JP2015185134A - RFID tag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control consumption of a power source even when a user forgets to perform an operation or the like for switching a mode of a communication part for transmitting/receiving a signal, or when the user accidentally performs a predetermined operation for transiting to another mode in a third mode state.SOLUTION: After a mode of an active communication part 4 is transited, when a command signal for transiting the mode is not received for predetermined time, the active communication part 4 is automatically transited to a designated mode or an original mode.

Description

  The present invention relates to an RFID tag that performs non-contact communication.

  In recent years, with the progress of an information-oriented society, information is recorded on tags attached to products and the like, and products and the like are managed using the tags. In information management using such a tag, an RFID tag capable of writing and reading information by non-contact communication with the tag is rapidly spreading due to its excellent convenience.

  As the RFID tag, an active RFID tag capable of communicating over a long distance of about several tens of meters with a built-in power supply is often used in order to reduce the size and ensure a communicable distance. Such an active RFID tag starts signal transmission / reception triggered by a trigger signal transmitted from a reader (see, for example, Patent Document 1). For this reason, it is necessary to make the trigger signal receivable, and power consumption is increased.

  Therefore, it is conceivable that an event signal is periodically transmitted from the RFID tag side and signal transmission / reception is started by receiving a response signal from a reader that has received the event signal. The transmission of the event signal can be performed with a setting shorter than the time during which the trigger code from the reader can be received, so that power consumption can be reduced.

JP 2011-76477 A

  A product managed using an RFID tag as described above may pass through an area where transmission of radio waves is prohibited, for example, by air. In that case, the event signal cannot be periodically transmitted from the RFID tag as described above, so that the signal can be received and the power consumption is increased.

  Therefore, in a state where contactless communication is not performed with respect to the RFID tag, contactless communication is performed with respect to the RFID tag by keeping the RFID tag in a state where neither an event signal is transmitted nor a signal is received from the reader. In such a state, wasteful power consumption can be prevented. However, in such a state, when contactless communication is performed with respect to the RFID tag, access from the reader is not possible, and subsequent contactless communication is not possible. It will be possible.

  In view of such problems, the applicant of the present invention transmits a signal corresponding to the command signal when the communication unit that transmits and receives the signal transmits the event signal and receives the command signal corresponding to the event signal. When a command signal for switching the mode is received having the first mode, the second mode in which only the command signal is received, and the third mode in which no event signal is transmitted and no command signal is received Furthermore, a technique has been devised in which the communication unit transitions to another mode when the communication unit transitions to another mode and a predetermined operation is detected in the state of the third mode.

  In this technology, the communication unit can control power consumption according to the surrounding environment and usage conditions by transitioning to the first mode, the second mode, and the third mode according to the command signal. And when the predetermined operation is detected in the third mode in which the communication unit cannot receive the command signal, the communication unit transitions to either the first mode or the second mode, Since it can be received, by making the operation performed when starting non-contact communication with the RFID tag a predetermined operation, non-contact communication can be performed when necessary while reducing power consumption. It becomes like this.

  However, after switching to the first mode or the second mode according to the command signal and performing processing using the mode, the mode is switched although it is not necessary to maintain the mode. If the command signal is not given to the RFID tag, the power consumption is not properly controlled according to the surrounding environment and use conditions.

  In addition, even when the above-described predetermined operation is mistakenly performed while the communication unit is in the third mode, the communication unit transitions to either the first mode or the second mode. Therefore, after that, if it is not recognized for a long time that the predetermined operation has been mistakenly performed, the power is wasted.

  The present invention has been made in view of the problems of the conventional techniques as described above, and when a communication unit that transmits and receives signals transmits an event signal and receives a command signal corresponding to the event signal. In what has the 1st mode which transmits information according to a command signal, the 2nd mode which performs only reception of a command signal, and the 3rd mode which does not perform transmission of an event signal and reception of a command signal, Appropriate control of power consumption is possible even if you forget to perform an operation to switch the mode, or when a predetermined operation for switching to another mode is mistakenly performed in the state of the third mode. An object is to provide an RFID tag that can be used.

In order to achieve the above object, the present invention provides:
A power source, a first antenna, an active communication unit that is driven by the power source and transmits / receives signals via the first antenna, and a control unit that performs control according to signal transmission / reception in the active communication unit In the RFID tag that has,
The active communication unit transmits an event signal, and when a command signal corresponding to the event signal is received, a first mode that transmits information corresponding to the command signal, and a second mode that only receives the command signal And a third mode that does not transmit the event signal and receive the command signal,
The controller is
When the active communication unit receives a command signal for switching modes in the state of the first or second mode, the active communication unit transitions the active communication unit to another mode,
When the predetermined operation is detected by a detection unit that detects a predetermined operation in a state where the active communication unit is in the third mode, the active communication unit is shifted to another mode,
When the time limit for the mode after the transition is specified, the active communication unit is changed from the first mode to the second mode or from the second mode to the first mode according to a command signal. After the transition to the mode, when the active communication unit does not receive a command signal for transitioning the active communication unit to another mode for a certain period of time, the active communication unit is changed from the first mode to another mode. Or the transition from the second mode to the third mode, and the transition of the active communication unit from the third mode to another mode when the predetermined operation is detected, When the active communication unit does not receive a signal for a certain period of time, the active communication unit is returned to the third mode.

  In the present invention configured as described above, when non-contact communication is not performed with respect to the RFID tag, the active communication unit driven by the power source is set to the third mode. In the third mode, the active communication unit does not transmit or receive signals, so that almost no power is consumed. When a predetermined operation is detected by the detection means while the active communication unit is in the third mode, the active communication unit transitions to either the first mode or the second mode under the control of the control unit. To do. When the active communication unit is in the first or second mode, when the command signal for switching the mode of the active communication unit is transmitted, the active communication unit is in the first or second mode. Since the command signal can be received, the command signal is received by the active communication unit. Then, under the control of the control unit, depending on the command signal received by the active communication unit, when the active communication unit is in the first mode, either the second mode or the third mode, or When the active communication unit is in the second mode, the mode transits to either the first mode or the third mode.

  In this way, the active communication unit controls the power consumption according to the surrounding environment and usage conditions by switching to the first mode, the second mode, and the third mode according to the command signal. Can do. Further, in the state of the third mode in which the active communication unit cannot receive the command signal, when the predetermined operation is detected by the detection unit, the active communication unit is in either the first mode or the second mode. Since the command signal can be received, the active communication unit cannot receive the command signal by setting the operation performed when starting non-contact communication to the RFID tag as a predetermined operation. Even in this mode, contactless communication is possible when necessary.

  Here, when the time limit is specified for the mode after the transition, the active communication unit transitions from the first mode to the second mode or from the second mode to the first mode according to the command signal. After that, when a command signal for switching the active communication unit to another mode is not received by the active communication unit for a certain period of time, the active communication unit changes from the first mode to the other mode, or from the second mode to the second mode. Transition to mode 3 will be made. As a result, the active communication unit does not need to maintain the mode after transitioning to the first mode or the second mode according to the command signal and performing processing using the mode. Even when the command signal for switching the mode is not given to the RFID tag, the power consumption is appropriately controlled according to the surrounding environment and use conditions. In addition, after a predetermined operation is detected by the detecting unit in the state where the active communication unit is in the third mode, the command signal is transmitted after the active communication unit transitions to either the first mode or the second mode. If it is not received for a certain period of time, it is determined that a predetermined operation for changing the active communication unit from the third mode to another mode is erroneously performed, and the control unit controls the active communication unit in the third mode. Returned to Thereby, it is avoided that the power source is wasted when a predetermined operation for causing the active communication unit to transition to another mode in the state of the third mode is erroneously performed.

  And a second antenna and a passive communication unit that is driven by an electromotive force generated in the second antenna by non-contact communication and transmits / receives a signal by non-contact communication via the second antenna. When the passive communication unit receives a command signal for switching the mode while the active communication unit is in the third mode, the active communication unit switches the active communication unit to another mode so that the active communication unit Even in the state of the third mode in which no signal can be received, the active communication unit shifts to the first mode, the second mode, and the third mode according to the command signal, thereby reducing power consumption. The active control unit can be activated while controlling.

  According to the present invention, when the time limit is specified for the mode after the transition, the active communication unit changes from the first mode to the second mode or from the second mode to the first mode according to the command signal. After the transition to the mode, when the command signal for transitioning the active communication unit to another mode is not received by the active communication unit for a certain period of time, the active communication unit is changed from the first mode to the second mode by the control of the control unit. Since the transition to the third mode or the second mode to the third mode is made, the active communication unit transits to the first mode or the second mode according to the command signal and uses the mode. After the process has been performed, it is not necessary to maintain the mode, but the command signal for that is forgotten to perform the operation for switching the mode. Even when not given the FID tag, by transition to the power consumption is small mode, it is possible to reduce the consumption of power. In addition, after a predetermined operation is detected by the detecting unit in the state where the active communication unit is in the third mode, the command signal is transmitted after the active communication unit transitions to either the first mode or the second mode. If the signal is not received for a certain period of time, the active communication unit is returned to the third mode by the control of the control unit, so that the predetermined operation for causing the active communication unit to transition to another mode in the third mode state is erroneously performed. If this is done, it is possible to avoid wasting power.

  And a second antenna and a passive communication unit that is driven by an electromotive force generated in the second antenna by non-contact communication and transmits / receives a signal by non-contact communication via the second antenna. When the active communication unit is in the third mode and the passive communication unit receives a command signal for switching the mode, the active communication unit Even in the state of the third mode in which the command signal cannot be received, when the command signal is received by the passive communication unit, the active communication unit is changed between the first mode and the second mode according to the command signal. The mode can be changed to the third mode, whereby the active control unit can be activated while controlling the power consumption.

It is a block diagram which shows embodiment of the RFID tag of this invention. It is a figure for demonstrating operation | movement of the RFID tag in the mode which the active communication part shown in FIG. 1 has. It is a figure which shows an example of the articles | goods managed using the RFID tag shown in FIG. It is a figure which shows an example of the system configuration which manages the cool box shown in FIG. FIG. 5 is a diagram for explaining a change in the state of the RFID tag in the case of managing the cold box shown in FIG. 3 in the system shown in FIG. 4. It is a figure for demonstrating the reception operation | movement of the wakeup command in the silent 1 mode of the active communication part shown in FIG. It is a figure for demonstrating the transmission / reception operation | movement of the signal in the normal mode of the active communication part shown in FIG. It is a figure for demonstrating the transmission / reception operation | movement of the temperature log data in the normal mode of the active communication part shown in FIG. It is a figure for demonstrating the mode transition of the active communication part when transient mode is designated in the RFID tag shown in FIG.

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

  FIG. 1 is a block diagram showing an embodiment of an RFID tag according to the present invention.

  In this embodiment, as shown in FIG. 1, a battery 1 as a power source, two antennas 2 and 3, an active communication unit 4, a passive communication unit 5, a control microcomputer 6 as a control unit, and an interface unit 7 And an RFID tag 10 composed of a memory 8.

  As the battery 1, an appropriate battery such as an alkaline battery or a nickel battery can be used, and serves as a power source for the entire RFID tag 10.

  The antenna 2 serves as the first antenna in the present invention. The antenna 2 resonates with the radio wave transmitted from the reader in a wireless RFID such as 2.45 GHz or UHF band (860 to 960 MHz). For transmitting and receiving signals between the two.

  The antenna 3 is the second antenna in the present invention, has a coil shape, and performs non-contact communication using a 13.56 MHz frequency band. By the electromagnetic induction in the non-contact communication, An electromotive force is generated when a current flows, and a power source based on the electromotive force is supplied to the passive communication unit 5 to transmit and receive signals to and from the reader.

  The active communication unit 4 is driven by the battery 1, modulates / demodulates the signal, and transmits / receives a signal to / from the reader by non-contact communication via the antenna 2 using a wireless RFID such as 2.45 GHz or UHF band. And has three modes.

  The passive communication unit 5 is driven by a power source supplied from the antenna 3, modulates / demodulates the signal, and transmits / receives a signal to / from the reader through non-contact communication via the antenna 3 in the 13.56 MHz frequency band. That is, the passive communication unit 5 is driven by the electromotive force generated in the antenna 3 by non-contact communication.

  The control microcomputer 6 performs control according to signal transmission / reception in the active communication unit 4 and the passive communication unit 5.

  The interface unit 7 controls an interface with a connected external device.

  The memory 8 stores the tag ID of the RFID tag 10 and information acquired from an external device via the interface unit 7.

  Here, three modes of the active communication unit 4 will be described.

  FIG. 2 is a diagram for explaining the operation of the RFID tag 10 in the mode of the active communication unit 4 shown in FIG.

  As shown in FIG. 2, the active communication unit 4 shown in FIG. 1 has a normal mode that is the first mode, a silent 1 mode that is the second mode, and a silent 2 mode that is the third mode. Have.

  In the normal mode, the active communication unit 4 periodically transmits an event signal that triggers non-contact communication via the antenna 2. Although the command signal is not intermittently received from the reader, a response signal to the event signal is received via the antenna 2 immediately after the event signal is transmitted. When the response signal is a command signal that requests transmission of information, information corresponding to the received command signal is transmitted.

  In the silent 1 mode, the active communication unit 4 does not transmit an event signal and intermittently receives a wakeup command as a command signal via the antenna 2.

  In the silent 2 mode, the active communication unit 4 does not transmit an event signal or intermittently receive a command signal.

  In addition, when the active communication unit 4 is in any of the above three modes, the passive communication unit 5 is driven by the electromotive force generated in the antenna 3 by non-contact communication, and thus can always be accessed via the antenna 3. The command signal can be received via the antenna 3.

  The article management using the RFID tag 10 described above will be described below.

  FIG. 3 is a diagram showing an example of an article managed using the RFID tag 10 shown in FIG.

  As shown in FIG. 3, the RFID tag 10 shown in FIG. 1 is used for management of the cold box 50. In this case, the RFID tag 10 is attached to the outer surface of the cold box 50 with the temperature sensor 20, the open / close sensor 30, and the display device 40 being connected via the interface unit 7, for example.

  The temperature sensor 20 is installed inside the cold box 50 and detects the temperature inside the cold box 50. In addition, when the inside of the cold box 50 is partitioned into a plurality of regions and the plurality of regions are set to different temperatures, the temperature sensor 20 is installed for each of the plurality of regions.

  The open / close sensor 30 is a detection means in the present invention, and is composed of, for example, an optical sensor or the like. The open / close sensor 30 is installed inside the cold box 50 and detects the operation of opening the cold box 50 by detecting light. To do.

  The display device 40 is composed of an LCD, electronic paper, or the like, and displays the temperature detected by the temperature sensor 20.

  In addition to the temperature sensor 20, the open / close sensor 30, and the display device 40, the RFID tag 10 can be connected to any device such as an outside air temperature sensor or an impact sensor that detects the outside air temperature. The detected information can be acquired by the RFID tag 10 via the interface unit 7.

  FIG. 4 is a diagram illustrating an example of a system configuration for managing the cold insulation box 50 illustrated in FIG. 3.

  In the following, as shown in FIG. 4, the cold box 50 shown in FIG. 3 is transported from the delivery base 60 to the carry-in base 70, and after the cold storage box 50 is unpacked at the transport base 70, A management method when the cold box 50 is returned will be described.

  In the delivery base 60 where the cold box 50 is delivered, a reader 61 that reads information by transmitting and receiving signals to and from the RFID tag 10 by non-contact communication, and a communication device 62 that can be connected to the data center 80 are provided. Is arranged.

  A receiving area 71 and a loading / unpacking area 72 are provided at a loading base 70 where the cold box 50 is loaded and unpacked. The RFID tag 10 is also provided in each of the receiving area 71 and the loading / unpacking area 72. Readers 73 and 74 for reading information by transmitting and receiving signals by non-contact communication with the communication center 75 and communication devices 75 and 76 connectable to the data center 80 are arranged.

  The data center 80 is a base for managing the conveyance status of the cold box 50, and includes a communication device 81 that can be connected to the communication devices 62, 75, and 76, and a database 82 in which the conveyance status of the cold box 50 is stored. have.

  FIG. 5 is a diagram for explaining a change in the state of the RFID tag 10 when the cool box 50 shown in FIG. 3 is managed in the system shown in FIG.

  The cold box 50 shown in FIG. 3 is delivered from the delivery base 60. The active communication unit 4 of the RFID tag 10 is in the silent 2 mode as an initial state (step 1). In the silent 2 mode, the active communication unit 4 does not transmit or receive signals, so that almost no power is consumed. Further, the temperature sensor 20 sequentially detects the temperature inside the cold box 50, and this temperature data is transmitted to the RFID tag 10. In the RFID tag 10, the temperature data transmitted from the temperature sensor 20 is received via the interface unit 7 and stored in the memory 8 as temperature log data under the control of the control microcomputer 6. Further, the temperature detected by the temperature sensor 20 is displayed on the display device 40.

  When a command signal for switching to the silent 1 mode is transmitted from the reader 61 provided at the delivery base 60 to the RFID tag 10 in which the active communication unit 4 is in the silent 2 mode, the command signal is transmitted to the antenna. 3, electromagnetic induction occurs, current flows through the antenna 3 due to the electromagnetic induction, and electromotive force is generated in the antenna 3. Power from the electromotive force generated in the antenna 3 is supplied to the passive communication unit 5, the passive communication unit 5 is driven, and the command signal transmitted from the reader 61 is received by the passive communication unit 5 (step 2). As described above, in the silent 2 mode, although the active communication unit 4 does not transmit and receive signals, the passive communication unit 5 is generated in the antenna 3 due to electromagnetic induction when the command signal is received by the antenna 3. Since it is driven by electromotive force, the command signal transmitted from the reader 61 can be received.

  Then, under the control of the control microcomputer 6, the active communication unit 4 transitions to the silent 1 mode in accordance with the command signal received by the passive communication unit 5 (step 3).

  Further, the tag ID stored in the memory 8 of the RFID tag 10 is read by the reader 61 in communication via the passive communication unit 5 between the reader 61 and the RFID tag 10, and the read tag ID, etc. Is transmitted from the communication device 62, and this information is received by the communication device 81 of the data center 80. In the data center 80, the cold box in which the RFID tag 10 identified by the received tag ID is attached. The fact that 50 is delivered from the delivery base 60 at the transmission time of the tag ID is registered in the database 82 and managed.

  The cold box 50 delivered from the delivery base 60 is transported to the carry-in base 70 by, for example, air transportation by aircraft. At this time, since the active communication unit 4 is in the silent 1 mode, the command signal is intermittently received, but the event signal is not transmitted. Therefore, no radio waves are transmitted via the antenna 2, and there is no problem even when passing through an area where transmission of radio waves is prohibited as in an aircraft.

  The cold box 50 delivered from the delivery base 60 is first carried into the reception area of the carry-in base 70. In this state, the active communication unit 4 of the RFID tag 10 attached to the cold box 50 is in the silent 1 mode (step 4).

  When the wake-up command is transmitted from the reader 73 provided in the reception area 71 to the RFID tag 10 in which the active communication unit 4 is in the silent 1 mode, the wake-up command is transmitted via the antenna 2 to the active communication. Received by the unit 4 (step 5).

  FIG. 6 is a diagram for explaining the reception operation of the wakeup command in the silent 1 mode of the active communication unit 4 shown in FIG.

  In the silent 1 mode, as shown in FIG. 6, the active communication unit 4 receives the command signal intermittently, and the wakeup command 101 transmitted from the reader 73 is received in the section in the receiving state. Will be.

  The wakeup command 101 is a command signal for switching the active communication unit 4 to the normal mode. Therefore, when the wakeup command 101 is received by the active communication unit 4, the control microcomputer 6 controls the The active communication unit 4 transitions to the normal mode (step 6).

  When the active communication unit 4 transitions to the normal mode, the tag ID stored in the memory 8 is read by the control microcomputer 6 and transmitted to the reader 73 via the active communication unit 4. The tag ID transmitted to the reader 73 is transmitted to the data center 80 via the communication device 75, and the tag received by the data center 80 is received by the communication device 81 of the data center 80. It is registered and managed in the database 82 that the cold box 50 to which the RFID tag 10 identified by the ID is attached is received at the carry-in base 70 at the transmission time of the tag ID.

  Thereafter, when a command signal for switching to the silent 2 mode is transmitted from the reader 73 to the RFID tag 10 in which the active communication unit 4 is in the normal mode, this command signal is activated via the antenna 2. Received by the communication unit 4 (step 7).

  FIG. 7 is a diagram for explaining a signal transmission / reception operation in the normal mode of the active communication unit 4 shown in FIG.

  In the normal mode, as shown in FIG. 7, the active communication unit 4 periodically transmits an event signal 102 that triggers non-contact communication via the antenna 2, and intermittently receives command signals from the reader. Is not performed, but is in a reception state in a certain section immediately after transmission of the event signal 102, and in this reception state, a response signal 103 to the event signal 102 is received via the antenna 2. Therefore, a command signal for making a transition to the silent 2 mode can be received as the response signal 103.

  Then, under the control of the control microcomputer 6, the active communication unit 4 transitions to the silent 2 mode according to the command signal received by the active communication unit 4 (step 8).

  Thereafter, the cold box 50 is carried into the carry-in / unpack area 72 from the reception area 71. In this state, the active communication unit 4 of the RFID tag 10 attached to the cold box 50 is in the silent 2 mode (step 9).

  When the cold box 50 is unpacked in the carry-in / unpacking area 72, the opening / closing sensor 30 installed inside the cold box 50 detects an operation of unpacking the cold box 50 (step 10). When an operation for unpacking the cold box 50 is detected, a signal indicating that is transmitted from the open / close sensor 30 to the RFID tag 10.

  In the RFID tag 10, when the signal transmitted from the open / close sensor 30 is received via the interface unit 7, the active communication unit 4 transitions to the silent 1 mode under the control of the control microcomputer 6 (step 11).

  When a wake-up command is transmitted from the reader 74 provided in the carry-in / unpacking area 72 to the RFID tag 10 in which the active communication unit 4 is in the silent 1 mode, the wake-up command is transmitted via the antenna 2. Received by the active communication unit 4.

  The wake-up command is a command signal for causing the active communication unit 4 to transition to the normal mode as described above. Therefore, when the wake-up command is received by the active communication unit 4 (step 12), the wake-up command is used for control. Under the control of the microcomputer 6, the active communication unit 4 transitions to the normal mode (step 13).

  A command signal for requesting the temperature log data stored in the memory 8 is transmitted from the reader 74 to the RFID tag 10 in which the active communication unit 4 is in the normal mode. Via the active communication unit 4.

  FIG. 8 is a diagram for explaining a temperature log data transmission / reception operation in the normal mode of the active communication unit 4 shown in FIG.

  As described above, in the normal mode, the active communication unit 4 periodically transmits an event signal and does not receive a command signal intermittently from the reader, but receives it in a certain interval immediately after the event signal is transmitted. It is in a state. Therefore, as shown in FIG. 8, in this reception state, the sensor log request command 104 for requesting the temperature log data stored in the memory 8 can be received via the antenna 2 with respect to the event signal.

  When the sensor log request command 104 is received by the RFID tag 10, a command response signal 105 is transmitted from the active communication unit 4 to the reader 74, and then transmitted / received by the active communication unit 4 under the control of the control microcomputer 6. The channel to be used is switched to a channel for transmitting temperature log data, and the channel used for signal transmission / reception in the reader 74 is also switched to a channel for receiving temperature log data.

  Then, in the control microcomputer 6, a log of temperature data stored in the memory 8 is read and transmitted to the reader 74 via the active communication unit 4 (step 14).

  As described above, in the silent 2 mode, the active communication unit 4 neither transmits an event signal nor receives a command signal. However, when the cold box 50 is unpacked in the carry-in unpacking area 72, the RFID tag 10 In order to obtain the temperature log data stored in the memory 8, the active communication unit 4 is automatically switched to the silent 1 mode when the operation of unpacking the cold box 50 is detected, and then the silent 1 mode is entered. By receiving the wake-up command, the active communication unit 4 is shifted to the normal mode, whereby the temperature log data stored in the memory 8 of the RFID tag 10 can be acquired by the reader 74.

  When the transmission of the log of the temperature data stored in the memory 8 is completed, a command response signal 105 is transmitted from the active communication unit 4 to the reader 74 and is used for signal transmission / reception in the active communication unit 4 under the control of the control microcomputer 6. The channel is switched to the channel for transmitting the event signal, and the channel used for signal transmission / reception in the reader 74 is switched to the channel for receiving the event signal.

  In the normal mode, the tag ID stored in the memory 8 is read by the control microcomputer 6 and transmitted to the reader 74 via the active communication unit 4. The tag ID transmitted to the reader 74 is transmitted together with the temperature log data to the data center 80 via the communication device 75, and the tag ID and the temperature log data are received by the communication device 81 of the data center 80. In the data center 80, the cold box 50 to which the RFID tag 10 identified by the received tag ID is attached has been unpacked at the carry-in base 70 at the transmission time of the tag ID, and the inside of the cold box 50 The temperature history is registered in the database 82 and managed.

  After that, when a command signal for switching to the silent 2 mode is transmitted from the reader 74 to the RFID tag 10 in which the active communication unit 4 is in the normal mode, this command signal is sent to the active communication via the antenna 2. Received by the unit 4 (step 15).

  Then, under the control of the control microcomputer 6, the active communication unit 4 transitions to the silent 2 mode according to the command signal received by the active communication unit 4 (step 16).

  The cold box 50 thus unpacked is returned to the delivery base 60 in a state where the active communication unit 4 is in the silent 2 mode. In the process in which the cold box 50 is returned from the carry-in base 70 to the delivery base 60, non-contact communication is not performed with respect to the RFID tag 10, so that the active communication unit 4 can be set to the silent 2 mode. As a result, almost no power is consumed.

  As described above, the active communication unit 4 changes between the normal mode, the silent 1 mode, and the silent 2 mode in which the power consumption is different depending on the presence / absence of the signal transmission / reception operation according to the command signal. The power consumption can be controlled according to the usage conditions. And even if it is in the state of silent 2 mode in which the active communication part 4 cannot receive a command signal, the cold storage box 50 performed when acquiring the temperature log data memorize | stored in the memory 8 of the RFID tag 10 is unpacked. When the operation is detected, the active communication unit 4 is automatically switched to the silent 1 mode, and the active communication unit 4 is activated to be able to receive a command signal. Thereafter, the wake-up command is issued in the silent 1 mode. By receiving, the active communication unit 4 is changed to the normal mode, and the temperature log data can be acquired by the reader 74.

  Here, the silent 1 mode in step 11 will be described in detail.

  In the RFID tag 10 shown in FIG. 1, a transient mode with a time limit can be set in the normal mode or the silent 1 mode.

  FIG. 9 is a diagram for describing mode transition of the active communication unit 4 when the transient mode is set in the RFID tag 10 illustrated in FIG. 1.

  In the transient mode, after the command signal is received as described above or the operation of unpacking the cold box 50 is detected and the mode of the active communication unit 4 is changed, the active communication unit is changed in the changed mode. When 4 does not receive a command signal for a certain period of time, the mode of the active communication unit 4 is automatically changed to another mode under the control of the control microcomputer 6. Such a transient mode functions by preliminarily specifying the mode transition destination and the time until the transition to the RFID tag 10. That is, when the transient mode is set, the time limit of the mode after the transition is specified for the RFID tag 10, and the following mode is used in the RFID tag 10 in which the transient mode is not set. No transition is made.

  As shown in FIG. 9, in the transient mode, the function after the mode of the active communication unit 4 is changed by receiving a command signal and the operation of unpacking the cold box 50 are detected. The functions after the transition of the four modes are different from each other, and these can be set individually.

  In order to switch the mode of the active communication unit 4 after the transition of the mode of the active communication unit 4 when the mode of the active communication unit 4 is changed after the mode of the active communication unit 4 is changed due to the reception of the command signal. If the command signal is not received for a specified period of time, the mode of the active communication unit 4 automatically transitions to the specified mode. Specifically, after the mode of the active communication unit 4 transitions to the normal mode, if the command signal for switching the mode of the active communication unit 4 is not received for a certain period of time, the mode of the active communication unit 4 is changed to the silent 1 mode. A transition is automatically made to the designated mode of the silent 2 mode. Further, after the mode of the active communication unit 4 transitions to the silent 1 mode, if the command signal for switching the mode of the active communication unit 4 is not received for a certain period of time, the mode of the active communication unit 4 automatically changes to the silent 2 mode. Transition.

  On the other hand, after the mode of the active communication unit 4 is changed after the operation of unpacking the cold box 50 is detected, if the transient mode is set, the mode of the active communication unit 4 is changed and then the active mode is changed. If the command signal for switching the mode of the communication unit 4 is not received for a specified time, the mode of the active communication unit 4 automatically returns to the original mode. Specifically, in the state where the cold box 50 is unpacked, the mode of the active communication unit 4 is the silent 2 mode. Therefore, the active communication unit is detected when the operation of unpacking the cold box 50 is detected. After the mode 4 changes from the silent 2 mode to the normal mode or the silent 1 mode, if the command signal for switching the mode of the active communication unit 4 is not received for a specified time, the mode of the active communication unit 4 is silent 2 Return to mode automatically.

  The RFID tag 10 according to the present embodiment is configured so that the mode of the active communication unit 4 is the silent 2 mode after the mode of the active communication unit 4 is changed by detecting the operation of unpacking the cold box 50 among the transient modes described above. The function to automatically return to is set.

  For this reason, in the silent 1 mode in step 11, when the signal transmitted from the open / close sensor 30 is received via the interface unit 7 and the wakeup command is not received by the active communication unit 4 for a certain period of time (step 17). ), The active communication unit 4 returns to the silent 2 mode under the control of the control microcomputer 6.

  Thereby, for example, when the cold box 50 is carried into the carry-in / unpack area 72 from the reception area 71 or when the cold box 50 is returned from the carry-in base 70 to the unloading base 60, the cold box 50 is erroneously set. When the package is unpacked, the active communication unit 4 enters the silent 1 mode for a certain period of time and then returns to the silent 2 mode, thereby avoiding unnecessary power consumption. In the case where the open / close sensor 30 is an optical sensor, even if the cold box 50 is not unpacked, light enters the cold box 50 due to breakage of the cold box 50, etc. Even if it is determined that the package has been unpacked, it is possible to avoid wasting power.

  In the silent 1 mode, the event signal is not transmitted, and the wake-up command as a command signal is intermittently received via the antenna 2, so that the cold box 50 is unpacked by mistake and the active communication unit 4 Even if it temporarily transits to the silent 1 mode, there is no problem when the cold insulation box 50 is air transported by aircraft.

  Also, among the transient modes described above, after the mode of the active communication unit 4 transitions to the normal mode due to the reception of the wake-up command, the mode of the active communication unit 4 automatically transitions to the designated mode. If the function is set, the command signal for changing the mode of the active communication unit 4 to the silent 2 mode is not received for a certain time after the active communication unit 4 changes to the normal mode in step 6 or step 13. The active communication unit 4 automatically transitions to the designated mode among the silent 1 mode and the silent 2 mode.

  As a result, the active communication unit 4 transitions to the normal mode, and after the tag ID stored in the memory 8 is transmitted to the reader 73 in step 6, a log of the temperature data stored in the memory 8 is displayed in step 13. Even if it is not necessary to maintain the normal mode after being transmitted, even if it is forgotten to give the RFID tag 10 a command signal for switching the active communication unit 4 to the silent 2 mode, a certain time After the elapse of time, the active communication unit 4 automatically shifts to the silent 2 mode, and radio waves are not transmitted during the conveyance of the cold box 50, so that power consumption can be appropriately controlled according to the surrounding environment.

  In the present embodiment, when the RFID tag 10 receives the wake-up command in the silent 1 mode, the active communication unit 4 transitions to the normal mode. When the command signal is received by the active communication unit 4, the active communication unit 4 may be switched to the silent 2 mode under the control of the control microcomputer 6, or the normal mode is switched to the silent 1 mode. When the command signal for causing the active communication unit 4 to be received is received, the active communication unit 4 may be switched to the silent 1 mode under the control of the control microcomputer 6. Even in these cases, after the mode of the active communication unit 4 is changed, a transient mode in which the mode of the active communication unit 4 automatically changes when a command signal for changing the mode is not received for a certain period of time is set. Then, the active communication unit 4 can be automatically changed from the silent 1 mode to the silent 2 mode and from the normal mode to the silent 1 mode.

  Further, when an operation for unpacking the cold box 50 is detected in the silent 2 mode, the active communication unit 4 has transitioned to the silent 1 mode. However, an operation for unpacking the cold box 50 in the silent 2 mode is detected. In this case, the active communication unit 4 may be switched to the normal mode under the control of the control microcomputer 6. In this case, if the command signal is not received for a certain period of time, the active communication unit 4 enters the silent 2 mode. Will return.

  In the present embodiment, the open / close sensor 30 that detects an operation of unpacking the cold box 50 has been described as an example of the detection unit. However, a predetermined operation that is performed when performing non-contact communication with the RFID tag 10 is described. Any other sensor, switch, or the like may be used as long as the operation is detected.

DESCRIPTION OF SYMBOLS 1 Battery 2, 3 Antenna 4 Active communication part 5 Passive communication part 6 Control microcomputer 7 Interface part 8 Memory 10 RFID tag 20 Temperature sensor 30 Opening / closing sensor 40 Display apparatus 50 Cold box 60 Delivery base 61,73,74 Reader 62,75 , 76, 81 Communication device 70 Loading base 71 Reception area 72 Loading / unpacking area 80 Data sensor 82 Database 101 Wake-up command 102 Event signal 103 Response signal 104 Sensor log request command 105 Command response signal

Claims (2)

A power source, a first antenna, an active communication unit that is driven by the power source and transmits / receives signals via the first antenna, and a control unit that performs control according to signal transmission / reception in the active communication unit In the RFID tag that has,
The active communication unit transmits an event signal, and when a command signal corresponding to the event signal is received, a first mode that transmits information corresponding to the command signal, and a second mode that only receives the command signal And a third mode that does not transmit the event signal and receive the command signal,
The controller is
When the active communication unit receives a command signal for switching modes in the state of the first or second mode, the active communication unit transitions the active communication unit to another mode,
When the predetermined operation is detected by a detection unit that detects a predetermined operation in a state where the active communication unit is in the third mode, the active communication unit is shifted to another mode,
When the time limit for the mode after the transition is specified, the active communication unit is changed from the first mode to the second mode or from the second mode to the first mode according to a command signal. After the transition to the mode, when the active communication unit does not receive a command signal for transitioning the active communication unit to another mode for a certain period of time, the active communication unit is changed from the first mode to another mode. Or the transition from the second mode to the third mode, and the transition of the active communication unit from the third mode to another mode when the predetermined operation is detected, An RFID tag, wherein the active communication unit is returned to the third mode when the signal is not received by the active communication unit for a predetermined time. The RFID tag according to claim 1, wherein
A second antenna;
A passive communication unit that is driven by the electromotive force generated in the second antenna by non-contact communication, and that transmits and receives signals by non-contact communication through the second antenna;
An RFID tag that causes the active communication unit to transition to another mode when the passive communication unit receives a command signal for switching the mode while the active communication unit is in the third mode. .

Images