JP2014021811A - Measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish connection between a measuring device body and each of measuring units in a short time concerning a measuring instrument where the measuring device body and each of the measuring units are connected via a radio network.SOLUTION: A measuring instrument includes: multiple measuring units 20; and a measuring device body 10 for processing measurement data measured by each of the measuring units 20 in a predetermined manner. In the measuring instrument, the measuring units and the measuring device body are connected by radio communication means to be bi-directionally communicable, measurement in each of the measuring units 20 is started based on a measurement start signal from the measuring device body 10, and the measurement data is sequentially collected by the measuring device body 10. Bluetooth (R) and ZigBee (R) are provided as the radio communication means. Connection between the measuring device body 10 and each of the measuring units 20 in the power supply of the measuring device body 10 is performed by ZigBee (R). ZigBee (R) is switched into Bluetooth (R) when communication by Bluetooth (R) is established after connection by ZigBee (R).

Description

  The present invention relates to a measurement device that collects measurement data measured by measurement units arranged at a plurality of locations and performs a predetermined process on the measurement device body, and more specifically, between the measurement device body and the measurement unit. The present invention relates to a measurement apparatus that is connected wirelessly.

  For example, in an indoor air conditioning design provided as a store, office, etc., temperature measurement units called data loggers for temperature measurement are arranged on the ceiling, wall surface, floor surface, etc. of the room, and these temperature measurement units The measurement data measured in this way is collected in the main body of the measuring device as the master device, and the temperature distribution in the room is analyzed.

  When collecting data from each measurement unit, normally, as described in Patent Document 1, the measurement unit is docked to the measurement device main body, or the measurement unit and the measurement device main body are connected by wiring. ing. As another method, a method of collecting data using an SD card or the like is also known.

  However, in the method of docking the measurement unit to the measurement device main body, it is necessary to remove the measurement unit from the installation location and carry it to the measurement device main body. Further, even in a method of collecting data using an SD card or the like, it is necessary for an operator to go to a place where each measurement unit is installed, and in any case, it takes time and labor.

  According to the method of connecting the measurement unit and the measuring instrument main body with wiring, measurement data can be collected in real time in the measuring instrument main body, but it takes time to perform wiring work especially when there are many measuring units. .

  In addition, when the wiring length is long, the wiring cost is increased, and there is a problem that miswiring or noise due to the connection to the connection port is likely to be mixed. Also, it is difficult to add or delete measurement units.

JP 2011-187686 A

  Therefore, an object of the present invention is to connect the measuring instrument main body and each measuring unit with a wireless network that does not require wiring, in particular, a short-range wireless network such as Bluetooth (registered trademark) or Zigbee (registered trademark). In the measuring apparatus formed as described above, the connection between the measuring instrument main body and each measuring unit can be established in a short time.

  In order to solve the above-mentioned problems, the present invention includes a plurality of measurement units that measure a predetermined physical quantity, and a measuring instrument body that processes measurement data measured by each measurement unit. And the measuring instrument main body are connected so as to be capable of two-way communication by wireless communication means, and measurement is performed in each measuring unit based on a measurement start signal from the measuring instrument main body, and the measurement data is sequentially transmitted to the measuring instrument. In the measurement apparatus collected in the main body, the wireless communication means has Bluetooth and Zigbee, and the connection between the measurement main body and each measurement unit when the measurement main body is turned on is as follows. When the communication by Bluetooth is established after the connection by ZigBee and the connection by the ZigBee is established, There has been characterized in that it is switched to the Bluetooth from the ZigBee.

  In the present invention, data transfer may be performed by the ZigBee until the Bluetooth connection is established.

  The switching from the Zikbee to the Bluetooth is preferably performed by software of the control unit of the measuring device main body.

  According to the present invention, when there are eight or more measurement units connected to the measuring instrument main body, the communication by Bluetooth is applied to seven of them, and the communication by ZigBee is applied to the eighth and subsequent units. Will be.

  According to the present invention, when connecting the measuring instrument main body and each measuring unit with a short-range wireless network, the short-range wireless communication means has Bluetooth and Zigbee, and the power supply of the measuring instrument main body The connection between the measuring instrument main unit and each measuring unit at the time of input is performed by ZigBee, and Bluetooth is used for communication after the connection, so that the connection between the measuring instrument main unit and each measuring unit is established in a short time. be able to.

  In addition, since each measurement unit and the measuring instrument main body are connected wirelessly, wiring (connection cable) is not required, and the measurement unit can be easily installed in a place where wiring is difficult. it can.

  In addition, since the measurement data of each measurement unit can be collected sequentially in the main body of the measuring instrument, the main body of the measuring instrument can display the measurement result etc. in almost real time, save it to media, Communication is possible. Moreover, according to the short-range wireless communication means such as Bluetooth or ZigBee, a wireless PAN (Personal Area Network) can be constructed with low cost and low power consumption.

(A) The image figure which shows the piconet constructed | assembled by Bluetooth, (b) The timing chart which shows the frequency hopping performed by Bluetooth. (A) The block diagram which shows the structure of the measuring device main body used by this invention, (b) The block diagram which shows a preferable example of the communication module with which a measuring device main body is provided. (A) The block diagram which shows the structure of the measurement unit used by this invention, (b) The block diagram which shows a preferable example of the communication module with which a measurement unit is provided.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3, but the present invention is not limited to this.

  In the embodiment of the present invention shown in FIG. 1, a plurality of measurement units 20 a to 20 g (seven in this example) as slave devices are preferably two with respect to one measuring device main body 10 as a master device. .. A wireless network is constructed by connecting to enable two-way communication using short-range wireless communication means using 4 GHz band radio waves. In addition, when it is not necessary to distinguish each measurement unit 20a-20g in particular, it is set as the measurement unit 20 as a general term.

  Currently, there are Bluetooth (registered trademark) and Zigbee (registered trademark) as short-range wireless communication means using 2.4 GHz band radio waves. Bluetooth will be described here. For ZigBee, the frequency band used differs depending on the country, and the frequency band is, for example, the 900 MHz band in the United States and the 800 MHz band in Europe.

  Bluetooth is a communication technology that realizes audio signals and data communication over a short distance using radio waves in the 2.4 GHz band, and is mainly applied to small communication devices characterized by low cost and low power consumption.

In Bluetooth, the frequency band of 2402 to 2480 MHz is divided into 79 frequency bands by 1 MHz, and communication is performed while pseudo-randomly changing the frequency band to be used every 625 μs, as shown in FIG. This is called frequency hopping, and the communication frequency f (k) is expressed by the following equation.
Communication frequency f (k) = 2402 + k (MHz), where k = 0, 1, 2,... 78

  According to the Bluetooth standard, the number of measurement units (slave devices) 20 that can be connected to one measuring device body (master device) 10 is limited to a maximum of seven as shown in FIG. The wireless network based on Bluetooth is called “Piconet”.

  The measuring instrument main body 10 controls the piconet so that it can communicate in the same frequency band within the same time within the piconet, and each measuring unit 20 is synchronized with the measuring instrument main body 10 under the control of the measuring instrument main body 10. Communicate.

  In Bluetooth, communication is performed in units of time called slots. A slot is a time for communication in the same frequency band, and the time interval is 625 μs. When communication in one slot is completed, slot numbers are sequentially added and hopped to the next frequency band.

  This slot number is called a Bluetooth clock, takes a value of 28 bits, and is shared in the same piconet. When the Bluetooth clock is an even number, communication is performed from the measurement device main body 10 to the measurement unit 20, and the measurement device main body 10 designates the measurement unit 20 and starts communication.

  The measuring instrument body 10 sends a synchronization signal at the start of communication, and the measuring unit 20 synchronizes with the measuring instrument body 10 based on the synchronization signal. The measuring instrument body 10 transmits the contents of the data after the synchronization signal. When the Bluetooth clock is an odd number, communication is performed from the measurement unit 20 to the measurement device main body 10, and the measurement unit 20 specified by the slot communicates with the measurement device main body 10.

  Next, intra-piconet synchronization will be described. The measurement units 20 existing in the same piconet can communicate with each other by sharing the frequency hopping pattern of the measuring instrument body 10 and the Bluetooth clock.

  The frequency hopping pattern is uniquely calculated from the Bluetooth device address of the measuring device main body 10 and the Bluetooth clock, and the Bluetooth device address and the Bluetooth clock are given from the measuring device main body 10 to the measurement unit 20 of the connection partner when the piconet is constructed. The Bluetooth device address is a 48-bit address uniquely given to identify the measurement unit 20.

  The measurement unit 20 calculates a hopping pattern based on the given address and clock value, and a piconet is formed when communication with the measuring instrument main body 10 becomes possible using the hopping pattern. In this way, the state in which the frequency hopping pattern and the Bluetooth clock are shared in the piconet with reference to the measuring device main body 10 is referred to as intra-piconet synchronization.

  Referring to FIG. 2A, the measuring instrument main body 10 includes a control unit 11 including a microcomputer or the like as an operation subject. A communication module 12 that communicates with the measurement unit 20 in the piconet is connected to the control unit 11. The communication module 12 may be either a Bluetooth specification or a ZigBee specification.

  The control unit 11 includes a setting unit 13 for setting various operation conditions and the like, an interface 14 for communicating with an external device, a storage unit 15 for storing measurement data, an address of the measurement unit 20, and a liquid crystal panel. A display unit 16 is connected.

  Referring to FIG. 3A, the measurement unit 20 includes a sensor 21 that measures a predetermined physical quantity, a control unit 24 including a microcomputer, and a communication module 25 as a basic configuration. As the communication module 25, a communication module having the same specifications as those employed in the measuring instrument main body 10 is used.

  The sensor 21 may be a temperature sensor, a humidity sensor, a current sensor, a voltage sensor, a sensor for detecting vibration or acceleration, and the like. However, the sensor 21 includes a plurality of sensors 21 and includes a plurality of measurement channels. It is also possible to scan and import the measured data.

  According to this embodiment, the physical quantity (measurement data) measured by the sensor 21 is amplified to a predetermined value by the amplifier 22 and then converted to digital data by the A / D converter 23 and input to the control unit 24 for control. The unit 24 transmits each data or a plurality of data collectively to the measuring instrument main body 10 via the communication module 25.

  The control unit 11 of the measuring instrument main body 10 processes the measurement data transmitted from each measurement unit 20 in a predetermined manner, and preferably displays the measurement data on the display unit 16 in real time, and stores the data in the storage unit 15 or externally via the interface 14. Communicates with a device (for example, a personal computer).

  According to this embodiment, as described above, the communication between the measuring instrument main body 10 and each measuring unit 20 is performed wirelessly in the same piconet, so that the wiring connecting the measuring instrument main body 10 and the measuring unit 20 is performed. (Connection cable) is unnecessary, and the measurement unit can be easily installed in a place where wiring is difficult.

  Further, since the measurement data of each measurement unit 20 can be sequentially collected in the measuring instrument main body 10, the measuring instrument main body 10 displays the measurement result etc. in almost real time, saves it to a medium, and external equipment (for example, a personal computer). ). Note that ZigBee may be employed instead of Bluetooth.

  Next, an outline of the procedure from connection to start of measurement will be described. It is assumed that the measurement unit 20 has an internal power source such as a battery, and the power source is turned on first. First, as procedure 1, the control unit 11 of the measuring instrument main body 10 automatically establishes wireless connection with each measuring unit 20 when the measuring instrument main body 10 is powered on. As procedure 2, the operator sets measurement conditions (for example, a range, a recording length, etc.) in the setting unit 13.

  Next, as procedure 3, the operator presses a measurement start button (not shown). As a result, the measurement conditions set in the setting unit 13 are transmitted from the communication module 12 to each measurement unit 20, and each measurement unit 20 starts measurement in response to this. If measurement conditions are set in advance, step 2 is omitted, and steps 1 to 3 are performed.

  By the way, when Bluetooth is used for the communication modules 12 and 25, it takes time to connect in the procedure 1 in Bluetooth. Usually, the connection time is about 500 ms per unit. However, when the number of connected units increases to a maximum of seven units, it may take about 5 seconds in some cases.

  Therefore, when the measurement is started in the procedure 3, the measuring instrument body 10 and the measurement unit 20 may not be connected. In such a case, it is necessary to wait for measurement to start until connection is established, and measurement may not be started immediately after the power is turned on.

  Speaking of connection time, Zikbee is faster than Bluetooth. ZigBee is a wireless standard for wireless networks, and can be connected instantly after power is turned on. On the other hand, the communication speed (data transfer speed) is 250 kbps for Zicbee, whereas 1 Mbps for Bluetooth, Bluetooth is faster than Zicbee.

  Therefore, in the present invention, as shown in FIG. 2B, a Bluetooth module 121 and a ZigBee module 122 are mounted as the communication module 12 on the measuring instrument body 10 side, and these modules 121 and 122 are connected to the control unit 11. Switchable by software.

  Similarly, as shown in FIG. 3B, the communication module 25 on the measurement unit 20 side is also equipped with a Bluetooth module 251 and a ZigBee module 252, and these modules 251 and 252 are installed by software of the control unit 24. Switchable.

  In the present invention, in order to solve the problem that the Bluetooth connection time is long, the ZigBee modules 122 and 252 are employed when the power is turned on. According to this, as the measuring instrument main body 10 is turned on, the measuring instrument main body 10 and the measuring unit 20 are automatically connected in a short time by ZigBee, so that the measurement waiting time can be improved. . Note that the measuring unit 20 is assumed to be powered on in advance by, for example, an internal battery.

  After connection by ZigBee, the communication module is switched to the Bluetooth module 121, 251 side by the software of each control unit 11, 24, and communication (including data transmission from the measurement unit 20) is performed by Bluetooth having a high communication speed. Do. Note that communication by ZigBee is performed until communication by Bluetooth is performed.

  In this embodiment, switching from ZigBee to Bluetooth is led by the control unit 24 on the measurement unit 20 side.

  That is, while transmitting data from the measurement unit 20 to the measuring instrument main body 10 in ZigBee, the control unit 24 checks whether transmission by Bluetooth is possible and confirms that the connection by Bluetooth has been established. Transmits data via Bluetooth.

  The measuring device main body 10 receives data transmitted from the measuring unit 20 regardless of whether it is ZigBee or Bluetooth. When changing the communication, a command for changing the communication is transmitted from the measuring instrument body 10 to the measuring instrument unit 20.

  In Bluetooth, there is a restriction that the number of measurement units 20 that can be connected to one measuring instrument main body 10 is limited to seven, but according to Zikbee, a maximum of 65535 can be connected simultaneously.

  Accordingly, when the measurement sampling rate may be slow and it is desired to use eight or more measurement units 20, it is preferable to select the ZigBee modules 121 and 251; In the above case, Bluetooth may be used for 1 to 7 units, and communication by ZigBee may be used for the 8th and subsequent units.

10 Measuring instrument body (master equipment)
DESCRIPTION OF SYMBOLS 11 Control part 12 Communication module 121 Bluetooth module 122 Zigbee module 13 Setting part 14 Interface 15 Memory | storage part 16 Display part 20 (20a-20g) Measurement unit (slave apparatus)
21 Sensor 24 Control unit 25 Communication module 251 Bluetooth module 252 ZigBee module

Claims (4)

A plurality of measurement units for measuring a predetermined physical quantity, and a measurement device main body for predetermined processing of measurement data measured by each measurement unit, wherein each measurement unit and the measurement device main body are wirelessly communicated. In a measurement device that is connected so as to be capable of bidirectional communication, and is measured in each measurement unit based on a measurement start signal from the measurement device body, and those measurement data are sequentially collected in the measurement device body,
The wireless communication means includes Bluetooth and Zigbee, and the measuring instrument main body and each measuring unit are connected by the Zigbee when the measuring instrument main body is turned on. A measuring apparatus, wherein the wireless communication means is switched from the ZigBee to the Bluetooth when communication by the Bluetooth is established after connection.   The measuring apparatus according to claim 1, wherein data transfer is performed by the ZigBee until a connection by the Bluetooth is established.   3. The measuring apparatus according to claim 1, wherein the switching from the Zikbee to the Bluetooth is performed by software of a control unit of the measuring instrument main body.   4. The measurement unit according to claim 1, wherein the number of measurement units is eight or more, seven of which are subjected to communication by the Bluetooth, and the eighth and subsequent units are subjected to communication by the ZigBee. The measuring apparatus according to item 1.

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