Remote transmission system, monitoring station, and line monitoring method

Abstract

To provide a remote transmission system, a monitoring station, and a line monitoring method that allow a condition of a wireless line between a master station and a plurality of slave stations to be known in advance.SOLUTION: In a remote transmission system in which a master station (monitoring station 1) and a plurality of slave stations (observation stations TM) are connected via wireless lines, and data is transmitted between the master station and the plurality of slave stations at a predetermined time period, the slave station comprises a transmission unit which transmits encoded preventive maintenance data including at least image data, during an idle time period other than a period during which monitoring control data is transmitted or received between the master station and slave station within the predetermined time period. The master station comprises: a receiving unit that receives the preventive maintenance data from the slave station; and a condition determination unit that determines a condition of a wireless line between the master station and the slave station depending on whether the received preventive maintenance data is successfully decoded.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a remote transmission system, a monitoring station, and a line monitoring method.

Background Art

[0002] As an example of a remote transmission system, there is a telemeter system. For example, in a telemeter observation system, a monitoring station (parent station) controls the collective calling of observation stations (child stations) to collect and print various data including, for example, water level, rainfall, meteorological observation data, etc. The observation stations automatically return the various acquired data in response to the calling control from the monitoring station. Also, the monitoring station collects various data by means of a call executed at a predetermined interval or a manual call.

[0003] Also, as another example of a remote transmission system, there is a discharge warning system for warning downstream when discharging water from a dam or the like.

[0004] Both the telemeter system and the discharge warning system are important systems in the event of a disaster, so it is important to check the radio line quality from normal times when no disaster has occurred.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0006] Traditionally, transmission defects in wireless lines have been detected through periodic operational checks. However, operational checks only reveal problems with the wireless line after data loss occurs, resulting in a reactive approach. In other words, the conventional method makes it difficult to know the state of the wireless line in advance.

[0007] The problem addressed by this invention was addressed in view of the above circumstances, and its purpose is to provide a technology that allows the status of a wireless line to be checked before wireless line data is lost, and that allows monitoring of whether the status of the wireless line is abnormal to be confirmed by a monitoring station's monitor. [Means for solving the problem]

[0008] In a remote transmission system according to an embodiment in which a master station and a plurality of slave stations are connected by a wireless line and data is transmitted between the master station and the plurality of slave stations at a predetermined period, the slave station includes a transmitting unit that transmits encoded preventive maintenance data, which includes at least image data, during idle time in the predetermined period other than the period in which monitoring and control data is transmitted or received between the master station and the slave station, and the master station includes a receiving unit that receives the preventive maintenance data from the slave station and a status determination unit that determines the state of the wireless line between the master station and the slave station based on whether the received preventive maintenance data has been successfully decoded. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a block diagram showing an example of a schematic configuration of a telemetry observation system in the first embodiment. [Figure 2] Figure 2 shows an example of the functional block of a monitoring station in the first embodiment. [Figure 3] Figure 3 shows an example of the functional block of an observation station in the first embodiment. [Figure 4] Figure 4 shows an example of preventive maintenance data. [Figure 5]Figure 5 shows an example of the observation data and predictive maintenance data transmission procedure in the first embodiment. [Figure 6] Figure 6 is a flowchart showing an example of the procedure for decoding and displaying preventive maintenance data in the first embodiment. [Figure 7] Figure 7 shows an example of a composite image displayed on the display device in the first embodiment. [Figure 8] Figure 8 shows an example of a functional block diagram of a monitoring station in the second embodiment. [Figure 9] Figure 9 shows an example of a functional block diagram of an observation station in the second embodiment. [Figure 10] Figure 10 is a flowchart showing an example of the operation support data transmission procedure in the second embodiment. [Figure 11] Figure 11 is a diagram illustrating the procedure for generating operational support data. [Figure 12] Figure 12 is a flowchart showing an example of the procedure for decoding operational support data in the second embodiment. [Figure 13] Figure 13 shows an example of a composite image displayed on the display device in the second embodiment. [Figure 14] Figure 14 shows an image illustrating the procedure for analyzing a composite image. [Figure 15] Figure 15 shows an example of the functional block of a monitoring station in the third embodiment. [Figure 16] Figure 16 shows an example of the functional block of an observation station in the third embodiment. [Figure 17] Figure 17 shows an example of the observation data and predictive maintenance data transmission procedure in the third embodiment. [Figure 18] Figure 18 is a block diagram showing an example of a schematic configuration of a discharge alarm system in the third embodiment. [Figure 19] Figure 19 shows an example of the functional block of a monitoring station in the third embodiment. [Figure 20]FIG. 20 is a diagram showing an example of functional blocks of the warning station in the third embodiment. [Figure 21] FIG. 21 is a diagram showing an example of a line inspection signal and a preventive maintenance data transmission procedure in the fourth embodiment. [Figure 22] FIG. 22 is a diagram showing the relationship between the S / N ratio of the wireless line and the number of decoding errors and the relationship between the preventive maintenance data transmission time and the number of decoding errors.

Mode for Carrying Out the Invention

[0010] Hereinafter, a remote transmission system, a monitoring station, and a line monitoring method will be described in detail with reference to the drawings. In the following embodiments, parts with the same number are assumed to perform the same operation, and repeated explanations are omitted. For example, when there are a plurality of identical or similar elements, a common reference numeral may be used to describe each element without distinction, or a branch number may be used in addition to the common reference numeral to describe each element separately.

[0011] The telemetering system includes an old-type telemetering system (hereinafter referred to as "telemetering system (call type)") in which an observation station, which is a slave station, returns observation / measurement results in response to a call signal from a monitoring station, which is a master station, and a telemetering system (hereinafter referred to as "telemetering system (stand-alone type)") in which the observation station, which is a slave station, has a timing function and autonomously returns observation / measurement data when the set time arrives at the observation station. The telemetering system (call type) has, for example, a system configuration conforming to the Ministry of Land, Infrastructure, Transport and Tourism standard specification (National Electric Communication Specification No. 21), and the telemetering system (call type) has, for example, a system configuration conforming to the Ministry of Land, Infrastructure, Transport and Tourism standard specification (National Electric Communication Specification No. 54). In addition, the discharge warning system has, for example, a system configuration conforming to the Ministry of Land, Infrastructure, Transport and Tourism standard specification (National Electric Communication Specification No. 27).

[0012] [First Embodiment] As the first embodiment, an embodiment applied to the telemetering system (call type) will be described.

[0013] (composition) Figure 1 is a block diagram showing an example of a schematic configuration of a telemetering system (call type) in the first embodiment. The telemetering system (call type) comprises a monitoring station 1 as the master station, and a first observation station TM1, a second observation station TM2, and a third observation station TM3 as slave stations. Here, when it is not necessary to distinguish between the first observation station TM1, the second observation station TM2, and the third observation station TM3, they are simply referred to as observation station TM.

[0014] Each device in a telemetering system (call-type) is installed, for example, in a river information system or a dam management system to observe rainfall, water levels, etc., in a river or upstream of a dam.

[0015] Monitoring station 1 is located at a designated location in the administrative building of the city or town that manages the river, or in the dam management office that manages the dam. For example, monitoring station 1 sends a call to each data substation 22 at predetermined intervals (10 minutes, 15 minutes, 30 minutes, or 1 hour intervals, in accordance with National Electrical Communications Standard No. 21), and the data substations 22 respond in sequence, thereby collecting observation data, which is monitoring and control data.

[0016] Monitoring station 1 and the first observation station TM1, the second observation station TM2, and the third observation station TM3 can transmit and receive signals and data in half-duplex mode, for example, via a 70MHz / 400MHz / 450MHz band radio link. Here, monitoring station 1 and the first observation station TM1, the second observation station TM2, or the third observation station TM3 may also transmit and receive data via a relay station (not shown). In addition, monitoring station 1 and each observation station TM may be connected by wire.

[0017] Monitoring station 1 includes a monitoring device 11, a data master station 12, a wireless device 13, an antenna 131, a printer 14a, an operation unit 14b, a display device 15a, and the like. The internal configuration of monitoring station 1 will be explained later with reference to Figure 2.

[0018] The first observation station TM1 is a sub-station that measures water level and rainfall. The first observation station TM1 comprises an observation device 21a, a data sub-station 22a, a radio device 23a, a water level gauge 24a, and a rain gauge 24b. The observation device 21a, the data sub-station 22a, and the radio device 23a will be explained later with reference to Figure 3.

[0019] Here, the water level gauge 24a acquires river or lake level change data as observation data. The rain gauge 24b acquires rainfall data as observation data. For example, the water level gauge 24a and the rain gauge 24b output the acquired observation data as requested by the observation device 21a.

[0020] The second observation station TM2 is a sub-station equipped with meteorological observation equipment. The second observation station TM2 comprises an observation device 21b, a data sub-station 22b, a radio device 23b, and meteorological observation equipment 24c.

[0021] The meteorological observation equipment 24c acquires meteorological data, including temperature, humidity, and atmospheric pressure, as observation data. For example, the meteorological observation equipment 24c outputs the acquired observation data in response to a request from the observation device 21a.

[0022] The third observation station TM3 is a sub-station equipped with meteorological observation equipment. The third observation station TM3 comprises an observation device 21c, a data sub-station 22c, meteorological observation equipment 24d, and a radio device 23c. The observation station TM may be connected to the monitoring station 1 by wire. For example, a third observation station TM3 may be connected to the monitoring station 1 by wire. In this case, the radio device 23c and antenna 231c are not required, and the observation device 21c receives calls from the monitoring device 11. The observation device 21c then transmits the observation data acquired by the meteorological observation equipment 24d to the monitoring station 1.

[0023] Furthermore, the data slave station 22c receives a call from the data master station 12. The data slave station 22c then acquires the preventive maintenance data and transmits the acquired preventive maintenance data to the data master station 12.

[0024] Observation data transmitted by observation station TM is sent to monitoring station 1 via a wireless link. For example, if the wireless link deteriorates, the observation data may not be able to be transmitted correctly to monitoring station 1, resulting in missing data.

[0025] Here, preventative maintenance data is transmitted as digital data, while observational data is transmitted as analog data. Generally, digital data is more susceptible to the condition of the wireless link than analog data. That is, depending on the condition of the wireless link, analog data may be received correctly, while digital data may experience errors and not be received correctly.

[0026] Therefore, in this embodiment, by determining whether the monitoring station 1 can successfully decode the preventive maintenance data, the monitoring station 1 is able to know the status of the wireless link before the observation data is missing.

[0027] Next, I will explain the configuration of monitoring station 1.

[0028] Figure 2 shows an example of the functional block of the monitoring station 1 in the first embodiment.

[0029] First, the wireless device 13 transmits various calls from the monitoring device 11 to the wireless network via the antenna 131. Note that if the observation station TM is connected by wire, the wireless device 13 and antenna 131 do not need to be provided by the monitoring station 1. To illustrate this, the wireless device 13 is shown with a dotted line in Figure 1.

[0030] The monitoring device 11 generates a call at a predetermined time and outputs the generated call to the wireless device 13. Alternatively, it transmits the call to the observation station TM, which is connected by a wire. The monitoring device 11 also receives various observation data corresponding to the call via the wireless device 13 or from the observation station TM, which is connected by a wire.

[0031] As shown in Figure 2, the monitoring device 11 of monitoring station 1 is a computer comprising a control unit 111, a program storage unit 112, a data storage unit 113, a communication interface 114, and an input / output interface 115. The control unit 111, program storage unit 112, data storage unit 113, communication interface 114, and input / output interface 115 are connected to each other via a bus so as to be able to communicate with each other. In addition, the input / output interface 115 is connected to the input / output device 14 so as to be able to communicate with each other.

[0032] The control unit 111 is a control unit that controls the monitoring device 11. The control unit 111 includes a hardware processor such as a central processing unit (CPU). For example, the control unit 111 may be an integrated circuit capable of executing various programs.

[0033] Furthermore, the control unit 111 includes an observation call control unit 1111 and a video call control unit 1112.

[0034] The observation call control unit 1111 generates calls at predetermined intervals and outputs the generated calls to the radio device 13 via the communication interface 114. The radio device 13 then transmits the received calls to each observation station TM.

[0035] The video call control unit 1112 generates a video call when instructed by the administrator or at a set time, and outputs the generated video call to the control unit 121.

[0036] The program storage unit 112 can use a combination of non-volatile memory that allows writing and reading at any time, such as EPROM (Erasable Programmable Read Only Memory), HDD (Hard Disk Drive), and SSD (Solid State Drive), as a storage medium, and non-volatile memory such as ROM (Read Only Memory). The program storage unit 112 stores programs necessary for executing various processes. In other words, the control unit 111 can perform various controls and operations by reading and executing programs stored in the program storage unit 112.

[0037] The data storage unit 113 is a storage device that uses a combination of non-volatile memory, such as an HDD or memory card, which allows for writing and reading at any time, and volatile memory, such as RAM (Random Access Memory), as storage media. The data storage unit 113 is used to store data acquired and generated during the process in which the control unit 111 executes a program and performs various processing.

[0038] The communication interface 114 is an interface that enables the transmission and reception of various types of data between the wireless device 13 and the data master station 12.

[0039] The input / output interface 115 is connected to the input / output device 14. The input / output interface 115 is an interface that enables the transmission and reception of information between the monitoring device 11 and the input / output device 14. The input / output interface 115 may also be integrated with the communication interface 114.

[0040] The input / output device 14 includes the printer 14a, the control unit 14b, etc., as shown in Figure 1.

[0041] Printer 14a is one of the user interfaces that outputs various information on paper. Operation unit 14b is one of the user interfaces that accepts various operations or settings from the administrator.

[0042] Furthermore, the input / output device 14 may include a keyboard, pointing device, etc., for inputting various types of information. The input / output device 14 may also include a reader / writer for writing or reading data to or from a memory medium such as a USB memory stick. Additionally, the input / output device 14 may include a display, etc., for displaying various types of data to the administrator.

[0043] During downtime after receiving various observation data, the data master station 12 receives preventive maintenance data corresponding to a call via the wireless device 13 or from the observation station TM connected by wire. The preventive maintenance data will be described later.

[0044] The data master station 12 is a computer comprising a control unit 121, a program storage unit 122, a data storage unit 123, a communication interface 124, and an input / output interface 125. The control unit 121, program storage unit 122, data storage unit 123, communication interface 124, and input / output interface 125 are connected to each other via a bus so as to be able to communicate with each other. In addition, the input / output interface 125 is connected to the input / output device 15 so as to be able to communicate with each other.

[0045] The control unit 121 of the data master station 12 is a control unit that controls the data master station 12. The control unit 121 includes a hardware processor such as a central processing unit (CPU). For example, the control unit 121 may be an integrated circuit capable of executing various programs.

[0046] Furthermore, the control unit 121 includes a receiving unit 1211, a decoding control unit 1212, a decoding state determination unit 1213, an image synthesis unit 1214, and a display control unit 1215.

[0047] The receiving unit 1211 receives preventive maintenance data transmitted from the observation station TM. The receiving unit 1211 may store the received preventive maintenance data in the received data storage unit 1231.

[0048] The decoding control unit 1212, for example, in response to receiving a video call from the video call control unit 1112, acquires the preventive maintenance data stored in the received data storage unit 1231. Then, the decoding control unit 1212 decodes the preventive maintenance data. Here, the preventive maintenance data is encoded using a general-purpose image compression standard such as ITC_H.264. Therefore, the decoding control unit 1212 decodes the preventive maintenance data using a decoding method compliant with the general-purpose image compression standard such as ITC_H.264.

[0049] The decoding status determination unit 1213 determines whether the decoded preventive maintenance data has been successfully decoded.

[0050] The image synthesis unit 1214 generates a composite image for each observation station TM by combining normal images and abnormal reception images stored in the image data storage unit 1232 of the data storage unit 123 (described later) with information identifying the observation station TM.

[0051] The display control unit 1215 causes the composite image to be displayed on the display device 15a included in the input / output device 15.

[0052] The program storage unit 122 can use a combination of non-volatile memory, such as EPROM, HDD, or SSD, which allows for on-demand writing and reading, and other non-volatile memory, such as ROM, as storage media. The program storage unit 122 stores programs necessary for executing various processes. In other words, the control unit 121 can perform various controls and operations by reading and executing programs stored in the program storage unit 122.

[0053] The data storage unit 123 is a storage device that uses a combination of non-volatile memory, such as an HDD or memory card, which allows for writing and reading at any time, and volatile memory, such as RAM, as storage media. The data storage unit 123 is used to store data acquired and generated during the process in which the control unit 121 executes a program and performs various processing.

[0054] The data storage unit 123 includes a received data storage unit 1231 and an image data storage unit 1232.

[0055] The received data storage unit 1231 is used, for example, to store preventive maintenance data transmitted from each observation station TM.

[0056] The image data storage unit 1232 is used, for example, to store normal images and images with reception errors. For example, normal images and images with reception errors are images used when generating a composite image.

[0057] The communication interface 124 is an interface that enables the transmission and reception of various types of data between the wireless device 13 and the monitoring device 11.

[0058] The input / output interface 125 is connected to the input / output device 15. The input / output interface 125 is an interface that enables the transmission and reception of information between the data master station 12 and the input / output device 15. The input / output interface 125 may also be integrated with the communication interface 124.

[0059] The input / output device 15 includes the display device 15a shown in Figure 1, etc.

[0060] The display device 15a is, for example, a liquid crystal panel, which displays various information and is one of the user interfaces that accepts various operations and settings by tapping by an administrator or the like.

[0061] Furthermore, the input / output device 15 may include a keyboard, pointing device, etc., for inputting various types of information. The input / output device 15 may also include a reader / writer for writing or reading data to or from a memory medium such as a USB memory stick.

[0062] In Figures 1 and 2, the monitoring device 11 and the data master station 12 are shown as separate devices, but they may be a single device. That is, the monitoring device 11 and the data master station 12 only need to have one control unit, one program storage unit, one data storage unit, one communication interface, and one input / output interface. Also, the input / output device 14 and the input / output device 15 may be a single input / output device.

[0063] Next, I will explain the configuration of observation station TM.

[0064] Figure 3 shows an example of the functional block of the observation station TM in the first embodiment.

[0065] The wireless device 23a transmits data received from the observation device 21a or data slave station 22a to the wireless link via the antenna 231a. Note that if the first observation station TM1 is connected by wire, the wireless device 23a and antenna 231a do not need to be provided by the first observation station TM1. To illustrate this, the wireless device 23a is shown with a dotted line in Figure 1.

[0066] The observation equipment 24 includes at least one of the water level gauge 24a, rain gauge 24b, and meteorological observation equipment 24c shown in Figure 1.

[0067] The observation device 21a receives a call via the wireless device 23a. The observation device 21a then outputs the observation data acquired by the observation equipment 24 to the wireless device 23a.

[0068] As shown in Figure 3, the observation equipment 21 of the observation station TM is a computer comprising a control unit 211, a program storage unit 212, a data storage unit 213, a communication interface 214, and an input / output interface 215. The control unit 211, program storage unit 212, data storage unit 213, communication interface 214, and input / output interface 215 are connected to each other via a bus so as to be able to communicate with each other. In addition, the input / output interface 215 is connected to the observation equipment 24 so as to be able to communicate with each other.

[0069] The control unit 211 controls the observation device 21. The control unit 211 includes a hardware processor such as a central processing unit (CPU). For example, the control unit 211 may be an integrated circuit capable of executing various programs.

[0070] Furthermore, the control unit 211 includes an observation control unit 2111 and a startup signal control unit 2112.

[0071] The observation control unit 2111 stores the observation data, which is monitoring and control data observed by the observation equipment 24, in the data storage unit 213. When it receives a call from the monitoring station 1, it retrieves the observation data stored in the data storage unit 213 and transmits the retrieved observation data to the monitoring station 1 via the communication interface 214.

[0072] After receiving a call from the monitoring station, the activation signal control unit 2112 outputs an activation signal to the data slave station 22 after a predetermined time allocated to each observation station TM has elapsed.

[0073] The program storage unit 212 can use a combination of non-volatile memory, such as EPROM, HDD, or SSD, which allows for on-demand writing and reading, and other non-volatile memory, such as ROM, as storage media. The program storage unit 212 stores programs necessary for executing various processes. In other words, the control unit 211 can perform various controls and operations by reading and executing programs stored in the program storage unit 212.

[0074] The data storage unit 213 is a storage unit for storing various observation data observed by the observation equipment 24. The data storage unit 213 is a storage device that uses a combination of non-volatile memory, such as an HDD or memory card, which can be written to and read at any time, and volatile memory, such as RAM, as storage media. The data storage unit 213 is used to store data acquired and generated in the process of the control unit 211 executing a program and performing various processing.

[0075] The communication interface 214 is an interface that enables the transmission and reception of various types of data between the wireless device 23 and the monitoring station 1 and the data slave station 22, which is connected by wire.

[0076] The input / output interface 215 is connected to the observation equipment 24 and is an interface that enables the transmission and reception of information between the observation device 21 and the observation equipment 24. The input / output interface 215 may also be integrated with the communication interface 214.

[0077] The data substation 22 is a device that receives calls via the radio device 23. The data substation 22a acquires preventive maintenance data and outputs the acquired preventive maintenance data to the radio device 23.

[0078] The data slave station 22 is a computer comprising a control unit 221, a program storage unit 222, a data storage unit 223, and a communication interface 224. The control unit 221, the program storage unit 222, the data storage unit 223, and the communication interface 224 are connected to each other via a bus so that they can communicate with one another.

[0079] The control unit 221 is a control unit that controls the data slave station 22. The control unit 221 includes a hardware processor such as a central processing unit (CPU). For example, the control unit 221 may be an integrated circuit capable of executing various programs.

[0080] Furthermore, the control unit 221 includes a transmission unit 2211. When the transmission unit 2211 receives a startup signal from the startup signal control unit 2112, it acquires the preventive maintenance data stored in the data storage unit 223 (described later) and transmits the acquired preventive maintenance data to the monitoring station 1 via the communication interface 224.

[0081] The program storage unit 222 stores programs necessary for executing various processes. In other words, the control unit 221 can perform various controls and operations by reading and executing programs stored in the program storage unit 222. The program storage unit 222 can use a combination of non-volatile memory that allows writing and reading at any time, such as EPROM, HDD, or SSD, and non-volatile memory such as ROM, as the storage medium.

[0082] The data storage unit 223 includes a preventive maintenance data storage unit 2231. The preventive maintenance data storage unit 2231 is used to store preventive maintenance data.

[0083] The data storage unit 223 is a storage device that uses a combination of non-volatile memory, such as an HDD or memory card, which allows for constant writing and reading, and volatile memory, such as RAM, as storage media. The data storage unit 223 is used to store data acquired and generated during the process in which the control unit 221 executes a program and performs various processing.

[0084] Figure 4 shows an example of preventive maintenance data. Preventive maintenance data is data conforming to a general-purpose image compression transmission standard such as ITC_H.264, and includes a data set containing a start code, stream ID PES / PTS / STS / Stuffing, and video data. The video data is digital data, and is a video signal encoded using a general-purpose image compression method such as ITC_H.264.

[0085] Furthermore, for example, the video data may be image data displaying a single color for about 10 seconds. The video data, in its encoded state, may have a transmission capacity of 12Kbit or less. For example, the video data may have a transmission capacity of 1200bps × 10 seconds. On the other hand, if the video data is not encoded, it may have a transmission capacity of 36Kbit or less. For example, unencoded video data may have a transmission capacity of 1200bps × 30 seconds.

[0086] Furthermore, in addition to the data set including video data, the preventive maintenance data may also include information for identifying observation stations TM, such as start codes or stream IDs PES / PTS / STS / Stuffing.

[0087] The communication interface 224 is an interface that enables the transmission and reception of various types of data between the wireless device 23 and the observation device 21.

[0088] Here, Figures 1 and 3 show an example where the observation device 21 and the data slave station 22 are separate devices, but they may be a single device. That is, the observation device 21 and the data slave station 22 only need to have one control unit, one program storage unit, one data storage unit, one communication interface, and one input / output interface.

[0089] (operation) Figure 5 shows an example of the observation data and predictive maintenance data transmission procedure in the first embodiment. As shown in Figure 5, the TM (Telemeter) data period is repeated at a predetermined interval (10-minute interval in the example in Figure 5). The TM data period can be shortened depending on the situation if more detailed observation is required (for example, when rainfall increases sharply due to torrential downpours, etc., for example, shortened from a 10-minute interval under normal circumstances to a 1-minute interval during heavy rain). Here, the preventive maintenance data period is set to a predetermined time during idle periods (10 minutes in the example in Figure 5) when observation data other than the TM data period is not being transmitted.

[0090] As shown in Figure 5, when the TM data period begins, the observation call control unit 1111 of the monitoring device 11 generates a call and transmits a call signal to each observation station TM via the communication interface 114, etc. Each observation control unit 2111 of the observation devices 21 (in the example of Figure 5, observation devices 21a to 21c) transmits observation data (e.g., water level data, rainfall, meteorological data, etc.) to the monitoring device 11 in response to the call. The observation data may be transmitted at a transmission rate of, for example, 200 bps or 1200 bps.

[0091] Once the TM data period ends, that is, after receiving observation data from all observation stations (TMs), the preventive maintenance data period begins.

[0092] During the preventive maintenance data period, the activation signal control unit 2112 of the observation device 21 generates an activation signal after a predetermined time allocated to each observation station TM has elapsed following a call, and outputs the generated activation signal to the data slave station 22. The transmitting unit 2211 of the data slave station 22 (data slave stations 22a to 22c in the example of Figure 5), which has received the activation signal, acquires the preventive maintenance data stored in the preventive maintenance data storage unit 2231. Here, the acquired preventive maintenance data is encoded using a general-purpose image compression technique such as ITC_H.264. The transmitting unit 2211 then transmits the acquired preventive maintenance data to the data master station 12. The preventive maintenance data may be transmitted at a transmission rate of 1200 bps.

[0093] As shown in Figure 5, each data slave station 22 transmits preventive maintenance data in a predetermined order and at predetermined intervals.

[0094] The receiving unit 1211, provided in the control unit 121 of the data master station 12, may receive preventive maintenance data and store the received preventive maintenance data in the received data storage unit 1231. For example, the receiving unit 1211 may identify observation stations TM according to the order in which the preventive maintenance data is received and store the preventive maintenance data in the received data storage unit 1231 in association with each observation station TM. Alternatively, the receiving unit 1211 may identify observation stations TM based on identification information contained in the preventive maintenance data and store the preventive maintenance data in the received data storage unit 1231 in association with each observation station TM.

[0095] Figure 6 is a flowchart showing an example of the procedure for decoding and displaying preventive maintenance data in the first embodiment. The operation of this flowchart is realized when the control unit 121 of the data master station 12 reads and executes the program stored in the program storage unit 122.

[0096] This flowchart begins when the control unit 121 receives a video call from the video call control unit 1112 of the control unit 111. For example, the timing at which the video call control unit 1112 generates and transmits the video call to the control unit 121 can be arbitrary, for example, after receiving preventive maintenance data from all slave stations.

[0097] In step ST101, the decoding control unit 1212 acquires the preventive maintenance data stored in the received data storage unit 1231. The preventive maintenance data to be acquired may be the preventive maintenance data of the observation station TM with the smallest number that has not yet been decoded.

[0098] For example, if a video call has just been received, the decoding control unit 1212 acquires the preventive maintenance data received from the first observation station TM1. Also, if a decoding instruction is received from the display control unit 1215, the preventive maintenance data may be acquired in accordance with that decoding instruction.

[0099] For example, if a decoding instruction is received after a video call instruction is received, the decoding control unit 1212 may acquire the preventive maintenance data received from the second observation station TM2.

[0100] In step ST102, the decoding control unit 1212 decodes the preventive maintenance data. For example, the decoding control unit 1212 decodes the preventive maintenance data using a decoding method compliant with a general-purpose image compression standard such as ITC_H.264 used to encode the preventive maintenance data. The decoding control unit 1212 outputs the decoded preventive maintenance data to the decoding status determination unit 1213.

[0101] In step ST103, the decoding status determination unit 1213 determines whether the decoded preventive maintenance data is a decoding error. For example, if the signal-to-noise ratio (S / N ratio) of the wireless line is high, the preventive maintenance data cannot be decoded correctly. In such cases, the process proceeds to step ST104. On the other hand, if the S / N ratio of the wireless line is low, the preventive maintenance data can be decoded correctly. In such cases, the process proceeds to step ST105.

[0102] In step ST104, the image synthesis unit 1214 acquires an image of a reception error. If the preventive maintenance data could not be decoded correctly, the decoding status determination unit 1213 outputs an error decoding signal to the image synthesis unit 1214 indicating that the preventive maintenance data could not be decoded correctly. Upon receiving an abnormal decoding signal, the image synthesis unit 1214 acquires the abnormally received image stored in the image data storage unit 1232.

[0103] In step ST105, the image synthesis unit 1214 acquires a normal image. If the preventive maintenance data has been successfully decoded, the decoding status determination unit 1213 outputs a normal decoding signal to the image synthesis unit 1214 indicating that the preventive maintenance data has been successfully decoded. Upon receiving the normal decoding signal, the image synthesis unit 1214 acquires the normal image stored in the image data storage unit 1232.

[0104] In step ST106, the image synthesis unit 1214 generates a composite image. The image synthesis unit 1214 combines the acquired image (normal image or reception abnormal image) with information identifying the observation station TM corresponding to that image. Then, the image synthesis unit 1214 synthesizes the combined images of each observation station TM to generate a composite image. The image synthesis unit 1214 outputs the synthesized composite image to the display control unit 1215.

[0105] In step ST107, the display control unit 1215 determines whether it has decoded the preventive maintenance data from all observation stations TM. For example, if there are still uncombined images in the composite image, the display control unit 1215 determines that it has not decoded the preventive maintenance data from all observation stations TM. The display control unit 1215 then generates a decode instruction and outputs it to the decode control unit 1212. The process then returns to step ST101.

[0106] On the other hand, if the composite image contains all the composite images, the display control unit 1215 determines that the composite image is complete. In this case, the process proceeds to step ST108.

[0107] In step ST108, the display control unit 1215 outputs a composite image. The display control unit 1215 outputs the composite image to the display device 15a of the input / output device 15 through the input / output interface 125.

[0108] Figure 7 shows an example of a composite image displayed on the display device 15a in the first embodiment. Figure 7 shows an example where there are 24 observation stations TM. In this example, observation stations TM1 through TM7, TM9 through TM16, and TM18 through TM24 all display normal images. On the other hand, observation stations TM8 and TM17 display abnormal reception images (shown with diagonal lines in Figure 7).

[0109] In this way, by having the administrator check the composite image displayed on the display device 15a, it becomes possible to check the status of the wireless communication line between the monitoring station 1 and the observation station TM at a glance.

[0110] For example, when an administrator inspects an observation station TM that repeatedly displays reception abnormalities, they can check the status of the wireless connection and maintain it to prevent any data loss during observation.

[0111] Furthermore, while the example in Figure 6 shows a case where a composite image is generated after receiving preventive maintenance data from all observation stations TM and then receiving a video call from the monitoring device 11, the data master station 12 may update the composite image each time it receives preventive maintenance data. That is, each time the data master station 12 receives preventive maintenance data, it may execute steps ST102 to ST106 and step ST108 and output the composite image to the display device 15a.

[0112] (Effects of the first embodiment) According to the first embodiment described above, the status of the wireless link can be checked by confirming the reception status of the preventive maintenance data, which is digital data. This makes it possible to know the status of the wireless link before observation data is lost.

[0113] [Second Embodiment] (composition) In the first embodiment, an example was described in which pre-encoded preventive maintenance data is transmitted to the monitoring station 1. In the second embodiment, an example is described in which images, sounds, etc., acquired by the observation station TM are encoded and transmitted together with the preventive maintenance data. Here, the telemetering system (call type) in the second embodiment is the same as in Figure 1.

[0114] Figure 8 shows an example of a functional block diagram of monitoring station 1 in the second embodiment. The monitoring station 1 in the second embodiment differs from the first embodiment in that the control unit 121 of the data master station 12 includes an analysis control unit 1216, and the data storage unit 123 includes a display data storage unit 1233.

[0115] The display data storage unit 1233 is used to store the composite image displayed on the display device 15a by the display control unit 1215.

[0116] The analysis control unit 1216 retrieves the composite image stored in the display data storage unit 1233 after instructions from the administrator or after a predetermined period has elapsed. For example, the analysis control unit 1216 analyzes the retrieved composite image to see if there are any observation stations TM that have displayed reception abnormality images more than a predetermined number of times.

[0117] Figure 9 shows an example of a functional block diagram of observation station TM. The observation station TM of the second embodiment differs from the first embodiment in that the data slave station 22 is equipped with an input / output interface 225, to which a camera 25 and a microphone 26 are connected. Furthermore, the control unit 221 is equipped with an acquired information processing unit 2212 and an encoding unit 2213, and the data storage unit 223 is equipped with an acquired information storage unit 2232.

[0118] The acquired information storage unit 2232 is used to store image data acquired by the camera 25 and audio data acquired by the microphone 26.

[0119] Camera 25 captures images of the scenery at the location where the observation station TM is located, and acquires image data. Here, the image data may be a still image or a video. For example, the image data may be a still image or a video with a resolution of 1920 x 1080. The image data is then stored in the acquired information storage unit 2232 under the control of the control unit 111.

[0120] Microphone 26 acquires audio data from the location where the observation station TM is located. The audio data is then stored in the acquired information storage unit 2232 under the control of the control unit 111.

[0121] When the acquired information processing unit 2212 receives a startup signal from the startup signal control unit 2112, it acquires image data and audio data stored in the acquired information storage unit 2232. Furthermore, the acquired information processing unit 2212 converts the acquired image data and audio data to a size suitable for low bitrate transmission, for example, 1200bps.

[0122] The encoding unit 2213 encodes (compresses) the image data and audio data. Here, the encoding method may be a general method that can encode the data to a size suitable for low bitrate transmission of 1200 bps, for example.

[0123] Furthermore, in addition to acquiring the preventive maintenance data stored in the preventive maintenance data storage unit 2231, the transmission unit 2211 generates operational support data, including encoded image data and audio data, and transmits it to the monitoring station 1. In other words, the operational support data is data transmitted by the observation station TM in place of the preventive maintenance data described in the first embodiment.

[0124] (operation) In the second embodiment, the procedure for transmitting observation data is the same as the procedure described with reference to Figure 5, so redundant explanations are omitted.

[0125] Figure 10 is a flowchart showing an example of the operation support data transmission procedure in the second embodiment. The operation of this flowchart is realized when the control unit 221 of the data substation 22 reads and executes the program stored in the program storage unit 222.

[0126] This flowchart is initiated when the data slave station 22 receives a startup signal from the startup signal control unit 2112. The timing of the startup signal transmission from the startup signal control unit 2112 may be the same as described with reference to Figure 5.

[0127] In step ST201, the information acquisition processing unit 2212 acquires image data and audio data. When the control unit 221 receives a start signal, the information acquisition processing unit 2212 acquires the image data and audio data stored in the information acquisition storage unit 2232. The image data may be image data from any time stored in the information acquisition storage unit 2232. Similarly, the audio data may be audio data from any time stored in the information acquisition storage unit 2232.

[0128] In step ST202, the acquired information processing unit 2212 performs preprocessing on the acquired data. As preprocessing, the acquired information processing unit 2212 resizes the image data and extracts the audio data. If the resolution of the image data is 1920×1080, the acquired information processing unit 2212 resizes it to a resolution suitable for low bitrate transmission of, for example, 1200bps (for example, a resolution of 160×128). Similarly, the acquired information processing unit 2212 extracts the audio data to a size suitable for low bitrate transmission (for example, 5 seconds of audio data). Then, the acquired information processing unit 2212 outputs the resized image data and the extracted audio data to the encoding unit 2213.

[0129] In step ST203, the encoding unit 2213 encodes the image data and audio data. The encoding unit 2213 performs encoding (compression) on the resized image data and extracted audio data. The encoding method may be a general method that can encode the data to a size suitable for low bitrate transmission at 1200 bps. The encoding unit 2213 then outputs the encoded image data and audio data to the transmission unit 2211.

[0130] In step ST204, operational support data is generated. The transmission unit 2211 retrieves the preventive maintenance data stored in the preventive maintenance data storage unit 2231. The transmission unit 2211 then generates operational support data including encoded image data, audio data, and preventive maintenance data.

[0131] In step ST205, the transmitter 2211 transmits the operational support data to the data master station 12. The transmitter 2211 transmits the generated operational support data to the data master station 12, at least through the communication interface 214.

[0132] Furthermore, as explained in Figure 5, each data slave station 22 transmits operational support data in a predetermined order and at predetermined intervals.

[0133] The receiving unit 1211 provided in the control unit 121 of the data master station 12 may receive operational support data and store the received operational support data in the received data storage unit 1231. For example, the receiving unit 1211 may store operational support data transmitted from all data slave stations 22 in the received data storage unit 1231.

[0134] Figure 11 is a diagram illustrating the procedure for generating operational support data. As shown in Figure 11, first, the camera 25 captures the scenery and other images of any location where the observation station TM is installed, generating image data. Additionally, the microphone 26 collects sound from the surrounding area of ​​the observation station TM, generating audio data. The generated image and audio data are stored in the acquired information storage unit 2232.

[0135] The acquired information processing unit 2212 then performs preprocessing such as resizing the image data and separating the audio data so that it is a size suitable for low bitrate transmission. The encoding unit 2213 then encodes the preprocessed image data and audio data. The transmission unit 2211 then acquires the preventive maintenance data stored in the preventive maintenance data storage unit 2231 and generates operation support data that includes the encoded image data and audio data, as well as the preventive maintenance data. The transmission unit 2211 then transmits the generated operation support data to the monitoring station 1.

[0136] Here, Figures 10 and 11 show an example where the operational support data includes image data, audio data, and predictive maintenance data, but the operational support data only needs to include at least one of the image data, audio data, and predictive maintenance data.

[0137] For example, data substation 22 may not have all of the camera 25, microphone 26, and preventive maintenance data. For instance, if data substation 22 only has the camera 25, the operational support data transmitted by data substation 22 will include image data and preventive maintenance data.

[0138] Figure 12 is a flowchart showing an example of the procedure for decoding operational support data in the second embodiment.

[0139] The operation of this flowchart is realized when the control unit 121 of the data master station 12 reads and executes the program stored in the program storage unit 122.

[0140] This flowchart begins when the control unit 121 receives a video call from the video call control unit 1112 of the control unit 111. For example, the timing at which the video call control unit 1112 generates and transmits the video call to the control unit 121 can be arbitrary, for example, after receiving operational support data from all slave stations.

[0141] In step ST301, the decoding control unit 1212 acquires the operational support data stored in the received data storage unit 1231. The operational support data to be acquired may be the operational support data of the observation station TM with the smallest number that has not yet been decoded. For example, if a video call has just been received, the decoding control unit 1212 acquires the operational support data received from the first observation station TM1.

[0142] Furthermore, if a decoding instruction is received from the display control unit 1215, the decoding control unit 1212 may acquire operational support data in accordance with the decoding instruction. For example, if a decoding instruction is received after a video call instruction has been received, the decoding control unit 1212 may acquire operational support data received from the second observation station TM2.

[0143] In step ST302, the decoding control unit 1212 decodes the operational support data. For example, the decoding control unit 1212 decodes the operational support data using a decoding method corresponding to the encoding used for the operational support data. The decoding control unit 1212 outputs the decoded operational support data to the decoding status determination unit 1213.

[0144] In step ST303, if the operation support data has been successfully decoded, the decoding status determination unit 1213 determines whether the preventive maintenance data has been successfully received.

[0145] In step ST304, the image synthesis unit 1214 acquires a normal image. If the preventive maintenance data has been successfully decoded, the decoding status determination unit 1213 outputs a normal decoding signal to the image synthesis unit 1214 indicating that the preventive maintenance data has been successfully decoded. Upon receiving the normal decoding signal, the image synthesis unit 1214 acquires the normal image stored in the image data storage unit 1232.

[0146] In step ST305, the decryption status determination unit 1213 determines whether the operation support data contains audio data. If it determines that the preventive maintenance data cannot be decrypted successfully, the decryption status determination unit 1213 determines whether the operation support data contains audio data. If it determines that the operation support data contains audio data, the decryption status determination unit 1213 determines whether the audio data was successfully decrypted.

[0147] In step ST306, the image synthesis unit 1214 receives the audio data. If it determines that the audio data has been successfully decoded, the decoding status determination unit 1213 outputs the decoded audio data to the image synthesis unit 1214.

[0148] In step ST307, the decoding status determination unit 1213 determines whether the operation support data contains image data. If it determines that the operation support data does not contain audio data, or that the audio data cannot be decoded properly, the decoding status determination unit 1213 determines whether the operation support data contains image data. If it determines that image data is included, the decoding status determination unit 1213 determines whether the image data was successfully decoded.

[0149] In step ST308, the image synthesis unit 1214 receives the image data. If it determines that the image data has been successfully decoded, the decoding status determination unit 1213 outputs the decoded image data to the image synthesis unit 1214.

[0150] In step ST309, the image synthesis unit 1214 acquires the received abnormal image. If it is determined that the operation support data does not contain image data, or that the image data cannot be decoded properly, for example, if the signal-to-noise ratio of the wireless line is high, the decoding status determination unit 1213 determines that the operation support data cannot be decoded properly. In this case, the decoding status determination unit 1213 outputs an abnormal decoding signal to the image synthesis unit 1214 indicating that none of the preventive maintenance data, audio data, or image data could be decoded properly. Upon receiving the abnormal decoding signal, the image synthesis unit 1214 acquires the received abnormal image stored in the image data storage unit 1232.

[0151] In step ST310, the image synthesis unit 1214 generates a composite image. The image synthesis unit 1214 combines the acquired image (normal image, audio data, image data, or image with reception abnormality) with information identifying the observation station TM corresponding to that image.

[0152] In this case, when using audio data as a composite image, the image synthesis unit 1214 may, for example, obtain information from the data storage unit 123 to display "Audio" as an image. The image synthesis unit 1214 then synthesizes the combined images of each observation station TM to generate a composite image. The image synthesis unit 1214 outputs the synthesized composite image to the display control unit 1215.

[0153] In step ST311, the display control unit 1215 determines whether it has decoded the preventive maintenance data from all observation stations TM. For example, if there are still uncombined images in the composite image, the display control unit 1215 determines that it has not decoded the operational support data from all observation stations TM. The display control unit 1215 then generates a decode instruction and outputs it to the decode control unit 1212. The process then returns to step ST301.

[0154] On the other hand, if the composite image contains all the composite images, the display control unit 1215 determines that the composite image is complete. In this case, the process proceeds to step ST312.

[0155] In step ST312, the display control unit 1215 outputs a composite image. The display control unit 1215 outputs the composite image to the display device 15a of the input / output device 15 through the input / output interface 125.

[0156] In the second embodiment, the display control unit 1215 may store the composite image to be output to the display device 15a in the display data storage unit 1233. For example, the composite image stored in the display data storage unit 1233 may be stored in a format that can be displayed on the display device 15a according to the administrator's instructions.

[0157] Figure 13 shows an example of a composite image displayed on the display device 15a in the second embodiment. The example in Figure 13 shows a case where there are 24 observation stations TM, similar to the example in Figure 7. In the example in Figure 13, the first observation station TM1, etc., displays a normal image. The third observation station TM3, etc., displays image data, and the tenth observation station TM10 and the twentieth observation station TM20 display audio. On the other hand, the eighth observation station TM8 and the seventeenth observation station TM17 display images with reception abnormalities.

[0158] In this way, by having the administrator check the composite image displayed on the display device 15a, it becomes possible to check the status of the wireless communication line between the monitoring station 1 and the observation station TM at a glance.

[0159] Figure 14 shows an image illustrating the procedure for analyzing a composite image. As described above, the display control unit 1215 stores the composite image in the display data storage unit 1233. The analysis control unit 1216 retrieves the composite image stored in the display data storage unit 1233 after instructions from the administrator or after a predetermined period has elapsed. The analysis control unit 1216 then analyzes the retrieved composite image to see if there are any abnormal observation stations TM. For example, the analysis control unit 1216 analyzes whether there are any observation stations TM that have displayed abnormal reception images more than a predetermined number of times.

[0160] If the analysis reveals that there are abnormal observation stations TM, a composite image with a modified display indicating that something is wrong may be output to the display device 15a. In the example in Figure 14, the 8th observation station TM8 and the 17th observation station TM17 are shown with diagonal lines to indicate that they are abnormal.

[0161] (Effects of the second embodiment) According to the second embodiment described above, the status of the wireless link can be checked by verifying whether the digital data, such as operational support data, predictive maintenance data, audio data, and image data, has been successfully decoded. This makes it possible to know the status of the wireless link before observation data is lost.

[0162] [Third Embodiment] Next, a third embodiment will be described. The third embodiment describes an embodiment that enables preventive maintenance of the quality of both the downlink and uplink wireless links by enabling half-duplex transmission and reception of preventive maintenance data between the data master station 12 and the slave station.

[0163] (composition) In the third embodiment, a telemetering system (call type) is configured with a data master station 12 and a data slave station 22 capable of transmitting and receiving preventive maintenance data in half-duplex mode. Here, the general configuration of the telemetering system (call type) is the same as the block diagram described with reference to Figure 1, so a redundant explanation is omitted.

[0164] Figure 15 shows an example of the functional block of monitoring station 1 in the third embodiment. The monitoring station 1, which is the master station in the third embodiment, differs from the first embodiment in that the control unit 121 includes a transmission unit 1217 and the data storage unit 123 includes a preventive maintenance data storage unit 1234. The preventive maintenance data storage unit 1234 is used to store preventive maintenance data. The preventive maintenance data may be encoded preventive maintenance data, as in the first embodiment.

[0165] The transmitting unit 1217 acquires preventive maintenance data upon instruction from the administrator or at a predetermined time, and transmits the preventive maintenance data to the observation station TM via the communication interface 124.

[0166] Figure 16 shows an example of the functional block of the observation station TM in the third embodiment. The observation station TM, which is a slave station in the third embodiment, differs from the first embodiment in that the control unit 221 includes a receiving unit 2214, the data storage unit 223 includes an acquired information storage unit 2232, and the control unit 211 does not include a startup signal control unit 2112.

[0167] The acquired information storage unit 2232 is a storage unit that temporarily stores preventive maintenance data.

[0168] The receiving unit 2214 of the observation station TM is a receiving unit that receives preventive maintenance data transmitted from the data master station 12. The received preventive maintenance data is then stored in the acquired information storage unit 2232.

[0169] (operation) Figure 17 shows an example of the observation data and predictive maintenance data transmission procedure in the third embodiment. The call and observation data transmitted during the TM data period are the same as those described in Figure 5, so a redundant explanation is omitted here.

[0170] Once the TM data period ends, that is, after receiving observation data from all observation stations (TMs), the preventive maintenance data period begins.

[0171] During the preventive maintenance data period, the transmission unit 1217 of the data master station 12 retrieves the preventive maintenance data stored in the preventive maintenance data storage unit 1234 when instructed by the administrator or at a predetermined time, and transmits the preventive maintenance data to the observation station TM via the communication interface 124. Here, the retrieved preventive maintenance data is encoded using a general-purpose image compression technique such as ITC_H.264.

[0172] In the example shown in Figure 17, the transmitter 1217 transmits preventive maintenance data to the data slave station 22a.

[0173] The receiving unit 2214 of the data slave station 22a receives the preventive maintenance data transmitted from the data master station 12. The received preventive maintenance data is then stored in the acquired information storage unit 2232. The receiving unit 2214 may also output a signal to the transmitting unit 2211 indicating that the preventive maintenance data has been received.

[0174] The transmitting unit 2211 acquires the preventive maintenance data stored in the acquired information storage unit 2232. Then, the transmitting unit 2211 sends the acquired preventive maintenance data back to the data master station 12.

[0175] As shown in Figure 17, the transmitter 1217 transmits preventive maintenance data to all data slave stations 22. Meanwhile, the data slave stations 22 that receive the preventive maintenance data send the received preventive maintenance data back to the data master station 12, so that the preventive maintenance data is transmitted and received in half-duplex.

[0176] The data master station 12 may transmit preventive maintenance data in a predetermined order and at predetermined intervals.

[0177] The procedure for decoding and displaying preventive maintenance data at the data master station 12 is the same as the decoding and display procedure described with reference to Figure 6, so a redundant explanation is omitted here.

[0178] (Effects of the third embodiment) According to the third embodiment described above, by transmitting preventive maintenance data, which is digital data, from monitoring station 1 to each observation station TM, and receiving preventive maintenance data in return from each observation station TM, the status of the radio link can be confirmed by checking the reception status of the radio link, including both the downlink and uplink radio links. This makes it possible to know the status of the radio link before observation data is lost.

[0179] [Modified versions of the first, second, and third embodiments] The first, second, and third embodiments described above describe a so-called call-type telemeter that responds to a call signal from a master station (monitoring station 1) and returns observation results, but the invention is not limited to this. The telemeter system to which the present invention is applied can also be a telemeter system (standalone type) as described in National Telecommunications Bureau Notification No. 54.

[0180] For example, in the case of a telemetering system (autonomous), the monitoring device 11 of monitoring station 1 does not need to transmit a call to the observation device 21 of the first observation station TM1. Also, according to National Telecommunications Standard No. 54, the observation data, which is monitoring and control data, is collected at intervals of 5 minutes, 10 minutes, 30 minutes, or 1 hour. Here, the transmission timing of each observation station TM is assumed to be appropriately adjusted in advance to prevent the observation data from colliding.

[0181] In other words, in the case of a telemetry system (autonomous type), at a predetermined time, each observation device 21 of the observation station TM autonomously transmits observation data to the monitoring device 11 of the monitoring station 1 at a pre-set time.

[0182] In this case, the data slave station 22 of the observation station TM may be configured to transmit preventive maintenance data or operational support data to the data master station 12 of the monitoring station 1 in the manner of the first, second, and third embodiments, after a predetermined time has elapsed since the transmission of observation data from the monitoring device 11 of the monitoring station 1.

[0183] Furthermore, the telemetering system may also be configured to use both a call-type telemetering system and a standalone telemetering system.

[0184] In this case, for the telemetering system (call type), the monitoring device 11 of monitoring station 1 is required to send a call signal to the call type observation station TM. Furthermore, the timing of the transmission of measurement data from the observation station TM to the monitoring device 11 of monitoring station 1 is pre-adjusted so that the transmission timing of the call type and observation station TM does not conflict with the transmission timing of the standalone observation station TM.

[0185] Therefore, preventive maintenance data or operational support data can be transmitted at times when the calling observation station TM and the autonomous observation station TM are not transmitting.

[0186] [Fourth Embodiment] Next, a fourth embodiment will be described in which the system is applied to a discharge alarm system.

[0187] A discharge warning system is installed downstream of a dam or similar structure and is designed to warn of a rapid rise in water levels downstream when an emergency discharge from the dam is necessary. It can be activated by broadcasting an emergency alert or sounding a siren.

[0188] (composition) Figure 18 is a block diagram showing an example of a schematic configuration of a discharge alarm system in the fourth embodiment. The discharge alarm system comprises a master station monitoring station 1, and multiple slave stations: a first alarm station AL1, a second alarm station AL2, and a third alarm station AL3. Here, when it is not necessary to distinguish between the first alarm station AL1, the second alarm station AL2, and the third alarm station AL3, they are simply referred to as alarm station AL.

[0189] Monitoring station 1 and alarm station AL are, for example, monitoring station 1 and alarm station AL in accordance with National Telecommunications Standard No. 27.

[0190] Monitoring station 1 includes a control monitoring device 16, a data master station 12, a wireless device 13, an antenna 131, a printer 14a, an operation unit 14b, a display device 15a, etc. The data master station 12, wireless device 13, antenna 131, printer 14a, operation unit 14b, and display device 15a can be the same as those described for monitoring station 1 with reference to Figure 1, so redundant explanations are omitted here.

[0191] When emergency discharges such as water releases are carried out from a dam, etc., the control and monitoring device 16 of monitoring station 1 transmits an alarm control signal to the alarm station AL, causing it to sound a siren, emit a simulated sound, and broadcast an audio message. Upon receiving the alarm control signal, the alarm station AL, after sounding a siren, emitting a simulated sound, and broadcasting an audio message, sends an alarm response signal back to the control and monitoring device 16 of monitoring station 1. The control and monitoring device 16 of monitoring station 1 receives the alarm response signal to ascertain the operating status of the alarm station AL and prints and displays the information.

[0192] Furthermore, the control monitoring device 16 of monitoring station 1 transmits a line inspection signal to each alarm station AL at predetermined intervals (for example, once a day) in order to check the operating status of the alarm stations AL. Upon receiving the line inspection signal, the alarm station AL performs a predetermined operation check and returns the check result as a line inspection response signal. The control monitoring device 16 of monitoring station 1 understands the operating status of each alarm station AL by receiving the line inspection response signal.

[0193] The first alarm station AL1 is a siren alarm station equipped with a siren alarm device 31a, a data slave station 32a, a radio device 33a, a speaker 34a, a siren 34b, and a rotating light 34c.

[0194] The second alarm station AL2 is a speaker alarm station equipped with a speaker alarm device 31b, a data slave station 32b, a radio device 33b, a speaker 34a, and a rotating light 34c.

[0195] The third alarm station AL3 comprises a siren alarm device 31c, a data slave station 32c, a radio device 33c, a siren 34b, and a rotating light 34c. Here, the data slave station 32b and the siren alarm device 31c can have the same configuration as the data slave station 32a and the siren alarm device 31a described above, so a redundant explanation is omitted.

[0196] Figure 19 shows an example of the functional block of monitoring station 1 in the fourth embodiment. The control and monitoring device 16 is a computer comprising a control unit 161, a program storage unit 162, a data storage unit 163, a communication interface 164, and an input / output interface 165. The control unit 161, program storage unit 162, data storage unit 163, communication interface 164, and input / output interface 165 are connected to each other via a bus so as to be able to communicate with each other. In addition, the input / output interface 165 is connected to the input / output device 14 so as to be able to communicate with each other.

[0197] The input / output device 14, control unit 161, program storage unit 162, data storage unit 163, communication interface 164, and input / output interface 165 have the same functions as the control unit 111, program storage unit 112, data storage unit 113, communication interface 114, and input / output interface 115, which were described with reference to Figure 2, so a redundant explanation will be omitted.

[0198] Furthermore, the control unit 161 differs from the control unit 111 of the first embodiment in that it includes a line inspection control unit 1611.

[0199] The line inspection control unit 1611 generates a line inspection signal, which is a control monitoring signal, upon receiving instructions from the administrator or at a pre-set time. The line inspection signal is, for example, a signal for any of the data slave stations 32 and includes an instruction to return preventive maintenance data. The line inspection control unit 1611 then transmits the generated line inspection signal to the data slave stations 32, at least through the communication interface 164.

[0200] Furthermore, the control unit 161 is, of course, capable of generating an alarm call in response to a call instruction from the administrator and transmitting the alarm call to the alarm station AL.

[0201] Here, Figures 17 and 18 show an example where the control monitoring device 16 and the data master station 12 are separate devices, but they may be a single device. That is, the control monitoring device 16 and the data master station 12 only need to have one control unit, one program storage unit, one data storage unit, one communication interface, and one input / output interface. Also, the input / output device 14 and the input / output device 15 may be a single input / output device.

[0202] Figure 20 shows an example of the functional block of alarm station AL in the fourth embodiment. As shown in Figure 20, the alarm device 31 of the alarm station AL is a computer comprising a control unit 311, a program storage unit 312, a data storage unit 313, a communication interface 314, and an input / output interface 315. The control unit 311, the program storage unit 312, the data storage unit 313, the communication interface 314, and the input / output interface 315 are connected to each other via a bus so as to be able to communicate with each other.

[0203] Furthermore, the input / output interface 315 is connected to the alarm device 34 in a communicative manner. Here, the alarm device 34 includes at least one of the speaker 34a, siren 34b, and rotating light 34c shown in Figure 16.

[0204] Since the wireless device 33a can have the same configuration as the wireless device 23a described with reference to Figure 1, a redundant explanation will be omitted here.

[0205] The siren alarm device 31a performs operations such as sounding a siren, sounding a simulated sound, and broadcasting voice messages using the speaker 34a, siren 34b, and rotating light 34c, based on alarm control signals from the control monitoring device 16. Here, the speaker alarm device 31b of the first alarm station performs operations such as sounding a siren, sounding a simulated sound, and broadcasting voice messages, while the speaker alarm device 31b of the second alarm station performs operations other than sounding a siren, excluding the siren sounding of the siren alarm device 31a, and the siren alarm device 31c of the third alarm station performs operations other than sounding a simulated sound, excluding the siren alarm sounding of the siren alarm device 31a.

[0206] Furthermore, the siren alarm device 31a sends a message to the control and monitoring device 16 regarding its operation status.

[0207] The control unit 311, program storage unit 312, data storage unit 313, communication interface 314, and input / output interface 315 have the same functions as the control unit 211, program storage unit 212, data storage unit 213, communication interface 214, and input / output interface 215, which were described with reference to Figure 3, so a redundant explanation will be omitted.

[0208] Of course, when the control unit 311 receives an alarm call, it may activate the alarm device 34 and perform an alarm operation.

[0209] The data slave station 32a receives a line inspection signal, which is control monitoring data from the data master station 12, and transmits preventive maintenance data to the data master station 12 in accordance with the line inspection signal.

[0210] The data substation 32 is a computer comprising a control unit 321, a program storage unit 322, a data storage unit 323, and a communication interface 324. The control unit 321, the program storage unit 322, the data storage unit 323, and the communication interface 324 are connected to each other via a bus so that they can communicate with one another.

[0211] Furthermore, the control unit 321 differs from the control unit 221 of the first embodiment in that it includes a receiving unit 3212.

[0212] The control unit 321, program storage unit 322, data storage unit 323, and communication interface 324 have the same functions as the control unit 221, program storage unit 222, data storage unit 223, and communication interface 224, which were described with reference to Figure 3, so a redundant explanation will be omitted.

[0213] The receiving unit 3212 receives the line inspection signal at least through the communication interface 324. The receiving unit 3212 then outputs the line inspection signal to the transmitting unit 3211.

[0214] (operation) Figure 21 shows an example of the circuit inspection signal and preventive maintenance data transmission procedure in the fourth embodiment. As shown in Figure 21, the line inspection control unit 1611 of the control unit 161 in the control monitoring device 16 generates a line inspection signal when it receives instructions from the administrator or at a pre-set time. The line inspection signal is, for example, a signal for any of the data slave stations 32 and includes an instruction to send back preventive maintenance data. The line inspection signal also includes a time setting for how long the preventive maintenance data should be transmitted.

[0215] The line inspection control unit 1611 then transmits the generated line inspection signal to the data slave station 32, at least through the communication interface 164. In the example shown in Figure 21, the line inspection control unit 1611 first transmits the line inspection signal to the data slave station 32a.

[0216] The receiving unit 3212 of the data substation 32 receives the line inspection signal at least through the communication interface 324. The receiving unit 3212 then outputs the line inspection signal to the transmitting unit 3211.

[0217] The transmitting unit 3211 acquires the preventive maintenance data stored in the preventive maintenance data storage unit 2231 for a period of time corresponding to the set time included in the line inspection signal. Here, the acquired preventive maintenance data is encoded using a general-purpose image compression technology such as ITC_H.264. The transmitting unit 3211 then transmits the acquired preventive maintenance data to the data master station 12.

[0218] Note that the procedure for decoding the preventive maintenance data at the data master station 12 is the same as the procedure described with reference to Figure 6, so a redundant explanation will be omitted.

[0219] As shown in Figure 21, the control monitoring device 16 transmits a line inspection signal to each data slave station 32, and each data slave station 32 transmits preventive maintenance data for a time set by the line inspection signal. Here, the transmission time of the preventive maintenance data transmitted by each data slave station 32 may be set differently for each slave station.

[0220] Figure 22 shows the relationship between the signal-to-noise ratio (S / N ratio) and the number of decoding errors in a wireless link, as well as the relationship between the transmission time of preventive maintenance data and the number of decoding errors. As shown in Figure 22(a), there is a proportional relationship where the number of decoding errors increases as the signal-to-noise ratio (S / N ratio) of the wireless link increases, i.e., as the condition of the wireless link deteriorates. Also, as shown in Figure 22(b), there is a proportional relationship where the number of coding errors increases as the transmission time of preventive maintenance data increases, i.e., as the amount of preventive maintenance data increases. From these findings, it is possible to use the transmission time of preventive maintenance data as an indicator of the wireless link's S / N ratio.

[0221] Furthermore, the example in Figure 22(a) shows that data encoding errors (missing data for preventive maintenance), which are digital data, occur at a lower signal-to-noise ratio (S / N ratio) than when analog observation / control data is missing. By observing preventive maintenance data, it becomes possible to detect an increasing S / N ratio early and implement preventive maintenance.

[0222] (Effects of the fourth embodiment) According to the fourth embodiment described above, the status of the wireless link can be checked by confirming the reception status of the preventive maintenance data, which is digital data. This makes it possible to know the status of the wireless link before observation data is lost.

[0223] Furthermore, by changing the transmission time of the preventive maintenance data transmitted from each data slave station 32, it is possible to determine the approximate signal-to-noise ratio of the wireless link.

[0224] [Modified version of the fourth embodiment] The fourth embodiment is an embodiment applied to a discharge alarm device, but is not limited to the above configuration. The fourth embodiment may be combined with the second to third embodiments described above.

[0225] Specifically, in the discharge warning system, as in the second embodiment described above, in addition to the preventive maintenance data, images, sounds, etc., acquired by the warning station AL around the warning station AL may be encoded and transmitted together with the preventive maintenance data.

[0226] Furthermore, in the discharge alarm system, as in the third embodiment described above, preventive maintenance data may be transmitted and received in half-duplex mode between the master station (monitoring station 1) and the slave station (alarm station AL). In this case, it may be possible to verify the quality of the wireless link, including information on the uplink wireless link and the downlink wireless link.

[0227] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0228] 1…Monitoring station 11...Monitoring device 111... Control Unit 1111... Observation Call Control Unit 1112...Video Call Control Unit 112...Program memory unit 113...Data storage unit 114…Communication Interface 115… Input / Output Interface 12...Data master station 121... Control Unit 1211... Receiver 1212...Decoding and Control Unit 1213...Decoding status determination unit 1214...Image synthesis unit 1215...Display Control Unit 1216...Analysis and Control Unit 1217...Transmitter 122...Program memory unit 123...Data storage unit 1231...Received data storage unit 1232...Image data storage unit 1233... Display data storage unit 1234... Preventive maintenance data storage unit 124…Communication Interface 125… Input / Output Interface 13...Wireless device 131… Antenna 14… Input / Output Devices 14a... Printer 14b...Operation unit 15… Input / Output Devices 15a...display device 16…Control and monitoring device 161... Control Unit 1611... Circuit Inspection and Control Unit 162...Program memory unit 163...Data storage unit 164…Communication Interface 165… Input / Output Interface TM... Observation Station 21... Observation equipment 211... Control Unit 212...Program memory unit 213...Data storage unit 214…Communication Interface 215… Input / Output Interface 22...Data Substation 221... Control Unit 2111... Observation and Control Unit 2112...Startup signal control unit 2211...Transmitter 2212... Information Acquisition Processing Unit 2213...encoding section 2214... Receiver 222...Program memory unit 223...Data storage unit 2231... Preventive maintenance data storage unit 2232…Acquired information storage unit 224…Communication Interface 225… Input / Output Interface 23...Wireless device 231… Antenna 24… Observation equipment 24a…Water level gauge 24b…Rain gauge 24c…Meteorological observation equipment 24d... Meteorological observation equipment 25... Camera 26... Mike AL…Alarm station 31...Alarm device 311... Control Unit 312...Program memory unit 313...Data storage unit 314…Communication Interface 315… Input / Output Interface 32...Data Substation 321... Control Unit 3211...Transmitter 3212... Receiver 322...Program memory unit 323...Data storage unit 324…Communication Interface 325… Input / Output Interface 33...Wireless device 34...Alarm 34a...Speaker 34b... Siren 34c... Rotating light

Claims

1. In a remote transmission system in which a master station and multiple slave stations are connected by a wireless link, and data is transmitted between the master station and the multiple slave stations at predetermined intervals, The aforementioned substation is The transmission unit includes, during the idle time in the predetermined period other than the period for transmitting or receiving monitoring and control data transmitted or received between the master station and the slave station, a transmission unit that transmits encoded preventive maintenance data, which includes at least image data, The aforementioned base station, A receiving unit that receives the preventive maintenance data from the aforementioned substation, A status determination unit that determines the status of the wireless communication line between the master station and the slave station based on whether the received preventive maintenance data has been successfully decoded, A remote transmission system equipped with the following features.

2. The aforementioned remote transmission system is a telemetering system in which the master station is a monitoring station and the slave stations are observation stations. The monitoring and control data transmitted or received between the master station and the slave station is observation data observed by the observation station, transmitted from the observation station to the monitoring station. The receiving unit of the monitoring station receives encoded preventive maintenance data, which includes at least image data, during the idle time after receiving the observation data transmitted from the observation station within a predetermined period. The remote transmission system according to claim 1.

3. The telemetering system is a call-type telemetering system in which the observation station transmits the observation data in response to a call signal from the monitoring station. The preventive maintenance data transmitted from the observation station is In response to an observation call transmitted from the monitoring station to acquire the observation data, the data is received within a predetermined time. The remote transmission system according to claim 2.

4. The telemetering system is an autonomous telemetering system in which the observation station autonomously transmits the observation data at a predetermined time set in advance. The preventive maintenance data received from the observation station is received autonomously at a predetermined time. The remote transmission system according to claim 2.

5. The aforementioned base station, A storage unit that stores normal images and images with reception errors, An image synthesis unit that, if it determines that the preventive maintenance data cannot be decoded properly, acquires the reception abnormality image, and if it determines that the preventive maintenance data can be decoded properly, acquires a normal image, and generates a composite image by combining the acquired image with information identifying each of the slave stations, for each slave station. A display control unit that displays the composite image on a display device, The remote transmission system according to claim 1, further comprising:

6. The remote transmission system according to claim 5, wherein the composite image is generated after receiving the preventive maintenance data from all of the slave stations.

7. The remote transmission system according to claim 5, wherein the composite image is updated each time the preventive maintenance data is received from the slave station.

8. The transmitting unit of the aforementioned substation encodes the acquired images and sounds of the surrounding area of ​​the substation and transmits them together with the preventive maintenance data. The receiving unit of the aforementioned base station is In addition to the preventive maintenance data transmitted from the aforementioned substation, operational support data including image data and audio data is received. The status determination unit of the master station determines whether the operation support data has been successfully decoded, If it is determined that the aforementioned operational support data has been successfully decoded, the status of the wireless line is determined based on whether the aforementioned preventive maintenance data has been successfully decoded. The remote transmission system according to claim 1.

9. If the status determination unit determines that the preventive maintenance data has not been decoded correctly, it determines the status of the wireless line based on whether the audio data has been decoded correctly. The remote transmission system according to claim 8.

10. If the status determination unit determines that the audio data has not been decoded correctly, it determines the status of the wireless line based on whether the image data has been decoded correctly. The remote transmission system according to claim 9.

11. The aforementioned base station, A storage unit that stores normal images, images with reception errors, and audio images, If it is determined that the operational support data has not been decoded properly, or if it is determined that the image data has not been decoded properly, the image abnormal reception image is acquired; if it is determined that the preventive maintenance data has been decoded properly, the normal image is acquired; if it is determined that the audio data has been decoded properly, the audio image is acquired; if it is determined that the image data has been decoded properly, the image data is acquired; and the image synthesis unit generates a composite image for each observation station by combining the acquired image with information identifying each of the substations. A display control unit that displays the composite image on a display device, Furthermore, The remote transmission system according to claim 8.

12. The storage unit stores the composite image, An analysis control unit that analyzes the status of the wireless link between the slave station and the master station based on the composite image, The remote transmission system according to claim 11, further comprising:

13. The aforementioned base station, The system further includes a transmitting unit that transmits preventive maintenance data to the aforementioned substation. The receiving unit of the slave station sends back the received preventive maintenance data to the master station. The remote transmission system according to claim 1.

14. The remote transmission system is a discharge alarm system in which the master station is a monitoring station and the slave stations are alarm stations, The monitoring and control data transmitted or received between the master station and the slave station is a line inspection signal transmitted from the master station to the slave station. The aforementioned monitoring station, A transmitting unit that transmits the aforementioned line inspection signal to the alarm station, A receiving unit that receives the preventive maintenance data after transmitting the aforementioned line inspection signal, The remote transmission system according to claim 1, comprising:

15. The aforementioned line inspection signal includes setting information indicating the period for transmitting the aforementioned preventive maintenance data, and the period indicated by the setting information differs for each of the aforementioned alarm stations. The remote transmission system according to claim 14.

16. In a telemetering system, a monitoring station is connected to an observation station by a wireless link, A receiving unit that receives encoded preventive maintenance data, including at least image data, from the observation station during the idle time after receiving monitoring and control data from the observation station within a predetermined cycle, A status determination unit that determines the status of the wireless link between the observation station and the monitoring station based on whether the received preventive maintenance data has been successfully decoded, A surveillance station equipped with these facilities.

17. A monitoring station connected to an alarm station via a wireless link in a discharge warning system, A transmitting unit that transmits a line inspection signal to the alarm station, A receiving unit receives encoded preventive maintenance data, including at least image data, from the alarm station during the idle time after transmitting the line inspection signal to the alarm station. A status determination unit that determines the status of the wireless link between the alarm station and the monitoring station based on whether the received preventive maintenance data has been successfully decoded, A surveillance station equipped with these facilities.

18. A method for monitoring lines in a telemetering system, The receiving unit of the monitoring station receives, during a period of time within a predetermined cycle after receiving monitoring and control data from an observation station connected to the monitoring station by a wireless link, encoded preventive maintenance data, including at least image data, from the observation station. The status determination unit of the monitoring station determines the status of the radio link between the observation station and the monitoring station based on whether the preventive maintenance data has been successfully decoded. A line monitoring method comprising the following features.

19. A method for monitoring the circuit of a discharge alarm system, The monitoring station's transmission unit transmits a line inspection signal, The receiving unit of the monitoring station receives encoded preventive maintenance data, which includes at least image data, during the idle time after transmitting the line inspection signal to the alarm station connected to the monitoring station by a wireless link. The status determination unit of the monitoring station determines the status of the preventive maintenance data, thereby determining the status of the wireless communication line between the alarm station and the monitoring station. A line monitoring method comprising the following features.

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