JP2012033019A - Information processor and rfid tag - Google Patents

Abstract

To reduce power consumption of an RFID tag in an RFID tag and an information processing apparatus using the RFID tag.
An information processing apparatus includes a carrier transmission unit and a processing unit. The carrier transmission unit 32 includes a transmission pattern holding unit 33 that holds a transmission pattern of a carrier signal to be transmitted, and a transmission unit 34 that transmits a carrier signal based on the transmission pattern. The processing unit 35 operates by converting the signal transmitted from the transmission unit 34 into electric power, and outputs a detection signal in response to detection of a carrier signal, and a reception pattern holding unit 37 that holds a detection signal pattern. , And a reception pattern holding unit 37, and an analysis unit 38 for analyzing the pattern of the detection signal.
[Selection] Figure 1

Description

  The present invention relates to an information processing apparatus and an RFID tag.

  Conventionally, an RFID (Radio Frequency Identification) tag is used for management of merchandise and maintenance information. In the RFID tag, individual information is read from and written to an IC (Integrated Circuit) tag by wireless communication.

  Some RFID tags receive a radio signal transmitted from, for example, a reader / writer device, and perform a predetermined operation based on a signal included in the received signal. For example, when a predetermined signal is included in the received signal, power is supplied from the power supply unit in the tag to the processing unit in the tag, and reading is performed from the memory in the tag when another predetermined signal is included. There is an RFID tag that operates to transmit data to a reader / writer device. A tag that incorporates a power supply unit such as a battery in the RFID tag and operates with electric power supplied from the power supply unit may be referred to as an active type tag.

  On the other hand, there is an RFID tag called a passive type that does not incorporate a battery. In a passive type RFID tag, power is generated by rectifying radio waves transmitted from a reader / writer device, and this power is supplied to a memory in the tag to write information in the memory. There is an RFID tag called a semi-passive type. In the semi-passive type RFID tag, the built-in sensor is operated by the power supplied from the built-in battery, and the power induced from the radio wave from the reader / writer device is used for communication with the reader / writer device as in the passive type. It is done.

  FIG. 15 is a block diagram showing an information processing apparatus including a conventional semi-passive type RFID tag and a reader / writer device. As shown in FIG. 15, the reader / writer device 1 generates command information by the command generation unit 2 based on an instruction from the host. The generated command information is transmitted on the carrier signal from the transmission RF circuit 3 to the RFID tag 4 via the antenna.

  FIG. 16 is a block diagram showing a conventional semi-passive type RFID tag. As shown in FIG. 16, when the RFID tag 4 receives a radio wave including command information via the antenna, the power regeneration circuit 6 regenerates power and supplies the regenerated power to each part of the passive tag unit 5. In the passive tag unit 5, data is read from and written to the memory 10 by the tag controller 9 based on command information received by the transmission / reception circuit 8. Command data for controlling the operation of the device such as the sensor 19 is also written into the memory 10 by the tag controller 9. The carrier detection signal generation circuit 7 generates a carrier detection signal based on the supply and stop of power from the power regeneration circuit 6.

  In the controller unit 11, the carrier signal detection unit 12 detects the on / off state of the carrier signal based on the carrier detection signal. When the carrier signal is off, the power switch 16 is switched by the device control unit 13, and power is supplied to the memory 10 from the power supply circuit 17 driven by the battery 18. Then, the memory access unit 15 accesses the memory 10 and reads command data stored in the memory 10. The command control unit 14 interprets an instruction based on the read command data, and performs control such as turning on or off the power of a device such as the sensor 19 by the device control unit 13.

  FIG. 17 is an operation timing chart of the conventional information processing apparatus. As shown in FIG. 17, in the RFID tag 4, when the carrier detection signal 25 is turned on, the controller unit 11 accesses the memory 10 by the memory access unit 15. Then, the controller unit 11 confirms whether or not a command for the controller unit is written in the memory 10. Since the controller unit 11 cannot distinguish between a command for the controller unit and a command for the passive tag unit, a start command 21 for the controller unit, a read command 22 for the passive tag unit, and a write command for the passive tag unit 23 and the stop command 24 for the controller unit, the memory access 26 by the controller unit 11 occurs. The device such as the sensor 19 transitions from the sleep state to an operation state such as sensing by the start command 21 for the controller unit, and transitions from the operation state to the sleep state by the stop command 24 for the controller unit.

International Publication No. 2009/019735 Pamphlet JP 2008-9826 A Special table 2007-525859 gazette

  However, in a conventional information processing apparatus using a semi-passive type RFID tag, memory access by the controller unit occurs each time the RFID tag detects a carrier signal from the reader / writer device, and command data for the controller unit is stored in the memory. It is checked whether or not is written. For this reason, when the RFID tag is present in a range in which a carrier signal from the reader / writer device can be received, there is a problem in that power consumption increases due to frequent memory access by the controller unit. In particular, when a memory with a high power consumption such as a ferroelectric memory (FRAM: Ferroelectric Random Access Memory) is used, battery consumption becomes severe due to frequent memory access.

  An object is to provide an information processing apparatus and an RFID tag capable of reducing power consumption.

  The information processing apparatus includes a carrier transmission unit and a processing unit. The carrier transmission unit includes a transmission pattern holding unit and a transmission unit. The transmission pattern holding unit holds the transmission pattern of the carrier signal to be transmitted. The transmission unit transmits a carrier signal based on the transmission pattern. The processing unit includes a reception unit, a reception pattern holding unit, and an analysis unit. The receiving unit operates by converting a signal transmitted from the transmitting unit into electric power, and outputs a detection signal in response to detection of the carrier signal. The reception pattern holding unit holds the pattern of the detection signal. The analysis unit refers to the reception pattern holding unit and analyzes the pattern of the detection signal.

  In the information processing device and the RFID tag, the power consumption of the processing unit can be reduced.

1 is a block diagram illustrating an information processing apparatus according to a first embodiment. FIG. 10 is a block diagram illustrating an information processing apparatus according to a second embodiment. FIG. 10 is a schematic diagram illustrating an example of a start command in the information processing apparatus according to the second embodiment. FIG. 10 is a schematic diagram illustrating an example of a stop command in the information processing apparatus according to the second embodiment. 6 is a block diagram illustrating an RFID tag according to Embodiment 2. FIG. FIG. 10 is a schematic diagram illustrating an example of a pattern table in the information processing apparatus according to the second embodiment. FIG. 10 is a schematic diagram illustrating an example of a memory access table in the information processing apparatus according to the second embodiment. 10 is a flowchart illustrating a processing procedure in the reader / writer device according to the second embodiment. 10 is a flowchart illustrating a processing procedure in a passive tag portion of an RFID tag according to Embodiment 2; 10 is a flowchart illustrating a processing procedure in a controller unit of the RFID tag according to the second embodiment. FIG. 6 is a schematic diagram for explaining processing in a controller unit of an RFID tag according to a second embodiment. 10 is a flowchart illustrating a processing procedure for a start command in the RFID tag according to the second embodiment. 10 is a flowchart illustrating a processing procedure for a stop command in the RFID tag according to the second embodiment. FIG. 10 is an operation timing diagram of the information processing apparatus according to the second embodiment. It is a block diagram which shows the conventional information processing apparatus. It is a block diagram which shows the conventional RFID tag. It is an operation | movement timing diagram of the conventional information processing apparatus.

  Exemplary embodiments of an information processing apparatus and an RFID tag will be described below in detail with reference to the accompanying drawings. The information processing device and the RFID tag transmit a carrier signal from the carrier transmission unit based on the transmission pattern, and the processing unit analyzes the detection signal pattern output in response to the detection of the carrier signal, thereby saving the processing unit. Electricity is intended.

Example 1
FIG. 1 is a block diagram of an information processing apparatus according to the first embodiment. As illustrated in FIG. 1, the information processing apparatus 31 includes a carrier transmission unit 32 and a processing unit 35. The carrier transmission unit 32 includes a transmission pattern holding unit 33 and a transmission unit 34. The transmission pattern holding unit 33 holds a transmission pattern of a carrier signal transmitted to the processing unit 35. The transmission unit 34 transmits a carrier signal to the processing unit 35 based on the transmission pattern held in the transmission pattern holding unit 33.

  The processing unit 35 includes a reception unit 36, a reception pattern holding unit 37, and an analysis unit 38. The receiving unit 36 receives the signal transmitted from the transmitting unit 34, converts the received signal into electric power, and operates. The receiving unit 36 outputs a detection signal in response to detection of the carrier signal. The reception pattern holding unit 37 holds a detection signal pattern. The analysis unit 38 refers to the reception pattern holding unit 37 and analyzes the pattern of the detection signal output from the reception unit 36.

  According to the first embodiment, by analyzing the detection signal pattern in the processing unit 35, the command included in the signal transmitted by the carrier transmission unit 32 can be interpreted. No need to read. Therefore, power saving of the processing unit 35 can be achieved. In particular, when a command is read from a memory with high power consumption such as a ferroelectric memory, the power consumption of the processing unit 35 can be reduced by reducing the amount of access to the memory.

(Example 2)
In the second embodiment, the information processing apparatus according to the first embodiment is applied to an RFID tag system.

FIG. 2 is a block diagram of the information processing apparatus according to the second embodiment. As shown in FIG. 2, an RFID tag system 41 as an information processing apparatus includes a reader / writer device 42 as a carrier transmission unit and an RFID tag 47 as a processing unit.

Explanation of Reader / Writer Device The reader / writer device 42 includes a pattern generation table 43 as a transmission pattern holding unit, a command generation unit 44 as a transmission unit, a pattern generation unit 45, and a transmission RF (Radio Frequency) circuit 46. . The command generation unit 44 generates command information for a passive tag unit (to be described later) and command information for a controller unit (to be described later) of the RFID tag 47 based on an instruction from the host. In the pattern generation table 43, the transmission pattern of the carrier signal is stored for each command for the controller unit of the RFID tag 47, for example.

  The pattern generation unit 45 refers to the pattern generation table 43 and generates a carrier signal transmission pattern corresponding to the type of command for the controller unit of the RFID tag 47. The transmission RF circuit 46 converts the command information for the controller unit and the command information for the passive tag unit into radio signals and transmits them from the antenna. The command generation unit 44 and the pattern generation unit 45 may be realized by a processor executing a program that causes a computer to execute a processing procedure in a reader / writer device to be described later. This program may be stored in a memory accessible to the processor. The pattern generation table 43 may be stored in a memory accessible by the processor.

FIG. 3 is a schematic diagram illustrating an example of a start command in the information processing apparatus according to the second embodiment. The start command is one of commands for the controller unit of the RFID tag 47. In response to the start command, for example, a device such as a sensor (described later) provided in the RFID tag 47 starts operation.

  As shown in FIG. 3, the transmission pattern of the carrier signal corresponding to the start command has a stop period (dt) of 30 ms between the carrier signal 71 and the carrier signal 72, for example. One carrier signal 71 includes, for example, four on periods 73 to 76 and off periods between them. The start command pattern shown in FIG. 3 corresponds to the pattern described as “start, 30, 1, 0, 3” in the pattern generation table 43 shown in FIG.

  FIG. 4 is a schematic diagram illustrating an example of a stop command in the information processing apparatus according to the second embodiment. The stop command is one of commands for the controller unit of the RFID tag 47. By the stop command, for example, a device such as a sensor described later provided in the RFID tag 47 stops its operation.

  As shown in FIG. 4, the transmission pattern of the carrier signal corresponding to the stop command has a stop period (dt) of 100 ms between the carrier signal 71 and the carrier signal 72, for example. The stop command pattern shown in FIG. 4 corresponds to the pattern described as “stop, 100, 0, 0, 4” in the pattern generation table 43 shown in FIG.

  In addition, the transmission pattern of the carrier signal corresponding to the command for the controller unit of the RFID tag 47 is not limited to the example shown in FIG. In the example shown in FIG. 3 or FIG. 4, the length of the stop period (dt) of the carrier signals 71 and 72 is changed by a command for the controller unit. On the other hand, the length of the carrier signals 71 and 72 may be changed by a command for the controller unit, or both the length of the carrier signals 71 and 72 and the length of the stop period (dt) may be changed.

Description of Pattern Generation Table As shown in FIG. 2, the pattern generation table 43 includes “command name”, “dt”, “write” for each command for the controller unit of the RFID tag 47 as a carrier signal transmission pattern. Number, “read number” and “carrier number” data are stored. The “command name” is, for example, a start representing a start command or a stop representing a stop command.

  “Dt” is data defining a carrier signal stop period. If “dt” is 30, for example, the carrier signal stop period is 30 ms.

  “Number of writes” is data defining the number of on periods of a carrier signal on which a signal of a write command for the passive tag portion is placed. If the “number of writes” is 0, for example, a write command signal is not included in the carrier signal. If the “number of writes” is 1, for example, the write command signal is placed in one on period of the carrier signal. In the RFID tag 47 by the write command, data is written to a designated area of the memory in the RFID tag 47. One of data written to the memory in the RFID tag 47 by the write command includes an ID (Identifier) and parameter information of a device such as a sensor that is operated by the start command.

  “Number of reads” is data that defines the number of on periods of a carrier signal on which a signal of a read command for the passive tag portion is placed. If the “read number” is 0, for example, the read command signal is not included in the carrier signal. If the “number of reads” is 1, for example, the read command signal is placed in one ON period of the carrier signal. By the read command, the RFID tag 47 reads data from the designated area of the memory in the RFID tag 47.

  “Number of carriers” is data defining the number of ON periods of a carrier signal not carrying a signal such as a write command or a read command, that is, a carrier signal that is not modulated. If the “number of carriers” is 3, for example, no modulation is applied during the three ON periods of the carrier signal.

  When the “number of writes” and the “number of reads” are not zero, the write command or read command signal may be carried on one carrier signal 71 (or 72), or a plurality of carrier signals 71 (or 72). It may be put on. When the “number of writes” and the “number of reads” are not zero, the write command or read command signal may be placed in one on period of the carrier signal 71 (or 72) or in a plurality of on periods. May be.

  As an example, a write command signal or a read command signal may be placed on the first carrier signal 71 of the carrier signal transmission pattern. Further, as an example, a signal of a write command or a read command may be placed in the leading on period 73 of the carrier signal 71 (or 72). In the pattern of the start command in the pattern generation table 43 shown in FIG. 2, the write command signal is placed in the leading on period 73 of the leading carrier signal 71 in the diagram shown in FIG. The remaining carrier signal 72 and the remaining three ON periods 74 to 76 of the first carrier signal 71 are not modulated. In the pattern of the stop command in the pattern generation table 43 shown in FIG. 2, no modulation is applied to any of the on periods 73 to 76 of any of the carrier signals 71 and 72 in the diagram shown in FIG.

FIG. 5 is a block diagram of an RFID tag according to the second embodiment. As shown in FIG. 5, the RFID tag 47 includes a passive tag unit 51, a controller unit 57, a power switch 65, a power circuit 66, a battery 67, and a sensor 68. The controller unit 57 is normally in a sleep state and is in a state of waiting for receiving a carrier detection signal from the passive tag unit 51.

  The passive tag unit 51 includes a power regeneration circuit 52 as a receiving unit, a carrier detection signal generation circuit 53, a transmission / reception circuit 54, a tag controller 55, and a memory 56. An example of the memory 56 is a ferroelectric memory (FRAM). The power regeneration circuit 52 converts the carrier signal received via the antenna into electric power. The carrier detection signal generation circuit 53, the transmission / reception circuit 54, the tag controller 55, and the memory 56 operate with power supplied from the power supply reproduction circuit 52.

  The carrier detection signal generation circuit 53 detects a carrier signal while power is supplied from the power supply regeneration circuit 52. When the carrier detection signal generation circuit 53 detects the carrier signal, it outputs a carrier detection signal as a detection signal.

  The transmission / reception circuit 54 transmits / receives signals to / from the reader / writer device 42 by wireless communication. The tag controller 55 receives the command information sent from the reader / writer device 42 from the transmission / reception circuit 54. When the tag controller 55 receives the read command, the tag controller 55 reads the data from the designated area in the memory 56 and returns it to the reader / writer device 42 via the transmission / reception circuit 54. When the tag controller 55 receives a write command, the tag controller 55 writes data in a designated area in the memory 56.

  The controller unit 57 includes a timer 58, a carrier signal detection unit 59, a pattern table 60 as a reception pattern holding unit (pattern holding unit), a pattern analysis unit 61 as an analysis unit, a command control unit 62, a device control unit 63, and a memory access unit. 64. The carrier signal detection unit 59 detects the carrier detection signal output from the carrier detection signal generation circuit 53. The carrier signal detection unit 59 acquires time information from the timer 58 and sends it to the pattern analysis unit 61 each time the level of the carrier detection signal is switched from low to high or from high to low.

  The pattern analysis unit 61 refers to the pattern table 60 and analyzes a command for the controller unit based on the time information acquired from the carrier signal detection unit 59. In the pattern table 60, data of a carrier detection signal verification pattern is registered (see FIG. 6). The pattern analysis unit 61 notifies the command control unit 62 of the analyzed command data.

  The command control unit 62 allows the memory access unit 64 to access the memory 56 via the device control unit 63 based on the notified command data and information related to memory access described later (see FIG. 7, memory access table). Control. The memory access unit 64 reads the ID and parameter information of a device such as the sensor 68 from the designated area of the memory 56 under the control of the device control unit 63. The command control unit 62 determines whether or not the ID read from the memory 56 matches its own ID. The read parameter information is transferred from the memory access unit 64 to the device control unit 63.

  The device control unit 63 turns on or off the power of the designated device such as the sensor 68 based on the ID and parameter information of the device such as the sensor 68. Data acquired by the sensor 68 is transferred to the memory access unit 64 and written to the memory 56 by the memory access unit 64. Examples of the sensor 68 include a temperature sensor that detects the temperature of the environment, a humidity sensor that detects the humidity of the environment, and an acceleration sensor that detects vibration and impact. The carrier signal detection unit 59, the pattern analysis unit 61, the command control unit 62, the device control unit 63, and the memory access unit 64 are programs for causing a computer to execute processing procedures, start processing procedures, and stop processing procedures in a controller unit described later. It may be realized by execution by a processor. This program may be stored in a memory accessible to the processor. The pattern table 60 may be stored in a memory accessible by the processor.

  The controller unit 57 is supplied with power from a power supply circuit 66 driven by a battery 67. When accessing the memory 56 by the memory access unit 64, the memory 56 operates with power supplied from the power supply circuit 66. Power is supplied to the memory 56 from the power supply circuit 66 and from the power regeneration circuit 52 of the passive tag unit 51. When the power switch 65 is switched under the control of the device control unit 63, power is supplied to the memory 56 from either the power circuit 66 or the power regeneration circuit 52.

FIG. 6 is a schematic diagram illustrating an example of a pattern table in the information processing apparatus according to the second embodiment. As shown in FIG. 6, the pattern table 60 includes a “command name” such as start and stop for each command for the controller unit of the RFID tag 47, and a carrier detection signal stop period as a carrier detection signal verification pattern. Each data of “dt” is stored. The carrier detection signal stop period is the same as the carrier signal stop period.

Description of Memory Access Table FIG. 7 is a schematic diagram illustrating an example of a memory access table in the information processing apparatus according to the second embodiment. As shown in FIG. 7, in the memory access table 69, for example, “command name” such as start or stop for each command for the controller unit of the RFID tag 47, “parameter presence / absence” indicating whether there is a parameter, and the memory 56 Each data of “parameter area” indicating a parameter storage area is stored. In the example shown in FIG. 7, there are parameters for the start command, and the parameters are stored in the area of 0x00013 to 0x00020. Since there is no parameter for the stop command, the parameter storage area is not specified. The memory access table 69 is included in the command control unit 62, for example. The memory access table 69 may be stored in a memory accessible by the processor.

Description of Processing Procedure in Information Processing Device A processing procedure in the RFID tag system as the information processing device according to the second embodiment will be described. A processing procedure in the reader / writer device 42, a processing procedure in the passive tag unit 51 of the RFID tag 47, and a processing procedure in the controller unit 57 of the RFID tag 47 will be described in this order.

FIG. 8 is a flowchart of a process procedure in the reader / writer apparatus according to the second embodiment. As shown in FIG. 8, when the reader / writer device 42 is powered on and processing in the reader / writer device 42 is started, the command generation unit 44 issues command information for the passive tag unit according to an instruction from the host. It is determined whether or not (step S1). When issuing command information for the passive tag unit (step S1: Yes), the command generation unit 44 generates command information for the passive tag unit (step S8). Next, the transmission RF circuit 46 issues and transmits command information for the passive tag unit (step S9).

  When command information for the passive tag unit is not issued (step S1: No), the command generation unit 44 determines whether or not command information for the controller unit is issued (step S2). When command information for the controller unit is not issued (step S2: No), the process returns to step S1 and waits for an instruction to issue command information from the host.

  On the other hand, when issuing command information for the controller unit (step S2: Yes), the command generation unit 44 generates command information for the controller unit (step S3). When control information is necessary when the RFID tag 47 operates based on command information for the controller unit, the control information is embedded in a write command for the passive tag unit. As an example of the control information embedded in the write command for the passive tag unit, there are, for example, the ID and parameter information of a device such as the sensor 68.

  Next, the pattern generation unit 45 generates a transmission pattern of a carrier signal corresponding to the type of command for the controller unit (step S4). For example, a carrier signal transmission pattern having a 30 ms stop period (dt) in the case of a start command and a 100 ms stop period (dt) in the case of a stop command is generated. Next, the transmission RF circuit 46 issues command information for the controller unit (step S5).

  In this state, it waits for the transmission of command information for the controller unit to end (step S6: No). When the transmission of command information for the controller unit ends (step S6: Yes), or when the transmission of command information for the passive tag unit ends in step S9, the command generation unit 44 determines whether or not to issue the next command information. Is determined (step S7). When the next command information is issued (step S7: Yes), the process returns to step S1 and waits for an instruction to issue command information from the host. When not issuing the next command information (step S7: No), a process is complete | finished.

FIG. 9 is a flowchart illustrating a processing procedure in the passive tag portion of the RFID tag according to the second embodiment. When the RFID tag 47 receives the carrier signal, the power supply regeneration circuit 52 turns on the passive tag unit 51. Then, as shown in FIG. 9, when the process in the passive tag unit 51 is started, the tag controller 55 receives the ID and command information via the transmission / reception circuit 54 (step S11).

  Next, the tag controller 55 determines whether or not the received ID matches its own ID (step S12). If the IDs do not match, the RFID tag 47 waits to receive a signal with the matching ID (step S12: No). If the IDs match (step S12: Yes), the tag controller 55 interprets the received command information (step S13). Then, the tag controller 55 performs command processing according to the interpreted command type (step S14). If the command type is a write command (step S14: write command), the tag controller 55 writes data in the designated area of the memory 56 (step S17), and ends the process.

  If the command type is a read command (step S14: read command), the tag controller 55 reads data from the designated area of the memory 56 (step S15). Next, the tag controller 55 outputs the read data to the transmission / reception circuit 54 (step S16), and ends the process. The data passed to the transmission / reception circuit 54 is transmitted to the reader / writer device 42. If the command type is neither a write command nor a read command (step S14: other), the tag controller 55 determines that the command interpretation has failed and ends the process without doing anything.

FIG. 10 is a flowchart illustrating a processing procedure in the controller unit of the RFID tag according to the second embodiment. FIG. 11 is a schematic diagram illustrating processing in the controller unit of the RFID tag according to the second embodiment.

  As shown in FIG. 10, the controller unit 57 is initialized when the controller unit 57 starts processing. In the initial state, the controller unit 57 is in a sleep state, and is in a state of waiting for an interrupt due to the input of the carrier detection signal from the carrier detection signal generation circuit 53. Further, the power supply to the memory 56 by the battery 67, the power supply circuit 66 and the power switch 65 is invalid, that is, the power in this power supply system is not supplied to the memory 56 (step S21).

  In the sleep state, the carrier signal detection unit 59 determines whether the level of the carrier detection signal has changed following access to the passive tag unit 51 (conditional branch: A, step S22). If there is no change in the level of the carrier detection signal (step S22: No), the process waits until it changes. When the level of the carrier detection signal changes (step S22: Yes), the controller unit 57 is activated. Then, the carrier signal detection unit 59 acquires time information from the timer 58. The time at this time is Ts (step S23).

  Next, the carrier signal detection unit 59 determines whether or not the level of the carrier detection signal has changed following access to the passive tag unit 51 (conditional branch: B, step S24). When there is no change in the level of the carrier detection signal (step S24: No), it waits until it changes. When the level of the carrier detection signal changes (step S24: Yes), the carrier signal detection unit 59 acquires time information from the timer 58. The time at this time is set to Te (step S25).

  Next, the carrier signal detection unit 59 determines whether or not the level of the carrier detection signal has been switched from low to high in the conditional branch of B (step S24) (conditional branch: C, step S26). In the first and third rounds from step S24 to step S26, the level change of the carrier detection signal is not low to high (see FIG. 11). Therefore, in this case (step S26: No), the carrier signal detection unit 59 newly sets Te at this time as Ts (Ts = Te, step S31). Then, the process returns to step S24.

  On the other hand, in the second and fourth rounds from step S24 to step S26, the change in the level of the carrier detection signal is from low to high (see FIG. 11). Therefore, in this case (step S26: Yes), the carrier signal detection unit 59 sets the time information obtained by subtracting Ts from Te as the carrier detection signal stop period dt (dt = Te−Ts, step S27).

  For example, in the example of the pattern table 60 shown in FIG. 6, when the carrier detection signal stop period dt is 30 ms (step S27: dt = 30 ms), the pattern analysis unit 61 determines that the command for the controller unit is a start command. Interpret. Thereby, a start process described later is performed (step S29). When the stop period dt of the carrier detection signal is 100 ms (step S27: dt = 100 ms), the pattern analysis unit 61 interprets that the command for the controller unit is a stop command. Thereby, a stop process described later is performed (step S28).

  After the start process or stop process ends, or when the carrier detection signal stop period dt is neither 30 ms nor 100 ms (step S27: Other), the carrier signal detection unit 59 newly sets Te at this time as Ts. (Ts = Te, step S30). And it returns to step S24 and repeats from step S24 to step S31 after this.

FIG. 12 is a flowchart of a process procedure for a start command in the RFID tag according to the second embodiment. As shown in FIG. 12, when the start process is started, the command control unit 62 determines whether the current state is a start state, that is, whether a device such as the sensor 68 is operating ( Step S41). If it is in the start state (step S41: Yes), the process is terminated.

  When it is not in the start state (step S41: No), power in the power supply system by the battery 67, the power supply circuit 66, and the power switch 65 is supplied to the memory 56. Then, the memory access unit 64 reads data such as ID and parameter information from the area specified by the memory access table 69 in the memory 56 (step S42). The command control unit 62 determines whether or not the ID read from the memory 56 matches its own ID (step S43). If the IDs do not match (step S43: No), the process ends.

  When the IDs match (step S43: Yes), the device control unit 63 activates a device such as the sensor 68 based on the parameter information read from the memory 56, and starts the operation (step S44). Then, the command control unit 62 sets the current state to the start state (step S45) and ends the process.

Description of Stop Process FIG. 13 is a flowchart of a process procedure for a stop command in the RFID tag according to the second embodiment. As shown in FIG. 13, when the stop process is started, the command control unit 62 determines whether or not the current state is a stop state, that is, a device such as the sensor 68 is not operating ( Step S51). If it is in the stop state (step S51: Yes), the process is terminated.

  If not in the stop state (step S51: No), the device control unit 63 stops the operation of all the devices such as the sensors 68 (step S52). Then, the command control unit 62 sets the current state to the stop state (step S53) and ends the process.

FIG. 14 is an operation timing diagram of the information processing apparatus according to the second embodiment. As shown in FIG. 14, in the RFID tag 47, a memory access 85 is generated by the controller unit 57 when a start command 81 for the controller unit is generated, and data such as ID and parameter information is read from the memory 56. In the case of the read command 82 for the passive tag unit, the write command 83 for the passive tag unit, and the stop command 84 for the controller unit, the memory access by the controller unit 57 does not occur. Therefore, according to the second embodiment, for example, compared with the conventional example shown in FIG. 17, the number of times of memory access by the controller unit 57 is reduced to ¼ that of the conventional example. It will be better.

  Note that the commands for the controller unit may be prepared as appropriate in addition to the start command and the stop command. In addition, commands for the passive tag unit may be appropriately prepared in addition to the write command and the read command.

Reference Signs List 31 Information processing device 32 Carrier transmission unit 33 Transmission pattern holding unit 34 Transmission unit 35 Processing unit 36 Reception unit 37 Reception pattern holding unit 38 Analysis unit

Claims (5)

A transmission pattern holding unit for holding a transmission pattern of a carrier signal to be transmitted;
A transmission unit for transmitting a carrier signal based on the transmission pattern;
A carrier transmitter having
A receiver that operates by converting a signal transmitted from the transmitter into electric power, and outputs a detection signal in response to detection of a carrier signal;
A reception pattern holding unit for holding a pattern of the detection signal;
An analysis unit that analyzes the pattern of the detection signal with reference to the reception pattern holding unit;
A processing unit having
An information processing apparatus comprising:   The information processing apparatus according to claim 1, wherein the carrier signal transmission pattern has a different carrier signal stop period for each pattern.   The analysis unit determines a pattern of the detection signal based on a period of the second level when the level of the detection signal transitions from the first level to the second level and returns to the first level again. The information processing apparatus according to claim 1, wherein the information processing apparatus analyzes the information processing apparatus. A receiver that operates by converting the received carrier signal into electric power, and outputs a detection signal in response to detection of the carrier signal;
A pattern holding unit for holding a collation pattern for collating a transmission pattern transmitted by a transmission source of the carrier signal;
An analysis unit that analyzes the pattern of the detection signal with reference to the pattern holding unit;
An RFID tag comprising:   The analysis unit determines a pattern of the detection signal based on a period of the second level when the level of the detection signal transitions from the first level to the second level and returns to the first level again. The RFID tag according to claim 4, wherein the RFID tag is analyzed.

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