the PLC 50. The RF communication control unit 20 converts digital string data read between the RF tag 40 and the RF communication control unit into data such as octal code, hexadecimal code, and sixty-four-stroke code.

The RF communication control unit 20 transmits command signals to and receives response signals from a predetermined plurality of RF tags 40 via the antenna 35. The RF communication control unit 20 may be configured to perform a decoding process of the response signal received from the RF tag 40. In addition, the wireless communication with the RF tag 40 via the antenna 35 is communication at a speed of several milliseconds to several tens milliseconds per byte.

As shown in fig. 3(a), the reader/writer 10 may include a plurality of units each of which is separate. For example, the reader/writer 10 may have a configuration in which the control unit 120 having the function of the upper communication control unit 11 and a part of the function of the RF communication control unit 20, the amplifier unit 130 for amplifying a signal, and the antenna 35 are separated from each other.

As shown in fig. 3 (b), the reader/writer 10 may be configured such that the upper communication control unit 11, the RF communication control unit 20, and the antenna 35 are integrally formed.

As shown in fig. 1, the RF communication control unit 20 includes an RF tag identification unit 21 and a memory processing unit 22.

The RF tag identification unit 21 identifies a predetermined plurality of RF tags as target RF tags. The RF tag identification unit 21 reads identification information stored in a memory of the RF tag 40 via the antenna 35 from each of the plurality of communicable RF tags 40 present in the communicable area of the antenna 35. The RF tag identification unit 21 performs the following collision avoidance (collision) processing: the communicable RF tags 40A, 40B, 40C corresponding to the read identification information are identified as the target RF tags 40A, 40B, 40C.

The identification information of the RF tag 40 includes, in addition to information for identifying the individual of each RF tag 40, identification information of other RF tags 40 included in a predetermined set of a plurality of RF tags 40 that hold individual information of one workpiece 101 (see fig. 1). In the anti-collision process, the RF tag identification unit 21 identifies the target RF tags 40A, 40B, and 40C by identifying a set of the plurality of RF tags 40 that holds the individual information of one workpiece 101 (see fig. 1) with reference to the identification information of each of the plurality of communicable RF tags 40.

The RF communication control unit 20 causes the storage unit 30 to store identification information read by the RF communication control unit 20 from each of the target RF tags 40A, 40B, and 40C via the antenna 35. The RF tag identification unit 21 manages identification information of the target RF tags 40A, 40B, and 40C stored in the storage unit 30 as an index, and thereby sets addresses of memories included in the target RF tags 40A, 40B, and 40C in the virtual memory space. The RF tag identification unit 21 manages identification information as an index, for example, and sets addresses by regarding the memory blocks of the target RF tags 40A, 40B, and 40C as the first, second, and third of the virtual memory space in accordance with the order of sorting the indexes.

The identification information of the RF tag 40 is, for example, an identification number individually set for each RF tag 40. These identification numbers are combinations of english alphabets and numerals, and the RF tag identification unit 21 sorts the identification numbers in at least one of the english alphabets and the numerals to determine the order of reading or writing data.

In this way, when at least one of reading and writing data from and into the memory included in each of the plurality of target RF tags 40A, 40B, and 40C is performed, the reader/writer 10 sets the reading order when detecting the plurality of target RF tags 40A, 40B, and 40C to the order sorted using the identification number as the index. Thus, the reader/writer 10 does not need to perform the following processing: information on the order in which the plurality of target RF tags 40 are read out or the order in which the plurality of target RF tags 40 are written is recorded in advance in association with, for example, the identification number of each RF tag 40. Therefore, the reader/writer 10 can efficiently integrate data read or written with the plurality of target RF tags 40A, 40B, and 40C.

The PLC 50 may be configured to recognize the number of target RF tags that are instructed to read or write data from/to the reader/writer 10. At this time, the PLC 50 transmits a command for reading or writing data including information on the number of target RF tags to the reader/writer 10. The RF tag identification unit 21 acquires the number information indicating the number of the target RF tags received from the PLC 50 via the upper communication control unit 11. The RF tag identification unit 21 may identify the RF tags 40 that can communicate as the target RF tags 40A, 40B, and 40C when the acquired solid state information matches the number of RF tags 40 that can communicate in the communication-capable area.

The PLC 50 may be a target RF tag that can transmit a command including identification information for identifying a command for reading or writing data from or to the reader/writer 10. The RF tag identification unit 21 may perform collision avoidance processing based on the identification information for identifying the target RF tag received from the PLC 50 via the upper communication control unit 11 and the identification information read from each of the communicable RF tags 40.

The memory processing unit 22 integrates the memories included in the target RF tags 40A, 40B, and 40C identified by the RF tag identification unit 21 into one virtual memory space. For example, when each of the target RF tags 40A, 40B, and 40C has a memory capacity of 2KB, the memory processing unit 22 integrates these memories and performs at least one of reading and writing as one virtual memory space having a memory capacity of virtually 6 KB.

Thus, by using a plurality of RF tags 40, which are generally finished products having a small memory capacity, a user can store information of a capacity that cannot be completely stored in the memory of one RF tag 40 in one virtual memory space in which the memories of the plurality of RF tags 40 are integrated. Therefore, it is not necessary to use an expensive RF tag having a large memory capacity, and thus it is possible to increase the capacity of information that can be managed by the RF tag 40 while suppressing an increase in cost.

The RF tag identification unit 21 may calculate the total memory capacity of the RF tags 40 that are present in the communication-capable area, and identify the RF tags 40 that are to be communicated as the target RF tags 40A, 40B, and 40C when the amount of data required for the memory processing performed by the memory processing unit 22 is equal to or less than the total memory capacity. The storage unit 30 may store identification information of a plurality of RF tags 40 that can communicate with the reader/writer 10 and the memory capacity of each RF tag 40 in advance. The RF tag identification unit 21 calculates the total memory capacity of the communicable RF tags 40 by calculating the total memory capacity of the RF tags 40 corresponding to the identification information stored in the storage unit 30 based on the identification information read from the plurality of communicable RF tags 40.

Fig. 4 is a diagram showing an example of the flow of data between the reader/writer 10 and the target RF tags 40A, 40B, and 40C. Fig. 4 shows the flow of data when the reader/writer 10 reads data from the target RF tags 40A, 40B, and 40C in response to a command from the PLC 50 to read 4000 bytes of data from the number 1000 of the virtual memory space of 6 KB.

First, the RF communication control unit 20 of the reader/writer 10 reads, by using the function of the RF tag identification unit 21, identification information stored in the memory of the RF tag 40 from each of the plurality of communicable RF tags 40 existing in the communicable area of the antenna 35 via the antenna 35. The RF tag identification unit 21 refers to the identification information read from each of the communicable RF tags 40, performs anti-collision processing, and identifies the target RF tags 40A, 40B, and 40C. The RF tag identification unit 21 sets an address in the virtual memory space for each of the memories of the identified target RF tags 40A, 40B, and 40C.

The RF communication control unit 20 first transmits a read command requesting to read 1000 bytes of data from the memory No. 1000 to the first RF tag 40A by using the function of the memory processing unit 22. The memory processing unit 22 acquires 1000 bytes of data transferred from the RF tag 40A in response to the transmitted read command.

Next, the memory processing section 22 transmits a read command requesting to read 2000 bytes of data from the 0000 # of the memory to the second RF tag 40B. The memory processing unit 22 acquires 2000 bytes of data transferred from the RF tag 40B in response to the transmitted read command.

Next, the memory processing section 22 transmits a read command requesting to read 1000 bytes of data from the 0000 # of the memory to the third RF tag 40C. The memory processing unit 22 acquires 1000 bytes of data transferred from the RF tag 40C as a response to the transmitted read command.

Note that, although the example shown in fig. 4 shows data reading, when data is written to a predetermined plurality of target RF tags 40 by wireless communication, the memory processing unit 22 may also write to one virtual memory space by integrating the memories included in the respective target RF tags. The reader/writer 10 can write data to the target RF tags 40A, 40B, and 40C in a reverse flow to the data reading process, for example, in response to a command from the PLC 50 to write 4000 bytes of data from the number 1000 of the virtual memory space of 6 KB.

When data is written to a predetermined plurality of target RF tags 40, the RF communication control unit 20 identifies the target RF tags 40A, 40B, and 40C by the function of the RF tag identification unit 21, and sets addresses in the virtual memory space for the memories of the identified target RF tags 40A, 40B, and 40C, respectively.

The RF communication control unit 20 first transmits a write command for writing 1000 bytes of data from the memory No. 1000 to the RF tag 40A to be processed first, and writes 1000 bytes of data to the RF tag 40A, using the function of the memory processing unit 22.

Next, the memory processing unit 22 transmits a write command for writing 2000 bytes of data from the 0000 number of the memory to the RF tag 40B to be the second processing target, and writes 2000 bytes of data to the RF tag 40B.

Next, the memory processing unit 22 transmits a write command for writing 1000 bytes of data from the 0000 number of the memory to the RF tag 40C to be processed, and writes 1000 bytes of data to the RF tag 40C.

In this way, the reader/writer 10 can integrate the memories included in the plurality of target RF tags 40 as one virtual memory space, thereby increasing the capacity of information that can be managed by the RF tags 40.

[ example 1 of the flow of data read processing by the reader/writer 10 ]

Fig. 5 is a flowchart showing specific example 1 of the flow of the data reading process by the reader/writer 10.

When the RF communication control unit 20 of the reader/writer 10 acquires a command for reading data received from the PLC 50 via the upper communication control unit 11, it first executes anti-collision processing using the function of the RF tag identification unit 21 (step S1).

The RF communication control unit 20 determines whether or not the collision avoidance process is normally ended (step S2). If the RF tag identification unit 21 can identify a plurality of predetermined target RF tags 40A, 40B, and 40C, the RF communication control unit 20 determines that the collision avoidance process has ended normally (YES in step S2), and proceeds to step S3. If the RF tag identification unit 21 cannot identify the predetermined target RF tags 40A, 40B, and 40C, the RF communication control unit 20 determines that the collision avoidance processing has not normally ended (NO in step S2), and transmits the processing for the command to the PLC 50 with an abnormal end.

The RF communication control unit 20 performs the memory processing of reading by the function of the memory processing unit 22 using the address in the virtual memory space of the memory included in each of the target RF tags 40A, 40B, and 40C set by the RF tag specification unit 21. The memory processing unit 22 first transmits a read command to the RF tag 40A of the first processing target among the target RF tags 40A, 40B, and 40C (step S3).

The RF communication control unit 20 determines whether or not the read command can be normally transferred by wireless communication with the RF tag 40A of the first processing object (step S4). For example, when the target RF tag 40A is out of the communicable area of the antenna 35, the read command cannot be passed and it is determined that the RF tag is abnormal. If RF communication control unit 20 determines that the read command can be normally delivered to RF tag 40A (YES in step S4), it proceeds to step S5. If it is determined that the read command cannot be normally delivered to the RF tag 40A (NO in step S4), the RF communication control unit 20 transmits the processing abnormality end for the command to the PLC 50.

The RF communication control unit 20 reads data from the RF tag 40A to be processed first by using the function of the memory processing unit 22 (step S5). When the data read command received from the PLC 50 is a command to read 4000 bytes of data from the number 1000 of the virtual memory space of 6KB, the memory processing unit 22 receives 1000 bytes of data from the number 1000 of the RF tag 40A as a response.

The memory processing unit 22 then transmits a read command to the RF tag 40B to be processed, which is the second of the target RF tags 40A, 40B, and 40C (step S6).

The RF communication control unit 20 determines whether or not the read command can be normally transferred by wireless communication with the RF tag 40B of the second processing target (step S7). For example, when the target RF tag 40B is out of the communicable area of the antenna 35, the read command cannot be passed and it is determined that the RF tag is abnormal. If RF communication control unit 20 determines that the read command can be normally delivered to RF tag 40B (YES in step S7), it proceeds to step S8. If it is determined that the read command cannot be normally delivered to the RF tag 40B (NO in step S7), the RF communication control unit 20 transmits the processing abnormality end for the command to the PLC 50.

The RF communication control unit 20 reads data from the second processing target RF tag 40B by using the function of the memory processing unit 22 (step S8). When the data read command received from the PLC 50 is a command to read 4000 bytes of data from the number 1000 of the virtual memory space of 6KB, the memory processing unit 22 receives 2000 bytes of data from the number 0000 of the RF tag 40B as a response.

The memory processing unit 22 then transmits a read command to the RF tag 40C to be processed, which is the third one of the target RF tags 40A, 40B, and 40C (step S9).

The RF communication control unit 20 determines whether or not the read command can be normally transferred by wireless communication with the RF tag 40C of the third processing object (step S10). For example, when the target RF tag 40C is out of the communication-enabled area of the antenna 35, the read command cannot be received and it is determined that the RF tag is abnormal. If RF communication control unit 20 determines that the read command can be normally delivered to RF tag 40C (YES in step S10), it proceeds to step S11. If it is determined that the read command cannot be normally delivered to the RF tag 40C (NO in step S10), the RF communication control unit 20 transmits the processing abnormality end for the command to the PLC 50.

The RF communication control unit 20 reads data from the RF tag 40C to be processed of the third party by using the function of the memory processing unit 22 (step S11). When the data read command received from the PLC 50 is a command to read 4000 bytes of data from the number 1000 of the virtual memory space of 6KB, the memory processing unit 22 receives 1000 bytes of data from the number 0000 of the RF tag 40C as a response, and transmits the normal end of the processing for the command to the PLC 50.

The RF communication control unit 20 integrates the 4000-byte data received from the target RF tags 40A, 40B, and 40C by the function of the memory processing unit 22, and transmits the integrated data to the PLC 50.

As described above, when all the target RF tags 40A, 40B, and 40C are present in the communicable area of the antenna 35 at the time of performing the memory processing and all the target RF tags 40A, 40B, and 40C are specified by the RF tag specification unit 21, the memory processing unit 22 sequentially performs the memory processing on all the target RF tags 40A, 40B, and 40C.

[ example 2 of the flow of the data read processing by the reader/writer 10 ]

Fig. 6 is a flowchart showing specific example 2 of the flow of the data reading process performed by the reader/writer 10. As shown in fig. 6, when the RF communication control unit 20 of the reader/writer 10 acquires a command for reading data received from the PLC 50 via the upper communication control unit 11, the anti-collision processing is executed by the function of the RF tag identification unit 21, and the target RF tag set is confirmed (step S21).

The RF tag identification unit 21 may read the identification information of each of the plurality of target RF tags included in one set written in the memory of at least one of the plurality of target RF tags present in the communication-capable area of the antenna 35, and may check the target RF tag set. For example, in the memory of RF tag 40A, the identification information of

RF tags

40B and 40C is written in advance together with the identification information of RF tag 40A. The RF tag identification unit 21 may confirm that the target RF tag set includes the RF tags 40A, 40B, and 40C based on the identification information of the RF tags 40A, 40B, and 40C read from the memory of the RF tag 40A.

In addition, information indicating the reading order of each of the target RF tags may be recorded in the memory of at least one of the plurality of target RF tags together with the identification information of each of the plurality of target RF tags included in one set. At this time, the above-described sorting process using the identification number as an index may be omitted.

The RF tag identification unit 21 may be configured to confirm that the target RF tag set includes the RF tags 40A, 40B, and 40C based on information of the target RF tag set included in the command read from the data received from the PLC 50. In this case, the command from the PLC 50 includes information of the RF tags 40A, 40B, and 40C in the RF tag set indicating the data reading target. For example, the command from the PLC 50 may include identification information of each of the RF tags 40A, 40B, and 40C constituting the RF tag set.

The data read command received from the PLC 50 may include information indicating the read order of each target RF tag. In this case, the above-described sorting process using the id number as an index can be omitted.

The RF communication controller 20 performs the anti-collision process and the confirmation of the target RF tag set in step S21 by using the function of the RF tag identification unit 21, and then executes the processes of step S22 to step S31. The processing of steps S22 to S31 is the same as the processing of steps S2 to S11 described above, and thus the description thereof is omitted.

[ application example of data read processing by reader/writer 10 ]

In addition, at the time point when the memory processing unit 22 performs the memory processing, not all of the target RF tags 40A and the RF tag 40B, RF tag 40C may exist in the communicable area of the antenna 35. In this case, the memory processing unit 22 may sequentially perform memory processing for the target RF tags existing in the communication-capable area of the antenna 35, and sequentially perform memory processing for the remaining target RF tags at a time point when the remaining target RF tags enter the communication-capable area of the antenna 35. For example, consider the following case: in a production line in which a tray 100 having an RF tag 40 mounted thereon is conveyed by a conveyor, the RF tags 40 gradually enter the communicable area of the antenna 35 in sequence due to the conveyance movement of the tray 100.

Fig. 7 is a diagram showing the flow of data among the PLC 50, the reader/writer 10, and the RF tags 40A, 40B, and 40C when not all of the target RF tags 40A, 40B, and 40C are present in the communicable area of the antenna 35.

As shown in fig. 7, the RF communication control unit 20 of the reader/writer 10 acquires a read command received from the PLC 50 via the upper communication control unit 11. The RF communication control unit 20 specifies a predetermined plurality of target RF tags 40 by the function of the RF tag specifying unit 21. The RF tag identification unit 21 may identify the plurality of target RF tags 40 by referring to the contents of the command from the PLC 50.

The RF tag identification unit 21 may identify the plurality of target RF tags 40 by referring to the identification information read from the RF tag 40A existing in the communication-capable area of the antenna 35. The RF tag identification unit 21 refers to identification information of a plurality of predetermined target RF tags 40 included in identification information read from the RF tags 40 existing in the communicable area of the antenna 35, and identifies the target RF tags 40A, 40B, and 40C.

When the RF tag 40 is not present in the communicable area of the antenna 35, the RF tag identification unit 21 may wait until the RF tag 40 reaches the communicable area of the antenna 35, confirm that the RF tag 40 reaches the communicable area of the antenna 35, and then read the identification information from the RF tag 40.

The memory processing unit 22 has a function of checking whether or not each of the predetermined target RF tags 40A, 40B, and 40C specified by the RF tag specification unit 21 is present in the communicable area of the antenna 35. The memory processing unit 22 has the following functions: when the predetermined target RF tags 40A, 40B, and 40C identified by the RF tag identification unit 21 do not exist in the communicable area of the antenna 35, it is checked whether or not they have reached the communicable area of the antenna 35. The memory processing unit 22 sequentially executes data reading processing from the target RF tag 40 existing in or reaching the communication-capable area of the antenna 35.

For example, the memory processing unit 22 identifies the target RF tags 40A, 40B, and 40C by the RF communication control unit 20 acquiring a read command from the PLC 50, and then reads data from the target RF tag 40A existing in the communicable area of the antenna 35. When the read command acquired from the PLC 50 is a command to read 4000 bytes from the 1000 th memory, the memory processing unit 22 first reads 1000 bytes of data from the 1000 th memory of the target RF tag 40A.

The memory processing unit 22 then confirms that the target RF tag 40B has reached the communication-capable area of the antenna 35, and reads 2000 bytes of data from the 0000 number of the memory of the target RF tag 40B. Then, the memory processing unit 22 confirms that the target RF tag 40C has reached the communication-capable area of the antenna 35, and reads 1000 bytes of data from the 0000 number of the memory of the target RF tag 40C.

In this way, the reader/writer 10 can expand the read range of the target RF tag 40 even outside the communication-capable area of the antenna 35, and sequentially read data from the plurality of target RF tags 40. Thus, by integrating the memories included in the plurality of target RF tags 40 to use them as one virtual memory space, the capacity of information that can be managed by the RF tags 40 can be increased.

In addition, when data is written to a predetermined plurality of target RF tags 40 by wireless communication, the memory processing unit 22 may also perform data writing to the plurality of target RF tags 40 as one virtual memory space by integrating the memories included in the respective target RF tags. The reader/writer 10 can write data to the target RF tags 40A, 40B, and 40C in a reverse flow to the data reading process in accordance with a command from the PLC 50. That is, the memory processing unit 22 can confirm that the target RF tag 40 has reached the communication-capable area of the antenna 35, and write data of a predetermined capacity at a predetermined position in the memory of the target RF tag 40.

[ flow of processing by the memory processing unit 22 ]

Fig. 8 is a flowchart showing an example of the flow of data reading processing performed by the memory processing unit 22 when not all of the target RF tags 40A, 40B, and 40C are present in the communicable area of the antenna 35.

The RF communication control unit 20 waits for the first RF tag 40A from among the RF tags 40A, 40B, and 40C specified by the function of the RF tag specification unit 21 to read data to a communication area of the antenna 35, and reads data of a predetermined capacity from a predetermined position in the memory of the RF tag 40A by the function of the memory processing unit 22 (step S41).

The RF communication control unit 20 determines whether the memory processing unit 22 can read data normally from the target RF tag 40A (step S42). If RF communication control unit 20 determines that memory processing unit 22 can read data from target RF tag 40A normally (YES in step S42), the routine proceeds to step S43. If the RF communication control unit 20 determines that the memory processing unit 22 cannot normally read data from the target RF tag 40A (NO in step S42), it notifies the PLC 50 of the abnormal end of data reading and ends the processing.

The RF communication control unit 20 notifies the PLC of the reception of the response from the target RF tag 40A (step S43).

The RF communication control unit 20 waits for the second RF tag 40B to read data to a predetermined capacity from a predetermined position in the memory of the RF tag 40B by the function of the memory processing unit 22 after the arrival of the second RF tag 40B in the communication area of the antenna 35 (step S44).

The RF communication control unit 20 determines whether the memory processing unit 22 can read data normally from the target RF tag 40B (step S45). If RF communication control unit 20 determines that memory processing unit 22 can read data from target RF tag 40B normally (YES in step S45), the routine proceeds to step S46. If the RF communication control unit 20 determines that the memory processing unit 22 cannot normally read data from the target RF tag 40B (NO in step S45), it notifies the PLC 50 of the abnormal end of data reading and ends the processing.

The RF communication control unit 20 notifies the PLC of the reception of the response from the target RF tag 40B (step S46).

The RF communication control unit 20 waits for the third RF tag 40C to read data to a predetermined capacity from a predetermined position in the memory of the RF tag 40C by the function of the memory processing unit 22 after the arrival of the third RF tag 40C in the communication-capable area of the antenna 35 (step S47).

The RF communication control unit 20 determines whether the memory processing unit 22 can read data normally from the target RF tag 40C (step S48). If RF communication control unit 20 determines that memory processing unit 22 can read data from target RF tag 40C normally (YES in step S48), the routine proceeds to step S49. If the RF communication control unit 20 determines that the memory processing unit 22 cannot normally read data from the target RF tag 40C (NO in step S48), it notifies the PLC 50 of the abnormal end of data reading and ends the processing.

The RF communication control unit 20 notifies the PLC of the reception of the response from the target RF tag 40C, integrates the data read from each of the target RF tags 40A, 40B, and 40C, and transmits all the data to the PLC 50 (step S49), thereby notifying the PLC 50 of the normal end of the processing for the command and ending the processing.

[ implementation by software ]

The control block of the reader/writer 10 (particularly, the upper communication control unit 11 and the RF communication control unit 20) may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

In the latter case, the reader/writer 10 includes a computer that executes commands of a program as software for realizing the respective functions. The computer includes, for example, one or more processors, and includes a computer-readable recording medium storing the program. In the computer, the processor reads the program from the recording medium and executes the program, thereby achieving the object of the present invention. As the processor, for example, a CPU can be used. As the recording medium, a tape, an optical disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used in addition to the "non-transitory tangible medium", such as a ROM or the like. Further, a RAM or the like for expanding the program may be included. The program may be provided to the computer via any transmission medium (a communication network, a broadcast wave, or the like) that can transmit the program. In addition, an embodiment of the present invention can be realized by a form of a data signal embedded in a carrier wave for embodying the program by electronic transmission.

[ conclusion ]

A reader/writer according to an embodiment of the present invention is configured to perform at least one of reading and writing of data with an RF tag by wireless communication, and includes: an RF tag identification unit that identifies a predetermined plurality of RF tags as target RF tags; and a memory processing unit that integrates the memories included in the plurality of target RF tags, and performs memory processing of at least one of reading and writing as one virtual memory space.

According to this configuration, the memories included in the plurality of target RF tags can be integrated to perform at least one of reading and writing memory processing as one virtual memory space. Thus, by using a plurality of normally finished RF tags having a small memory capacity, information necessary for the capacity of a memory which cannot be completely stored in one RF tag can be stored in one virtual memory space and used. Therefore, an increase in cost of the RF tag can be suppressed, and the capacity of information that can be managed by the RF tag can be increased.

In the reader/writer according to an embodiment of the present invention, the RF tag identification unit may manage identification information of the target RF tag as an index, and thereby set an address of a memory included in each of the target RF tags in the virtual memory space.

According to this configuration, when at least one of reading and writing of data from and to the memory included in each of the plurality of target RF tags is performed, the reading order when the plurality of target RF tags are detected can be predetermined to be the order corresponding to the identification number managed as the index. Thus, it is not necessary to additionally perform the following processing: information on the order of reading out or writing to the plurality of target RF tags, and the like are recorded in advance. Therefore, data integration can be performed efficiently. Therefore, even if memories of a plurality of object RF tags are used as one virtual memory space, data processing can be efficiently performed and the data capacity can be increased.

In the reader/writer according to an embodiment of the present invention, the RF tag identification unit may receive number information indicating the number of the target RF tags from an external higher-level device, and identify the communicable RF tag as the target RF tag when the number information matches the number of communicable RF tags existing in a communicable area.

With this configuration, the reader/writer can appropriately determine the number of communicable RF tags corresponding to the command from the host device as the target RF tag.

In the reader/writer according to an embodiment of the present invention, the RF tag specifying unit may calculate a total memory capacity of the RF tags capable of communication existing in the communication-capable area, and may specify the RF tag capable of communication as the target RF tag when the amount of data required for the memory processing is equal to or less than the total memory capacity.

According to this configuration, the reader/writer can confirm that the total memory capacity of the plurality of target RF tags has reached the capacity required for memory processing, and then perform at least one of reading and writing of data. Thus, when memories of a plurality of target RF tags are used as one virtual memory space, the capacity required for reading or writing data does not become insufficient in the middle of memory processing and ends abnormally. Therefore, the reader/writer can efficiently perform at least one of reading and writing of data to the plurality of target RF tags.

In the reader/writer according to an embodiment of the present invention, the RF tag identification unit may read the identification information from a communicable RF tag in which identification information of a plurality of the target RF tags is recorded, among communicable RF tags existing in a communicable area, and identify a communicable RF tag corresponding to the read identification information as the target RF tag.

According to the above configuration, the identification information read from the communicable RF tags can be referred to, thereby identifying the plurality of target RF tags and efficiently identifying the target RF tags.

In the reader/writer according to an embodiment of the present invention, the memory processing unit may sequentially perform memory processing on all the object RF tags when all the object RF tags are present in a communication-capable area at a time point of performing the memory processing, and may sequentially perform memory processing on the object RF tags present in the communication-capable area when not all the object RF tags are present in the communication-capable area at a time point of performing the memory processing, and may sequentially perform memory processing at a time point when the remaining object RF tags enter the communication-capable area.

According to this configuration, the specifiable areas of the plurality of target RF tags can be expanded to the outside of the communication-capable area, and at least one of reading and writing of data can be performed using the memories of the plurality of RF tags that do not enter the communication-capable area as one virtual memory space.

According to the method, the memories included in the plurality of object RF tags are integrated to perform at least one of reading and writing as one virtual memory space. Thus, by using a plurality of normally finished RF tags having a small memory capacity, information necessary for the capacity of a memory which cannot be completely stored in one RF tag can be stored in one virtual memory space and used. Therefore, an increase in cost of the RF tag can be suppressed, and the capacity of information that can be managed by the RF tag can be increased.

According to the above configuration, it is possible to increase the capacity of information that can be managed by the RF tag while suppressing an increase in the cost of the RF tag.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Description of the symbols

10: read-write machine

11: upper communication control unit

20: RF communication control unit

21: RF tag determination unit

22: memory processing unit

30: storage unit

50: PLC (Upper machine)

40(40A, 40B, 40C): RF tag

Claims

1. A reader/writer that performs at least one of reading and writing of data by wireless communication with a radio frequency tag, comprising:

a radio frequency tag determination unit configured to determine a plurality of predetermined radio frequency tags as target radio frequency tags; and

and a memory processing unit which integrates the memories included in the plurality of target radio frequency tags and performs memory processing of at least one of reading and writing as one virtual memory space.

2. The reader/writer according to claim 1,

the radio frequency tag identification unit manages identification information of the target radio frequency tag as an index, and sets an address of a memory included in each of the target radio frequency tags in the virtual memory space.

3. The reader/writer according to claim 2,

the radio frequency tag identification unit receives number information indicating the number of the target radio frequency tags from an external host device, and identifies the communicable radio frequency tags as the target radio frequency tags when the number information matches the number of communicable radio frequency tags existing in a communicable area.

4. The reader/writer according to claim 2 or 3,

the radio frequency tag identification unit calculates a total memory capacity of a communicable radio frequency tag existing in a communicable area, and identifies the communicable radio frequency tag as the target radio frequency tag when a data amount required for the memory processing is equal to or less than the total memory capacity.

5. The reader/writer according to claim 2,

the radio frequency tag identification unit reads identification information of a plurality of target radio frequency tags from communicable radio frequency tags existing in a communicable area, and identifies a communicable radio frequency tag corresponding to the read identification information as the target radio frequency tag.

6. The reader/writer according to any one of claims 1, 2 and 5,

the memory processing unit sequentially performs memory processing on all the target radio frequency tags when all the target radio frequency tags are present in a communicable area at a time point when the memory processing is performed,

the memory processing unit sequentially performs memory processing on the target radio frequency tags existing in the communication-capable area when not all the target radio frequency tags are present in the communication-capable area at a time point of performing the memory processing, and sequentially performs memory processing at a time point when the remaining target radio frequency tags enter the communication-capable area.

7. A control method of a reader-writer is characterized by comprising the following steps:

determining a plurality of specified radio frequency tags as object radio frequency tags; and

the memory processing is performed by integrating the memories included in the plurality of target radio frequency tags to perform at least one of reading and writing as one virtual memory space.

8. A program that causes the reader/writer according to any one of claims 1 to 6 to operate, and

and a computer configured to function as the radio frequency tag determination unit and the memory processing unit.