Communication system, control device, and communication method

Abstract

To save power and also to efficiently transmit measurement data indicating an actuation state of a steam trap to a server at appropriate timing.SOLUTION: A communication system includes: a repeating device communicable with measurement devices and a server: and a control device communicable with a time server for clocking a standard time and the repeating device. A first computer of the control device performs: controlling power supply and interruption to the repeating device; correcting a first time being the present time in the control device immediately after a start of the power supply to the repeating device so as to coincide with the standard time; and transmitting first information indicating the first time after the correction to the repeating device. A second computer of the repeating device performs: setting the first time indicated by the received first information as a second time being the present time in the repeating device; and transferring measurement data received from the measurement device to the server. When a third time being the present time in the measurement device is different from the second time, a third computer of the measurement device corrects the third time to coincide with the second time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for transmitting measurement data on the operating state of a steam trap. [Background technology]

[0002] In plants equipped with steam piping systems, condensate (drain) may occur within the piping system due to heat exchange or heat radiation. If this condensate remains within the piping system, it will cause a decrease in operating efficiency. For this reason, steam traps are generally installed in appropriate locations within the piping system, and the condensate is discharged outside the piping system using these steam traps.

[0003] If the sealing performance of a steam trap is impaired due to aging, malfunction, or the like, steam in a steam piping system will leak to the outside through the steam trap, resulting in unnecessary steam loss. For this reason, an inspection device such as that disclosed in Patent Document 1 listed below is used to periodically measure the temperature and vibration of the steam trap, and the operating condition of each steam trap is diagnosed based on this measurement data and necessary information such as threshold values.

[0004] However, large-scale plants may have thousands or even tens of thousands of steam traps installed. In such cases, it takes a great deal of time for workers to manually diagnose the operating status of each steam trap. For this reason, some facilities have adopted communication systems that automatically diagnose the operating status of multiple steam traps.

[0005] Specifically, in the above communication system, a measuring device is permanently installed in each steam trap, and this measuring device measures the operating condition of each steam trap. Multiple measuring devices installed within close proximity are grouped, and a relay device (parent device, router) capable of communicating with multiple measuring devices belonging to each group and a server is also provided. The multiple measuring devices belonging to each group then transmit measurement data to the server via the relay device, and the server uses the received measurement data to diagnose the operating condition of each steam trap. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 2954183 Summary of the Invention

[0007] However, the performance of the circuits that measure the current time in each of the measuring devices and relay devices that make up the above communication system varies. As a result, a difference occurs between the current time in the measuring device and the current time in the relay device. This difference accumulates day by day, which can cause the relay device to be unable to receive the measurement data that it is scheduled to receive from the measuring device at a predetermined time. Similarly, a difference occurs between the current time in the relay device and the current time in the server. This difference accumulates day by day, which can cause the server to be unable to receive the measurement data that it is scheduled to receive from the relay device at a predetermined time.

[0008] In addition, to save power, it is preferable to cut off the power supply to the relay device except during the time periods when multiple measurement devices are transmitting measurement data. However, in this case, it is necessary to initialize the current time on the relay device every time the power supply to the relay device is started. [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a communication system, a control device, and a relay device that can save power and efficiently transmit measurement data indicating the operating status of a steam trap to a server at an appropriate time. [Means for solving the problem]

[0010] (1) A communication system according to one aspect of the present invention is a communication system including a measuring device installed on a steam trap and transmitting measurement data indicating the operating status of the steam trap; a relay device capable of communicating with the measuring device and a server; a time server that keeps standard time for a predetermined region; and a control device capable of communicating with the relay device. A first computer included in the control device controls the supply and cut-off of power to the relay device, and immediately after starting to supply power to the relay device, corrects a first time, which is the current time on the control device, to match the standard time and transmits first information indicating the corrected first time to the relay device. A second computer included in the relay device sets the first time indicated in the first information received from the control device as a second time, which is the current time on the relay device, and transfers the measurement data received from the measuring device to the server. A third computer included in the measuring device corrects the third time, if there is a difference between a third time, which is the current time on the measuring device, and the second time, to match the second time.

[0011] In this aspect, the first computer included in the control device controls the supply and cut-off of power to the relay device, so that the power supply to the relay device is cut off except when the relay device is scheduled to receive measurement data from the measurement device and transfer the received measurement data to the server, thereby reducing power consumption in the relay device.

[0012] In this aspect, immediately after the supply of power to the relay device is started, the first time, which is the current time of the control device corrected to match the standard time, is set as the second time, which is the current time of the relay device, thereby reducing the effort required to initially set the second time each time the supply of power to the relay device is started.

[0013] In this aspect, if there is a difference between a third time, which is the current time on the measurement device, and the second time, the third time is corrected to match the second time. That is, in this aspect, the current times on both the relay device and the measurement device are corrected to match standard time. Therefore, measurement data indicating the operating state of the steam trap can be transmitted from the measurement device to the server via the relay device at an appropriate time.

[0014] (2) In the communication system described in (1) above, the first computer may cut off the supply of power to the relay device when a predetermined time has elapsed since the first computer started supplying power to the relay device.

[0015] According to this aspect, the time during which power is supplied to the relay device can be limited to a predetermined time, thereby reducing the power consumption of the relay device.

[0016] (3) In the communication system described in (1) above, the third computer may transmit second information indicating the third time to the relay device together with the measurement data, and the second computer may further, when receiving the second information, if there is a difference between the third time indicated by the second information and the second time, return third information indicating the second time, and when receiving the third information, the third computer may correct the third time to match the second time indicated by the third information.

[0017] In this aspect, if there is a difference between the third time indicated by the second information transmitted together with the measurement data and the second time, the third time is corrected to match the second time indicated by the third information. Therefore, the third time, which is the current time in the measurement device, can be corrected to be the same as the second time, which is the current time in the relay device.

[0018] (4) In the communication system described in (1) above, the measuring device and the relay device may be equipped with a communication unit having a relay function of a flood-type mesh network, and the third computer may put the measuring device into a sleep state after a predetermined time has elapsed from the start of transmission of the measurement data.

[0019] According to this aspect, the measuring device enters a sleep state after a predetermined time has elapsed since the start of measurement data transmission. Therefore, the power required for the communication unit of the measuring device to receive and transmit measurement data transferred from other measuring devices in the relay function can be limited to a predetermined time. This allows the measuring device to save power consumption.

[0020] (5) In the communication system described in (1) above, the operating state of the steam trap may be the temperature and vibration of the steam trap.

[0021] According to this aspect, measurement data indicating the temperature and vibration of the steam trap is transmitted to the server via the relay device, allowing the server to appropriately diagnose the operating condition of the steam trap, for example, based on the temperature and vibration of the steam trap contained in the measurement data.

[0022] (6) Another aspect of the present invention provides a control device that is installed on a steam trap and can communicate with a measuring device that transmits measurement data indicating the operating state of the steam trap, a relay device that can communicate with a server, and a time server that keeps standard time for a predetermined region. The relay device includes a power supply control unit that sets a first time indicated by first information received from the control device as a second time that is the current time in the relay device, transfers the measurement data received from the measuring device to the server, and controls the supply and cut-off of power to the relay device, and a correction unit that, immediately after starting to supply power to the relay device, corrects the current time in the control device to match the standard time and transmits information indicating the corrected current time in the control device to the relay device as the first information.

[0023] According to this aspect, the same effects as those of the communication system described in (1) above can be obtained.

[0024] (7) Another aspect of the present invention provides a communication method in a communication system including a measuring device installed on a steam trap and transmitting measurement data indicating the operating status of the steam trap, a relay device capable of communicating with the measuring device and a server, a time server that keeps track of standard time for a predetermined region, and a control device capable of communicating with the relay device, wherein a first computer included in the control device controls the supply and cut-off of power to the relay device, and immediately after starting to supply power to the relay device, corrects a first time, which is the current time on the control device, to match the standard time and transmits first information indicating the corrected first time to the relay device, a second computer included in the relay device sets the first time indicated in the first information received from the control device as a second time, which is the current time on the relay device, and transfers the measurement data received from the measuring device to the server, and a third computer included in the measuring device corrects the third time, if there is a difference between a third time, which is the current time on the measuring device, and the second time, to match the second time.

[0025] According to this aspect, the same effects as those of the communication system described in (1) above can be obtained. [Effects of the Invention]

[0026] According to the present invention, it is possible to provide a communication system, a control device, and a relay device that can save power and efficiently transmit measurement data indicating the operating status of a steam trap to a server at an appropriate time. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a diagram illustrating an overall configuration of a communication system. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control device. [Figure 3]FIG. 2 is a block diagram showing the configuration of a measurement device. [Figure 4] FIG. 2 is a block diagram showing the configuration of a relay device. [Figure 5] 10 is a flowchart showing a flow of a process for starting and stopping a relay device. [Figure 6] 10 is a flowchart showing the flow of a measurement data transmission and reception process. DETAILED DESCRIPTION OF THE INVENTION

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Elements with the same reference numerals in different drawings indicate the same or corresponding elements.

[0029] <System configuration> 1 is a diagram showing the overall configuration of a communication system 100. The communication system 100 includes a plurality of measuring devices 1, a relay device 2, a control device 4, and a server 5.

[0030] The plurality of measuring devices 1 and relay devices 2 have a function for performing short-range wireless communication such as Bluetooth (registered trademark) Mesh, and form a so-called flood network.

[0031] A plurality of measuring devices 1 are permanently installed (set up) at each of a plurality of steam traps installed at appropriate locations in a piping system of a plant or the like equipped with a steam piping system. Each measuring device 1 measures the operating state of the steam trap where it is installed. Each measuring device 1 uses the relay function of the flooding network to transfer packets containing measurement data indicating the measured operating state, information indicating the destination device (hereinafter referred to as destination information), information indicating the source device (hereinafter referred to as source information), and the like, to a relay device 2, either via one or more measuring devices 1 or without going through the packets.

[0032] A flooding mesh network, also known as a flooding mesh network, is a network in which each device (hereinafter referred to as a node) arranged in a mesh pattern sequentially transmits data to other nodes in a flood-like manner. Specifically, each node belonging to a flooding mesh network has a relay function. The relay function is a function that broadcasts packets containing data to be transmitted and destination information, receives packets broadcast by other nodes, and further broadcasts (transfers) the received packets.

[0033] If packets are repeatedly sent and received between specific nodes, like a game of catch, the packets may not reach their destination. To avoid this, the relay function temporarily stores (caches) packets that have been received. Furthermore, if the relay function receives a packet that is identical to the stored packet, the received packet is discarded without being broadcast.

[0034] For example, the solid thick arrow portion in Fig. 1 shows an example in which, when the measurement device 1 at the bottom left uses the relay function of the flooding mesh network to send a packet to the relay device 2, the packet sent from the measurement device 1 at the bottom left is broadcast by multiple nodes and transmitted to the relay device 2. Also, the dashed thick arrow portion in Fig. 1 shows an example in which, when the relay device 2 uses the relay function of the flooding mesh network to send a packet to the measurement device 1 at the bottom left, the packet sent from the relay device 2 is broadcast by multiple nodes and transmitted to the measurement device 1 at the bottom left.

[0035] The control device 4 is connected to the relay device 2 using a power cable 49, and controls the supply and cut-off of power to the relay device 2. The control device 4 also has a time correction function. The time correction function is a function that corrects the current time on the control device 4 so that the current time (first time) on the control device 4 matches the standard time by communicating via a network 9 with a time server 3, such as an NTP (Network Time Protocol) server, that keeps standard time in an area (predetermined area) where multiple measurement devices 1 and relay devices 2 are located. The network 9 is, for example, the Internet, a LAN, or a mobile phone network. The control device 4 is, for example, configured by an information processing device such as a personal computer.

[0036] Under the control of the control device 4, the relay device 2 transfers packets received from each of the plurality of measuring devices 1 to the server 5 via the network 9 while power is being supplied via the power cable 49.

[0037] Server 5 diagnoses the operating state of the steam trap where each measuring device 1 is installed, based on the measurement data etc. contained in the packet received from relay device 2. Server 5 also manages the operating states of multiple steam traps by storing the identification information of the steam trap where each measuring device 1 is installed, the diagnostic data indicating the results of the diagnosis, and the measurement data used for the diagnosis, in association with each other.

[0038] Next, a detailed description will be given of the configuration of the control device 4. Fig. 2 is a block diagram showing the configuration of the control device 4. The control device 4 includes a power supply unit 40, an operation unit 41, a display unit 42, a communication unit 43, a storage unit 44, and a control unit 45 (first computer).

[0039] The power supply unit 40 is configured with a power supply circuit that converts commercial power into a DC voltage of a predetermined level, and supplies power to each component of the control device 4. The power supply unit 40 also supplies power to the relay device 2 via a power cable 49 under the control of a power supply control unit 451, which will be described later.

[0040] The operation unit 41 is configured using a keyboard, a mouse, or the like for the user to input various information. The display unit 42 is configured using a liquid crystal display, an organic EL display, or the like. However, the operation unit 41 and the display unit 42 may be configured integrally by using a touch panel display. The control device 4 may have a simplified configuration that does not include the operation unit 41 and the display unit 42. The communication unit 43 is configured using a communication circuit that communicates with external devices such as the relay device 2 and the time server 3 via the network 9. The storage unit 44 is configured using any rewritable storage device such as an HDD, SSD, or flash memory.

[0041] The control unit 45 is configured by a microcomputer equipped with a CPU, memory, a crystal oscillator, etc. The control unit 45 has a clock unit 450. The control unit 45 also has a power supply control unit 451 and a correction unit 452 as functions realized by the CPU executing a predetermined program.

[0042] The timekeeping unit 450 is configured with a crystal oscillator, a memory, and an arithmetic circuit, and measures the current time (first time) in the control device 4. Specifically, the timekeeping unit 450 counts the number of clock signals output from the crystal oscillator at a predetermined cycle using the arithmetic circuit. The timekeeping unit 450 updates the current time stored in the memory of the control unit 45 by adding the product of the counted number and the cycle of the clock signal using the arithmetic circuit.

[0043] The power supply control unit 451 controls the supply and cut-off of power to the relay device 2. Specifically, at a predetermined start-up time (for example, 1:00 PM), the power supply control unit 451 controls the power supply unit 40 to start supplying power to the relay device 2 via the power cable 49. When a predetermined time (for example, one minute) has elapsed since the predetermined start-up time (for example, 1:00 PM), the power supply control unit 451 controls the power supply unit 40 to cut off the supply of power to the relay device 2. The start-up time and the predetermined time are, for example, input by a user operating the operation unit 41. The start-up time and the predetermined time are not limited to this, and may also be included in information received by the communication unit 43 from an external device.

[0044] The specified time can be set to, for example, a time longer than the time it is expected to take from when the measuring device 1 starts measuring the operating status of the steam trap where it is installed, to when a packet containing the measurement data is sent to the relay device 2, and for the packet forwarded by the relay device 2 to reach the server 5.

[0045] The correction unit 452 corrects the current time kept by the clock unit 450 so that it coincides with the standard time kept by the time server 3. This realizes the time correction function of the control device 4.

[0046] Specifically, the correction unit 452 controls the communication unit 43 to communicate with the time server 3 via the network 9, thereby acquiring the standard time kept by the time server 3. The correction unit 452 rewrites the current time stored in the memory provided in the control unit 45 with the standard time acquired from the time server 3.

[0047] Next, a detailed description will be given of the configuration of the measurement device 1. Figure 3 is a block diagram showing the configuration of the measurement device 1. The measurement device 1 includes a temperature sensor 11, a vibration sensor 12, a power supply unit 13, a communication unit 14, and a control unit 15 (third computer).

[0048] Temperature sensor 11 is configured using a thermocouple, an amplifier circuit, an AD conversion circuit, etc. Temperature sensor 11 is installed at the inlet (primary side) of the steam trap where it is installed (hereinafter referred to as the target steam trap), measures the temperature of the target steam trap, and outputs temperature data indicating the measurement result to control unit 15.

[0049] Vibration sensor 12 is configured using a piezoelectric element, an amplifier circuit, an AD conversion circuit, etc. Vibration sensor 12 is installed at the discharge section (secondary side) of the target steam trap, etc., measures the vibration of the target steam trap, and outputs vibration data indicating the measurement results to control unit 15.

[0050] The power supply unit 13 is configured by a secondary battery such as a lithium ion battery, and supplies power to each unit in the measurement device 1.

[0051] The communication unit 14 is configured using a communication circuit having a relay function of a flood-type mesh network such as a Bluetooth (registered trademark) mesh network. Under the control of the control unit 15, the communication unit 14 uses the relay function to transmit the instructed transmission data to the instructed destination.

[0052] Specifically, the relay function of the communication unit 14 broadcasts a data packet including transmission data and destination information instructed by the control unit 15, as described above with reference to Fig. 1. The relay function also receives a packet broadcast by the communication unit 14 of another measurement device 1, and further broadcasts the received packet. The relay function is also configured to temporarily store (cache) a packet once received in a memory (not shown) built into the communication unit 14, and not broadcast the packet if a packet identical to the stored packet is received.

[0053] Furthermore, the communication unit 14 receives packets containing destination information indicating the present measurement device 1, which have been broadcast by the other measurement devices 1 and relay devices 2 using the relay function of the flooding mesh network, via the communication units 14 of one or more of the other measurement devices 1. Note that the present measurement device 1 refers to the measurement device 1 equipped with the communication unit 14. Furthermore, the communication unit 14 directly receives packets containing destination information indicating the present measurement device 1, which have been broadcast by the communication unit 14 of any nearby measurement device 1, without going through the other measurement devices 1.

[0054] The control unit 15 is configured by a microcomputer equipped with a CPU, memory, a crystal oscillator, etc. The control unit 15 has a clock unit 150. The control unit 15 also has a measurement unit 151, a processing unit 152, and a correction unit 153 as functions realized by the CPU executing a predetermined program.

[0055] The timekeeping unit 150 is composed of a crystal oscillator, a memory, and an arithmetic circuit, and keeps track of the current time (third time) in the measuring device 1. Specifically, the timekeeping unit 150 counts the number of clock signals output from the crystal oscillator at a predetermined cycle using the arithmetic circuit. The timekeeping unit 150 updates the current time stored in the memory of the control unit 15 by adding the product of the counted number and the cycle of the clock signal using the arithmetic circuit. Note that the performance of the crystal oscillator and arithmetic circuit included in the control unit 15 of each measuring device 1 varies. For this reason, the current time kept by the timekeeping unit 150 may vary among multiple measuring devices 1.

[0056] The measurement unit 151 performs a measurement process to measure the temperature and vibration of the target steam trap as the operating state of the target steam trap.

[0057] Specifically, in the measurement process, measurement unit 151 causes temperature sensor 11 to measure the temperature of the target steam trap, and acquires temperature data indicating the temperature of the target steam trap output by temperature sensor 11. In addition, in the measurement process, measurement unit 151 causes vibration sensor 12 to measure the vibration of the target steam trap, and acquires vibration data indicating the vibration of the target steam trap output by vibration sensor 12. However, measurement unit 151 is not limited to this, and in the measurement process, measurement unit 151 may measure only one of the temperature and vibration of the target steam trap as the operating state of the target steam trap.

[0058] The processing unit 152 causes the measurement unit 151 to perform a measurement process, and performs a measurement transmission process to transmit to the relay device 2, using the relay function of the communication unit 14, a packet containing measurement data indicating the operating state of the target steam trap measured in the measurement process and information indicating the current time measured by the timing unit 150 (hereinafter, second information).

[0059] Specifically, in the measurement transmission process, processing unit 152 acquires temperature data and vibration data indicating the temperature and humidity of the target steam trap measured in the measurement process as the operating state of the target steam trap. Processing unit 152 uses the acquired temperature data and vibration data as measurement data indicating the operating state of the target steam trap.

[0060] Processing unit 152 causes the relay function of communication unit 14 to broadcast a packet containing the measurement data, identification information for the target steam trap, data indicating the date and time when the measurement process was performed, destination information indicating relay device 2, source information indicating this measurement device 1, and second information indicating the current time stored in the memory of control unit 15. The date and time when the measurement process was performed may be the date and time when the measurement process started, or the date and time when acquisition of both the temperature data and the vibration data was completed.

[0061] At a predetermined startup time (for example, 1:00 PM), the processing unit 152 cancels the sleep state of the measuring device 1 and starts the measurement and transmission process. After a predetermined time (for example, 10 seconds) has elapsed since the start of the measurement and transmission process, the processing unit 152 puts the measuring device 1 into the sleep state. The sleep state is a state in which the power supply from the power supply unit 13 to the temperature sensor 11, the vibration sensor 12, and the communication unit 14 is cut off.

[0062] When communication unit 14 receives a correction instruction packet (described later) from relay device 2, correction unit 153 corrects the current time (third time) measured by timing unit 150 so that it matches the current time (second time) at relay device 2 indicated by third information (described later) included in the correction instruction packet. Specifically, correction unit 153 rewrites the current time stored in the memory provided in control unit 15 to the current time at relay device 2 indicated by the third information.

[0063] Next, a detailed description will be given of the configuration of the relay device 2. Fig. 4 is a block diagram showing the configuration of the relay device 2. The relay device 2 includes a communication unit 23 and a control unit 25 (second computer).

[0064] Like the communication unit 14, the communication unit 23 is configured using a communication circuit having a relay function of a flood-type mesh network such as a Bluetooth (registered trademark) Mesh network. Like the communication unit 14, the communication unit 23 uses the relay function under the control of the control unit 25 to transmit the instructed transmission data to the instructed destination device.

[0065] Furthermore, the communication unit 23 receives packets containing destination information indicating the relay device 2, which have been broadcast by each of the multiple measurement devices 1 included in the communication system 100 using the relay function of the communication unit 14, via the communication unit 14 of one or more other measurement devices 1. Furthermore, the communication unit 23 receives packets containing destination information indicating the relay device 2, which have been broadcast by the communication unit 14 of any measurement device 1 present in the vicinity of the relay device 2, directly without going through the other measurement devices 1.

[0066] Communication unit 23 outputs the measurement data, identification information of the target steam trap, sender information, and second information contained in the received packet to control unit 25. Communication unit 23 further has a communication circuit for performing long-distance communication via network 9 such as the Internet, a LAN, or a mobile phone network.

[0067] The control unit 25 is configured by a microcomputer equipped with a CPU, memory, a crystal oscillator, etc. The control unit 25 includes a clock unit 250. The control unit 25 also includes a setting unit 251, an instruction unit 252, and a transfer unit 253 as functions realized by the CPU executing a predetermined program.

[0068] Like the timekeeping unit 150, the timekeeping unit 250 is configured with a crystal oscillator, a memory, and an arithmetic circuit, and keeps track of the current time (second time) in the relay device 2. Specifically, the timekeeping unit 250 counts the number of clock signals output from the clock signal circuit at a predetermined cycle using the arithmetic circuit. The timekeeping unit 250 updates the current time stored in the memory of the control unit 25 by adding the product of the counted number and the cycle of the clock signal using the arithmetic circuit.

[0069] Immediately after the supply of power to the relay device 2 is started, the setting unit 251 sets an initial value of the current time in the relay device 2, which is measured by the time measuring unit 250, based on information received by the communication unit 23.

[0070] If there is a difference between the current time at each measuring device 1 indicated by the second information included in the packet received from each measuring device 1 and the current time at the relay device 2 measured by the timing unit 250, the instruction unit 252 uses the relay function of the communication unit 23 to return a correction instruction packet including information indicating the current time measured by the timing unit 250 (hereinafter, third information).

[0071] For example, suppose the second information included in a packet received from a certain measuring device 1 indicates "12:59:50," and the current time kept by the timing unit 250 indicates "1:00 PM." In this case, there is a difference of "10 seconds" between the time indicated by the second information and the current time kept by the timing unit 250. Therefore, the instruction unit 252 causes the relay function of the communication unit 23 to broadcast a correction instruction packet that includes destination information indicating the measuring device 1 indicated by the source information included in the packet received from the measuring device 1, and third information indicating "1:00 PM," the current time kept by the timing unit 250.

[0072] The transfer unit 253 controls the communication unit 23 to transfer packets received from each measuring device 1 to the server 5 via the network 9 .

[0073] Next, a description will be given of the flow of the start-up and shutdown process of the relay device 2, which is performed by the control device 4. Fig. 5 is a flowchart showing the flow of the start-up and shutdown process of the relay device 2.

[0074] In the control device 4, when a predetermined start-up time (for example, 1:00 PM) arrives (YES in step S11), the power supply control unit 451 starts supplying power to the relay device 2 (step S12). As a result, power is supplied to each unit of the relay device 2, and the relay device 2 starts up.

[0075] Immediately after step S12, the correction unit 452 corrects the current time kept by the timing unit 450 so that it matches the standard time kept by the time server 3 (step S13). Next, the correction unit 452 controls the communication unit 43 to transmit, to the relay device 2, first information indicating the current time in the control device 4 after being corrected in step S13 (step S14).

[0076] After step S14, the power supply control unit 451 remains in a standby state until a predetermined time (for example, one minute) has passed since the predetermined start-up time (for example, 1:00 PM) (NO in step S15). On the other hand, when the predetermined time (for example, one minute) has passed since the predetermined start-up time (for example, 1:00 PM) (YES in step S15), the power supply control unit 451 controls the communication unit 43 to transmit information (hereinafter, stop instruction information) to the relay device 2 instructing the relay device 2 to stop operating (step S16).

[0077] After step S16, if the communication unit 43 has not received cutoff permission information, which will be described later, from the relay device 2 (NO in step S17), the power supply control unit 451 enters a standby state. On the other hand, if the communication unit 43 has received cutoff permission information, which will be described later, from the relay device 2 (YES in step S17), the power supply control unit 451 cuts off the power supply to the relay device 2 (step S18). After step S18, the processing from step S11 onwards is repeated.

[0078] Next, the flow of the measurement data transmission and reception process will be described with reference to the flowchart of FIG.

[0079] In each measuring device 1, when a predetermined start-up time (e.g., 1:00 PM) arrives (YES in step S101), the processing unit 152 controls the power supply unit 13 to cancel the sleep state of the measuring device 1 (step S102). Specifically, in step S102, the processing unit 152 causes the power supply unit 13 to start supplying power to the temperature sensor 11, the vibration sensor 12, and the communication unit 14, thereby canceling the sleep state of the measuring device 1. This enables the communication unit 14 to use its relay function, and the communication unit 14 becomes able to receive packets broadcast by the relay function of the communication unit 14 of another measuring device 1.

[0080] Next, the processing unit 152 executes a measurement transmission process consisting of steps S103 and S104. Specifically, in step S103, the processing unit 152 causes the measurement unit 151 to execute the measurement process.

[0081] Next, in step S104, the processing unit 152 uses the relay function of the communication unit 14 to transmit a packet to the relay device 2, which includes measurement data indicating the temperature and vibration of the target steam trap measured in the measurement process of step S103, the second information, source information indicating the measurement device 1, and destination information indicating the relay device 2, as described above.

[0082] As a result, in each of the multiple measuring devices 1, the relay function of the communication unit 14 broadcasts a packet including measurement data indicating the temperature and vibration of the target steam trap measured in the measurement process of step S103 and destination information indicating the relay device 2. In addition, packets are received from other measuring devices 1, and the received packets are broadcast. As a result, the measurement data included in the packets broadcast from each of the multiple measuring devices 1 is transmitted to the relay device 2 with or without going through one or more other measuring devices 1.

[0083] After step S104, it is assumed that the communication unit 14 receives a correction instruction packet before a predetermined time (e.g., 10 seconds) has elapsed since the measurement transmission process was started in step S103 (NO in step S105). The time when the measurement transmission process was started refers to the time when the measurement process in step S103 was started.

[0084] In this case (YES in step S106), correction unit 153 corrects the current time kept by clock unit 150 so that the current time kept by clock unit 150 matches the current time kept by relay device 2 indicated by the third information included in the correction instruction packet (step S107). In this case, the processes from step S103 onwards are performed based on the current time corrected in step S107.

[0085] On the other hand, after step S104, if a predetermined time has not elapsed since the measurement transmission process was started in step S103 (NO in step S105), and if the communication unit 14 has not received a correction instruction packet (NO in step S106), the processing from step S103 onwards is performed.

[0086] After step S104, when a predetermined time has elapsed since the measurement and transmission process was started in step S103 (YES in step S105), processing unit 152 puts measurement device 1 into a sleep state (step S108) and ends the process.

[0087] Meanwhile, step S13 (FIG. 5) is executed in the control device 4, and power supply to the relay device 2 is started, thereby starting the relay device 2. Immediately after the relay device 2 is started, when the communication unit 23 receives the first information (YES in step S201), the setting unit 251 sets the current time kept by the timing unit 250 to the current time in the control device 4 indicated by the first information (step S202).

[0088] Here, the current time in the control device 4 indicated by the first information received by the communication unit 23 is corrected in step S13 (FIG. 5) so as to coincide with the standard time kept by the time server 3. Therefore, in step S202, the current time kept by the timing unit 250 is set to the same time as the standard time kept by the time server 3.

[0089] After step S202, if the communication unit 23 receives a packet sent by each measuring device 1 (YES in step S203), the instruction unit 252 determines whether there is a difference between the current time (hereinafter referred to as the second time) measured by the timing unit 250 and the time (hereinafter referred to as the third time) measured by the timing unit 150 indicated by the second information contained in the packet (step S204).

[0090] Assume that instructing unit 252 determines in step S204 that there is a difference between the second time and the third time (NO in step S204). In this case, instructing unit 252 replies, using the relay function of communication unit 23, a correction instruction packet including destination information indicating measurement device 1 indicated by the source information included in the packet received in step S203 and third information indicating the second time (step S205).

[0091] On the other hand, it is assumed that in step S204, the instruction unit 252 determines that there is no difference between the second time and the third time (YES in step S204), in which case the transfer unit 253 controls the communication unit 23 to transfer the packet received in step S203 to the server 5 (step S206).

[0092] After steps S205 and S206, if the communication unit 23 has not received the stop instruction information from the control device 4 (NO in step S207), the processing from step 203 onwards is performed. On the other hand, if the communication unit 23 has received the stop instruction information from the control device 4 after steps S205 and S206 (YES in step S207), the control unit 25 controls the communication unit 23 to transmit cutoff permission information indicating that it is acceptable to cut off the power supply to the relay device 2 to the control device 4 (step S208), and ends the processing.

[0093] As described above, according to the present embodiment, the control unit 45 of the control device 4 controls the supply and cut-off of power to the relay device 2. Therefore, the power supply to the relay device 2 is cut off except for the time when the relay device 2 is scheduled to receive measurement data from multiple measurement devices 1 and transfer the received measurement data to the server 5, thereby making it possible to save power consumption in the relay device 2.

[0094] Furthermore, in this embodiment, immediately after the supply of power to the relay device 2 is started, the current time in the control device 4, which has been corrected to match the standard time, is set as the current time in the relay device 2. This reduces the effort required to initially set the current time in the relay device 2 every time the supply of power to the relay device 2 is started.

[0095] Furthermore, in this embodiment, if there is a difference between the current time in the measuring device 1 and the current time in the relay device 2, these current times are corrected to match. That is, in this embodiment, the current times in the relay device 2 and the measuring device 1 are corrected to match the standard time. Therefore, measurement data indicating the operating state of the steam trap can be transmitted from the measuring device 1 to the server 5 via the relay device 2 at an appropriate timing.

[0096] The above-described aspects are merely examples of embodiments of the present invention, and the present invention is not limited to the above-described aspects. For example, the following modified embodiments may be used.

[0097] (1) In the above embodiment, an example has been described in which the communication unit 14 included in each measuring device 1 is configured using a communication circuit having a relay function of a flooded mesh network. However, instead of the communication circuit, the communication unit 14 may be configured with a communication circuit that performs long-distance communication via a network 9 such as the Internet, a LAN, or a mobile phone network. This allows the communication unit 14 and the relay device 2 to transmit and receive the packets and the correction instruction packets via the network 9. In this case, the communication unit 23 included in the relay device 2 may not be configured with a communication circuit having a relay function of a flooded mesh network. Alternatively, the communication unit 14 and the communication unit 23 may be configured using a communication circuit having various functions of a routed mesh network instead of a communication circuit having a relay function of a flooded mesh network.

[0098] (2) Steps S102 and S108 (FIG. 6) may be omitted in the measurement device 1. This may allow the relay function of the communication unit 23 in the measurement device 1 to be used at all times. [Explanation of symbols]

[0099] 1: Measuring equipment 2: Relay device 3: Time server 4: Control device 5: Server 14: Communications Department 15: Control unit (third computer) 23: Communications Department 25: Control unit (second computer) 45: Control unit (first computer) 100: Communication Systems 451: Power supply control unit 452: Correction unit

Claims

1. A communication system comprising: a measuring device that is installed on a steam trap and transmits measurement data indicating the operating state of the steam trap; a relay device that can communicate with the measuring device and a server; a time server that keeps standard time for a predetermined region; and a control device that can communicate with the relay device, The first computer included in the control device Controlling the supply and cut-off of power to the relay device; Immediately after starting the supply of power to the relay device, correcting a first time, which is a current time in the control device, to match the standard time, and transmitting first information indicating the corrected first time to the relay device; The second computer included in the relay device setting the first time indicated by the first information received from the control device as a second time that is a current time in the relay device; Transferring the measurement data received from the measurement device to the server; The third computer included in the measuring device If there is a difference between a third time, which is the current time of the measurement device, and the second time, correcting the third time so that it coincides with the second time. Communication system.

2. The first computer When a predetermined time has elapsed since the start of power supply to the relay device, the power supply to the relay device is cut off. The communication system of claim 1 .

3. the third computer transmits second information indicating the third time together with the measurement data to the relay device; the second computer further replies with third information indicating the second time when receiving the second information and there is a difference between the third time indicated by the second information and the second time; When the third computer receives the third information, it corrects the third time so that it coincides with the second time indicated by the third information. The communication system of claim 1 .

4. The measuring device and the relay device A communication unit having a relay function of a flood-type mesh network, the third computer puts the measurement device into a sleep state after a predetermined time has elapsed since the start of transmission of the measurement data; The communication system of claim 1 .

5. The operating conditions of the steam trap are the temperature and vibration of the steam trap. The communication system of claim 1 .

6. a relay device that can communicate with a measuring device and a server that are installed on a steam trap and transmit measurement data indicating the operating state of the steam trap; and a control device that can communicate with a time server that keeps standard time for a predetermined region, the relay device sets the first time indicated by the first information received from the control device as a second time, which is the current time in the relay device, and transfers the measurement data received from the measurement device to the server; a power supply control unit that controls supply and cut-off of power to the relay device; a correction unit that corrects a current time in the control device so that the current time coincides with the standard time immediately after starting to supply power to the relay device, and transmits information indicating the corrected current time in the control device as the first information to the relay device; A control device comprising:

7. A communication method in a communication system including a measuring device that is installed on a steam trap and transmits measurement data indicating an operating state of the steam trap, a relay device that can communicate with the measuring device and a server, a time server that keeps standard time for a predetermined region, and a control device that can communicate with the relay device, The first computer included in the control device Controlling the supply and cut-off of power to the relay device; Immediately after starting the supply of power to the relay device, correcting a first time, which is a current time in the control device, to match the standard time, and transmitting first information indicating the corrected first time to the relay device; The second computer included in the relay device setting the first time indicated by the first information received from the control device as a second time that is a current time in the relay device; Transferring the measurement data received from the measurement device to the server; The third computer included in the measuring device If there is a difference between a third time, which is the current time of the measurement device, and the second time, correcting the third time so that it coincides with the second time. Communication method.

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