Measurement value monitoring system and measuring device

Abstract

To provide a measured value monitoring system capable of rapidly grasping a change in a situation inside a plant, while realizing improved power saving.SOLUTION: A measured value monitoring system comprises an indication value acquisition device for outputting a measured value; and a monitoring device for transmitting a down-link signal to the indication value acquisition device, while receiving an up-link signal from the indication value acquisition device. The indication value acquisition device comprises an acquisition part, an up-link transmission control part for transmitting the measured value to the monitoring device in first transmission timing (Tx) that is periodical, a down-link reception control part for shifting the down-link signal from the monitoring device to a receivable state in first reception timing (Rx) after the first transmission timing (Tx), and a state control part for controlling a state between a normal state and a low power-consumption state. The up-link transmission control part transmits the measured value in second transmission timing (tx) different from the first transmission timing (Tx), when the down-link reception control part receives the down-link signal.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a measurement value monitoring system and a measuring device, and more particularly to a measurement value monitoring system and a measuring device aiming to improve power saving performance.

Background Art

[0002] Conventionally, industrial measuring devices used in plants and the like have played an important role in monitoring the state of equipment, detecting abnormalities at an early stage, and determining the necessity of maintenance. For example, a pressure gauge installed in a plant pipe is widely used to monitor the state of the pipe and the fluid flowing through the pipe by detecting the pressure of the fluid flowing through the pipe.

[0003] In recent years, for the purpose of reducing the monitoring burden of workers in a plant, a measurement value monitoring system that connects a measuring device to a communication line and enables remote monitoring of the indicated value of the measuring device has attracted attention. More More more details, the measured value of the measuring device is transmitted to a remote server connected via a communication line. Thereby, since the state of the equipment can be monitored without the plant worker visually checking the measured value of the measuring device, it is possible to reduce the monitoring burden of the worker.

[0004] Patent Document 1 discloses a monitoring system including a terminal that collects sensor data, a monitoring device that monitors sensor data, and a repeater (gateway device) that relays communication data between the terminal and the monitoring device. The terminal and the repeater perform wireless communication conforming to the LoRaWAN (registered trademark) standard. Thereby, not only can sensor data be transmitted to the monitoring device, but also the power saving performance of the monitoring system can be improved.

[0005] More specifically, a terminal that performs wireless communication conforming to the LoRaWAN standard transitions to an active state during a predetermined period of performing wireless communication and transitions to a sleep state during a period of not performing wireless communication. Therefore, it is possible to suppress the power consumed by the terminal during the period of not performing wireless communication, and the power saving performance is improved. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2019 / 189597 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] While the technology disclosed in Patent Document 1 mentioned above can improve the power efficiency of a measurement value monitoring system that allows for remote monitoring of measured values, further improvements to the measurement value monitoring system were desired in order to quickly grasp the situation inside the plant and detect abnormalities early. These improvements will be explained in detail below.

[0008] Figure 15 shows the communication timing between a conventional terminal and a monitoring server. As shown in Figure 15, communication between the terminal and the monitoring server takes place at predetermined periodic intervals. When the communication timing arrives, the measured values ​​are sent from the terminal to the monitoring server. The communication from the terminal to the monitoring server is called uplink communication, and the communication timing (transmission slot) for uplink communication is indicated by "Tx" in Figure 15.

[0009] The monitoring device 60 sends an ACK signal or a control signal containing configuration information to the terminal one second and two seconds after receiving the measured value from the terminal. Communication from the monitoring server to the terminal is called downlink communication, and the communication timing (receive slot) of downlink communication is indicated by "Rx" in Figure 15. The LoRaWAN Class A communication standard specifies that uplink communication must occur before downlink communication.

[0010] The communication cycle between the terminal and the monitoring server is pre-set based on the nature of the measurement data. For example, if the measurement data has the characteristic of fluctuating over a long period, a relatively long communication cycle is set. On the other hand, if the measurement data has the characteristic of fluctuating over a short period, a relatively short communication cycle is set. Since the terminal operates in a sleep state during the idle phase, setting a long communication cycle can reduce the terminal's power consumption and improve power efficiency. On the other hand, setting a short communication cycle allows for early detection of changes in the plant's status.

[0011] However, because the communication cycle between the terminal and the monitoring server is predetermined, it was not possible to respond flexibly when the nature of the measurement data changed. In other words, even if the measurement data showed an abnormal value, wireless communication between the terminal and the monitoring server did not occur until the next predetermined communication phase arrived. Therefore, it was not possible to understand how the plant's condition was changing during the period until the next communication phase and to respond to those changes. For this reason, there was a need for a measurement value monitoring system that could improve power saving while also enabling early understanding of the plant's condition and detecting abnormalities.

[0012] This invention has been made in view of the above problems, and the object of this invention is to provide a measurement value monitoring system that can improve power saving and quickly grasp changes in conditions within a plant. [Means for solving the problem]

[0013] The above problem is solved by the measurement value monitoring system of the present invention, which comprises a measuring device that acquires and outputs a measurement value, and a monitoring device that receives an uplink signal from the measuring device and transmits a downlink signal to the measuring device, wherein the measuring device comprises a measurement value acquisition unit that acquires the measurement value, an uplink transmission control unit that transmits the measurement value acquired by the measurement value acquisition unit to the monitoring device at a predetermined periodic first transmission timing, a downlink reception control unit that transitions the downlink signal to a receivable state at a first reception timing after a predetermined time has elapsed from the first transmission timing to a receivable state that can be received by the monitoring device, a normal state that operates with a first power consumption at the first reception timing, and a low power consumption state that operates with a second power consumption lower than the first power consumption during a period different from the first reception timing The monitoring device has a state control unit that controls the state between a state and a state, and the monitoring device has an uplink receiving control unit that receives the uplink signal transmitted by the measuring device, a downlink transmission determination unit that determines whether to transmit the downlink signal after receiving the uplink signal, and a downlink transmission control unit that transmits the downlink signal to the measuring device based on the determination result of the downlink transmission determination unit, wherein when the downlink receiving control unit receives the downlink signal, the uplink transmission control unit transmits the measured value to the monitoring device at a second transmission timing different from the first transmission timing, the downlink receiving control unit transitions to the receivable state at a second reception timing after a predetermined time has elapsed from the second transmission timing, and the state control unit controls the state so that it returns to the normal state at the second reception timing. The measurement value acquisition unit acquires the measurement value of the analog meter by means of a magnet attached to a pointer mounted on the rotation shaft of the analog meter, and a magnetic sensor that detects the magnetic force generated by the magnet. The magnet has a main body made of an annular shape, and the central axis of the main body is positioned on the axis of the rotation shaft. A through hole is formed in the center of the main body in the direction of extraction, through which an extraction tool used to pull the pointer out of the rotation shaft passes. This will resolve the issue.

[0014] According to the above configuration, the measuring device and the monitoring device communicate at predetermined periodic first transmission timings and first reception timings. When the measuring device is not communicating, it transitions to a low-power state (sleep state). This makes it possible to suppress the power consumed by the measuring device and improve power saving. Furthermore, by transmitting a downlink signal from the monitoring device to the measuring device, communication can be performed at a second transmission timing different from the first transmission timing, allowing for monitoring of measured values. Therefore, the monitoring device can grasp the situation within the plant based on the measured values ​​received at the second transmission timing, without waiting for the next first transmission timing, and detect abnormalities early. Furthermore, with the above configuration, it becomes possible to understand the conditions inside the plant by attaching magnets and magnetic sensors to existing analog meters, without introducing new smart meters to the plant, thus enabling the construction of an inexpensive measurement value monitoring system. Furthermore, with the above configuration, plant workers can remove the magnet-attached pointer from the rotating shaft using a pulling tool, thereby reducing the workload involved in the maintenance of analog meters.

[0015] Furthermore, when the uplink transmission control unit receives the downlink signal from the downlink reception control unit, it is preferable that the uplink transmission control unit transmits the measured value to the monitoring device multiple times at the second transmission timing. According to the above configuration, the measuring device can transmit measured values ​​to the monitoring device multiple times at the second transmission timing, and can also receive downlink signals from the monitoring device multiple times after transmission. This makes it possible to increase the number of transmit / receive slots between the measuring device and the monitoring device in the event of an anomaly in the plant, thereby ensuring the necessary communication opportunities to respond to the anomaly.

[0016] Furthermore, it is preferable that the state control unit controls the state so that the measuring device enters an initial setting state with the first power consumption after startup, the uplink transmission control unit transmits the measured value or set value to the monitoring device multiple times at a third transmission timing different from the first transmission timing in the initial setting state, and the downlink reception control unit transitions to the receivable state at a third reception timing after a predetermined time has elapsed from the third transmission timing. According to the above configuration, it becomes possible to increase the number of transmit / receive slots between the measuring device and the monitoring device in the initial setup state of the measuring device, thereby ensuring the communication opportunities necessary for initial setup.

[0017] Furthermore, it is preferable that the downlink transmission determination unit determines whether or not it is necessary to change the setting value of the measuring device, and based on the determination result, determines whether or not to transmit the downlink signal, and that the downlink transmission control unit transmits the changed setting value to the measuring device based on the transmission determination result. According to the above configuration, when it becomes necessary to change the settings of the measuring device, it becomes possible to increase the number of transmit / receive slots between the measuring device and the monitoring device, thereby ensuring the communication opportunities necessary for changing the settings.

[0020] The above problem is solved by the measuring device of the present invention, which transmits an uplink signal to a monitoring device and receives a downlink signal from the monitoring device, comprising: a measurement value acquisition unit that acquires a measurement value; an uplink transmission control unit that transmits the measurement value acquired by the measurement value acquisition unit to the monitoring device at a predetermined periodic first transmission timing; a downlink reception control unit that transitions to a receivable state at a first reception timing after a predetermined time has elapsed from the first transmission timing, so that the downlink signal can be received from the monitoring device; and a state control unit that controls the state between a normal state in which the device operates with a first power consumption at the first reception timing and a low power consumption state in which the device operates with a second power consumption lower than the first power consumption for a period different from the first reception timing, wherein when the downlink reception control unit receives the downlink signal, the uplink transmission control unit transmits the measurement value to the monitoring device at a second transmission timing different from the first transmission timing, the downlink reception control unit transitions to the receivable state at a second reception timing after a predetermined time has elapsed from the second transmission timing, and the state control unit controls the state so that the device operates with the first power consumption at the second reception timing. The measuring device comprises a magnet attached to a pointer fitted onto the rotating shaft of an analog meter, and a magnetic sensor that detects the magnetic force generated by the magnet. The measuring value of the analog meter is acquired based on the magnetic force detected by the magnetic sensor. The magnet has a main body made of an annular shape, and the central axis of the main body is positioned on the axis of the rotating shaft. A through hole is formed in the center of the main body in the direction of extraction, through which an extraction tool used to pull the pointer out of the rotating shaft passes. This will resolve the issue.

[0021] According to the above configuration, the measuring device communicates at a predetermined periodic first transmission timing and first reception timing. When not communicating, the measuring device transitions to a low power consumption state (sleep state). Thereby, it is possible to suppress the power consumed by the measuring device and improve power saving performance. Also, the measuring device can communicate at a second transmission timing different from the first transmission timing and transmit the measured value by receiving a downlink signal from the monitoring device. Therefore, the monitoring device can grasp the situation in the plant based on the measured value received at the second transmission timing without waiting for the next first transmission timing, and can detect an abnormality at an early stage. Furthermore, with the above configuration, it becomes possible to understand the conditions inside the plant by attaching magnets and magnetic sensors to existing analog meters, without introducing new smart meters to the plant, thus enabling the construction of an inexpensive measurement value monitoring system. Furthermore, with the above configuration, plant workers can remove the magnet-attached pointer from the rotating shaft using a pulling tool, thereby reducing the workload involved in the maintenance of analog meters.

Advantages of the Invention

[0022] According to the measured value monitoring system of the present invention, it is possible to improve power saving performance and quickly grasp changes in the situation in the plant.

Brief Description of the Drawings

[0023] [Figure 1] It is a diagram for explaining the overall configuration of the measured value monitoring system. [Figure 2A] It is a front view of the pressure gauge with the indicated value acquisition device attached. [Figure 2B] It is a rear view of the pressure gauge with the indicated value acquisition device attached. [Figure 3] It is an exploded perspective view of the pressure gauge and the indicated value acquisition device. [Figure 4] It is a cross-sectional view of the pressure gauge and the indicated value acquisition device. [Figure 5] It is a diagram showing the configuration of the indicated value acquisition device. [Figure 6] It is an explanatory diagram of the periodic communication timing. [Figure 7] It is an explanatory diagram of the communication timing at the time of setting change. [Figure 8]This is a diagram illustrating the communication timing after the indicator value acquisition device has been activated. [Figure 9] This is an explanatory diagram of the communication timing and state control of the instruction value acquisition device. [Figure 10] This diagram shows the functional configuration of the monitoring device. [Figure 11] This diagram shows the flow of communication control processing. [Figure 12] This is a perspective view of a pulling tool. [Figure 13A] This diagram shows the state before the pointer is pulled out with the extraction tool. [Figure 13B] This diagram shows the pointer after it has been pulled out using a pull-out tool. [Figure 14A] This diagram shows the state before using the extraction tool. [Figure 14B] This diagram shows the extraction tool positioned along the axis of the rotating shaft. [Figure 14C] This figure shows the state in which the tip of the fixed shaft is in contact with the rotating shaft. [Figure 14D] This diagram shows the pointer pulled out from the rotating shaft. [Figure 15] This diagram shows the communication timing between conventional terminal communication and the gateway. [Modes for carrying out the invention]

[0024] The following description of a measurement value monitoring system 1 according to one embodiment of the present invention (hereinafter referred to as "this embodiment") will be given with reference to Figures 1 to 14D. However, the embodiments described below are merely examples to facilitate understanding of the present invention and do not limit it. In other words, the present invention can be modified and improved without departing from its spirit, and of course, equivalents thereof are included in the present invention.

[0025] The measurement value monitoring system 1 of the present invention is used to acquire measurement values ​​from a pressure gauge 20 installed in a plant and to monitor these measurement values ​​using a remote monitoring device 60. By using the measurement value monitoring system 1 of the present invention, the workload of workers is reduced. Furthermore, by using the measurement value monitoring system 1 of the present invention, power saving is improved and monitoring personnel can quickly grasp changes in the conditions inside the plant.

[0026] <Overall configuration of measurement value monitoring system 1> Figure 1 shows an example of the overall configuration of the measurement value monitoring system 1. As shown in Figure 1, the measurement value monitoring system 1 mainly consists of a reading acquisition device 10 attached to a pressure gauge 20, a monitoring device 60 that monitors the reading value (measured value) acquired by the reading value acquisition device 10, and a repeater 50 that relays communication between the reading value acquisition device 10 and the monitoring device 60. The repeater 50 and the monitoring device 60 are connected via a publicly available communication line NW such as the Internet.

[0027] The pressure gauge 20 is installed in the piping within the plant and used to detect abnormalities in the piping and the fluid flowing inside the piping. In Figure 1, three pressure gauges 20 are shown, but the number of pressure gauges 20 is not limited to this. For example, four or more pressure gauges 20 may be installed in the piping within the plant and used to detect abnormalities. In this embodiment, the pressure gauge 20 is described as an example of an analog meter for monitoring the plant's condition, but it is not limited to this. For example, the present invention may be applied to thermometers, hygrometers, and vibration meters.

[0028] The indicator value acquisition device 10, which corresponds to the measuring device, is attached to a pressure gauge 20 that is pre-installed in the plant. The indicator value acquisition device 10 acquires the indicated value (corresponding to the measured value) indicated by the pointer 24 of the pressure gauge 20, and outputs the acquired indicated value to the monitoring device 60 via the relay device 50. In other words, the indicator value acquisition device 10 reads the indicated value of the pressure gauge 20 on behalf of the plant workers and stores it as measurement data in the monitoring device 60. This makes it possible to reduce the workload of the plant workers. Furthermore, the measurement value monitoring system 1 can be easily constructed by attaching the indicator value acquisition device 10 to the existing pressure gauge 20 without introducing a new pressure gauge 20 to the plant.

[0029] As described later, the reading acquisition device 10 acquires the reading (measured value) of the pressure gauge 20 using the angle detector 12. The acquired reading is transmitted to the repeater 50 by LPWA (Low Power Wide Area) communication, for example, wireless communication compliant with the LoRaWAN standard. However, the reading acquisition device 10 may also transmit the reading to the monitoring device 60 using a communication interface compatible with Wi-Fi (registered trademark) or LTE.

[0030] The repeater 50 is a gateway device connected to a publicly available communication line NW such as the Internet, and relays wireless communication signals between the value acquisition device 10 and the monitoring device 60. The repeater 50 receives the readings from multiple pressure gauges 20 installed in the plant and relays them to the monitoring device 60. The repeater 50 also receives control signals, including set values, from the monitoring device 60 to the value acquisition device 10 and relays them to the value acquisition device 10.

[0031] The monitoring device 60 stores instruction values ​​transmitted from the plant and provides them to the plant's monitoring personnel as monitoring data. The monitoring device 60 functions as a storage server that stores instruction values ​​acquired at the plant, and also as a monitoring server that provides monitoring data to the plant's monitoring personnel. This enables the plant's monitoring personnel to determine whether there are any abnormalities in the plant's equipment and whether maintenance is required.

[0032] The configuration of the measurement value monitoring system 1 shown in Figure 1 is illustrative and not intended to limit the configuration of the measurement value monitoring system 1. Although not shown in Figure 1, a network server compliant with the LoRaWAN standard may be connected to the communication line NW and may play a role in controlling communication between the repeater 50 and the monitoring device 60.

[0033] <Pressure gauge 20> First, the pressure gauge 20 will be described. Figure 3 is a partially exploded perspective view showing the configuration of the pressure gauge 20 and the indicator value acquisition device 10. As shown in Figure 3, the pressure gauge 20 has a main body 21, a scale plate 22, a rotating shaft 23, a pointer 24, and a fixing member 25. In addition, an outer frame 27 and a transparent plate 26 held by the outer frame 27 are attached to the front side of the main body 21 so that the scale plate 22 and the pointer 24 can be seen.

[0034] The main body 21 is a Bourdon tube, which is an elastic pressure measuring device. Inside the main body 21 is a well-known rotating mechanism that receives the pressure of the fluid to be measured and mechanically rotates the rotating shaft 23. A scale plate 22 with markings is attached to the front side of the main body 21. The rotating shaft 23 protrudes from the center of the scale plate 22. The pointer 24, which rotates around the rotation axis 23, is fixed to the rotation axis 23 by a fixing member 25. More specifically, the pointer 24 is fixed to the rotation axis 23 by fitting a fitting hole 25a formed in the center of the fixing member 25 onto the rotation axis 23 via the pointer 24.

[0035] When maintenance work is performed on the pressure gauge 20, the outer frame 27 and the transparent plate 26 are removed from the main body 21 by rotating the outer frame 27 relative to the main body 21. Next, the pointer 24 is pulled out from the rotating shaft 23 using the extraction tool 30, which will be described later. This makes it possible to replace the pointer 24 and perform maintenance work on the main body 21.

[0036] <Indication Value Acquisition Device 10> Next, the indicator value acquisition device 10 will be described. Figures 2A and 2B show the external appearance of the pressure gauge 20 and the indicator value acquisition device 10 attached to the pressure gauge 20. Figure 2A is a front view, and Figure 2B is a rear view. As shown in Figure 3, the indicator value acquisition device 10 mainly consists of a magnet 11, an angle detector 12, and a measurement processor 14.

[0037] The magnet 11 is attached to the front side of the pointer 24. The magnet 11 has a magnet body 11a which is an annular shape. In other words, the magnet 11 has an inner surface and an outer surface, and a through hole 11b is formed in the center. The central axis of the magnet 11 is located on the axis of the rotation axis 23. The magnet 11 is a neodymium magnet that generates a strong magnetic field, but is not limited to this. The magnet 11 may be a permanent magnet other than a neodymium magnet, and may be a samarium cobalt magnet (samarium-cobalt magnet) or a ferrite magnet. By employing a ring-shaped neodymium magnet, the magnet 11 can be made lighter, allowing it to rotate with sufficient tracking ability without affecting the movement of the pointer 24. Furthermore, the through hole 11b formed inside the ring-shaped magnet 11 is through which the fixed shaft 31 of the extraction tool 30, described later, passes. In other words, the through hole 11b is formed so that the extraction tool 30 can pass through in the extraction direction P extending along the axis of the rotation shaft 23.

[0038] As shown in Figures 2A and 3, the angle detector 12 is mounted on a transparent plate 26 having a plane perpendicular to the axis of the rotation shaft 23. The angle detector 12 includes a case body 12a, a magnetic sensor 12b housed in the case body 12a, and an angle conversion unit 12c (see Figure 5). The case body 12a is a resin housing with a substantially rectangular parallelepiped shape. The case body 12a can be fixed to the transparent plate 26 with adhesive or double-sided tape.

[0039] As shown in Figure 4, the magnetic sensor 12b is housed at the tip of the case body 12a and positioned to face the magnet 11 directly on the axis of the rotation shaft 23. The magnetic sensor 12b detects the magnetic force and magnetic field generated by the magnet 11. The magnetic sensor 12b is a tunnel magnetoresistive element. By positioning the magnetic sensor 12b to face the magnet 11 directly and employing a tunnel magnetoresistive element, the magnetic force and magnetic field generated by the magnet 11 can be detected with high sensitivity and accuracy.

[0040] As shown in Figures 2A and 4, a position marker 12d is formed at the tip of the case body 12a to allow external confirmation of the housing position of the magnetic sensor 12b. By fixing the case body 12a to the transparent plate 26 so that the position marker 12d is positioned on the axis of the rotation shaft 23, it is possible to position the magnetic sensor 12b housed in the case body 12a directly opposite the magnet 11. Note that the shape of the position marker 12d is not limited to the shape shown in Figure 2A. It is sufficient that the housing position of the magnetic sensor 12b can be confirmed from outside the case body 12a, and the position marker 12d may have a cross shape. This makes it possible to easily confirm the position of the magnetic sensor 12b. The angle conversion unit 12c converts the detected value from the magnetic sensor 12b into an angle signal and outputs it to the measurement processor 14 via the connecting cable 13.

[0041] As shown in Figure 2B, the measurement processor 14 is fixed to the back of the main body 21 of the pressure gauge 20 and is electrically connected to the angle detector 12 via a connecting cable 13. The measurement processor 14 has a case body 14a, and the antenna 14b, the measurement unit 141 (described later), the wireless communication unit 142, and the power supply unit 143 are housed inside the case body 14a (see Figure 5). The case body 14a is a resin housing having a substantially rectangular parallelepiped shape. The case body 14a can be attached to the back of the main body 21 with adhesive or double-sided tape, but is not limited to this.

[0042] Antenna 14b transmits and receives wireless communication signals. As shown in Figures 2A and 2B, antenna 14b is positioned so as not to overlap with the main unit 21 in the front-to-back direction. This suppresses a decrease in the transmit and receive gains of antenna 14b, and makes it possible to secure a stable wireless communication channel between the measurement processor 14 and the repeater 50.

[0043] <Configuration of the measurement and processing unit 14> Next, the configuration of the measurement processing unit 14 will be described. Figure 5 shows the configuration of the measurement processing unit 14. The measurement processing unit 14 mainly consists of a measurement unit 141, a wireless communication unit 142, and a power supply unit 143. The measurement unit 141 includes a processor, volatile memory, and non-volatile memory. By executing a program stored in the non-volatile memory, the processor enables the measurement unit 141 to function as an acquisition unit 141a, a measurement unit 141b, a communication control unit 141c, and a state control unit 141d.

[0044] The acquisition unit 141a acquires the angle signal output by the angle detector 12 and converts it into a pressure signal (measured value). The conversion from the angle signal to the pressure signal can be performed using a predetermined relational expression. The predetermined relational expression is, for example, a linear first-order equation. Alternatively, a correction value may be added to the value obtained by the linear first-order equation. The acquisition unit 141a outputs the obtained pressure signal to the measurement unit 141b. The acquisition unit 141a corresponds to the measurement value acquisition unit. The acquisition unit 141a may acquire the magnetic force signal detected by the magnetic sensor 12b and convert the magnetic force signal into a pressure signal. In this case, it is preferable that the acquisition unit 141a includes an ADC (analog-to-digital converter) and a filter circuit.

[0045] The measurement unit 141b calculates statistical values ​​of the pressure signal (measured value) output by the acquisition unit 141a. Specifically, the measurement unit 141b calculates the average value of the amplitude level of the pressure signal over a predetermined measurement period, but is not limited to this. It is sufficient that the plant status can be understood and abnormalities detected based on the measurement results output by the measurement unit 141b, and minimum and maximum values ​​may also be calculated along with the average value.

[0046] Furthermore, the measurement unit 141b may calculate the frequency parameters of the pressure signal output by the acquisition unit 141a. Specifically, the frequency parameters can be obtained by calculating the average value over a predetermined measurement period and counting the number of times the pressure signal intersects the average value (cross points). Here, the cross points are defined as points where the pressure signal changes from a value smaller than the average value to a value larger than the average value, and points where it changes from a value larger than the average value to a value smaller than the average value. The measurement unit 141b then outputs the value obtained by dividing the total number of cross points by 2 as the estimated frequency of the pressure signal. In this way, by obtaining crossover points relative to the average value, it becomes possible to obtain the frequency parameters of the pressure signal with fewer computational resources (processor processing power or volatile memory storage capacity) than with FFT (Fast Fourier Transform), thereby reducing the power consumption of the measurement processor 14.

[0047] The communication control unit 141c controls the wireless communication between the value acquisition device 10 and the monitoring device 60. Specifically, the communication control unit 141c controls uplink transmission, which is transmitted from the value acquisition device 10 to the monitoring device 60 via the repeater 50, and downlink reception, which is transmitted from the monitoring device 60 via the repeater 50. Uplink transmission is the communication performed to transmit measured values, etc., acquired by the value acquisition device 10, which is an IoT edge device, to the monitoring device 60. Downlink reception, on the other hand, is the communication performed to receive control signals, including setting parameters (corresponding to setting values), transmitted by the monitoring device 60 to the value acquisition device 10.

[0048] Figure 6 shows the communication timing between the indicator value acquisition device 10 and the monitoring device 60. As shown in Figure 6, communication between the indicator value acquisition device 10 and the monitoring device 60 is performed periodically in communication phases that occur at a predetermined interval. The predetermined interval is, for example, 6 hours (4 times a day), but is not limited to this. The predetermined interval may be, for example, 12 hours or 24 hours.

[0049] As shown in Figure 6, communication between the indicator value acquisition device 10 and the monitoring device 60 begins with an uplink transmission from the indicator value acquisition device 10 to the monitoring device 60. Following the uplink transmission, two downlink receptions occur. When a transmission timing (hereinafter referred to as a transmission slot) arrives, the communication control unit 141c controls the wireless communication unit 142, described later, to transmit the measured value acquired by the instruction value acquisition device 10, or the statistical value calculated by the measurement unit 141b, to the monitoring device 60 via uplink. In Figure 6, "Tx" indicates a transmission slot (corresponding to the first transmission timing). The communication control unit 141c corresponds to the uplink transmission control unit.

[0050] The communication control unit 141c transitions to a state where it can receive downlink signals from the monitoring device 60 via the repeater 50 (corresponding to a receivable state) at the reception timing (hereinafter referred to as the reception slot), which is a predetermined time (for example, 1 second and 2 seconds) after the transmission slot. In Figure 6, "Rx" indicates the reception slot (first reception timing). The reception slot is set twice after the transmission slot. The communication control unit 141c corresponds to the downlink reception control unit. As described later, the communication control unit 141c is controlled to operate with low power consumption during the idle phase when no communication takes place between the instruction value acquisition device 10 and the monitoring device 60. This makes it possible to suppress the power consumption of the instruction value acquisition device 10, thereby improving power saving.

[0051] Conventionally, during the idle phase when uplink transmission from the indicator value acquisition device 10 to the monitoring device 60 was not performed, plant monitors were unable to ascertain the status of the plant. Therefore, even if plant monitors had concerns about the plant's condition, they had to wait until the next communication phase, and there was a need for a system that would allow them to grasp the situation inside the plant at an earlier stage. Accordingly, the measurement value monitoring system 1 in this embodiment is equipped with a mechanism that enables the acquisition of measurement values ​​from the indicator value acquisition device 10 at a timing different from that of periodic communication. This will be explained with reference to Figures 7 and 8.

[0052] Figure 7 shows the communication timing when a downlink signal is transmitted from the monitoring device 60 to the indicator value acquisition device 10. As shown in Figure 7, when the communication control unit 141c receives a downlink signal from the monitoring device 60, communication is performed at a timing different from the periodic communication timing described above. More specifically, when the communication control unit 141c receives a downlink signal in a periodic reception slot, it transmits the measured value to the monitoring device 60 multiple times without waiting for the next periodic communication timing to arrive. In Figure 7, "tx" indicates a second transmission slot (corresponding to the second transmission timing) that is different from the periodic transmission slot.

[0053] Then, after a predetermined time (for example, 1 second and 2 seconds) has elapsed since the second transmission slot, the communication control unit 141c transitions to a state where it can receive a downlink signal from the monitoring device 60 via the repeater 50 (corresponding to a receivable state). In Figure 7, "rx" indicates a second reception slot (corresponding to the second reception timing) that is different from the periodic reception slot.

[0054] As described later, when a plant monitor has concerns about the plant's condition, they can input a downlink signal transmission instruction to the monitoring device 60. When the monitoring device 60 determines that a downlink signal transmission instruction has been input, it transmits a downlink signal to the indicator value acquisition device 10. Specifically, the monitoring device 60 can transmit a control signal requesting a shortening of the communication cycle, or a set parameter, to the indicator value acquisition device 10. This allows the latest measured values ​​to be received from the indicator value acquisition device 10 multiple times without waiting for the next periodic communication timing. Therefore, plant monitors can grasp the plant's condition early and detect abnormalities. It also becomes possible to obtain the communication opportunities necessary for changing set parameters.

[0055] Figure 8 shows the communication timing after the indicator value acquisition device 10 is started up. As shown in Figure 8, the communication control unit 114c transmits the measured values ​​to the monitoring device 60 multiple times at timings different from the periodic communication timings described above during the initial setup phase (corresponding to the initial setup state) after startup. In Figure 8, "tx" indicates a third transmission slot (corresponding to the third transmission timing) that is different from the periodic transmission slot.

[0056] Then, in the initial setup phase, the communication control unit 141c transitions to a state where it can receive a downlink signal from the monitoring device 60 via the repeater 50 (corresponding to a receivable state) at a reception timing after a predetermined time (for example, 1 second and 2 seconds) has elapsed since the third transmission slot. In Figure 8, "rx" indicates a third reception slot (corresponding to the third reception timing) that is different from the periodic reception slots.

[0057] In this way, during the initial setup phase, by sending uplink signals multiple times from the indicator value acquisition device 10 to the monitoring device 60, the timing for sending downlink signals from the monitoring device 60 to the indicator value acquisition device 10 can be increased. This makes it possible to ensure opportunities to send and receive the necessary setting parameters during the initial setup.

[0058] Returning to Figure 5, the state control unit 141d controls the measurement processor 14 to transition between a communication phase (corresponding to the normal state) or initial setup phase (corresponding to the initial setup state) that operates with a first power consumption, and a rest phase (corresponding to the low power consumption state) that operates with a second power consumption that is less than the first power consumption. The measurement processor 14 communicates wirelessly with the monitoring device 60 during the communication phase and the initial setup phase. The measurement processor 14 does not communicate wirelessly with the repeater 50 during the rest phase.

[0059] Figure 9 shows the communication timing and state transition timing between the indicator value acquisition device 10 and the monitoring device 60. As shown in Figure 9, when the communication phase arrives, the wireless communication unit 142 acquires the measured values ​​and calculates statistical values ​​as described above, and transmits them to the monitoring device 60. After a predetermined time has elapsed from the transmission timing, the wireless communication unit 142 transitions to a state in which it can receive a downlink signal from the monitoring device 60. In Figure 9, two reception timings (reception slots) are shown, but there may be only one reception slot.

[0060] During the idle phase, the wireless communication unit 142 does not communicate wirelessly with the monitoring device 60. Therefore, the state control unit 141d cuts off the power supply to the wireless communication unit 142 during the idle phase. This allows the indicator value acquisition device 10 to operate with lower power consumption during the idle phase than during the communication phase.

[0061] The wireless communication unit 142 is a communication device compliant with the LoRaWAN® standard and is a wireless communication circuit used for bidirectional wireless communication with the monitoring device 60. The wireless communication unit 142 transmits the measured values ​​acquired by the acquisition unit 141a or the statistical values ​​calculated by the measurement unit 141b to the monitoring device 60 via the repeater 50. Furthermore, the wireless communication unit 142 receives a control signal from the monitoring device 60 via the repeater 50, which includes setting parameters for the measurement processor 14. The setting parameters may include the periodic communication cycle.

[0062] As described above, the wireless communication unit 142 has been described as a communication device compliant with the LoRaWAN standard, but it is not limited to this. The wireless communication unit 142 may also be a wireless device compliant with SIGFOX®, Wi-Fi®, or LTE.

[0063] The power supply unit 143 supplies the power required by the measurement unit 141 and the wireless communication unit 142 described above. The power supply unit 143 is a primary battery, specifically a lithium thionyl chloride battery. By using a lithium thionyl chloride battery with a large battery capacity, the workload associated with battery replacement can be reduced. However, it is sufficient that the power required by the measurement unit 141 and the wireless communication unit 142 described above can be supplied; for example, an alkaline battery or a lithium manganese dioxide battery may also be used. The power supply unit 143 may also have a secondary battery that can be recharged by power supply from an external source.

[0064] <Functional configuration of monitoring device 60> Next, the monitoring device 60 will be described. Figure 10 shows the functional configuration of the monitoring device 60. As shown in Figure 10, the monitoring device 60 mainly consists of a monitoring data output unit 61, an operation reception unit 62, an abnormality determination unit 63, a communication control unit 64, a communication unit 65, and a storage unit 66. The monitoring device 60 has a processor, volatile memory, and non-volatile memory, and functions as a monitoring data output unit 61, an operation reception unit 62, an abnormality determination unit 63, and a communication control unit 64 by executing a program stored in the non-volatile memory.

[0065] The monitoring data output unit 61 outputs the monitoring data stored in the storage unit 66 (described later) to an information processing terminal operated by a plant monitor connected via a display device (not shown) or a communication line NW. The monitoring data may be measured values ​​output by the instruction value acquisition device 10 described above, or their statistical values, or it may be data generated by applying a predetermined analysis process to the measured values. To support monitoring work by the monitor, the monitoring data output unit 61 can output the monitoring data as time-series data or output multiple monitoring data in a comparable manner.

[0066] The operation reception unit 62 receives input operations from plant monitors. Specifically, the operation reception unit 62 can receive input for changing the setting parameters of the instruction value acquisition device 10. The setting parameters include the communication cycle of the periodic communication described above. When the operation reception unit 62 receives input for changing the setting parameters, the communication control unit 64, which will be described later, determines that it is necessary to change the setting value of the instruction value acquisition device 10 and sends a downlink signal to the instruction value acquisition device 10. Furthermore, the operation reception unit 62 can receive input operations necessary for recording monitoring data or notifying external parties when a plant monitor detects an abnormality. This enables a rapid response when an abnormality is detected in the plant.

[0067] The abnormality detection unit 63 determines whether or not there is an abnormality in the plant equipment based on the monitoring data. Specifically, the abnormality detection unit 63 determines whether or not there is an abnormality by comparing the monitoring data with a predetermined threshold. However, the method of determining an abnormality is not limited to comparing with a threshold. The abnormality detection unit 63 may also estimate whether or not there is an abnormality by inputting the monitoring data into an abnormality detection model that has been built in advance by machine learning. Furthermore, the abnormality detection unit 63 may have a threshold learning means for learning thresholds by machine learning and a threshold setting means for dynamically setting the learned thresholds.

[0068] The communication control unit 64 acquires the measured values ​​output by the indicator value acquisition device 10 or the statistical values ​​described above by controlling the communication unit 65, which will be described later. In other words, the communication control unit 64 controls the indicator value acquisition device 10 to receive the uplink signal it transmits. The communication control unit 64 also determines whether or not to transmit a downlink signal to the indicator value acquisition device 10 based on the input operation received by the operation reception unit 62 and the determination result of the abnormality determination unit 63. In detail, when the operation reception unit 62 receives an input to change the setting parameter, or when the abnormality determination unit 63 determines that there is an abnormality, the communication control unit 64 determines that it is necessary to change the setting parameter of the indicator value acquisition device 10 and determines to transmit a downlink signal. The communication control unit 64 then transmits the setting parameter or control signal to the indicator value acquisition device 10 by controlling the communication unit 65. In other words, the communication control unit 64 transmits a downlink signal to the indicator value acquisition device 10. The communication control unit 64 corresponds to the uplink reception control unit, the downlink transmission determination unit, and the downlink transmission control unit.

[0069] The communication unit 65 is a communication interface circuit that can perform bidirectional communication with the repeater 50 via a publicly available communication line NW such as the Internet. The communication unit 65 receives an uplink signal consisting of measured values ​​or statistical values ​​output by the indicator value acquisition device 10 via the repeater 50. The communication unit 65 also transmits a downlink signal consisting of setting parameters to the indicator value acquisition device 10 via the repeater 50.

[0070] The storage unit 66 is a non-volatile auxiliary storage device consisting of an HDD (Hard Disk Drive) or an SSD (Solid State Drive), etc. The storage unit 66 stores the measured values ​​or statistical values ​​output by the instruction value acquisition device 10, and also stores programs executed by the processor of the monitoring device 60.

[0071] <Communication control processing> Next, the communication control process will be explained with reference to Figure 11. Figure 11 shows the flow of the communication control process performed by the monitoring device 60. As shown in Figure 11, first, the monitoring device 60 acquires the monitoring data stored in the storage unit 66 and outputs it to the display unit of the monitoring device 60 or to an information processing terminal operated by the monitoring officer (step S10).

[0072] Next, the monitoring device 60 determines whether or not it has received an uplink signal (step S11). If it is determined that the measurement values ​​transmitted by the IoT edge device, the instruction value acquisition device 10, have not been received as an uplink signal (step S11: No), the monitoring device 60 waits until it receives an uplink signal.

[0073] On the other hand, if it is determined that an uplink signal has been received (step S11: Yes), the monitoring device 60 determines whether or not to send a downlink signal to the indicator value acquisition device 10 via the repeater 50 (step S12). More specifically, it determines to send a downlink signal when it receives a change input for setting parameters entered by a monitor, or when the abnormality determination unit 63 detects an abnormality in the plant. However, it is not limited to these, and the monitoring device 60 may also send a downlink signal for the purpose of inspecting the plant.

[0074] If it is determined that a downlink signal should be transmitted (step S12: Yes), the monitoring device 60 transmits a downlink signal to the indicator value acquisition device 10 (step S13) and terminates the communication control process. The downlink signal is, for example, a control signal that includes the setting parameters of the indicator value acquisition device 10. On the other hand, if it is not determined that a downlink signal should be transmitted (step S12: No), the monitoring device 60 terminates the communication control process without transmitting a downlink signal to the indicator value acquisition device 10.

[0075] <Extraction tool 30> Next, the extraction tool 30 used to pull the pointer 24 out of the rotating shaft 23 of the pressure gauge 20 for maintenance will be described with reference to Figures 12, 13A, and 13B. Figure 12 shows a perspective view of the extraction tool 30. Figure 13A shows the state before the pointer 24 is pulled out of the rotating shaft 23. Figure 13B shows the state after the pointer 24 has been pulled out of the rotating shaft 23. In Figures 13A and 13B, the pressure gauge 20 is shown in a state where it has been removed from the plant piping and is lying on its side.

[0076] As shown in Figure 12, the extraction tool 30 mainly consists of a fixed shaft 31 extending in the extraction direction P and an extraction part 32 that is displaceable in the extraction direction P relative to the fixed shaft 31. The fixed shaft 31 has an elongated shape and includes a tip portion 31a, a threaded portion 31b, and an operating portion 31c. The tip portion 31a is located at one end of the fixed shaft 31 and contacts the rotating shaft 23 of the pressure gauge 20, as will be described later. The tip portion 31a has a tapered shape and becomes smaller in diameter towards the tip. The tip portion 31a is sized to be insertable into the fitting hole 25a of the fixed member 25, as will be described later.

[0077] The threaded portion 31b extends from the tip portion 31a in the withdrawal direction P and connects the tip portion 31a and the operating portion 31c. The outer circumference of the threaded portion 31b is threaded and has a diameter that allows it to be screwed into the threaded hole 32d formed in the withdrawal portion 32, which will be described later.

[0078] The operating part 31c is located at the end opposite to the tip part 31a. The outer surface of the operating part 31c is knurled to provide an anti-slip effect. This makes it possible to securely grip and rotate the operating part 31c with your fingers when operating it. By rotating the operating part 31c, the extraction part 32 can be displaced in the extraction direction P relative to the fixed shaft 31.

[0079] The extraction portion 32 has a ring shape and includes a notch 32a, a pair of extraction pieces 32b located on both sides of the notch 32a, a pair of arm portions 32c, and a screw hole 32d. The notch 32a is formed at the lower end of the extraction portion 32. As shown in Figure 13B, the notch 32a is formed in a position and shape that allows for the insertion of a fixing member 25 that fixes the pointer 24 to the rotation axis 23.

[0080] A pair of pull-out pieces 32b are provided adjacent to the notch 32a on the left and right sides of the notch 32a. As shown in Figures 13A and 13B, the pull-out pieces 32b have a thickness that allows them to enter the gap between the scale plate 22 of the pressure gauge 20 and the pointer 24, and press the pointer 24 from below upward when the pointer 24 is pulled out from the rotating shaft 23.

[0081] The pair of arms 32c extend in the extraction direction P from the pair of extraction pieces 32b, curving outwards to the left and right, and connect to each other at a position opposite the notch 32a. The arms 32c become thicker from bottom to top, and a screw hole 32d is formed at the thickest point.

[0082] The screw hole 32d is located at the end of the extraction portion 32 in the extraction direction P and is formed to penetrate the extraction portion 32 vertically. The aforementioned fixed shaft 31 passes through the screw hole 32d. Due to the screw groove formed on the inner surface of the screw hole 32d, the extraction portion 32 rotates relative to the fixed shaft 31 and is displaced in the extraction direction P.

[0083] <Extraction method according to guideline 24> Next, the method for removing the pointer 24 will be explained with reference to Figures 14A to 14D. Figures 14A to 14D show the procedure for removing the pointer 24 from the rotating shaft 23 using the extraction tool 30. In Figures 14A to 14D, the pressure gauge 20 is shown in a state where it has been removed from the plant piping and is lying on its side. Figure 14A shows an enlarged side view of the main part of the pressure gauge 20. As shown in Figure 14A, a central hole 22a is formed in the center of the scale plate 22 of the pressure gauge 20, and a rotating shaft 23 protrudes from the central hole 22a. The pointer 24 is fixed to the rotating shaft 23 via a fixing member 25 and rotates around the rotating shaft 23. The magnet 11 of the indicator value acquisition device 10 is fixed to the fixing member 25.

[0084] Next, Figure 14B shows the state in which the extraction tool 30 is attached to the pressure gauge 20. That is, the fixing member 25 is fitted into the notch 32a of the extraction tool 30, and the extraction piece 32b is positioned between the scale plate 22 and the pointer 24. At this time, the longitudinal direction of the fixing shaft 31 of the extraction tool 30 extends in the axial direction of the rotation shaft 23, i.e., the extraction direction P.

[0085] Next, Figure 14C shows the state in which the fixed shaft 31 descends by rotating the operating part 31c, and the tip portion 31a comes into contact with the upper end of the rotating shaft 23. More specifically, from the state shown in Figure 14B, by fixing the arm portion 32c of the extraction part 32 with one hand and rotating the operating part 31c with the other hand, the tip portion 31a is displaced downward relative to the extraction part 32. Here, the magnet 11 has a ring shape and a through hole 11b is formed in its center. More specifically, the magnet body 11a of the magnet 11 has a through hole 11b through which the extraction tool 30 passes in the extraction direction P. Therefore, the fixed shaft 31 is displaced downward by passing through the through hole 11b of the magnet 11 and the fitting hole 25a of the fixed member 25, and comes into contact with the rotating shaft 23. When the tip portion 31a of the fixed shaft 31 comes into contact with the upper end of the rotating shaft 23, it cannot be displaced any further downward relative to the pressure gauge 20. In other words, the position of the fixed shaft 31 in the extraction direction P relative to the pressure gauge 20 is fixed.

[0086] Figure 14D shows the state in which the pointer 24 has been withdrawn from the rotating shaft 23. More specifically, by further rotating the operating part 31c from the state shown in Figure 14C, the withdrawal part 32 is displaced upward relative to the fixed shaft 31. At this time, the withdrawal piece 32b presses against the lower surface of the pointer 24, pushing it upward from below. As a result, the pointer 24 and the fixed member 25 are withdrawn from the rotating shaft 23. As a result, the pointer 24 can be easily removed from the rotating shaft 23 by rotating the operating part 31c, reducing the burden on the worker and preventing damage to the pressure gauge 20 caused by forcibly removing the pointer 24.

[0087] Although an embodiment of the indicated value acquisition device 10 according to one embodiment of the present invention has been described, the above-described embodiment is merely an example to facilitate understanding of the present invention and does not limit the present invention. That is, the present invention can be modified and improved without departing from its spirit, and of course, the present invention includes equivalents thereof.

[0088] In the embodiment described above, it was explained that a reading acquisition device 10 attached to the pressure gauge 20 measures the reading of the pressure gauge 20 and transmits the measurement result to the monitoring device 60, but the invention is not limited to this. Any detector that can quickly grasp the status of equipment in the plant to detect abnormalities is acceptable, for example, measurement values ​​may be output to the monitoring device 60 from thermometers, hygrometers, vibration meters, etc. installed in the plant. Furthermore, the measuring device is not limited to detectors installed in plants. For example, it may be a smart meter used as a water meter or gas meter in a house, or a sensor attached to a means of transportation such as an automobile. [Explanation of symbols]

[0089] 1. Measurement Value Monitoring System 10. Indication acquisition device (measuring device) 11 Magnets 11a Magnet body (main body) 11b Through hole 12 Angle detector 12a Case 12b Magnetic sensor 12c Angle Conversion Unit 12d position marker 13 Connection Cables 14. Measuring and processing equipment 14a Case 14b Aerial line 141 Measurement Unit 141a Acquisition unit (measurement value acquisition unit) 141b Measurement section 141c Communication Control Unit (Uplink Transmission Control Unit, Downlink Reception Control Unit) 141d State Control Unit 142 Wireless Communication Unit 143 Power Supply Unit 20 Pressure gauges 21 Main body 22 scale plates 22a Center hole 23 Rotation axis 24 Guidelines 25 Fixing member 25a Fitting hole 26 Transparent plate 27 Outer frame 30 Extraction Tools 31 Fixed axis 31a Tip 31b Threaded part 31c Control unit 32 Pull-out section 32a Notch 32b Extraction piece 32c arm 32d threaded hole 50 Repeaters 60 Monitoring equipment 61 Monitoring data output unit 62 Operation Reception Section 63 Abnormality determination section 64. Communication Control Unit (Uplink Receiving Control Unit, Downlink Transmitting Control Unit) 65 Communication Unit 66 Memory section Network communication lines P Pull-out direction

Claims

1. A measurement value monitoring system comprising a measuring device that acquires and outputs measured values, and a monitoring device that receives an uplink signal from the measuring device and transmits a downlink signal to the measuring device, The aforementioned measuring device is A measurement value acquisition unit that acquires the aforementioned measurement value, An uplink transmission control unit transmits the measured values ​​acquired by the measured value acquisition unit to the monitoring device at a predetermined periodic first transmission timing, At the first reception timing, which occurs after a predetermined time has elapsed from the first transmission timing, a downlink reception control unit transitions the downlink signal to a receivable state that can be received by the monitoring device, The device has a state control unit that controls the state between a normal state in which it operates with a first power consumption at the first reception timing and a low power consumption state in which it operates with a second power consumption lower than the first power consumption during a period different from the first reception timing. The aforementioned monitoring device is An uplink receiving control unit that receives the uplink signal transmitted by the measuring device, A downlink transmission determination unit that determines whether to transmit the downlink signal after receiving the uplink signal, The system includes a downlink transmission control unit that transmits the downlink signal to the measuring device based on the determination result of the downlink transmission determination unit, When the downlink receiving control unit receives the downlink signal, the uplink transmission control unit transmits the measured value to the monitoring device at a second transmission timing that is different from the first transmission timing. The downlink reception control unit transitions to the receivable state at the second reception timing, which occurs after a predetermined time has elapsed from the second transmission timing. The state control unit controls the state so that it operates with the first power consumption at the second reception timing. The measuring device comprises a magnet attached to a pointer fitted onto the rotating shaft of an analog meter, and a magnetic sensor for detecting the magnetic force generated by the magnet. Based on the magnetic force detected by the magnetic sensor, the measured value of the analog meter is acquired. The magnet has a main body made of an annular shape, and the central axis of the main body is positioned on the axis of the rotation axis. A measurement value monitoring system characterized in that a through hole is formed in the center of the main body portion, through which a pull-out tool used to pull the pointer out from the rotating shaft passes in the pull-out direction.

2. The measurement value monitoring system according to claim 1, characterized in that when the uplink transmission control unit receives the downlink signal, the downlink reception control unit transmits the measured value to the monitoring device multiple times at the second transmission timing.

3. The state control unit controls the state of the measuring device after it is started up so that it enters an initial state where it operates at the first power consumption. The uplink transmission control unit, in the initial setting state, transmits the measured value or set value to the monitoring device multiple times at a third transmission timing that is different from the first transmission timing. The measurement value monitoring system according to claim 1 or 2, characterized in that the downlink receiving control unit transitions to the receivable state at the third receiving timing, which occurs after a predetermined time has elapsed from the third transmission timing.

4. The downlink transmission determination unit determines whether or not it is necessary to change the setting value of the measuring device, and based on the determination result, determines whether or not to transmit the downlink signal. The measurement value monitoring system according to claim 1 or 2, characterized in that the downlink transmission control unit transmits the modified setting value to the measurement device based on the transmission determination result.

5. A measuring device that transmits an uplink signal to a monitoring device and receives a downlink signal from the monitoring device, A unit for acquiring measured values, An uplink transmission control unit transmits the measured values ​​acquired by the measured value acquisition unit to the monitoring device at a predetermined periodic first transmission timing, At the first reception timing, which occurs after a predetermined time has elapsed from the first transmission timing, a downlink reception control unit transitions the downlink signal to a receivable state that can be received by the monitoring device, The system includes a state control unit that controls the state between a normal state in which the system operates with a first power consumption at the first reception timing and a low power consumption state in which the system operates with a second power consumption lower than the first power consumption during a period different from the first reception timing, When the downlink receiving control unit receives the downlink signal, the uplink transmission control unit transmits the measured value to the monitoring device at a second transmission timing that is different from the first transmission timing. The downlink reception control unit transitions to the receivable state at the second reception timing, which occurs after a predetermined time has elapsed from the second transmission timing. The state control unit controls the state so that it operates with the first power consumption at the second reception timing. The measuring device comprises a magnet attached to a pointer fitted onto the rotating shaft of an analog meter, and a magnetic sensor for detecting the magnetic force generated by the magnet. Based on the magnetic force detected by the magnetic sensor, the measured value of the analog meter is acquired. The magnet has a main body made of an annular shape, and the central axis of the main body is positioned on the axis of the rotation axis. The measuring device is characterized in that a through hole is formed in the center of the main body portion, through which a pull-out tool used to pull the pointer out from the rotating shaft passes in the pull-out direction.

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