JP4255506B2 - Interrogator, contactless data carrier system, and contactless data carrier data acquisition method - Google Patents

Description

The present invention relates to an interrogator, a non-contact data carrier system, and a data acquisition method for a non-contact data carrier, and is particularly applicable to a sensor system.

A non-contact data carrier system including a non-contact data carrier (responder) and an interrogator is used for various applications as a simple data processing system. Furthermore, as described in Patent Document 1, a non-contact data carrier is provided with a sensor such as a temperature sensor or a pressure sensor, and an application in which the non-contact data carrier system is applied to a measurement system has also appeared.
Japanese Patent Laid-Open No. 10-289297

  However, the non-contact data carrier and the non-contact data carrier system described in Patent Document 1 have the following problems.

  Since the non-contact data carrier includes a sensor such as a temperature sensor or a pressure sensor, the characteristics of the non-contact data carrier such as a low product unit price, small size, and light weight may be lost. For example, in order to convert an analog signal obtained by a sensor into digital data and transmit it from a non-contact data carrier to an interrogator, a certain amount of power necessary for transmission is required. If a battery is not provided on the non-contact data carrier, it is difficult to secure this necessary power, but if a battery is provided, the necessary power can be secured. However, if a battery is provided on the non-contact data carrier, the reduction in size and weight is impeded.

  Further, measurement items (temperature, pressure, etc.) are determined depending on the type of sensor provided in the non-contact data carrier. In other words, when there are a plurality of measurement items, a non-contact data carrier corresponding to each measurement item must be separately formed.

Therefore, the interrogator, the non-contact data carrier system, and the non-contact data carrier can maintain the characteristics of a non-contact data carrier that is low in product unit price, small and lightweight, and can have high flexibility for measurement items. data acquisition how it has been desired.

In order to solve such a problem, the non-contact data carrier system of the first aspect of the present invention has (1) an interrogator, and (2) at least one measurement port that exchanges data with the interrogator by wireless communication. A non-contact data carrier; and (3) a non-contact data source that generates a signal to be compared according to a surrounding physical quantity connected to at least one measurement port of the non-contact data carrier. The contact data carrier compares (2-1) a measurement port to which an external signal to be compared is input, and (2-2) compares the signal to be compared input from the measurement port with a threshold value, and determines the magnitude relationship between the two. In accordance with a comparison output request including an indication of a change value of the threshold value from the interrogator. , The above variable threshold To control the threshold from stage, the comparison result of the comparing means, or, a comparison control means for returning information related to the comparison result, (3) the interrogator, each time for sending the comparison output request The change value of the threshold value is instructed to the non-contact data carrier .

According to a second aspect of the present invention, non-contact data in the non-contact data carrier system according to the first aspect of the present invention, wherein a compared signal generation source for generating a compared signal according to a surrounding physical quantity is connected to at least one measurement port. An interrogator under the control of a carrier, wherein each time a comparison output request is sent to the non-contact data carrier, the non-contact data carrier is instructed to change the threshold value and the threshold value is changed. The comparison means of the comparison means is repeatedly executed to obtain information on the threshold at which the logic of the comparison result of the comparison means has changed from the return signal from the comparison control means, and It is characterized in that information on a physical quantity related to the comparison signal is obtained.

According to a third aspect of the present invention, there is provided the noncontact data carrier system according to the first aspect, wherein the interrogator is connected to at least one measurement port with a signal source to be compared that generates a signal to be compared according to a surrounding physical quantity. A non-contact data carrier data acquisition method for obtaining information on a physical quantity related to the compared signal generated by the compared signal generation source from the non-contact data carrier. (1) Each time the interrogator sends a comparison output request to the non-contact data carrier, the change value of the threshold is instructed to the non-contact data carrier, and the non-contact data carrier is changed to the threshold. A search step for repeatedly executing the comparison of the comparison means; and (2) information on the threshold at which the logic of the comparison result of the comparison means has changed is obtained from the interrogator or the non-contact data carrier. And (3) a physical quantity identification step in which the interrogator obtains information on the physical quantity related to the signal to be compared generated by the signal source to be compared based on information on a threshold whose logic has changed. It is characterized by including.

  According to the present invention, the same non-contact data carrier can be used for identification of various physical quantities without making the configuration of the non-contact data carrier expensive and complicated.

(A) less than the first embodiment, the interrogator according to the present invention, the non-contact data carrier system, and, a first embodiment of a data acquisition how the non-contact data carrier will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration of a contactless data carrier system according to the first embodiment.

  In FIG. 1, the non-contact data carrier system 1 of 1st Embodiment has the non-contact data carrier 2, the interrogator 3, and the high-order apparatus 4, and the non-contact data carrier 2 is 1 or more (FIG. 1 is 2). Sensor 5-1 and 5-2 can be connected as appropriate.

  In the case of the first embodiment, the non-contact data carrier 2 may be a fixed position or a portable type, and the interrogator 3 may be a fixed position or a portable type. (In the operation description to be described later, at least one of them is assumed to be portable). Further, there may be only one or a plurality of non-contact data carriers 2 with which the interrogator 3 can communicate (the description will be made assuming that there are a plurality of non-contact data carriers 2). The non-contact data carrier 2 and the sensors 5-1 and 5-2 may be connected continuously after being connected once, and are connected by an operator at every measurement. Also good.

  The non-contact data carrier 2 corresponds to an RFID tag, for example, and includes an ID tag core unit 10, a nonvolatile memory 11, antennas 12, 1 or a plurality (FIG. 1 shows two cases) of analog comparators 13- 1 and 13-2, and a variable threshold unit 14, and the same number of measurement ports 15-1 and 15-2 as the analog comparators 13-1 and 13-2, an external expansion terminal 16, and an external input And an output terminal (external I / O terminal) 17.

  The ID tag core unit 10 is a part that performs general processing as an ID tag to which a CPU, a wireless unit, and the like correspond. The ID tag core unit 10 is obtained by demodulating the radio signal captured by the antenna 12 into a digital signal (serial signal; interrogation signal) and analyzing the digital signal (or data obtained by serial / parallel conversion of the digital signal). The process according to the question from the interrogator 3 is executed, a response signal (for example, composed of parallel data) is formed, and the response signal (or a signal obtained by parallel / serial conversion of the response signal) is modulated. A response is made from the antenna 12. As an interrogation signal from the interrogator 3, there is a signal in a measurement mode as will be described later. At this time, the ID tag core unit 10 controls the operation in the measurement mode (in the claims) ID tag core unit 10 corresponds to “comparison control means” in FIG.

  The ID tag core unit 10 has a power source unit that obtains power necessary for operating the non-contact data carrier 2 from the radio signal captured by the antenna 12, and supplies the power source to each unit as operating power. (The power supply line is omitted in FIG. 1).

  The non-volatile memory 11 is made of, for example, FeRAM and stores data such as an ID assigned to the non-contact data carrier 2 and a program executed by the ID tag core unit 10. Note that threshold data to be described later may be stored in the nonvolatile memory 11. Further, as a program stored in the nonvolatile memory 11, there is a measurement mode program 11P.

  The antenna 12 is, for example, a transmission / reception shared antenna (transmission and reception may be separate). The antenna 12 is of a type that resonates at a predetermined frequency with, for example, an antenna coil and a capacitance component of an IC chip that constitutes the ID tag core unit 10 and the like, and the contactless data carrier 2 operates by the resonance. It is designed so that necessary energy can be extracted efficiently.

  Each of the analog comparators 13-1 and 13-2 includes, for example, a comparator circuit or a Schmitt trigger circuit, and is connected to the sensors 5-1 and 5 via the corresponding measurement ports 15-1 and 15-2. -2 detection signal (detection voltage) is compared with the threshold value (threshold voltage) by the variable threshold value unit 14, and logic "1" when the sensor detection signal is greater than the threshold, and logic "1" when the sensor detection signal is less than or equal to the threshold. "0" is output.

  The types of sensors 5-1 and 5-2 that can be connected to the non-contact data carrier 2 are not limited. For example, any temperature sensor, conductivity sensor, strain sensor, pressure sensor, concentration sensor, moisture sensor, resistance sensor, etc. may be used. However, each sensor 5-1, 5-2 needs to be a voltage output type. Moreover, it is preferable that each sensor 5-1, 5-2 can be adjusted with an amplifier or an attenuator with a built-in dynamic range of detection output.

  The variable threshold value unit 14 provides a threshold value (threshold voltage) corresponding to the threshold data given from the ID tag core unit 10 to the analog comparators 13-1 and 13-2. The variable threshold unit 14 includes, for example, a threshold data latch unit 14A and a plurality of resistors connected in series as shown in detail in FIG. 2, and selects a divided voltage to extract as a threshold (threshold voltage). The one having the forming unit 14B can be applied, and on / off of the switch in the threshold forming unit 14B is controlled according to the threshold data of the latch unit 14A, and a threshold (threshold voltage) corresponding to the threshold data is output.

  Here, the threshold data latched by the latch unit 14 </ b> A may be threshold data transferred from the interrogator 3 (in the case of the first measurement mode), or may be threshold stored in the nonvolatile memory 11. There is also a case of data (in the case of the second measurement mode).

  The external expansion terminal 16 is for outputting the threshold value (threshold voltage) set by the variable threshold value unit 14 so that it can be referred to from the outside. Further, the external input / output terminal (external I / O terminal) 17 can refer to data and programs stored in the nonvolatile memory 11 from the outside by wire, and new data to the nonvolatile memory 11 from the outside by wire. Or to be able to write programs.

  The interrogator 3 has the same hardware configuration as that of the prior art. For example, the interrogator 3 converts a radio signal obtained by modulating the interrogation signal into a non-contact data carrier 2 under the control of a host device 4 connected via a wired or wireless line. Is received, and a radio signal obtained by modulating the response signal returned from the non-contact data carrier 2 is received, and the response signal is extracted by performing a demodulation process. Here, in the case of the first embodiment, the interrogator 3 has a measurement mode program 3P (see FIG. 3), which will be described later, as an operation program, and when the host device 4 instructs to start the operation in the measurement mode. The main controller (not shown) of the interrogator 3 transmits and receives an interrogation signal and a response signal to and from the non-contact data carrier 2 according to the measurement mode program 3P. The exchange of the interrogation signal and the response signal between the interrogator 3 and the non-contact data carrier 2 is executed in accordance with or in accordance with a standard such as ISO15693.

  The host device 4 corresponds to, for example, a personal computer, activates the interrogator 3, and controls communication between the interrogator 3 and the non-contact data carrier 2. The host device 4 collects measurement data related to the non-contact data carrier 2. There may be a higher-level device connected to the higher-level device 4 by wire or wireless.

  Next, the operation in the measurement mode, which is a characteristic operation of the contactless data carrier system of the first embodiment, will be described.

  The interrogator 3 transmits, for example, an interrogation signal (modulation signal thereof) for confirming whether or not the non-contact data carrier 2 is periodically present in the vicinity, and a response signal ( ) Is returned, it is recognized that the non-contact data carrier 2 exists in the vicinity, and the host device 4 is notified of this including the ID included in the response signal.

  The host device 4 determines whether the ID of the non-contact data carrier 2 is a measurement mode operation target, whether to apply the first measurement mode or the second measurement mode, an effective measurement port, Measurement data corresponding to the minimum threshold value at each measurement port (minimum temperature if the measurement port is connected to a temperature sensor), or conversion of measurement data corresponding to one unit of threshold value at each measurement port (temperature sensor If the measurement port is connected, the table information 4T is associated with the temperature detection accuracy), and the host device 4 is in the case where the non-contact data carrier 2 existing in the vicinity is the operation target of the measurement mode. Gives to the interrogator 3 a start command for the measurement operation including information on whether to apply the first measurement mode or the second measurement mode and valid measurement ports. At this time, the interrogator 3 starts the measurement mode program 3P shown in FIG. In addition, when the host apparatus 4 notifies that the first measurement mode is applied, the record of the non-contact data carrier 2 in the table information 4T is updated so that the second measurement mode is applied next time. Let

  The interrogator 3 may be provided with the table information 4T as described above, and the interrogator 3 itself may confirm whether or not to start the measurement mode operation.

  Here, the first measurement mode is the first measurement operation mode for the non-contact data carrier 2 (including the case where it is regarded as the first by clearing the table information 4T), and the second measurement mode is This is the second and subsequent measurement operation modes for the non-contact data carrier 2.

  When the interrogator 3 starts the measurement mode program 3P shown in FIG. 3, first, the interrogator 3 determines whether to execute the operation of the first measurement mode or the operation of the second measurement mode (step 100).

  If in the first measurement mode, the interrogator 3 forms an inquiry signal for an initial measurement request in the first measurement mode and transmits it to the non-contact data carrier 2 (step 101), and a non-contact data carrier corresponding thereto. Wait for a reply from 2 (step 102).

  The interrogation signal here includes the ID of the non-contact data carrier 2, the first measurement mode, the minimum threshold data (or code indicating the minimum threshold data), the number of the measurement port, and the like. The ID tag core unit 10 of the non-contact data carrier 2 that has received such an interrogation signal recognizes that it is an interrogation signal to itself from the ID included in the interrogation signal, and the measurement mode is the first measurement mode. Is stored in the non-volatile memory 11, the threshold value related to the minimum threshold value data included in the question signal is set by the variable threshold value unit 14, and is associated with the number of the measurement port included in the question signal. The comparison result (“0” or “1”) of the analog comparator 13-1 or 13-2 is fetched. Then, the ID tag core unit 10 forms a response signal including the comparison result and sends it back to the interrogator 3. In addition, when the comparison result is “0”, the ID tag core unit 10 not only forms the response signal but also sets threshold data smaller than the threshold data at that time by a predetermined unit in the next second measurement mode. It is also stored in the nonvolatile memory 11 as threshold data at the start of measurement.

  The interrogator 3 that has received the response signal as described above determines whether the comparison result is “0” or “1” (step 103). If the comparison result is “1”, it is confirmed that the current threshold data is not the maximum (step 104), and a measurement request question signal is generated to indicate that the threshold data is one unit larger than this time. The data is transmitted to the contactless data carrier 2 (step 105), and a reply from the contactless data carrier 2 is awaited in the same manner as described above (step 102).

  If the threshold data in the current question signal is the maximum, the interrogator 3 sets the measured value to be larger than the maximum threshold related to the maximum threshold data (step 106), and will be described later. 108.

  If the comparison result in the response signal from the non-contact data carrier 2 is “0”, the interrogator 3 sets the measured value to an intermediate value between the two threshold values corresponding to the threshold data in the current and previous question signals. Set (step 107).

  Thereafter, it is determined whether or not an unmeasured measurement port remains (step 108), and if it remains, the process returns to step 101 to perform measurement for the measurement port (step 101 to step 107).

  When the measurement values for all the measurement ports for the contactless data carrier 2 are obtained as described above, the interrogator 3 transmits a query signal indicating the end of measurement to the contactless data carrier 2. (Step 109) Waiting for the reply (Step 110), the measurement result is transmitted to the host device 4 (Step 111), and the series of processes is terminated. At this time, the host device 4 converts the measurement result expressed by the threshold value (threshold voltage) into the measurement result (temperature) expressed by the measurement item (for example, temperature) while referring to the table information 4T. , Memorize it internally or send it to the outside. The interrogator 3 may also convert the expression relating to the measurement item (for example, temperature) into the measurement result (temperature).

  If the measurement mode instructed from the host device is the second measurement mode, the interrogator 3 forms an inquiry signal for an initial measurement request in the second measurement mode and transmits it to the non-contact data carrier 2 (step 112), and waits for a reply from the non-contact data carrier 2 (step 113).

  The question signal here includes the ID of the non-contact data carrier 2, the second measurement mode, the number of the measurement port, and the like. The contactless data carrier 2 (the ID tag core unit 10) that has received such an inquiry signal has a threshold value at which the comparison result changes from “1” to “0” by a control process as shown in FIG. Data is obtained, a response signal including the boundary threshold data is formed and returned to the interrogator 3.

  The interrogator 3 that has received the response signal as described above sets the measurement value to a value that is ½ unit smaller than the threshold value related to the boundary threshold data included in the response signal (step 114). When the boundary threshold data is the maximum threshold data, the measured value is set to be larger than the maximum threshold.

  Thereafter, it is determined whether or not an unmeasured measurement port remains (step 115), and if it remains, the process returns to step 112 to perform measurement for the measurement port (step 112 to step 114).

  As described above, even in the second measurement mode, when the measurement values for all the measurement ports for the non-contact data carrier 2 are obtained, the interrogator 3 proceeds to the above-described step 109, and the non-contact data A question signal indicating the end of measurement is transmitted to the carrier 2, waits for a reply (step 110), transmits the measurement result to the host device 4 (step 111), and the series of processing ends.

  Next, the control process of the non-contact data carrier 2 (the ID tag core unit 10) that has received the measurement request question signal in the second measurement mode will be described with reference to FIG.

  When the ID tag core unit 10 receives the question signal for the measurement request in the second measurement mode, the ID tag core unit 10 stores the threshold data for starting measurement of the measurement port specified by the number of the measurement port included in the question signal in the nonvolatile memory. 11 and set by the variable threshold unit 14 (steps 200 and 201), and the comparison result (“0” or “1”) of the analog comparator 13-1 or 13-2 associated with the number of the measurement port (Step 202). Then, it is determined whether the comparison result is “0” or “1” (step 203).

  If the comparison result is “1”, the ID tag core unit 10 confirms that the current threshold data is not the maximum (step 204), and increases the threshold data by one unit from this time (step 205). Returning to step 201 described above, the variable threshold unit 14 sets the threshold value.

  When the comparison result of “1” is obtained even with the maximum threshold data, the maximum threshold data is set as the boundary threshold data (step 206), and the process proceeds to step 210 described later.

  On the other hand, if the comparison result is “0”, the ID tag core unit 10 determines whether the applied threshold data is threshold data for measurement start (step 207), and the applied threshold data is measured. If it is time threshold data, the threshold data is updated to the minimum data (or data smaller than the threshold data for measurement start by a predetermined unit) (step 208), and the process returns to step 201 to change the variable threshold value section. 14 for setting.

  If the threshold data when “0” is obtained as the comparison result is not threshold data for measurement start, the current threshold data is set as the boundary threshold data (step 209). Then, a response signal including boundary threshold data is formed and returned to the interrogator 3 (step 210). Thereafter, the threshold data for measurement start stored in the nonvolatile memory 11 is updated to a value smaller than the boundary threshold data by a predetermined value (step 211), and the series of processing ends.

  According to the first embodiment, the following effects can be obtained.

  The non-contact data carrier of the first embodiment shows an example in which only the ID tag core unit 10 and the nonvolatile memory 11 are formed in one semiconductor integrated circuit (that is, the ID tag core unit 10 and the nonvolatile memory 11 are 1 Chip).

  However, the non-contact data carrier of this embodiment is not limited to the above-described chip configuration, and the analog comparator 13 and the variable threshold unit 14 are made into one chip, and the analog comparator 13 made into one chip and A multi-chip configuration of the variable threshold unit 14 and the above-described one-chip ID tag core unit 10 and the nonvolatile memory 11 may be employed.

  By adopting such a configuration, it can be expected that a non-contact data carrier corresponding to the measurement function can be realized at low cost, light weight and small size.

  Since the non-contact data carrier according to the first embodiment has an external sensor, the type of sensor is not limited when viewed from the non-contact data carrier. That is, the non-contact data carrier of the first embodiment is highly versatile with respect to measurement items. In addition, in the case of a conventional non-contact data carrier with a measurement function, since the sensor itself is mounted, it is actually difficult to make one non-contact data carrier correspond to a plurality of measurement items. However, in the case of the first embodiment, since the additional configuration is only the analog comparator and the threshold setting configuration for the analog comparator, it is easier to correspond to a plurality of measurement items than in the conventional case.

  In the case of the first embodiment, the threshold value is changed, the threshold value of the boundary between the comparison results “0” and “1” is searched, and the boundary threshold value is set as an indirect measurement value. In this respect, the configuration of the non-contact data carrier can be kept inexpensive, lightweight, and small, and it is necessary between the non-contact data carrier and the interrogator. The number of communication bits can be reduced.

  In the second and subsequent measurement operations, since the previous measurement result is used and the comparison result is set to the initial threshold value in the search operation for the boundary threshold value between “0” and “1”, the search time Can be shortened.

(B) Second Embodiment Next, interrogator according to the invention, the non-contact data carrier system, and, a second embodiment of a data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 5 is a block diagram showing the configuration of the contactless data carrier system of the second embodiment. The same and corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same and corresponding reference numerals. It shows.

  The second embodiment differs from the first embodiment described above in the internal configuration of the non-contact data carrier 2. The non-contact data carrier 2 of the second embodiment is provided with an analog comparator 13 in common for all of the plurality of measurement ports 15-1 and 15-2 (two examples in FIG. 5), and is common. An analog switch (selector) 20 is provided between the analog comparator 13 and the plurality of measurement ports 15-1 and 15-2, and the other configurations are the same as those in the first embodiment.

  The analog switch 20 selects one signal from the sensor detection signals from the measurement ports 15-1 and 15-2 and inputs the selected signal to the common analog comparator 13, and which measurement port 15-1, 15 Whether to select the sensor detection signal from -2 depends on the selection control signal from the ID tag core unit 10.

  Also in the case of the second embodiment, the ID tag core unit 10 performs almost the same control process as in the case of the first embodiment, but from an analog comparator corresponding to the measurement port (sensor) to be measured at that time. Instead of capturing the comparison result, the analog switch 20 is controlled so that the sensor detection signal from the measurement port (sensor) to be measured at that time is input to the common analog comparator 13, and the common analog comparison is performed. Capture the comparison results from the instrument.

  This second embodiment also provides the same effects as those of the first embodiment described above. When the number of measurement ports is larger, the second embodiment can be expected to reduce the size and simplification of the circuit in the non-contact data carrier.

(C) Third Embodiment Next, interrogator according to the invention, the non-contact data carrier system, and, a third embodiment of a data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 6 is a block diagram showing the configuration of the contactless data carrier system according to the third embodiment. The same and corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same and corresponding reference numerals. It shows.

  The third embodiment differs from the first embodiment described above in the internal configuration of the non-contact data carrier 2. Compared to the first embodiment described above, the third embodiment corresponds to each analog comparator 13-1, 13-2 (only one analog comparator 13-1 is shown in FIG. 6). Sensor port 15-1 (measurement port 15-1 strictly consists of a pair of ports 15-1P and 15-1N; the same applies to FIGS. 1 and 5, etc.) and 15-2. Bridge circuits 21-1 and 21-2 that expand the signal dynamic range are provided, and other configurations are the same as those of the first embodiment. If a bridge circuit is added to the configuration of the second embodiment, it is preferably provided on the output side of the analog switch 20.

  For example, as shown in FIG. 7, the bridge circuit 21-1 (same as 21-2) is a resistor bridge having one side of the sensor 5-1 connected via the measurement port pairs 15-1 P and 15-1 N. 21A and a difference unit 21B that extracts a voltage between the two output terminals of the bridge unit 21A, and an output voltage from the difference unit 21B is input to the analog comparator 13-1.

  According to the third embodiment, in addition to the same effects as those of the first embodiment described above, there is an effect that even if the sensor detection signal is a small signal, it can be detected with high accuracy.

(D) Fourth Embodiment Next, interrogator according to the invention, the non-contact data carrier system, and, a fourth embodiment of a data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 8 is a block diagram showing the configuration of the contactless data carrier system according to the fourth embodiment. The same and corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same and corresponding reference numerals. It shows. In FIG. 8, the interrogator 3 and the host device 4 are not shown.

  The fourth embodiment is different from the first embodiment described above in the internal configuration of the non-contact data carrier 2 and the external configuration on the sensor side. In the fourth embodiment, only the latch unit 14A that is one component of the variable threshold unit 14 is left inside the non-contact data carrier 2, and the threshold value forming unit 14B that is the other component of the variable threshold unit 14 is not used. It is provided outside the contact data carrier 2. That is, the non-contact data carrier 2 of the fourth embodiment includes an output port 22 for threshold data and an input port 23 for threshold (threshold voltage).

  The threshold data transfer from the latch unit 14A inside the non-contact data carrier 2 to the threshold value forming unit 14B outside the non-contact data carrier 2 is not limited to the parallel transfer as shown in FIG. It may be.

  In addition, the threshold forming unit 14B is provided outside the non-contact data carrier 2 so that the change (unit change) of the threshold (threshold voltage) corresponding to the difference of 1 bit of the threshold data can be arbitrarily set. Intended to be. For example, a 1-bit difference in threshold data can correspond to a threshold (threshold voltage) of 0.1 V, or can correspond to 0.2 V, and the operator can arbitrarily change the unit of the threshold (threshold voltage). Can be set. For example, a plurality of types of threshold value forming units having different unit changes such as a threshold value forming unit having a unit change of 0.1 V and a threshold value forming unit having a unit change of 0.2 V are prepared. 14B may be connected to the non-contact data carrier 2 to arbitrarily set the unit change of the threshold (threshold voltage). Further, an adjustment operator may be provided, and a threshold forming unit 14B that arbitrarily sets a unit change of the threshold (threshold voltage) according to the position of the adjustment operator may be connected to the non-contact data carrier 2. For example, as the variable threshold value forming unit, the resistors connected in series in FIG. 2 are replaced with variable resistors, and the resistance values of all the variable resistors are changed according to the position of the adjusting operator. Can do.

  According to the fourth embodiment, in addition to the same effects as those of the first embodiment described above, there is an effect that the step width of the threshold (threshold voltage) can be selected.

(E) Fifth Embodiment Next, interrogator according to the invention, the non-contact data carrier system, and, a fifth embodiment of a data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 9 is a block diagram showing the internal configuration of the contactless data carrier according to the fifth embodiment. The same and corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same and corresponding reference numerals. It shows.

  The fifth embodiment differs from the first embodiment described above in the internal configuration of the non-contact data carrier 2. In the case of the fifth embodiment, the nonvolatile memory 11 includes a threshold data correction table 11T-1 for each of the measurement ports 15-1 and 15-2 (only one measurement port 15-1 is shown in FIG. 9). , 11T-2 are stored.

  The threshold data correction table 11T-1 (the same applies to the table 11T-2) is obtained when threshold data defining the threshold value of the variable threshold value unit 14 is received or determined internally (see FIGS. 3 and 4). This is for obtaining corrected threshold data corresponding to the data, and the corrected threshold data is latched by the latch unit 14A of the variable threshold unit 14.

  In general, the state (value; for example, temperature) of the measurement target item and the output detection signal (for example, voltage value) of the sensor are not in a linear relationship and are nonlinear. Although not described in detail, in the first to fourth embodiments described above, the sensors 5-1 and 5-2 have a function of correcting the nonlinear relationship to a linear relationship, or the host device 4 However, it is assumed that it has a function of correcting the measurement result corresponding to the output detection signal to the state of the actual measurement target item. In the fifth embodiment, the input / output nonlinearity of the sensors 5-1 and 5-2 is compensated by correcting the threshold data.

  Here, since the types of the sensors 5-1 and 5-2 connected to the measurement ports 15-1 and 15-2 of the non-contact data carrier 2 are arbitrary, the threshold data correction table 11T-1 of the nonvolatile memory 11 is used. , 11T-2 can be arbitrarily rewritten. Rewriting (overwriting) is performed, for example, by transmitting a command string from the interrogator 3 or by inputting from the external input / output terminal 17.

  According to the fifth embodiment, in addition to the same effect as that of the first embodiment described above, there is an effect that the nonlinearity of the sensor connected to the non-contact data carrier can be compensated.

(F) Sixth Embodiment Next, interrogator according to the invention, the non-contact data carrier system, and, a sixth embodiment of the data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 10 is a block diagram showing the internal configuration of the contactless data carrier of the sixth embodiment. The same and corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same and corresponding reference numerals. It shows.

  The sixth embodiment is different from the first embodiment in that the non-contact data carrier 2 has a power supply control unit 24. The power supply control unit 24 operates to the analog comparators 13-1 and 13-2 (only 13-1 is shown in FIG. 10) and the variable threshold unit 14 according to the supply control signal from the ID tag core unit 10. The power supply is controlled (on or off). The ID tag core unit 10 controls the power supply control unit 24 in response to reception of a signal including a supply control command from the interrogator 3, receives a question signal that defines a measurement mode, and recognizes the end of a measurement operation. Accordingly, the power supply control unit 24 is controlled.

  That is, in a normal operation other than the measurement operation (a general communication operation with the interrogator 3 as the non-contact data carrier 2), only the measurement operations such as the analog comparators 13-1, 13-2 and the variable threshold unit 14 are performed. The power supply to the functioning part can be stopped.

  In the case of the non-contact data carrier 2 not equipped with a battery, the operating energy is obtained from the interrogator 3 side, but power is supplied to a portion that functions only for the measurement operation during general communication operation, and even a little power consumption. When this occurs, the effective communication distance becomes shorter than when no power consumption occurs. In order to prevent this, a power supply control unit 24 is provided.

  According to the sixth embodiment, in addition to the same effects as those of the first embodiment described above, even if a measurement function configuration is provided, a desired communication distance during normal operation (for example, a communication distance defined by a standard) The effect that can be secured.

(G) Seventh Embodiment Next, interrogator according to the invention, the non-contact data carrier system, and, the seventh embodiment of the data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 11 is a block diagram showing the configuration of the contactless data carrier system according to the seventh embodiment. The same or corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same or corresponding reference numerals. It shows. In FIG. 11, the interrogator 3 and the host device 4 are omitted, and only one analog comparator (13) is shown.

  The seventh embodiment is different from the first embodiment in that the non-contact data carrier 2 includes a pair of power supply external supply ports 25P and 25N and a power supply external supply control unit 26.

  The pair of power supply external supply ports 25P and 25N are connected to the power input terminals VINP and VINN (VINN is a ground side terminal) of the sensor 5 not equipped with a power supply, and from the non-contact data carrier 2 to the sensor 5 It is possible to supply power. The external power supply control unit 26 controls (on or off) the supply of operation power to the sensor 5 in accordance with a supply control signal from the ID tag core unit 10. The ID tag core unit 10 controls the external power supply control unit 26 in response to the reception of the signal including the supply control command from the interrogator 3, receives the inquiry signal that defines the measurement mode, recognizes the end of the measurement operation, etc. In response to this, the external power supply control unit 26 is controlled.

  According to the seventh embodiment, in addition to the effects similar to those of the first embodiment described above, even if the sensor is not equipped with a power supply (for example, a thermistor), the measurement operation can be performed. There is an effect that the desired communication distance during normal operation can be ensured (similar to the case of the sixth embodiment).

(H) Embodiment Next eighth interrogator according to the invention, the non-contact data carrier system, and, an eighth embodiment of the data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 12 is a block diagram showing the configuration of the contactless data carrier system according to the eighth embodiment. The same and corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same and corresponding reference numerals. It shows. In FIG. 12, the interrogator 3 and the host device 4 are omitted, and only one analog comparator (13) is shown.

  The eighth embodiment is different from the first embodiment in that the non-contact data carrier 2 has an operation command output port 27.

  The operation command output port 27 is provided to give an operation command indicating ON or OFF of the measurement operation output from the ID tag core unit 10 to the connected sensor 5. In the case of the eighth embodiment, it is assumed that the sensor 5 is controlled to be turned on / off by an operation command from the outside.

  In response to reception of a signal including an operation command from the interrogator 3, the ID tag core unit 10 outputs an operation command to the operation command output port 27, receives an interrogation signal that defines a measurement mode, and terminates the measurement operation. An operation command is output to the operation command output port 27 according to recognition or the like.

  For example, when there is a measurement timing of the sensor 5, the operator outputs an operation command in accordance with the timing from the host device 4, or after turning on the power of the sensor 5, a predetermined time elapses. After waiting, the host device 4 outputs an ON operation command, and arbitrarily controls the measurement operation state of the sensor 5. Note that an input port for inputting the power ON / OFF signal of the sensor 5 to the ID tag core unit 10 of the non-contact data carrier 2 is provided, and the ID tag core unit 10 supplies the operation command output port 27 based on the detection of the power ON of the sensor 5. An ON operation command may be output.

  According to the eighth embodiment, in addition to the same effects as those of the above-described first embodiment, there is an effect that the interrogator and the host device can control the operation state of the sensor via the non-contact data carrier.

(I) Ninth Embodiment Next, interrogator according to the invention, the non-contact data carrier system, and, a ninth embodiment of the data acquisition how the contactless data carrier with reference to the drawings will be described.

  FIG. 13 is a block diagram showing the configuration of the non-contact data carrier system of the ninth embodiment. The same and corresponding parts as those in FIG. 1 according to the first embodiment described above are assigned the same and corresponding reference numerals. It shows. In FIG. 13, the interrogator 3 and the host device 4 are omitted, and only one analog comparator (13) is shown.

  The ninth embodiment is different from the first embodiment in that the contactless data carrier 2 has a measurement mode on / off signal input port 28 connected to the measurement mode on / off signal generator 6.

  The measurement mode on / off signal generator 6 generates, for example, a measurement mode on / off signal that takes logic “0” (represents measurement mode off) or logic “1” (represents measurement mode on) according to the position of the toggle switch. The measurement mode on / off signal is generated and supplied to the ID tag core unit 10 via the measurement mode on / off signal input port 28.

  When the measurement mode on / off signal is logic “1”, the ID tag core unit 10 executes the measurement mode operation when the measurement mode operation is instructed from the interrogator 3, and the measurement mode on / off signal is logic “0”. In this case, even if the measurement mode operation is instructed from the interrogator 3, it is ignored and the measurement mode operation is not executed.

  When a timer is provided on the path from the measurement mode on / off signal input port 28 to the ID tag core unit 10 and the measurement mode on / off signal to the measurement mode on / off signal input port 28 temporarily changes to “1”, the measurement mode Even if the measurement mode on / off signal to the on / off signal input port 28 returns to “0”, a measurement mode on / off signal having a predetermined time of “1” may be input to the ID tag core unit 10.

  Further, the measurement mode on / off signal generator 6 and the sensor 5 do not have to be separate and independent. For example, the sensor 5 may include the measurement mode on / off signal generator 6 and generate a measurement mode on / off signal of “1” only when the sensor 5 is in a predetermined state (for example, a measurable state).

  According to the ninth embodiment, in addition to the same effects as those of the first embodiment described above, whether or not the measurement operation of the non-contact data carrier based on the request from the interrogator can be executed from the outside of the non-contact data carrier. The effect is that it can be instructed.

(J) Other Embodiments In the description of each of the above embodiments, various modified embodiments have been referred to. However, modified embodiments exemplified below can be cited.

  Needless to say, the technical ideas of the above-described embodiments may be combined with the technical ideas of the other embodiments as long as no contradiction arises. Further, when there are a plurality of measurement ports, the technical idea applied depending on the measurement port may be changed.

  In each of the above embodiments, the threshold value is changed during the period of searching for the measured value. However, the threshold value is fixed, and the DC level of the sensor detection signal is shifted according to the threshold data and input to the analog comparator. You may make it let it. That is, it does not matter which of the two inputs input to the analog comparator is shifted in accordance with the threshold data. In addition, although the expression of a claim can be read so that only the case where the threshold value side is changed is included, it includes the case where the DC level of the sensor detection signal is shifted.

  In each of the above-described embodiments, only the first measurement operation is performed in the first measurement mode in which the threshold value is gradually changed (increased) from the minimum value threshold value and two threshold values that change the logic of the comparison result are searched. Although shown, all the measurement operations may be performed in the first measurement mode.

The threshold value change in the first measurement mode may be a case where the threshold value gradually decreases from the maximum value threshold value.

  Note that the threshold value search method for changing the logic of the comparison result is not limited to the method of the first measurement mode described above. For example, a so-called binary search method can be applied. That is, assuming that the total number of thresholds is N, first, the N / 2th threshold value is set starting from the smallest value and the comparison result is fetched. If the logic is “0”, N / 4th threshold is set and the comparison result is taken in. On the other hand, if the logic of the first comparison result is “1”, the 3N / 4th threshold is set from the smallest and the comparison result is taken in, and so on. Then, the search range is narrowed down by half according to the logic of the previous comparison result, and two threshold values at which the logic of the comparison result changes are found.

  In each of the embodiments described above, the execution subject that changes the threshold data in the first measurement mode is the interrogator. However, the non-contact data carrier or the host device changes the threshold data in the first measurement mode. The execution subject to be executed may be used. Similarly, in each of the above embodiments, the execution subject that changes the threshold data in the second measurement mode is the non-contact data carrier. However, the interrogator or the host device has the threshold value in the second measurement mode. It may be an execution subject that changes data.

  In each of the above embodiments, in the measurement mode, the comparison result is returned from the non-contact data carrier to the interrogator, or threshold data whose logic has changed to “1” is returned. Other parameters indicating the measurement result may be returned. For example, using a variable threshold value portion where the charging voltage gradually changes such as a low-pass filter, the time from the charging start time to the time when the sensor detection signal exceeds the threshold is counted by a timer in the ID tag core portion, The timekeeping time (this timekeeping time corresponds to the threshold value information whose comparison result has changed) may be returned to the interrogator as a parameter representing the measured value.

  In each of the above embodiments, the threshold data itself is given from the interrogator to the non-contact data carrier. However, a threshold code that defines the threshold data is given, and the non-contact data carrier is a code / data conversion table of the nonvolatile memory. The threshold value data may be converted in accordance with the above. In this case, as a parameter representing the measurement result, a threshold code instead of threshold data may be returned from the non-contact data carrier to the interrogator.

  The information transmission method between the interrogator and the non-contact data carrier may be any of an electromagnetic coupling method and a microwave method. The non-contact data carrier may be a battery-mounted type. In this case, an electromagnetic induction method, an optical communication method, or the like can be applied.

  In each of the above embodiments, the case of an analog comparator that outputs the magnitude of a threshold as a comparison result has been shown. However, a window comparator that determines whether a sensor detection signal is in the range of + threshold to -threshold is applied. You may make it do. A digital comparator may be applied in consideration of a digital output sensor. For example, even in this case, the digital comparator may output a comparison result as to whether or not the sensor output data and the threshold data match. Such a digital comparator can be composed of, for example, an exclusive OR element provided for each bit and an OR element to which the outputs of all the exclusive OR elements are input.

  Further, in each of the above-described embodiments, one measurement item is obtained with one analog comparator, but a comparison result is obtained with a plurality of analog comparators for one measurement item. You may do it. For example, two analog comparators are provided for one measurement item, and different threshold values (for example, A and A + 1 units) are set for comparison, and two comparison results are obtained at the same time. You may make it transmit to a device.

  The number of semiconductor chips mounted on the contactless data carrier of each embodiment and what components are formed on each semiconductor chip may be arbitrary.

  In each of the embodiments described above, the interrogator obtains a response signal related to the measurement operation from one non-contact data carrier. However, the single interrogator has a plurality of non-contact data carriers. For example, if the measurement information is captured from each non-contact data carrier by the following processing 1 to processing 4, the measurement information can be efficiently captured.

  Process 1: The interrogator instructs the measurement mode by the broadcast function for all non-contact data carriers.

  Process 2: The interrogator gives threshold data to all non-contact data carriers by the broadcasting function and gradually increases the threshold data.

  Process 3: After the measurement mode is instructed, the non-contact data carrier checks the comparison result of the analog comparator every time the threshold data is given, and sets the threshold data when the comparison result is changed to the non-volatile data inside. Store in memory. When the threshold data when the comparison result is changed is stored in the internal nonvolatile memory, the non-contact data carrier does not execute the comparison operation thereafter even if the threshold data is given.

  Process 4: After sending the maximum threshold data, the interrogator designates each contactless data carrier individually (for example, by a polling method) and stores it in the nonvolatile memory of the contactless data carrier. Then, the threshold value data when the comparison result changes is captured.

  The functional division between the interrogator and the higher-level device is not limited to those in the above embodiments. In the claims, the higher-level devices for the non-contact data carrier are collectively called an interrogator.

  Further, the functional division of the non-contact data carrier and the interrogator for the fixed data holding surface or the like is not limited to those of the above embodiments. For example, the interrogator may be provided with a threshold data correction table, and the interrogator may execute threshold data correction processing.

It is a block diagram which shows the structure of the non-contact data carrier system of 1st Embodiment. It is a circuit diagram which shows the principal part structure of the variable threshold value part of 1st Embodiment. It is a flowchart which shows the operation | movement in the measurement mode of the interrogator of 1st Embodiment. It is a flowchart which shows the operation | movement in the 2nd measurement mode of the non-contact data carrier of 1st Embodiment. It is a block diagram which shows the structure of the non-contact data carrier system of 2nd Embodiment. It is a block diagram which shows the structure of the non-contact data carrier system of 3rd Embodiment. It is a circuit diagram which shows the example of an internal structure of the bridge circuit of 3rd Embodiment. It is a block diagram which shows the structure of the non-contact data carrier system of 4th Embodiment. It is a block diagram which shows the internal structure of the non-contact data carrier of 5th Embodiment. It is a block diagram which shows the internal structure of the non-contact data carrier of 6th Embodiment. It is a block diagram which shows the structure of the non-contact data carrier system of 7th Embodiment. It is a block diagram which shows the structure of the non-contact data carrier system of 8th Embodiment. It is a block diagram which shows the structure of the non-contact data carrier system of 9th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Non-contact data carrier system, 2 ... Non-contact data carrier, 3 ... Interrogator, 4 ... Host apparatus, 5-1, 5-2 ... Sensor, 6 ... Measurement mode on-off signal generator, 10 ... ID tag core 11: Non-volatile memory, 11T-1, 11T-2 ... Threshold data correction table, 12 ... Antenna, 13, 13-1, 13-2 ... Analog comparator, 14 ... Variable threshold unit, 15 and 15-1 , 15-2 ... measurement port, 16 ... external expansion terminal, 17 ... external input / output terminal (external I / O terminal), 20 ... analog switch, 21 ... bridge circuit, 22 ... output port for threshold data, 23 ... threshold ( Threshold voltage input port, 24 ... Power supply control unit, 25P, 25N ... Power supply external supply port, 26 ... Power supply external supply control unit, 27 ... Operation command output port, 28 ... Measurement mode on / off signal The Power port.

Claims (26)

Interrogator,
A non-contact data carrier having at least one measurement port for exchanging data with the interrogator by wireless communication;
A compared signal generation source configured to generate a compared signal according to a surrounding physical quantity, connected to at least one measurement port of the non-contact data carrier;
The contactless data carrier is
The above measurement port to which an external signal to be compared is input,
A comparison means for comparing the signal to be compared input from the measurement port with a threshold value and outputting a comparison result of logical values representing the magnitude relationship between the two;
Variable threshold means for outputting the threshold value;
Comparison control for controlling a threshold value from the variable threshold value means according to a comparison output request including an instruction of a change value of the threshold value from the interrogator and returning a comparison result of the comparison means or information related to the comparison result and means,
The interrogator instructs the non-contact data carrier to change a threshold value every time the comparison output request is sent .   2. The non-contact data carrier system according to claim 1, wherein the comparing means compares a signal to be compared made of an analog signal with a threshold value made of an analog signal.   3. The non-contact data according to claim 2, wherein the variable threshold means includes a plurality of resistors connected in series, and includes a threshold value forming unit that selects a divided voltage and extracts it as a threshold value formed of an analog signal. Carrier system.   The contactless data carrier system according to claim 1, wherein a plurality of corresponding pairs of the measurement port and the comparison means are provided.   4. The apparatus according to claim 1, comprising a plurality of the measurement ports, and signal selection means for inputting a signal to be compared from any one of the measurement ports to the common comparison means. 5. Non-contact data carrier system.   6. The non-contact data carrier system according to claim 1, further comprising bridge circuit means for expanding a dynamic range of a signal to be compared on a path from the measurement port to the comparison means. 7. The non-contact data carrier system according to claim 1, wherein the configuration of the variable threshold means is divided into two, and one of the components is an external element of the non-contact data carrier. . The non-contact data carrier comprises non-linearity compensation information storage means for storing non-linear information of a signal to be compared generation source that generates the signal to be compared according to a surrounding physical quantity,
The non-contact according to any one of claims 1 to 7, wherein the comparison control means changes information indicating an output threshold to the variable threshold means according to the storage information of the nonlinearity compensation information storage means. Data carrier system.   9. The non-contact data according to claim 1, wherein the non-contact data carrier has power control means for controlling on / off of supply of operating power to at least the comparison means and the variable threshold means. Carrier system.   The contactless data carrier according to any one of claims 1 to 9, wherein the contactless data carrier has a power supply external supply port that can supply power obtained from wireless energy from the interrogator to the outside. system.   11. The non-contact data carrier system according to claim 10, wherein the non-contact data carrier has power external supply control means for controlling on / off of power supply to the power external supply port.   The non-contact data carrier has an operation command output port for giving a command for instructing on / off of operation to an external signal-to-be-compared signal generating source that generates the signal to be compared in accordance with a surrounding physical quantity. The non-contact data carrier system according to claim 1.   The non-contact data carrier has an input port which takes in a comparison output request on / off signal from the outside and instructs the comparison control means to instruct whether to allow or ignore a comparison output request from the interrogator. The non-contact data carrier system according to claim 1.   14. The contactless data carrier according to claim 1, wherein at least one of the plurality of means constituting the contactless data carrier is formed on a semiconductor chip. system.   15. All or part of the plurality of means constituting the non-contact data carrier are formed by being dispersed on a plurality of semiconductor chips. Non-contact data carrier system. The interrogator, by repeatedly executing the comparison of the comparison means is changed threshold value, the threshold information of the logic changed in a comparison result of the comparing means obtained from the response signal from the comparison control means, the 16. The non-contact data carrier system according to claim 1, wherein information on a physical quantity related to the signal to be compared generated by the signal generation source to be compared is obtained.   16. The contactless data carrier system according to any one of claims 1 to 15, wherein one interrogator can communicate with a plurality of the contactless data carriers. The interrogator causes each non-contact data carrier to repeatedly execute the comparison of the comparison means with the changed threshold value by broadcast communication, and stores information on the threshold value at which the logic of the comparison result of the comparison means has changed. Let me know
Thereafter, the information of the threshold value with which the logic of the comparison result has changed is taken from each of the non-contact data carriers by individual communication to obtain information on the physical quantity related to the signal to be compared generated by the signal to be compared source. 18. A contactless data carrier system according to claim 17 , characterized in that A non-contact data carrier in the non-contact data carrier system according to claim 1, wherein a compared signal generation source that generates a compared signal according to a surrounding physical quantity is connected to at least one measurement port. A subordinate interrogator,
Each time a comparison output request is sent to the non-contact data carrier, the change value of the threshold value is instructed to the non-contact data carrier, and the comparison of the non-contact data carrier with the changed threshold value is repeatedly executed, The information of the threshold value at which the logic of the comparison result of the comparison means has changed is obtained from the return signal from the comparison control means, and the information on the physical quantity related to the signal to be compared generated by the signal to be compared source is obtained. Interrogator. The initial value of the change of the threshold value, the previous measurement scheduled, interrogator according to claim 19, characterized in that it is determined based on the threshold logic of the comparison result changes in the comparing means.   20. The interrogator according to claim 19, comprising a plurality of said non-contact data carriers. By means of broadcast communication, each non-contact data carrier is caused to repeatedly execute the comparison of the comparison means whose threshold value has been changed, and information on the threshold value in which the logic of the comparison result of the comparison means has changed is stored,
By subsequent individual communication, information on a threshold whose logic of the comparison result has changed is taken from each non-contact data carrier, and information on a physical quantity related to the signal to be compared generated by the signal to be compared source is obtained. The interrogator according to claim 21 , characterized in that: The non-contact data carrier system according to any one of claims 1 to 15, wherein the interrogator is connected to at least one measurement port with a signal source to be compared that generates a signal to be compared according to a surrounding physical quantity. A data acquisition method for a non-contact data carrier, which is under the control of a contact data carrier and obtains information on a physical quantity related to the compared signal generated by the compared signal generation source from the non-contact data carrier,
Each time the interrogator sends a comparison output request to the non-contact data carrier, the change value of the threshold value is instructed to the non-contact data carrier, and the non-contact data carrier compares the comparison means with the threshold value changed. A search process that repeatedly executes
A change threshold value recognition step in which the interrogator or the non-contact data carrier recognizes information on the threshold value at which the logic of the comparison result of the comparison means has changed;
The interrogator includes a physical quantity identification step for obtaining information on a physical quantity related to the signal to be compared generated by the signal source to be compared based on information on a threshold whose logic has changed. Data acquisition method. 24. The non-contact method according to claim 23 , wherein the search step determines an initial value for changing the threshold value based on a threshold value at which a logic of a comparison result of the comparison means is changed during the previous search step. Data carrier data acquisition method. 24. The data acquisition method for a non-contact data carrier according to claim 23 , wherein the interrogator obtains information on a physical quantity related to the signal to be compared from a plurality of the non-contact data carriers. The search step is performed in parallel for each non-contact data carrier by broadcast communication from the interrogator to the non-contact data carrier,
The change threshold value recognition step is executed by each of the non-contact data carriers, and internally stores information of a threshold value at which the logic of the comparison result of the comparison means has changed,
The physical quantity identification step is characterized in that the interrogator takes in threshold information whose logic of the comparison result has changed from each non-contact data carrier by individual communication, and repeatedly executes each non-contact data carrier. The method for obtaining data of a non-contact data carrier according to claim 25 .

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