High-voltage transmission line condition monitoring system based on LoRa

Abstract

The present invention relates to the technical field of power transmission line monitoring system, specifically to a high-voltage power transmission line working condition monitoring system based on LoRa, including a host computer, a 4G module, a wireless gateway, a LoRa module and a data acquisition terminal, wherein the data acquisition terminal is electrically connected to the LoRa module. The present invention has the advantages that: through the coordinated setting of the host computer, the 4G module, the wireless gateway, the LoRa module and the data acquisition terminal, the data acquisition terminal is responsible for collecting the information of the key nodes of the power transmission line and sending the collected data to the wireless gateway through the LoRa communication mode, the wireless gateway is responsible for receiving and summarizing the data collected by the nodes it manages and integrating the environmental data collected by itself, and sending the data to the background through the 4G communication mode, so as to realize the function of wireless real-time monitoring of the temperature of the key nodes of the high-voltage transmission line and the surrounding environment of the high-voltage transmission tower, and has the characteristics of low power consumption, stable operation, etc., and there is no need for detection personnel to go to the site for detection work.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission line monitoring systems, and in particular to a LoRa-based high-voltage power transmission line operating condition monitoring system. Background Art

[0002] With the continuous development of the national economy, the demand for electricity is increasing, and people have put forward higher requirements for power supply reliability. How to ensure the safe, high-quality and efficient operation of large-scale transmission lines is an important part of the construction of smart grids. The stable operation of power equipment is not only a safety requirement, but also a requirement for China's national development. In the actual operation of power lines, the connection of joints is prone to increase resistance due to loose bolts, dirty contact surfaces and electrochemical corrosion of copper and aluminum. Under high load and high current conditions, it is very easy to cause local overtemperature and cause various faults. In areas with special geographical environments, the impact on transmission lines is more serious, and it is very easy to collapse towers, which has a serious impact on transmission operations. The shaking of transmission lines due to natural factors will affect the stability of towers, causing damage and detachment of components connected between cables. In severe cases, it will cause the collapse of facilities and bring adverse consequences.

[0003] The traditional operation and maintenance method is to use infrared thermal imagers to perform thermal imaging analysis on the electrical parts of overhead transmission lines to determine whether the electrical parts are hot. Therefore, inspection personnel must go to the site for field measurements to obtain reliable and real data. This paper uses the Internet of Things technology to design a high-voltage transmission line condition monitoring system, which can wirelessly monitor the temperature of key nodes of high-voltage transmission lines and the surrounding environment of high-voltage transmission towers in real time, and has the characteristics of low power consumption and stable operation. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a LoRa-based high-voltage transmission line condition monitoring system, which has the advantages of being able to realize wireless real-time monitoring of the temperature of key nodes of the high-voltage transmission line and the surrounding environment of the high-voltage transmission tower, solving the problem that detection personnel must go to the site for field measurements.

[0005] In order to achieve the above purpose of not requiring detection personnel to go to the site for on-site measurement, the present invention provides the following technical solutions: a LoRa-based high-voltage transmission line condition monitoring system, comprising a host computer, a 4G module, a wireless gateway, a LoRa module and a data acquisition terminal, wherein the data acquisition terminal is electrically connected to the LoRa module, the LoRa module is electrically connected to the wireless gateway, the wireless gateway is electrically connected to the 4G module, and the 4G module is electrically connected to the host computer;

[0006] The data acquisition terminal includes a first data acquisition module, a data acquisition terminal MCU, a first communication module, a first power supply module and a first data storage device, wherein the first data acquisition module is electrically connected to the data acquisition terminal MCU, the data acquisition terminal MCU is electrically connected to the first communication module, the data acquisition terminal MCU is electrically connected to the first power supply module, the data acquisition terminal MCU is electrically connected to the first data storage device, the first communication module includes LoRa communication and USART communication, the first power supply module includes a power management unit, a temperature difference power generation device and a lithium battery pack, the lithium battery pack and the temperature difference power generation device are both electrically connected to the power management unit, and the first data acquisition module is a temperature sensor;

[0007] The wireless gateway includes a second data acquisition module, a wireless gateway MCU, a second data storage, a second communication module and a second power supply module. The second data acquisition module is electrically connected to the wireless gateway MCU, the wireless gateway MCU is electrically connected to the second data storage, the wireless gateway MCU is electrically connected to the second communication module, and the wireless gateway MCU is electrically connected to the second power supply module. The data acquisition module includes a rainfall sensor, a wind speed sensor and a dual-axis tilt sensor. The second communication module includes Bluetooth communication, LoRa communication, USART communication and 4G communication. The second power supply module includes a solar panel, a lithium battery pack and a power management unit. The solar panel and the lithium battery pack are both electrically connected to the power management unit.

[0008] The model of the data acquisition terminal MCU is STM32L011F4P6, the model of the first communication module is E22-400T22S, the model of the temperature sensor is DS18B20, and the core of the first communication module is SX1268, which transmits the data collected by the DS18B20 temperature sensor to the gateway part for data forwarding.

[0009] The temperature sensor, rainfall sensor, wind speed sensor and dual-axis tilt sensor are all provided with a sensor protection circuit, which includes a pin connector P1, resettable fuses F1 and F2; TVS diodes D1 and D4; resistors R23, R22, R25, R24 and R3; capacitor C7; dual-channel single-pole CMOS analog switch U2, and the model of the dual-channel single-pole CMOS analog switch U2 is MAX4644. The sensor protection circuit can prevent the damage of the sensor caused by reverse current caused by complex environment.

[0010] The data acquisition terminal is provided with a power detection circuit, which includes operational amplifiers U10A, U10B; capacitors C37, C39, C40; resistors R36, R39, R41, R44. The power detection circuit can detect and report the power, so that maintenance personnel can replace the battery in time to ensure the normal operation of the system.

[0011] The power management unit adopts a power management module, the model of the power management module is LTC3108, and a temperature difference power generation power management circuit is provided in the power management unit. The power management unit includes a power management module U3; capacitors C22, C23, C24, CR1, CR2, C25, C21, C20, C19; transformer T1; JP1; J1; E1. Through the temperature difference power generation power management circuit, it can be started and operated when using an extremely low input voltage power supply, providing continuous power for the data acquisition terminal.

[0012] The model of the wind speed sensor is SINDT-485, the model of the tilt sensor is SINDT-485, and the model of the rain sensor is JXBS-3001-GXYL. The wind speed sensor, the tilt sensor and the rain sensor all use 485 communication mode for data transmission. The 485 communication mode includes a 485 communication circuit. The communication circuit includes a communication chip U2; a capacitor C1; resistors R5, R6, R7, R8, and R9; fuses F1 and F2; and diodes D1 and D2. The wind speed sensor, the tilt sensor and the rain sensor can collect environmental data around the high-voltage transmission tower.

[0013] The model of the 4G module is USR-G770. The 4G module adopts 232 communication mode. A 232 communication circuit is provided in the 4G module. The communication circuit includes a communication chip U3; capacitors C3, C6, C11, C7, and C2; and a data interface connector RS1. The model of the communication chip U3 is SP3485EN-L / TR.

[0014] The first data storage device and the second data storage device are both provided with a data storage circuit, and the data storage circuit includes capacitors C41 and C42; resistors R51, R45, R47, R40, and R52; and a storage chip U11. The model of the storage chip is W25Q128FVSIGTR. The data storage circuit can prevent the data from being unable to be reported normally when the network is poor, and the data that cannot be reported is written into the Flash memory for storage, and uploaded again after the network is restored.

[0015] Compared with the prior art, the present invention provides a LoRa-based high-voltage transmission line condition monitoring system, which has the following beneficial effects:

[0016] 1. The LoRa-based high-voltage transmission line condition monitoring system is configured through the coordination of the host computer, 4G module, wireless gateway, LoRa module and data acquisition terminal. The data acquisition terminal is responsible for collecting information about key nodes of the transmission line and sending the collected data to the wireless gateway through the LoRa communication method. The wireless gateway is responsible for receiving and summarizing the data collected by the nodes it manages and integrating the environmental data collected by itself, and sending the data to the background through the 4G communication method, thereby realizing the function of wireless real-time monitoring of the temperature of key nodes of the high-voltage transmission line and the environment around the high-voltage transmission tower. It has the characteristics of low power consumption and stable operation, and there is no need for detection personnel to go to the site for detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall framework of the system of the present invention;

[0018] Figure 2 It is a schematic diagram of the data acquisition terminal framework of the present invention;

[0019] Figure 3 It is a schematic diagram of the wireless gateway framework of the present invention;

[0020] Figure 4 It is a schematic diagram of the sensor protection circuit of the present invention;

[0021] Figure 5 It is a schematic diagram of the electric quantity detection circuit of the present invention;

[0022] Figure 6 It is a schematic diagram of the thermoelectric power management circuit of the present invention;

[0023] Figure 7 It is a schematic diagram of the 485 communication circuit of the present invention;

[0024] Figure 8 It is a schematic diagram of the 232 communication circuit of the present invention;

[0025] Fig. 9 is a schematic diagram of a data storage circuit of the present invention;

[0026] Fig.10 It is a schematic diagram of the software design process of the data acquisition terminal of the present invention;

[0027] Fig.11 The figure is a schematic diagram of the wireless gateway software design process of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-11 , a LoRa-based high-voltage transmission line condition monitoring system includes a host computer, a 4G module, a wireless gateway, a LoRa module and a data acquisition terminal, the data acquisition terminal is electrically connected to the LoRa module, the LoRa module is electrically connected to the wireless gateway, the wireless gateway is electrically connected to the 4G module, and the 4G module is electrically connected to the host computer;

[0030] The data acquisition terminal includes a first data acquisition module, a data acquisition terminal MCU, a first communication module, a first power supply module and a first data storage device. The first data acquisition module is electrically connected to the data acquisition terminal MCU, the data acquisition terminal MCU is electrically connected to the first communication module, the data acquisition terminal MCU is electrically connected to the first power supply module, the data acquisition terminal MCU is electrically connected to the first data storage device, the first communication module includes LoRa communication and USART communication, the first power supply module includes a power management unit, a temperature difference power generation device and a lithium battery pack, the lithium battery pack and the temperature difference power generation device are both electrically connected to the power management unit, the first data acquisition module is a temperature sensor, and the data acquisition terminal LoRa is star-type networked. In order to reduce the energy consumption of the data acquisition terminal, TDMA communication technology is used for data acquisition. The terminal is managed to ensure that the data will not conflict and can enter the sleep state faster to achieve the purpose of energy saving. After completing the initialization work, the data acquisition terminal continues to wait for the configuration command of the gateway. The front-end address, working cycle and corresponding temperature threshold are configured through the configuration command. In order to realize the time allocation of TDMA, the logical time is allocated by the address. When the data is sent for the first time, the sending time period is fixed. After the configuration is completed, the allocated time period is waited for according to the logical address. When the sending time arrives, the data acquisition terminal sends the collected temperature data to the wireless gateway, and updates the time and reporting cycle after receiving the response frame of the gateway. After the data is transmitted to the gateway, the data acquisition terminal enters the sleep state and waits for the next sending time. The data acquisition terminal software is required in the data acquisition terminal. The design flow chart of the data acquisition terminal software is as follows: Fig.10 As shown;

[0031] The wireless gateway includes a second data acquisition module, a wireless gateway MCU, a second data storage, a second communication module and a second power supply module. The second data acquisition module is electrically connected to the wireless gateway MCU, the wireless gateway MCU is electrically connected to the second data storage, the wireless gateway MCU is electrically connected to the second communication module, the wireless gateway MCU is electrically connected to the second power supply module, the data acquisition module includes a rainfall sensor, a wind speed sensor and a dual-axis tilt sensor, the second communication module includes Bluetooth communication, LoRa communication, USART communication and 4G communication, the second power supply module includes a solar panel, a lithium battery pack and a power management unit, the solar cell The board and lithium battery pack are electrically connected to the power management unit. The model of the wireless gateway MCU is STM32F103RCT6. The wireless gateway serves as the coordinator of the star-shaped network of data acquisition terminals. It is used to gather the data collected by the data acquisition terminals and integrate them to the host computer. The wireless gateway sends data to the background regularly and checks the status of each serial port of the gateway in turn to process the corresponding received frames. In the wireless gateway part, the interrupt method is used to determine what kind of information the gateway has received, which are the configuration information of the Bluetooth serial port, the response frame sent by the background, and the sensor information sent by the data acquisition terminal through LoRa. The software design flow chart of the wireless gateway is as follows Fig.11 .

[0032] The model of the data acquisition terminal MCU is STM32L011F4P6, the model of the first communication module is E22-400T22S, and the model of the temperature sensor is DS18B20. The core of the first communication module is SX1268, which transmits the data collected by the DS18B20 temperature sensor to the gateway part for data forwarding.

[0033] The temperature sensor, rainfall sensor, wind speed sensor and dual-axis tilt sensor are all provided with a sensor protection circuit, which includes a pin connector P1, self-recovery fuses F1 and F2; TVS diodes D1 and D4; resistors R23, R22, R25, R24 and R3; capacitor C7; dual-channel single-pole CMOS analog switch U2, and the model of the dual-channel single-pole CMOS analog switch U2 is MAX4644, such as Figure 4 As shown, considering that the actual working environment of the data acquisition terminal is in a high-voltage environment, in order to avoid the damage of the sensor caused by the reverse current in the complex environment, a TVS diode and a PPTC self-recovery fuse are added to the interface of the sensor for protection. At the same time, the MAX4644 dual-channel single-pole CMOS analog switch is used to control the working state of the sensor, so that the sensor of the data acquisition terminal in the sleep state enters the disconnected state, further reducing the power consumption of the data acquisition terminal. The sensor protection circuit can avoid the damage of the sensor caused by the reverse current in the complex environment.

[0034] The data acquisition terminal is provided with a power detection circuit, which includes operational amplifiers U10A and U10B; capacitors C37, C39, and C40; and resistors R36, R39, R41, and R44. Figure 5 As shown, in order to ensure the robustness of the system, the data acquisition terminal needs to detect and report its own power so that maintenance personnel can replace the battery in time to ensure the normal operation of the system. The power detection uses the ADC of the MCU to collect the battery voltage and calculates it through the battery charge and discharge curve. The power detection circuit can detect and report the power, so that maintenance personnel can replace the battery in time to ensure the normal operation of the system.

[0035] The power management unit adopts a power management module, the model of the power management module is LTC3108, and a temperature difference power generation power management circuit is set in the power management unit. The power management unit includes a power management module U3; capacitors C22, C23, C24, CR1, CR2, C25, C21, C20, C19; transformer T1; JP1; J1; E1, such as Figure 6 As shown, temperature difference energy harvesting for sensor applications is mainly realized by semiconductor thermoelectric power generation chips based on the Seebeck effect. The Seebeck effect refers to the thermoelectric phenomenon of the voltage difference between two substances caused by the temperature difference between two different electrical conductors or semiconductors. Power management is performed through the power manager LTC3108 module. The LTC3108 device is designed for startup and operation with extremely low input voltage power supply. It can work with a minimum voltage input of 20mV, and a storage capacitor is added to the circuit design to provide continuous power for the data acquisition terminal. The thermoelectric power management circuit can start and operate with extremely low input voltage power supply, providing continuous power for the data acquisition terminal.

[0036] The model of the wind speed sensor is SINDT-485, the model of the tilt sensor is SINDT-485, and the model of the rain sensor is JXBS-3001-GXYL. The wind speed sensor, the tilt sensor, and the rain sensor all use 485 communication mode for data transmission. The 485 communication mode includes a 485 communication circuit, and the communication circuit includes a communication chip U2; a capacitor C1; resistors R5, R6, R7, R8, and R9; fuses F1 and F2; and diodes D1 and D2. The 485 communication circuit is as follows: Figure 7 As shown, the environmental data around the high-voltage transmission tower can be collected through the wind speed sensor, tilt sensor and rain sensor. The wind speed sensor, tilt sensor and rain sensor can all use 485 communication to transmit data. The RS485 isolation interface SP3485 has differential reception, differential drive and three-channel isolation functions. A maximum of 256 nodes can be connected to the bus.

[0037] The model of the 4G module is USR-G770. The 4G module adopts 232 communication mode. The 4G module is provided with a 232 communication circuit. The communication circuit includes a communication chip U3; capacitors C3, C6, C11, C7, C2; data interface connector RS1, and the model of the communication chip U3 is SP3485EN-L / TR. Figure 8 As shown, the wireless gateway integrates the data and transmits it to the background through the USR-G770-4G module. 4G adopts 232 communication mode and uses MAX232 chip for level conversion, converting TTL signal into 232 serial communication signal and sending it to 4G module.

[0038] The first data storage device and the second data storage device are both provided with a data storage circuit, the data storage circuit includes capacitors C41 and C42; resistors R51, R45, R47, R40 and R52; a storage chip U11, the model of which is W25Q128FVSIGTR. Fig. 9 As shown, in order to prevent the data from being unable to be reported normally when the network is poor, the data that cannot be reported is written into the Flash memory for storage, and uploaded again after the network is restored. The W25Q128 chip is used. The W25Q128 divides the 16M capacity into 256 blocks, each block is 64K bytes, each block is divided into 16 sectors, each sector is 4K bytes, and the W25Q128 has an erase cycle of up to 10W times, with a 20-year data retention period. The data storage circuit can prevent the data from being unable to be reported normally when the network is poor, and the data that cannot be reported is written into the Flash memory for storage, and uploaded again after the network is restored.

[0039] When in use, the data acquisition terminal is responsible for collecting information from key nodes of the transmission line and sending the collected data to the wireless gateway via LoRa communication. The wireless gateway is responsible for receiving and aggregating the data collected by the nodes it manages and integrating the environmental data collected by itself, and sending the data to the background via 4G communication, thereby performing wireless real-time monitoring of the temperature of key nodes of the high-voltage transmission line and the environment around the high-voltage transmission tower.

[0040] In summary, the LoRa-based high-voltage transmission line condition monitoring system is configured through the coordination of the host computer, 4G module, wireless gateway, LoRa module and data acquisition terminal. The data acquisition terminal is responsible for collecting information about key nodes of the transmission line and sending the collected data to the wireless gateway through LoRa communication. The wireless gateway is responsible for receiving and summarizing the data collected by the nodes it manages and integrating the environmental data collected by itself, and sending the data to the background through 4G communication, thereby realizing the function of wireless real-time monitoring of the temperature of key nodes of the high-voltage transmission line and the surrounding environment of the high-voltage transmission tower. It has the characteristics of low power consumption and stable operation, and there is no need for detection personnel to go to the site for detection.

[0041] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. The high-voltage transmission line condition monitoring system based on LoRa is characterized by: It includes a host computer, a 4G module, a wireless gateway, a LoRa module and a data acquisition terminal, wherein the data acquisition terminal is electrically connected to the LoRa module, the LoRa module is electrically connected to the wireless gateway, the wireless gateway is electrically connected to the 4G module, and the 4G module is electrically connected to the host computer; The data acquisition terminal includes a first data acquisition module, a data acquisition terminal MCU, a first communication module, a first power supply module and a first data storage device, wherein the first data acquisition module is electrically connected to the data acquisition terminal MCU, the data acquisition terminal MCU is electrically connected to the first communication module, the data acquisition terminal MCU is electrically connected to the first power supply module, the data acquisition terminal MCU is electrically connected to the first data storage device, the first communication module includes LoRa communication and USART communication, the first power supply module includes a power management unit, a temperature difference power generation device and a lithium battery pack, the lithium battery pack and the temperature difference power generation device are both electrically connected to the power management unit, and the first data acquisition module is a temperature sensor; The wireless gateway includes a second data acquisition module, a wireless gateway MCU, a second data storage, a second communication module and a second power supply module, the second data acquisition module is electrically connected to the wireless gateway MCU, the wireless gateway MCU is electrically connected to the second data storage, the wireless gateway MCU is electrically connected to the second communication module, the wireless gateway MCU is electrically connected to the second power supply module, the data acquisition module includes a rainfall sensor, a wind speed sensor and a dual-axis tilt sensor, the second communication module includes Bluetooth communication, LoRa communication, USART communication and 4G communication, the second power supply module includes a solar panel, a lithium battery pack and a power management unit, and the solar panel and the lithium battery pack are both electrically connected to the power management unit; The temperature sensor, rainfall sensor, wind speed sensor and dual-axis tilt sensor are all provided with a sensor protection circuit, which includes a pin connector P1, self-recovery fuses F1 and F2; TVS diodes D1 and D4; resistors R23, R22, R25, R24 and R3; capacitor C7; dual-channel single-pole CMOS analog switch U2, the model of which is MAX4644; P1 module pin 1 is connected to F2 self-recovery fuse and VCC3.3V voltage for power supply and D1TVS diode for grounding, P1 module pin 2 is connected to F1 self-recovery fuse and R23 voltage respectively for power supply and D1TVS diode for grounding, The circuit is connected to the PA9 terminal through the R22 resistor and the DQ terminal. The D4TVS diode is connected before the R23 resistor and the R22 resistor and grounded. The PA0 input signal is connected to the MAX4644 module 1 pin through the R25 resistor to input the signal into the module. The MAX4644 module 2 pin is connected to the VCC3.3V voltage power supply and connected to the 0.1uF capacitor C7 for grounding. The DQ signal is connected to the MAX4644 module 5 pin COM terminal. The MAX4644 module 6 pin NO switch terminal is connected to PA9 and connected to the VCC3V power supply through the R3 resistor. The MAX4644 module 4 pin NC switch terminal is connected to the R24 resistor and grounded. The data acquisition terminal is provided with a power detection circuit, which includes operational amplifiers U10A, U10B; capacitors C37, C39, C40; resistors R36, R39, R41, R44, and the VDD5V voltage is connected to the 2 port of the signal amplification module LM324DT1 through the R39 resistor. At the same time, the 5V voltage is connected to the resistor R36 after passing through the resistor R39, and then connected to the 1 port of the signal amplification module LM324DT1 and the 5 port of the signal amplification module LM324DT2. The VDD12M voltage enters the 3 port of the signal amplification module LM324DT1 after connecting to the R41 resistor, and is connected to the parallel circuit of the C37 capacitor and the R44 resistor to be grounded. The 6 port of the signal amplification module LM324DT2 is directly connected to the 7 port to output the PA4 signal terminal, and the C39 capacitor and the C40 capacitor are connected in parallel to the 12V voltage to be grounded.

2. The LoRa-based high-voltage transmission line condition monitoring system according to claim 1, characterized in that: The model of the data acquisition terminal MCU is STM32L011F4P6, the model of the first communication module is E22-400T22S, and the model of the temperature sensor is DS18B20.

3. The LoRa-based high-voltage transmission line condition monitoring system according to claim 2, characterized in that: The power management unit adopts a power management module, the model of the power management module is LTC3108, and a temperature difference power generation power management circuit is arranged in the power management unit.

4. The LoRa-based high-voltage transmission line condition monitoring system according to claim 3, characterized in that: The model of the wind speed sensor is SINDT-485, the model of the tilt sensor is SINDT-485, the model of the rain sensor is JXBS-3001-GXYL, and the wind speed sensor, the tilt sensor and the rain sensor all adopt 485 communication mode for data transmission, and the 485 communication mode includes 485 communication circuit.

5. The LoRa-based high-voltage transmission line condition monitoring system according to claim 4, characterized in that: The model of the 4G module is USR-G770, and the 4G module adopts 232 communication mode.

6. The LoRa-based high-voltage transmission line condition monitoring system according to claim 5, characterized in that: The first data storage device and the second data storage device are both provided with a data storage circuit.

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