JP5695483B2 - RF-ID media information reading system and control device - Google Patents

Description

  The present invention relates to an RF-ID media information reading system and a control device for reading information from an RF-ID media.

  In recent years, with the progress of the information society, information is recorded on a tag or label, and the tag or label is attached to a product or the like to manage the product or the like. In the management of products using such tags and labels, non-contact IC tags and non-contact IC labels equipped with ICs capable of writing and reading information in a non-contact state are used. Rapid spread due to excellent convenience.

  In such RF-ID media such as non-contact type IC tags and non-contact type IC labels, information is read from the RF-ID media by a reader / writer serving as inspection means before being shipped as a product. Defective products are being inspected.

  By the way, in a system that outputs radio waves, in order to avoid radio wave interference between multiple devices, so-called carrier sense is used to check whether the channel to be used is available by measuring the magnitude of received power. It is required by the Radio Law to carry out.

  Therefore, even when the RF-ID medium is inspected as described above, information for inspection is transmitted by radio waves from the reader / writer, so that radio wave interference between a plurality of readers / writers is avoided. In order to do this, it is confirmed whether or not the channel to be used is vacant, and if it is vacant, the channel is used for inspection (for example, see Patent Documents 1 and 2).

JP 2008-148215 A JP 2010-198180 A

  However, when reading information from RF-ID media, such as when testing RF-ID media by placing a plurality of readers / writers in close proximity and outputting radio waves, an empty channel is used with carrier sense as described above. Sweeping multiple channels to search for, etc., the process becomes complicated, and there is a high possibility that channels used between multiple devices will collide, and carrier sense will fail and RF-ID media will fail. There is a problem that information cannot be read.

  The present invention has been made in view of the above-described problems of the prior art, and in the case where information is read from an RF-ID medium using different channels in a plurality of reader / writers, carrier sense is performed. It is an object of the present invention to provide an RF-ID media reading system and a control device capable of efficiently performing the above-mentioned and avoiding that information cannot be read from the RF-ID media.

In order to achieve the above object, the present invention provides:
A plurality of readers / writers for reading information from an RF-ID medium, and a control device for allocating channels used for reading the information by the plurality of readers / writers from among a plurality of channels larger than the number of readers / writers Each of the plurality of readers / writers performs carrier sense using a channel assigned by the control device before reading information from the RF-ID medium, and succeeds in the carrier sense. In the RF-ID media reading system that reads information from the RF-ID media using the channel when
The controller is
When the plurality of readers / writers fail in carrier sense using an initial channel preset for each of the plurality of readers / writers, the reader / writers that have failed in the carrier sense are informed of the plurality of reader / writers. Any one of the one or a plurality of spare channels not set to any of the writers, or all of the one or a plurality of spare channels are assigned to any one of the plurality of readers / writers. In this case, the reader / writer to which the spare channel is assigned has a channel assigning unit for assigning a preset initial channel.

  In the present invention configured as described above, when carrier sense is executed before reading information from the RF-ID medium in the reader / writer, first, in each of the reader / writer, Carrier sensing is performed using an initial channel set in advance. When the reader / writer succeeds in carrier sense using this initial channel, information is read from the RF-ID medium using this initial channel. If the reader / writer fails in carrier sense using the initial channel, a spare channel that is not set in any of the plurality of readers / writers or a spare channel is set to a plurality of readers / writers. When assigned to any of the / writers, a preset initial channel is assigned to the reader / writer to which the spare channel is assigned, and carrier sensing is performed using the initial channel in the reader / writer.

  As described above, in a plurality of readers / writers that read information from the RF-ID media, when carrier sense using a preset initial channel fails, none of the plurality of readers / writers is set. One of the one or more spare channels, or the leader / writer to which the spare channel is assigned if all of the one or more spare channels are assigned to one of the plurality of reader / writers. Channels that are likely to be free are assigned to multiple readers / writers that read information from RF-ID media without sweeping empty channels, such that a preset initial channel is assigned to the writer. As a result, the carrier sense can be performed efficiently without complications. Which it is avoided that it becomes impossible to read information from the RF-ID media.

  As described above, in the present invention, when carrier sense using a preset initial channel fails in a plurality of readers / writers that read information from an RF-ID medium, any of the plurality of readers / writers is detected. If any one of the one or more spare channels not set, or one or more spare channels are all assigned to one of the plurality of reader / writers, the spare channel is There is a possibility that a plurality of readers / writers that read information from the RF-ID media are vacant without sweeping the vacant channels, such that the set initial channel is assigned to the assigned reader / writer. Since the configuration is such that a higher channel is assigned, Can perform carrier sense to look for Le efficiently, it can be avoided so that it becomes impossible to read information from the RF-ID media. In addition, since output, reception, and carrier sense of the same channel are not performed in the same system, the possibility of radio wave interference between a plurality of reader / writers can be significantly reduced.

It is a figure which shows one Embodiment of the RF-ID media information reading system of this invention. It is a figure which shows the detailed structure of the control apparatus shown in FIG. 1, (a) is a block diagram which shows a structure, (b) is an initial channel for every reader / writer in the initial channel memory | storage part shown to (a). It is a figure which shows the table set to (1). It is a flowchart for demonstrating the inspection method with respect to the RF-ID label in the RF-ID media information reading system shown in FIG. It is a figure which shows an example of a transition of the channel allocation process with respect to the reader / writer in the control apparatus shown in FIG. It is a figure which shows the example of the initial stage channel set when three test | inspection areas of RF-ID label as shown in FIG. 1 are provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing an embodiment of an RF-ID media information reading system according to the present invention.

  As shown in FIG. 1, the present embodiment is an inspection system for inspecting an RF-ID label 50 that is an RF-ID medium conveyed in six rows, and the RF-ID label 50 is conveyed. Antennas 21a to 21f are provided on the transport path 40 corresponding to each of the six rows, radio waves are output from the antennas 21a to 21f, and the RF-ID label 50 is inspected. Readers / writers 20a to 20f for reading information from the RF-ID label 50 in a non-contact state using radio waves output from the antennas 21a to 21f are connected to the antennas 21a to 21f, respectively. / The control device 10 is connected to the writers 20a to 20f. Then, each of the reader / writers 20a to 20f outputs radio waves from the antennas 21a to 21f using the channels assigned by the control device 10 and inspects the RF-ID label 50. Further, a trigger generator 30 for detecting the RF-ID label 50 is provided in the conveyance path 40 of the RF-ID label 50, and at the timing when the RF-ID label 50 is detected by the trigger generator 30. A trigger signal is generated, and the trigger signal is input to the control device 10.

  In the RF-ID media inspection system configured as described above, when a trigger signal is generated when the trigger generator 30 detects the RF-ID label 50, first, the reader / writers 20a to 20f are controlled. By performing carrier sense using the channel assigned by the apparatus 10, it is confirmed whether or not the channel to be used is vacant, and if it is vacant, radio waves are output from the antennas 21a to 21f using that channel. As a result, the RF-ID label 50 is inspected.

  2 is a diagram showing a detailed configuration of the control device 10 shown in FIG. 1. FIG. 2A is a block diagram showing the configuration, and FIG. 2B is an initial diagram in the initial channel storage unit 11 shown in FIG. It is a figure which shows the table in which the channel was set for every reader / writer 20a-20b. Note that the RW No. in the table shown in FIG. The reader / writer 20a is "1", the reader / writer 20b is "2", the reader / writer 20c is "3", the reader / writer 20d is "4", the reader / writer 20e is "5", and the reader / writer 20f is “6”.

  As shown in FIG. 2A, the control device 10 in this embodiment includes an initial channel storage unit 11, a channel assignment unit 12, and an RW operation control unit 13.

  In the initial channel storage unit 11, different channels are preset as initial channels for each of the reader / writers 20a to 20f. Specifically, as shown in FIG. 2B, ch1 is preset as an initial channel in the reader / writer 20a, ch2 is preset as an initial channel in the reader / writer 20b, and the reader / writer 20c Ch3 is preset as an initial channel, ch4 is preset as an initial channel for the reader / writer 20d, ch5 is preset as an initial channel for the reader / writer 20e, and ch6 is an initial channel for the reader / writer 20f. Is preset. These ch1 to ch6 have different frequencies. In addition, as channels that can be used in the reader / writers 20a to 20f, ch7 and ch8 exist as spare channels.

  The channel assignment unit 12 assigns a channel for performing carrier sense and subsequent inspection for the RF-ID label 50 in the reader / writers 20a to 20f, and the reader / writers 20a to 20f perform carrier sense. When the carrier sense using the initial channel preset in the reader / writer in the initial channel storage unit 11 fails in the reader / writers 20a to 20f, In the initial channel storage unit 11, if a spare channel that is not set to any of the reader / writers 20a to 20f or a spare channel is assigned to any of the reader / writers 20a to 20f, the spare channel is assigned. Reader / writer Assigning an initial channel that is set in the channel storage unit 11. In the present embodiment, the number of channels that can be allocated to the reader / writers 20a to 20f by the channel allocation unit 12 is eight, that is, ch1 to ch8, which is larger than the number of reader / writers 20a to 20f, as described above. ing. This is because the frequency band is defined by the outputs of the reader / writers 20a to 20f, and the number of channels is limited, so that the number of usable reader / writers must be one or more less than the number of channels. is there.

  The RW operation control unit 13 controls operations such as carrier sense and inspection of the RF-ID label 50 in the reader / writers 20a to 20f using the channels allocated by the channel allocation unit 12.

  The inspection method for the RF-ID label 50 in the above-described RF-ID media inspection system will be described below.

  FIG. 3 is a flowchart for explaining an inspection method for the RF-ID label 50 in the RF-ID media inspection system shown in FIG. FIG. 4 is a diagram showing an example of the transition of channel assignment processing for the reader / writers 21a to 21f in the control device 10 shown in FIG.

  When the RF-ID label 50 is transported through the transport path 40 and is detected by the trigger generator 30, a trigger signal is generated by the trigger generator 30 and input to the control device 10.

  Then, control for starting carrier sense is performed by the reader / writers 20a to 20f in the control device 10 (step 1). In addition, even if the antennas 21a to 21f provided on the conveyance path 40 in this embodiment are provided at different positions on the conveyance path 40 with respect to the traveling direction of the RF-ID label 50, the positional deviation is If the pitch of the RF-ID label 50 conveyed through the conveyance path 40 is the same, the trigger generator 30 generates the RF-ID label 50 after the sixth trigger is generated. When the trigger signal is generated at the timing when the signal is detected and the carrier sense is started, the RF-ID label 50 exists in the area facing each of the antennas 21a to 21f at the timing.

  In the control for starting carrier sense, first, each of the reader / writers 20a to 20f is preset for each reader / writer 20a to 20f in the initial channel storage unit 11 by the control of the RW operation control unit 13. In addition, the carrier sense is performed by measuring the received power through the antennas 21a to 21f in the initial channels ch1 to ch6. In the present embodiment, as described above, in the initial channel storage unit 11, ch1 is preset as an initial channel for the reader / writer 20a, and ch2 is preset as an initial channel for the reader / writer 20b. Ch3 is preset as an initial channel for the / writer 20c, ch4 is preset as the initial channel for the reader / writer 20d, ch5 is preset as the initial channel for the reader / writer 20e, and the reader / writer 20f Since ch6 is preset as an initial channel, carrier sense is performed using the channels ch1 to ch6 in the reader / writers 20a to 20f.

  Then, in the reader / writers 20a to 20f, when the reception power via the antennas 21a to 21f is equal to or lower than a predetermined value and the carrier sense using the initial channels ch1 to ch6 is successful (step 2), the RW operation control unit Under the control of 13, the RF-ID label 50 is inspected by reading information from the RF-ID label 50 via the antennas 21a to 21f using the radio waves of the assigned initial channel (step 3). In the example shown in FIG. 4, four reader / writers 20a and 20c to 20e among the reader / writers 20a to 20f succeed in the carrier sense, and RF is generated using the initial channels ch1, ch3 to ch5 used for the carrier sense. -The ID label 50 will be inspected.

  On the other hand, in the reader / writers 20a to 20f, when the reception power via the antennas 21a to 21f exceeds a predetermined value and the carrier sense fails, the channel allocating unit 12 of the control device 10 first starts with the initial channel storage unit 11. It is confirmed whether there is a spare channel that is not assigned to any of the reader / writers 20a to 20f, that is, a spare channel that is not assigned to any of the reader / writers 20a to 20f. (Step 4).

  If there is a spare channel available, the channel allocator 12 allocates the spare channel to the reader / writer that failed to sense the carrier (step 5). In this embodiment, there are two channels ch7 and ch8 as spare channels, and these are not yet assigned to any of the reader / writers 20a to 20f. Therefore, in the example shown in FIG. 4, carrier sense fails. The reserved channel ch7 is assigned to the reader / writer 20b, and the reserved channel ch8 is assigned to the reader / writer 20f.

  Then, under the control of the RW operation control unit 13, the received power via the antennas 21b and 21f in the spare channels ch7 and ch8 is measured in each of the reader / writers 20b and 20f to which the spare channels ch7 and ch8 are assigned. Thus, carrier sense is performed.

  In the reader / writers 20b and 20f, when the received power via the antennas 21b and 21f is equal to or lower than a predetermined value and the carrier sense is successful (step 6), the allocation is performed under the control of the RW operation control unit 13. The RF-ID label 50 is inspected by reading information from the RF-ID label 50 via the antennas 21b and 21f using the radio waves of the spare channels ch7 and ch8 (step 7). In the example shown in FIG. 4, among the reader / writers 20b and 20f, the reader / writer 20b has succeeded in carrier sensing, and the spare channel ch7 assigned to the reader / writer 20b is used to inspect the RF-ID label 50. Will be done.

  On the other hand, in the reader / writers 20b and 20f, when the reception power via the antennas 21b and 21f exceeds a predetermined value and the carrier sense fails, the process returns to step 4 and the channel allocation unit 12 of the control device 10 Among the spare channels that are not set in any of the reader / writers 20a to 20f in the initial channel storage unit 11, there are vacant spare channels, that is, spare channels that are not assigned to any of the reader / writers 20a to 20f. It is confirmed whether there is. Here, in this embodiment, since the spare channels ch7 and ch8 that are not set to any of the reader / writers 20a to 20f in the initial channel storage unit 11 are all allocated to the reader / writer, the channel allocation unit 12 Then, the initial channel set in the initial channel storage unit 11 is assigned to the reader / writer that has performed carrier sense using the spare channel with respect to the reader / writer that has failed in carrier sense (step 8). In the example shown in FIG. 4, the initial channel set in the initial channel storage unit 11 in the reader / writer 20 b in which the reader / writer 20 f fails in carrier sense and is performing carrier sense using the spare channel ch 7. ch2 is assigned to the reader / writer 20f.

  Then, under the control of the RW operation control unit 13, the reader / writer 20f to which the channel ch2 is assigned measures the received power via the antenna 21f in the channel ch2, thereby performing carrier sense.

  In the reader / writer 20f, when the received power via the antenna 21f is equal to or lower than a predetermined value and the carrier sense is successful (step 9), the radio wave of the assigned channel ch2 is controlled by the control of the RW operation control unit 13. Is used to read information from the RF-ID label 50 via the antenna 21f, thereby inspecting the RF-ID label 50 (step 10).

  When the reader / writer 20f fails in carrier sense when the received power via the antenna 21f exceeds a predetermined value, a message indicating a carrier sense error is output (step 11).

  As described above, in the plurality of reader / writers 20a to 20f that inspect the RF-ID label 50, when carrier sense using a preset initial channel fails, any of the reader / writers 20a to 20f is used. Unassigned reserved channels ch7 and ch8 are assigned, or when these reserved channels ch7 and ch8 are already assigned to any of the reader / writers 20a to 20f, the reader / writer to which the reserved channels ch7 and ch8 are assigned A channel that has a high possibility of being vacant without sweeping the vacant channel to the reader / writers 20a to 20f that inspects the RF-ID label 50 is assigned such that a preset initial channel is assigned to. Since it is assigned, carrier sense is complicated Is efficiently carried out without becoming will be avoided that it becomes impossible inspection of RF-ID label 50. In addition, radio waves in the same frequency band are not output redundantly, and output, reception, and carrier sense of the same channel are not performed in the system, so radio wave interference between multiple readers / writers can occur Can be significantly reduced.

(Other embodiments)
In the embodiment described above, in order to simplify the description, six antennas 21a to 21f are provided on the conveyance path 40 on which the RF-ID labels 50 are conveyed in six rows, and these antennas 21a are provided. In a system having six reader / writers 20a to 20f for inspecting the RF-ID label 50 through ~ 21f, initial channels ch1 to ch6 are preset in each of the reader / writers 20a to 20f, and two other In the system using the spare channels ch7 and 8 as an example, in the system using the UHF band frequency, 21 channels are actually set in the medium / high output band and 27 channels are set in the low power band. Yes. Therefore, as shown in the above-described embodiment, the conveyance paths 40 in which the RF-ID labels 50 are conveyed in six rows are provided in three areas, and these can be controlled by the control device 10 in the same manner as described above. Conceivable.

  FIG. 5 is a diagram showing an example of an initial channel set when three inspection areas for the RF-ID label as shown in FIG. 1 are provided.

  As shown in FIG. 5, RW boards for controlling six reader / writers provided in each of the three inspection areas of the RF-ID label are installed. This RW board is shown in FIG. Connected to the control device 10. In the control device 10, as described above, initial channels are preset for 18 reader / writers. As for the initial channel, adjacent channels are not set in the reader / writer provided in the same area, and interference between the reader / writer is less likely to occur.

  In the system configured as described above, similarly to the above, any one of the spare channels ch19 to ch21 or all of the spare channels ch19 to ch21 is the reader for the reader / writer that failed to sense the carrier using the initial channel. If a reader / writer is already assigned, a preset initial channel is assigned to the reader / writer. However, when a spare channel or an initial channel of another reader / writer is assigned, a plurality of these channels exist. In this case, a channel having a frequency farthest from the channel for which carrier sense has failed is assigned. Further, when there are a plurality of spare channels and other initial channels of reader / writers, and these frequencies are about the same distance from the channel in which carrier sensing has failed, a channel on the high frequency side is assigned.

  In the above-described embodiment, as an RF-ID media information reading system that reads information from the RF-ID media, the RF-ID label 50 is read by reading information from the RF-ID label 50 via the antennas 21a to 21f. However, the present invention is not limited to this as long as the reader / writer reads information from the RF-ID medium.

  In the above-described embodiment, the RF-ID label 50 has been described as an example of the RF-ID medium. However, as the RF-ID medium in the present invention, an RF-ID card, an RF-ID tag, or the like is used. Needless to say, it may be.

DESCRIPTION OF SYMBOLS 10 Control apparatus 11 Initial channel memory | storage part 12 Channel allocation part 13 RW operation | movement control part 20a-20f Reader / writer 21a-21f Antenna 30 Trigger generator 40 Conveyance path 50 RF-ID label

Claims (2)

A plurality of readers / writers for reading information from an RF-ID medium, and a control device for allocating channels used for reading the information by the plurality of readers / writers from among a plurality of channels larger than the number of readers / writers Each of the plurality of readers / writers performs carrier sense using a channel assigned by the control device before reading information from the RF-ID medium, and succeeds in the carrier sense. In the RF-ID media information reading system that reads information from the RF-ID media using the channel when
The controller is
When the plurality of readers / writers fail in carrier sense using an initial channel preset for each of the plurality of readers / writers, the reader / writers that have failed in the carrier sense are informed of the plurality of reader / writers. Any one of the one or a plurality of spare channels not set to any of the writers, or all of the one or a plurality of spare channels are assigned to any one of the plurality of readers / writers. In some cases, the RF-ID media information reading system includes a channel assignment unit that assigns a preset initial channel to a reader / writer to which the spare channel is assigned. Before reading information from the RF-ID medium, carrier sense is performed using the allocated channel, and when the carrier sense is successful, a plurality of readers / readers that read information from the RF-ID medium using the channel. A control device that allocates a channel used for reading the carrier sense and information from a plurality of channels larger than the number of reader / writers to a writer,
When the plurality of readers / writers fail in carrier sense using an initial channel preset for each of the plurality of readers / writers, the reader / writers that have failed in the carrier sense are informed of the plurality of reader / writers. Any one of the one or a plurality of spare channels not set to any of the writers, or all of the one or a plurality of spare channels are assigned to any one of the plurality of readers / writers. In this case, a control device having a channel assignment unit that assigns a preset initial channel to the reader / writer to which the spare channel is assigned.

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