RTU (remote terminal unit) equipment with interfaces uniformly supporting modular design

Abstract

The utility model provides an RTU (remote terminal unit) with interfaces uniformly supporting modular design, which is used for solving the technical problems of poor expandability and non-uniform interfaces of the existing RTU. The system comprises a control panel, the control panel is respectively connected with a wireless transmission module, a data storage module, a data encryption module, a power supply module and a data acquisition module, and the control panel is connected with a cloud platform through the wireless transmission module. And interfaces on the control panel, the wireless transmission module, the data storage module, the data encryption module, the power supply module and the data acquisition module are unified. According to the utility model, the functional modules with unified interfaces are designed according to different functions of the modules, and the functional modules can be directly spliced together, so that the development workload is greatly reduced, the development steps are simplified, and the portability is improved; and the expandability is strong, the maintenance is convenient, parallel development can be realized, and the interface uniformly supports the modular design.

Description

Technical Field

[0001] This utility model relates to the technical field of remote control, and in particular to an RTU device with a unified interface that supports modular design. Background Technology

[0002] RTU, or Remote Control Unit, also known as a remote telemetry unit or remote control unit, is widely used in industries such as water, oil fields, steam, gas, and power, where remote monitoring, metering management, usage control, and equipment control are required. It is an intelligent data acquisition device capable of acquiring signals from various sensors and devices in real time and transmitting the data wirelessly or via wired means to a host computer or cloud server for processing and analysis. The main functions of an RTU include data acquisition, data processing, data transmission, and remote control. It can monitor the operating status of various industrial equipment in real time and transmit the data to a host computer or cloud server for storage and analysis. Simultaneously, the RTU also has remote control capabilities, allowing for remote control and adjustment of industrial equipment via a host computer or cloud server.

[0003] RTUs have a wide range of applications and support a variety of data acquisition devices, requiring various data acquisition interfaces such as RS485, RS232, CAN, I2C, TTL, digital inputs, digital outputs, analog inputs, and analog outputs. To withstand harsh environments, they need to support multiple wireless communication functions for data transmission, such as 4G, 5G, 433MHz, LoRa, and Bluetooth. Furthermore, the complex environments demand high data security, requiring devices to support multiple encryption methods, such as SM2, SM3, SM4, AES128, DES, and SHA.

[0004] The diverse functionalities present challenges for RTU design. Existing RTUs feature hot-swappable individual modules with extremely low power consumption; when a module is not in operation, the control board directly controls it to enter sleep mode or power off. Furthermore, each module is divided into different series, allowing selection of different modules based on the specific operating scenario. The power module supports both AC power and DC battery power, with automatic switching between the two. The power module is responsible for supplying power to the node devices collecting data, and the supply voltage is continuously adjustable.

[0005] Utility model patent application number 201720791849.4 discloses a cellular remote control terminal, including a power supply, a SIM card circuit, an RF circuit, and a SOC system chip, compatible digital input interfaces, compatible digital output interfaces, compatible analog input interfaces, and compatible instrument interfaces. The power supply, compatible digital input interfaces, and compatible analog input interfaces are all connected to the input terminals of the SOC system chip, and the compatible digital output interfaces are connected to the output terminals of the SOC system chip. The SIM card circuit, RF circuit, and compatible instrument interfaces are bidirectionally connected. This utility model cellular remote control terminal uses a SOC system chip, integrating the functions of a microprocessor and a wireless communication module, improving system stability and functional configurability, while reducing device management costs. It is compatible with multiple interfaces and protocols, making it more widely applicable and highly practical. However, the aforementioned patent does not support networking between RTUs. If the RTUs are networked and one device has a communication problem, the data can be uploaded to the customer's cloud platform through the wireless transmission modules of other devices after networking. It is not convenient to expand the acquisition interface at any time. If the work site requires multiple types of multi-channel acquisition interfaces, it is not possible to quickly expand the interface. Utility Model Content

[0006] To address the technical problems of poor scalability and inconsistent interfaces in existing RTU devices, this utility model proposes an RTU device with a unified interface and modular design. The device is designed as functional modules with a unified interface based on the different functions of each module. The corresponding modules are spliced ​​together according to the required functions, supporting multiple acquisition boards to work simultaneously. This greatly reduces the development workload, simplifies the development steps, and improves portability. Furthermore, it has strong scalability, is easy to maintain, allows for parallel development, and supports modular design with a unified interface.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows: an RTU device with a unified interface supporting modular design includes a control board, which is connected to a wireless transmission module, a data storage module, a data encryption module, a power supply module, and a data acquisition module. The control board is connected to a cloud platform through the wireless transmission module. The interfaces on the control board, wireless transmission module, data storage module, data encryption module, power supply module, and data acquisition module are all unified.

[0008] Preferably, the control board is connected to the control output board and the data display module respectively; the power supply module is connected to the mains power and the storage battery respectively.

[0009] Preferably, the control board, wireless transmission module, data storage module, data encryption module, and data acquisition module are each provided with a power supply interface that matches the output terminal of the power supply module; the control board, wireless transmission module, data storage module, and data acquisition module are each provided with a communication interface; and the wireless transmission module, data storage module, data encryption module, and data acquisition module are each provided with a control interface that matches the control board.

[0010] Preferably, the control interface on the wireless transmission module includes a TXD interface, an RXD interface, and a first RST interface. The first RST interface, TXD interface, and RXD interface are all connected to the control interface of the control board to realize reset and the reception and transmission of commands.

[0011] The power supply interface of the wireless transmission module is connected to the output terminal of the power supply module through a voltage conversion circuit.

[0012] Preferably, the wireless transmission module includes a CAT.1 transmission unit, a 4G transmission unit, a 5G transmission unit, a 433MHz transmission unit, a LoRa transmission unit, and a Bluetooth transmission unit. All of these units are connected to the control board via external communication interfaces, and all are connected to the power supply module via power supply interfaces.

[0013] The CAT.1 transmission unit, 4G transmission unit, 5G transmission unit, 433MHz transmission unit, LoRa transmission unit and Bluetooth transmission unit use TTL level serial communication.

[0014] The voltage conversion circuit includes a power supply chip, and the input pin of the power supply chip is connected to the output terminal of the power supply module and the M_VEN pin of the control board through the switching transistor circuit I, respectively. The LX1 pin of the power supply chip is connected to the LX2 pin through the inductor L2, and the output terminal of the power supply chip outputs the required voltage through the second filter circuit.

[0015] Preferably, the wireless transmission module supports two types of IoT cards: NANO-SIM cards and E-SIM cards. The circuits of the NANO-SIM cards and E-SIM cards are connected in parallel. The VCC pin of the NANO-SIM card and the Vdd pin of the E-SIM card are both connected to the SIM card power supply pin of the wireless transmission module. The RST pin of both the NANO-SIM card and the E-SIM card are both connected to the SIM card reset pin of the wireless transmission module. The CLK pin of both the NANO-SIM card and the E-SIM card are both connected to the SIM read / write clock pin of the wireless transmission module. The DATA pin of the NANO-SIM card and the I / O pin of the E-SIM card are both connected to the DATA pin of the wireless transmission module.

[0016] Preferably, the data storage module includes an SD card and an EEPROM storage chip. The communication interfaces of the SD card and the EEPROM storage chip both support the SPI communication protocol. Therefore, the control interface of the data storage module includes a MOSI interface, a MISO interface, a CLK interface, and a CS interface. The MOSI interface, MISO interface, CLK interface, and CS interface are all connected to the control interface of the control board.

[0017] The data encryption module uses an encryption chip that supports the I2C communication interface. The control interface of the data encryption module includes an SDA interface, an SCL interface, and an RST interface, all of which are connected to the control interface of the control board.

[0018] Preferably, the power supply module includes an automatic power switching circuit and a step-up / step-down adjustable output circuit. Both the mains power and the battery are connected to the automatic power switching circuit, which outputs a voltage of 3.3V. The automatic power switching circuit is connected to the step-up / step-down adjustable output circuit, which outputs the required adjustable voltage. The battery is connected to the solar panel.

[0019] The automatic power switching circuit includes diodes D8 and D9. The AC mains power, Vin, is connected to the anode of diode D8. The battery, Vbat, is connected to the anode of diode D9. The cathodes of both diodes D8 and D9 are connected to the output power Vout. The gate of switching transistor Q5 is connected to the input power Vin through resistor R25. The input power Vin is grounded through resistor R28. The drain of switching transistor Q5 is connected to the battery backup power Vbat, and the source of switching transistor Q5 is connected to the output power Vout. When the input power Vin is powered, switching transistor Q5 is cut off through resistors R25 and R28, and the input power Vin is output to the output power Vout through diode D8. When the input power Vin is de-powered, diode D9 (a Schottky diode) provides a conduction voltage to the source of switching transistor Q5, and switching transistor Q5 is turned on through resistors R25 and R28, and the battery backup power Vbat is output to the output power Vout through switching transistor Q5.

[0020] The adjustable buck-boost output circuit is an adjustable buck-boost circuit with a switch. The adjustable buck-boost output circuit includes a boost power supply chip, which is connected to the output voltage via a boost circuit and a resettable fuse F5. The boost circuit includes a diode D10, an inductor L3, and a capacitor C18. The VIN and SHDN pins of the boost power supply chip are connected in parallel and then connected via a switching transistor circuit II to the output power supply Vout of the automatic power switching circuit, the BstVEN pin of the control board, and one end of the inductor L3. The other end of inductor L3 is connected to the positive terminal of diode D10. The positive terminal of diode D10 is connected to the SW pin of the boost power supply chip. The negative terminal of diode D10 is connected to one end of resettable fuse F5 and one end of capacitor C18. The other end of capacitor C18 is connected to the GND pin of the boost power supply chip. The input voltage feedback pin of the boost power supply chip is connected to one end of resettable fuse F5 through resistor R32. The DAC drive signal is connected to the input voltage feedback pin of the boost power supply chip through a voltage divider circuit.

[0021] Preferably, the data acquisition module includes an acquisition board, which is provided with an acquisition interface and a communication interface. The acquisition interface includes an RS485 interface, an RS232 interface, a digital input interface, a digital output interface, an analog input interface, and an analog output interface. The communication interface includes a first CAN interface, an I2C interface, and a TTL interface. The power supply interface of the acquisition board is connected to the power supply interface of the power supply module.

[0022] The RS485 interface is connected to the RS485 acquisition circuit, which includes a TTL to RS485 level conversion chip. The RE pin of the TTL to RS485 level conversion chip is connected to the output of the power supply module via resistor R11. The DE pin of the TTL to RS485 level conversion chip is grounded via resistor R19. The VCC pin of the TTL to RS485 level conversion chip is connected to the output of the power supply module and one end of capacitor C10, with the other end of capacitor C10 grounded. The B / Z pins of the TTL to RS485 level conversion chip are connected to one end of resistor R19, the positive terminal of TVS diode D3, and one end of resettable fuse F3, respectively. The resistors are connected in series. The other end of resistor R19 and the negative terminal of TVS protection tube D3 are grounded. The other end of resettable fuse F3 is connected to one end of resistor R12. The A / Y pins of the TTL to RS485 level conversion chip are connected to one end of resistor R21, the positive terminal of TVS protection tube D7, and one end of resettable fuse F4, respectively. The other end of resistor R21 is connected to the output terminal of the power supply module. The negative terminal of TVS protection tube D7 is grounded. The other end of resettable fuse F4 is connected to one end of resistor R18. The other end of resistor R12 is connected to the other end of resistor R18 through resistor R13. The other ends of resistor R12 and resistor R18 together output an RS485 differential signal.

[0023] The analog input interface is connected to a 4-20mA current analog acquisition circuit. The 4-20mA current analog acquisition circuit includes a sampling resistor R14, a first-order RC filter and a TVS protection transistor D5 connected in parallel with the sampling resistor R14, one end of the sampling resistor R14 is grounded and the other end is connected to the analog input interface to be acquired.

[0024] The switch input and output interfaces are all isolated and protected by circuits. The switch input interface is connected to one end of resistor R17 and the negative terminal of TVS protection diode D6 via diode D4. The positive terminal of TVS protection diode D6 is grounded. The other end of resistor R17 is connected to the positive terminal of the optocoupler control terminal of the optocoupler isolation chip. The collector of the output terminal of the optocoupler isolation chip is connected to one end of resistor R16 and the signal acquisition terminal. The other end of resistor R16 is connected to a 3.3V power supply. The negative terminal of the optocoupler control terminal and the emitter of the output terminal of the optocoupler isolation chip are both grounded.

[0025] The control signal of the digital output interface is connected to the source of the field-effect transistor Q3 through resistor R15. The source of the field-effect transistor Q3 is grounded through resistor R20. The drain of the field-effect transistor Q3 is connected to the digital output interface through a resettable fuse F2. The gate of the field-effect transistor Q3 is grounded. A diode is connected in anti-parallel between the gate and drain of the field-effect transistor Q3. The control signal of the digital output interface controls the conduction of the field-effect transistor Q3 after current limiting and voltage division through resistors R15 and R20, thereby controlling the output signal of the digital output interface DO_1.

[0026] Preferably, the switching transistor circuit I and the switching transistor circuit II include a first switching transistor and a first transistor. The drain of the first switching transistor is connected to the input pin of the power supply chip or the boost power supply chip as the output terminal. The source of the first switching transistor is connected to the input power supply. The source of the first switching transistor is connected to the gate of the first switching transistor through a first resistor. A diode is connected in anti-parallel between the source and drain of the first switching transistor. The gate of the first switching transistor is connected to the collector of the first transistor. The base of the first transistor is connected to one end of a second resistor. The other end of the second resistor is connected to the control board. The base of the first transistor is grounded through a third resistor. The emitter of the first transistor is grounded.

[0027] The second filtering circuit is a switching power supply step-down circuit. The second filtering circuit includes resistors R24 and R26 and capacitor C12. The output terminal of the power chip is connected to the voltage feedback pin of the power chip through resistor R24. The voltage feedback pin is grounded through resistor R26. The output voltage is divided by resistors R24 and R26 and then fed back to the voltage feedback pin. Based on the feedback voltage, the power chip dynamically controls the output voltage. The output terminal of the power chip is connected to one end of capacitor C12, and the other end of capacitor C12 is grounded.

[0028] The control board is equipped with LPUART, USART, UART, I2C1, SPI1, a second CAN, ADC, DAC, LCD, KEY, and GPIO interfaces. The LPUART, USART, and UART interfaces are all used for TTL level serial communication. The I2C1 interface is connected to the encryption chip. The SPI1 interface is connected to the data storage chip and clock chip. The second CAN interface is used to collect relevant signal data. The ADC interface is connected to the power supply module. The DAC drive signal of the adjustable buck-boost output circuit is connected to the DAC interface. The LCD and KEY interfaces are both connected to the data display module. The GPIO interfaces are connected to the first RST interface of the wireless transmission module, the CS interface of the storage chip, and the RST interface of the encryption chip, respectively.

[0029] Compared with the prior art, the beneficial effects of this utility model are: the RTU is divided into mutually independent, reusable and maintainable functional modules, each functional module has clearly defined functions and interfaces, and the interfaces of each functional module are compatible, allowing for independent development, testing and deployment.

[0030] Unified interface: RTU products can be directly connected to the hardware during the design process, which simplifies the development process and improves the maintainability of the equipment.

[0031] Modular design: Because the interface standard is unified, the software code development is relatively uniform. Parallel development of software programs improves development efficiency.

[0032] The equipment can be quickly assembled into an RTU product like building blocks, depending on different specifications, different working scenarios, different types of instruments and meters mounted on it, and a variety of wireless communication methods. Attached Figure Description

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a schematic diagram of the principle of this utility model.

[0035] Figure 2 This is the voltage conversion circuit of this utility model.

[0036] Figure 3 This is a combined circuit for NANO-Sin and E-Sim cards.

[0037] Figure 4 This is a circuit connection diagram of the data storage module of this utility model in a specific example.

[0038] Figure 5 This is a schematic diagram of the circuit and external interface of the data encryption module.

[0039] Figure 6 A flowchart illustrating the main workflow of the power supply module.

[0040] Figure 7 This is a circuit diagram for an automatic power switching circuit.

[0041] Figure 8 This is a circuit diagram for an adjustable buck-boost output circuit.

[0042] Figure 9This is the circuit diagram for the first data acquisition example of the data acquisition module.

[0043] Figure 10 This is the circuit diagram for the second data acquisition example of the data acquisition module.

[0044] Figure 11 This is the circuit diagram for the third example of data acquisition by the data acquisition module. Detailed Implementation

[0045] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0046] like Figure 1 As shown, an RTU device with a unified interface supporting modular design includes a control board. The control board is connected to a wireless transmission module, a data storage module, a data encryption module, a power supply module, and a data acquisition module. The control board connects to a cloud platform via the wireless transmission module and is also connected to a control output board and a data display module. The power supply module functions as follows: 1. Converting 220V AC mains voltage to 3.3V; 2. Converting battery voltage to 3.3V; 3. Switching to battery power when AC mains power is unavailable; 4. Providing power to external acquisition nodes, with the output voltage controlled by the control board. Figure 1 The overall module block diagram shows the control board responsible for controlling, acquiring, and processing data from all peripherals. Once the interface definitions are finalized, the module design must ensure that interfaces for modules with the same function are consistent and compatible. During equipment maintenance, the faulty module can be simply removed and replaced with a working one, ensuring reusability and maintainability of the aforementioned functional modules. All modules only need to retain the power supply interface and the most streamlined communication and control interfaces; other redundant interfaces are set to default states, ensuring that each functional module has clearly defined functions and interfaces, and that the interfaces of each functional module are compatible. The control output board contains controlled relays that activate the switch output interfaces when an alarm is triggered, such as closing a valve. The data display module is a digital display screen that, in addition to displaying basic information about the entire machine, such as network status, power supply voltage, and system version, also displays real-time acquired data such as pressure, concentration, flow rate, and temperature.

[0047] The wireless transmission module supports the following wireless communication methods: CAT.1, 4G, 5G, 433MHz, LoRa, and Bluetooth. Each wireless communication method is designed as an independent wireless transmission module, powered directly by a unified external voltage. The wireless transmission module includes CAT.1, 4G, 5G, 433MHz, LoRa, and Bluetooth transmission units. These units connect to the control board via external communication interfaces (communication signal pins), and to the power supply module via power supply interfaces. For example, to use the EC800E for communication transmission using the CAT.1 communication method, a pre-packaged EC800E wireless module can be directly used; that is, the CAT.1 transmission unit is the EC800E wireless module. If the data transmission volume is small and power consumption is a concern, the CAT.1 transmission unit can be selected. To balance transmission speed and power consumption, a 4G transmission unit can be selected. For high-concurrency, low-latency data transmission, a 5G transmission unit can be selected. For rapid, small-scale network deployment, a 433MHz transmission unit can be selected. If data does not need to be transmitted over the public network, a LoRa transmission unit can be selected. For high power consumption and short transmission distance, a Bluetooth transmission unit can be selected. All wireless transmission units share a unified module interface, allowing for direct replacement without redesigning hardware interfaces. This unified interface ensures high portability and reduces development time. The CAT.1, 4G, 5G, 433MHz, LoRa, and Bluetooth transmission units all use TTL-level serial communication, and the necessary control interface states in the original modules are fixed to the default values ​​required by the module.

[0048] The wireless transmission module is based on serial communication and only requires a necessary power supply. TTL level serial communication and reset control are sufficient for normal operation. The external communication interfaces are uniformly: a first 3.3V interface, a first GND interface, a TXD interface, an RXD interface, and a first RST interface. The first 3.3V interface and the first GND interface are connected to the output of the power supply module to power the wireless transmission module. The TXD interface, RXD interface, and first RST interface are connected to the TXD pin, RXD pin, and GPIO1 pin of the control board, respectively. The TXD pin is responsible for sending commands; the RXD pin is responsible for receiving commands; and the GPIO1 pin is responsible for controlling the reset of the wireless transmission module.

[0049] The first 3.3V interface and the first GND interface of the wireless transmission module are connected to the output of the power supply module via a voltage conversion circuit. Since different wireless communication modules have different power supply voltages—for example, the EC800E wireless module operates at 3.8V—the 3.3V output from the power supply module needs to be converted to 3.8V using a TPS63000 power chip. Figure 2As shown, the voltage conversion circuit includes a TPS63000 power supply chip. The input terminal of the TPS63000 power supply chip is connected to the output terminal of the power supply module. Specifically, the VIN pin of the TPS63000 power supply chip is connected to the output terminal of the power supply module and the M_VEN pin of the control board through the switching transistor circuit I. The function of the M_VEN pin of the control board is to control the on / off state of the power supply to the subsequent circuit. The switching transistor circuit I includes a switching transistor Q4 and a transistor Q6. The VIN pin of the TPS63000 power supply chip is connected to the drain of the switching transistor Q4. The source of the switching transistor Q4 is connected to the 3.3V voltage output from the power supply module. The output terminal of the power supply module is connected to the gate of the switching transistor Q4 through a resistor R23. The function of the resistor R23 is to keep the circuit normally off; the circuit is only turned on when the M_VEN pin is high. A diode is connected in anti-parallel between the source and drain of the switching transistor Q4. This diode is an internal parasitic diode of the switching transistor Q4. The gate of switching transistor Q4 is connected to the collector of transistor Q6. The base of transistor Q6 is connected to one end of resistor R27, and the other end of resistor R27 is connected to the M_VEN pin of the control board. One end of resistor R27 is grounded through resistor R29, and the emitter of transistor Q6 is grounded. Resistor R27 limits current, while resistor R29 keeps transistor Q6 normally off. Transistor Q6 only turns on when the M_VEN pin is high. Transistor Q6 drives switching transistor Q4; only when transistor Q6 is on can switching transistor Q4 be triggered to turn on. The VINA, EN, and PS / SY pins of the TPS63000 power chip are all connected to the drain of switching transistor Q4 through resistor R22. Resistor R22 is the enable resistor for the TPS63000 power chip; pulling it high enables the power supply circuit. The VINA, EN, and PS / SY pins of the TPS63000 power supply chip are all connected to the first GND interface via capacitor C13. Capacitor C13 serves as a filter to stabilize the EN (enable) signal of the power supply chip. The GND and PGND pins of the TPS63000 power supply chip are grounded. The LX1 pin of the TPS63000 power supply chip is connected to the LX2 pin via inductor L2, which is an energy storage inductor used for input filtering. The output terminal, VOUT pin, of the TPS63000 power supply chip is connected to the first 3.3V interface via a second filter circuit, which is a switching power supply step-down circuit. The second filter circuit includes resistors R24 and R26 and capacitor C12. The VOUT pin of the TPS63000 power chip is connected to the FB pin through resistor R24. The FB pin is grounded through resistor R26. The FB pin is a voltage feedback pin. The output power is divided by resistors R24 and R26 and then fed back to the FB pin. Based on the feedback voltage, the TPS63000 power chip can dynamically control the output voltage.The VOUT pin of the TPS63000 power chip is connected to one end of capacitor C12, and the other end of capacitor C12 is grounded. Capacitor C12 is an energy storage capacitor used for output filtering. The output voltage can be determined by adjusting the resistance values ​​of resistors R24 and R26.

[0050] The wireless transmission module supports both NANO-SIM and E-SIM IoT cards. The circuits for both cards are connected in parallel, such as... Figure 3 As shown, a stacked structure is adopted to reduce space occupation; the corresponding card slot is soldered according to the type used. One or more of the CAT.1, 4G, 5G, 433MHz, LoRa, and Bluetooth transmission units can be selected according to requirements. CAT.1, 4G, and 5G transmission units require a SIM card for network authentication; other transmission methods do not require a SIM card. For example... Figure 3 As shown, the VCC pin of the NANO-SIM card and the Vdd pin of the E-SIM card are both connected to one end of capacitor C14 and the SIM card power supply pin of the wireless transmission module, while the other end of capacitor C14 is grounded. The RST pins of both the NANO-SIM card and the E-SIM card are connected to the SIM card reset pin of the wireless transmission module. The CLK pins of both the NANO-SIM card and the E-SIM card are connected to the SIM read / write clock pin of the wireless transmission module. The CLK pins of both the NANO-SIM card and the E-SIM card are grounded through capacitor C16, which serves as a filter. The DATA pin of the NANO-SIM card and the I / O pin of the E-SIM card are both connected to the DATA pin of the wireless transmission module. The DATA pin of the wireless transmission module is connected to the SIM card power supply pin of the wireless transmission module through resistor R30 and grounded through capacitor C3. Resistor R30 is a pull-up resistor, and capacitor C3 is a filter capacitor. The wireless transmission module provides a clock signal via the CLK pin, reads data via the DATA and I / O pins, and controls reset via RST. The module offers both NANO-SIM and E-SIM interfaces. For card replacement, a NANO-SIM card can be inserted; for stable connection, an E-SIM card can be directly soldered on.

[0051] RTU supports large-capacity device storage. Different storage methods are selected for different working environments. This utility model supports two storage methods: SD card and EEPROM storage chip. Depending on the data volume, different storage capacities can be selected, such as 256M or 32G. However, both storage methods support the SPI communication protocol. Therefore, the data storage module uses a unified interface: a second 3.3V interface, a second GND interface, a MOSI interface, a MISO interface, a CLK interface, and a CS interface. The second 3.3V interface and the second GND interface are connected to the output of the power supply module. The MOSI, MISO, and CLK interfaces are connected to the MOSI, MISO, and CLK pins of the SPI1 pin on the control board, respectively. The MOSI pin is the command sending pin, the MISO pin is the command receiving pin, the CLK pin provides the clock, and the CS interface is the chip select pin. A low level indicates that the module is enabled. The CS interface is connected to the GPIO2 pin on the control board.

[0052] Taking the W25Q128 series memory chip as an example, this section introduces the relevant circuitry of the data storage module, such as... Figure 4 As shown, the WP pin of the memory chip is connected to the output of the power supply module through resistor R30. Resistor R31 is a pull-up resistor, keeping the memory chip in a wake-up state. The VCC and RST pins of the memory chip are both connected to the output of the power supply module, and both are grounded through capacitor C14, which acts as a filter capacitor to ensure stable chip operation. The CS pin of the memory chip is connected to the CS interface, the DO pin to the MISO interface, the DI pin to the MOSI interface, and the CLK pin to the CLK interface. The GND pin is grounded. The CS interface is the chip select pin; pulling it low enables the chip to operate. The DO pin is the data output pin of the memory chip. The CLK interface receives the clock signal from the control board, and the DI pin receives data commands from the control board.

[0053] RTU supports wireless data communication, and since data needs to be transmitted through public wireless networks, data security faces challenges. Currently, it supports mainstream encryption methods such as SM2, SM3, SM4, AES128, DES, and SHA, with different hardware encryption chips selected for different encryption methods. The encryption chips used in this utility model's data encryption module all support the I2C communication interface, and the electrical attributes of the external communication interfaces are uniformly set as follows: 3.3V third interface, GND third interface, SDA interface, SCL interface, and RST interface.

[0054] like Figure 5As shown, the relevant circuit of the data encryption module is illustrated using the Huada CIU98_D circuit, which supports SM2 encryption, as an example. U7 is the encryption chip, supporting SM2 encryption. The SDA interface of the encryption chip is connected to the SDA pin of the I2C1 on the control board to receive commands from the control board and to respond to data from the control board. The SCL interface of the encryption chip is connected to the SCL pin of the I2C1 on the control board to receive clock signals. The RST interface of the encryption chip is connected to GPIO3 on the control board for controlling the reset. The RST interface of the encryption chip is connected to the output of the power supply circuit through resistor R38. The VCC pin of the encryption chip is connected to the output of the power supply circuit, and the GND pin of the encryption chip is grounded. Resistor R38 is a pull-up resistor to stabilize the reset pin state at a high level.

[0055] The RTU supports multiple power supply methods, including AC power, battery power, and solar power. However, the input voltage of each subsystem is uniformly fixed at 3.3V. Therefore, this invention rectifies, filters, and steps down the input power supply to achieve an output voltage of 3.3V for the power supply module. The main workflow diagram of the power supply module is as follows: Figure 6 As shown, the power supply module includes an automatic power switching circuit and a step-up / step-down adjustable output circuit. Both mains power and the battery are connected to the automatic power switching circuit, which outputs a 3.3V voltage. The automatic power switching circuit is also connected to the step-up / step-down adjustable output circuit, which outputs the required adjustable voltage. The mains power, after rectification, filtering, and step-down, outputs 3.3V through the automatic power switching circuit. The DC power from the battery and solar energy also outputs 3.3V through the automatic power switching circuit. After power switching, the corresponding output voltage is obtained through the step-up / step-down adjustable output circuit. When external power is available, the device uses the external power supply. When the external power supply fails, the automatic power switching circuit switches to DC power. The power switching is seamless, with no power fluctuations and virtually no power loss.

[0056] like Figure 7As shown, the automatic power switching circuit includes diodes D8 and D9. The input power supply Vin is connected to the anode of diode D8, and the backup battery power supply Vbat is connected to the anode of diode D9. The cathodes of both diodes D8 and D9 are connected to the output power supply Vout. The gate of switching transistor Q5 is connected to the input power supply Vin through resistor R25. The input power supply Vin is grounded through resistor R28. Resistor R25 limits the current, and resistor R28 turns on switching transistor Q5 by lowering its gate level when the input power supply Vin is depleted. The drain of switching transistor Q5 is connected to the backup battery power supply Vbat, and the source of switching transistor Q5 is connected to the output power supply Vout. When the input power supply Vin is powered, Q5 (IRF7416) is cut off through resistors R25 and R28. At this time, the input power supply Vin is output to the output power supply Vout through diode D8. When the input power supply Vin is de-powered, diode D9 is a Schottky diode, which provides the turn-on voltage to the source of the switching transistor Q5. Q5 (IRF7416) is turned on through resistors R25 and R28. At this time, the battery backup power supply Vbat is output to the output power supply Vout through the switching transistor Q5. Since the switching transistor Q5 has almost no internal resistance after being turned on, the power efficiency of the battery backup power supply Vbat is almost lossless.

[0057] The adjustable buck-boost output circuit is a switch-equipped adjustable buck-boost circuit. Its advantages include high power efficiency, virtually no static power consumption, and continuous adjustable output voltage driven by a DAC, with an error accuracy within 100mV. When there is no power output, the power supply can be directly shut down by pulling Ven low, resulting in almost no current loss. Figure 8As shown, the adjustable boost / buck output circuit includes a boost power supply chip. This chip is connected to the output voltage via a boost circuit and a resettable fuse F5. The resettable fuse F5 protects the boost circuit. Diode D10, inductor L3, and capacitor C18 form a boost circuit. The VIN and SHDN pins of the boost power supply chip are connected in parallel and then connected to the output power supply Vout of the automatic power switching circuit and the BstVEN pin of the control board via switching transistor circuit II. The BstVEN pin controls the conduction of Q8; only when transistor Q8 is turned on can switching transistor Q7 be turned on, thus providing power to the subsequent circuits. The VIN and SHDN pins of the boost power supply chip are connected in parallel and then connected to the anode of diode D10 through inductor L3. The anode of diode D10 is connected to the SW pin of the boost power supply chip, and the cathode of diode D10 is connected to one end of resettable fuse F5 and one end of capacitor C18. The other end of capacitor C18 is connected to the GND pin of the boost power supply chip. The FB pin of the boost power supply chip is connected to one end of resettable fuse F5 through resistor R32. The DAC drive signal is connected to the FB pin and one end of resistor R37 through resistor R34. The other end of resistor R37 is grounded. Resistors R32, R34, and R37 together form a voltage divider circuit, making the voltage of the FB pin adjustable under the drive of the DAC signal.

[0058] (U6) The LMR64010 is a boost power supply chip. The FB pin of the boost power supply chip is the input voltage feedback pin, and the output voltage is fed back to the FB pin by resistor R32. The output voltage of the boost power supply chip is fixed. However, this invention requires continuously adjustable output voltage. Therefore, a DAC (Digital to Analog Converter) is introduced to drive and control the input voltage of the FB feedback pin. When the boost power supply chip U6 detects a change in the input voltage of the FB pin, it dynamically adjusts the output voltage to reach the preset value. The output voltage calculation formula is: Vout = ((1.23-DAC) / R34 + 1.23 / R37)*R32 + 1.23.

[0059] RTUs have a wide range of applications and need to interface with various instruments and meters, requiring data acquisition modules with various acquisition interfaces. These modules include a fourth 3.3V interface, a fourth GND interface, an RS485 interface, an RS232 interface, a CAN interface, an I2C interface, a TTL interface, digital input interfaces, digital output interfaces, analog input interfaces, and analog output interfaces. For ease of development, this application designs all acquisition interfaces onto acquisition boards, with a fixed 3.3V power supply. Each acquisition board has one of all the aforementioned acquisition interfaces. The number of acquisition boards used corresponds to the number of acquisition interfaces required.

[0060] The RS485 interface is connected to the RS485 data acquisition circuit. For example... Figure 9 The diagram illustrates the sub-circuit related to RS485 interface acquisition: if the RTU needs to acquire 4 channels of RS485 data, 4 acquisition boards are required. The RS485 acquisition circuit includes a TTL to RS485 level conversion chip. The RE pin of the TTL to RS485 level conversion chip is connected to the 3.3V output voltage from the power supply module through resistor R11. The DE pin of the TTL to RS485 level conversion chip is grounded through resistor R19. The RE pin is used for data reception, and the DE pin is the transmit control pin. The VCC pin of the TTL to RS485 level converter chip is connected to a 3.3V voltage and one end of capacitor C10, with the other end of capacitor C10 grounded. The B / Z pins of the TTL to RS485 level converter chip are connected to one end of resistor R19, the positive terminal of TVS diode D3, and one end of resettable fuse F3, respectively. The other end of resistor R19 and the negative terminal of TVS diode D3 are both grounded. The other end of resettable fuse F3 is connected to one end of resistor R12. The A / Y pins of the TTL to RS485 level converter chip are connected to one end of resistor R21, the positive terminal of TVS diode D7, and one end of resettable fuse F4, respectively. The other end of resistor R21 is connected to a 3.3V voltage, the negative terminal of TVS diode D7 is grounded, and the other end of resettable fuse F4 is connected to one end of resistor R18. The other end of resistor R12 is connected to the other end of resistor R18 through resistor R13. The other ends of resistor R12 and resistor R18 together output an RS485 differential signal.

[0061] The RS485 acquisition circuit supports low-power data acquisition. When DE=0V, RE=VCC, and DI=0V or VCC, the shutdown current is 0.01uA. When the RS485 acquisition circuit is in sleep mode, there is almost no current loss. U2 is a TTL to RS485 level converter chip. D3 and D7 are TVS protection transistors, which can filter out spike pulses on the RS485 bus. F3 and F4 are resettable fuses, which protect the circuit from damage and prevent excessive current in case of faults. Resistors R12 and R18 are isolation resistors, and resistor R13 is a matching resistor used for impedance matching and eliminating signal reflections. Resistor R21 is a pull-up resistor, pulling the potential up to a high level; resistor R9 is a pull-down resistor, pulling the potential down to a low level; capacitor C10 is a power supply filter capacitor; and resistors R11 and R19 are used to shut down chip U2 when the circuit is in sleep mode.

[0062] like Figure 10As shown, the analog input interface is connected to a 4-20mA analog current acquisition circuit. This circuit includes a sampling resistor R14, with a first-order RC filter and a TVS protection transistor D5 connected in parallel across R14. One end of the sampling resistor R14 is grounded, and the other end is connected to the analog input interface to be acquired. The 4-20mA analog current acquisition circuit uses a high-precision, low-temperature-drift sampling resistor R14, plus an external first-order RC filter. The parameters of resistor R10 and capacitor C11 can be determined based on the ripple frequency, filtering out most of the input ripple and making the sampling more accurate. D5 is a TVS protection transistor that absorbs spike pulses, achieving circuit protection.

[0063] All digital input and output interfaces on the data acquisition board employ isolation protection circuits to prevent external interference from affecting data acquisition and control. For example... Figure 11 The diagram shows the external connection circuits for the digital input and output interfaces. The digital input interface connects diode D4 to one end of resistor R17 and the negative terminal of TVS diode D6. The positive terminal of TVS diode D6 is grounded. The other end of resistor R17 is connected to the positive terminal of the optocoupler control terminal of the optocoupler isolation chip. The collector of the output terminal of the optocoupler isolation chip is connected to one end of resistor R16 and the signal acquisition terminal. The other end of resistor R16 is connected to a 3.3V voltage. The negative terminal of the optocoupler control terminal and the emitter of the output terminal of the optocoupler isolation chip are both grounded. Resistor R16 is a pull-up resistor. The digital input interface uses optocoupler isolation chip U3. Diode D4 is unidirectional and conducts to avoid interference from external input current. Current is limited by resistor R17. If the external input voltage is too high, the TVS diode D6 will clamp the voltage to the normal range.

[0064] The control signal of the digital output interface is connected to the source of MOSFET Q3 through resistor R15. The source of MOSFET Q3 is grounded through resistor R20. The drain of MOSFET Q3 is connected to the digital output interface through resettable fuse F2. The gate of MOSFET Q3 is grounded. A diode is connected in anti-parallel between the gate and drain of MOSFET Q3. The digital output interface uses MOSFET Q3 for open-drain output control. F2 is a resettable fuse that will disconnect the circuit if the current is too high, thus protecting the circuit. The control signal, after being current-limited and voltage-divided by resistors R15 and R20, controls the conduction of MOSFET Q3, thereby controlling the output signal of the digital output interface DO_1.

[0065] The RTU control board uses an STM32L496VET6 MCU, with all GPIOs pins routed to fixed functions. For example, the wireless transmission module driver, RS485 interface, RS232 interface, and TTL communication interface require a UART interface; the data storage chip and clock chip require an SPI1 interface; the data encryption chip requires an I2C1 interface; power supply voltage acquisition requires an ADC interface; adjustable external power supply voltage requires a DAC driver; data display requires an LCD interface; and control output requires GPIO interfaces. The control board's external interfaces include LPUART, USART, UART, I2C1, SPI1, a second CAN interface, PWM, ADC, DAC, LCD, KEY, and GPIO interfaces. The LPUART, USART, and UART interfaces are all used for TTL level serial communication. The I2C1 interface connects to the encryption chip, the SPI1 interface connects to the data storage chip and clock chip, and the second CAN interface is used to acquire relevant signal data. The ADC interface is connected to the power supply module; the DAC driver of the adjustable buck-boost output circuit is connected to the DAC interface; the LCD interface is connected to the digital display screen; and the KEY interface is connected to the buttons on the digital display screen to receive button signals. The GPIO interfaces are connected to the first RST interface of the wireless transmission module, the CS interface of the storage chip, and the RST interface of the encryption chip, respectively.

[0066] A complete RTU operates through a control board: (1) The power supply module provides standard voltage power to each module. (2) To collect data, the peripheral nodes connected to the RTU need to be powered. The control board sends an enable signal to the power supply module, which then powers the peripheral nodes. The control board can then start collecting data. (3) After the control board obtains data from the acquisition board, it encrypts the data using an encryption chip, stores the collected data in a storage chip, and sends the data to the cloud platform via a wireless transmission module. (4) After receiving the data sent by the RTU, the cloud platform sends control commands to the wireless transmission module. (5) After receiving the control commands from the wireless transmission module, the control board performs actions through the output interface of the control output board. (6) The control board displays a series of actions on a digital display screen, allowing the user to understand the current working status of the RTU.

[0067] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An RTU device with a unified interface supporting modular design, comprising a control board, characterized in that: The control panel is respectively connected to the wireless transmission module, the data storage module, the data encryption module, the power supply module and the data acquisition module. The control panel is connected to the cloud platform via the wireless transmission module. The interfaces on the control panel, the wireless transmission module, the data storage module, the data encryption module, the power supply module and the data acquisition module are unified.

2. The RTU device with unified interface support modular design according to claim 1, characterized in that: The control board is connected to the control output board and the data display module respectively; the power supply module is connected to the mains and the battery respectively.

3. The RTU device with unified interface support modular design according to claim 1 or 2, characterized in that: The control board, wireless transmission module, data storage module, data encryption module and data acquisition module are all provided with a power supply interface matching the output end of the power supply module, the control board, wireless transmission module, data storage module and data acquisition module are all provided with a communication interface, and the wireless transmission module, data storage module, data encryption module and data acquisition module are all provided with a control interface matching the control board.

4. The RTU device with unified interface support modular design according to claim 3, characterized in that: The control interface on the wireless transmission module includes a TXD interface, a RXD interface and a first RST interface, and the first RST interface, the TXD interface and the RXD interface are all connected to the control interface of the control board to realize reset and reception and transmission of instructions; The power supply interface of the wireless transmission module is connected to the output end of the power supply module through a voltage conversion circuit.

5. The RTU device with unified interface support modular design according to claim 4, characterized in that: The wireless transmission module includes a CAT.1 transmission unit, a 4G transmission unit, a 5G transmission unit, a 433MHz transmission unit, a Lora transmission unit and a Bluetooth transmission unit. The CAT.1 transmission unit, the 4G transmission unit, the 5G transmission unit, the 433MHz transmission unit, the Lora transmission unit and the Bluetooth transmission unit are all connected to the control board through an external communication interface, and the CAT.1 transmission unit, the 4G transmission unit, the 5G transmission unit, the 433MHz transmission unit, the Lora transmission unit and the Bluetooth transmission unit are all connected to the power supply module through a power supply interface; The CAT.1 transmission unit, 4G transmission unit, 5G transmission unit, 433MHz transmission unit, Lora transmission unit and Bluetooth transmission unit adopt TTL level serial communication; The voltage conversion circuit includes a power chip, and the input pin of the power chip is respectively connected to the output end of the power supply module and the M_VEN pin of the control board through the switch tube circuit I, the LX1 pin of the power chip is connected to the LX2 pin through the inductor L2, and the output end of the power chip outputs the required voltage through the second filter circuit.

6. The RTU device with unified interface supporting modular design according to claim 4 or 5, characterized in that: The wireless transmission module supports two types of Internet of Things cards, NANO-SIM card and E-Sim card. The circuits of the NANO-SIM card and the E-Sim card are connected in parallel. The VCC pin of the NANO-SIM card and the Vdd pin of the E-Sim card are both connected to the SIM card power supply pin of the wireless transmission module. The RST pins of the NANO-SIM card and the E-Sim card are both connected to the management SIM card reset pin of the wireless transmission module. The CLK pins of the NANO-Sin card and the E-Sim card are both connected to the SIM read and write clock pin of the wireless transmission module. The DATA pin of the NANO-Sim card and the I / O pin of the E-Sim card are both connected to the DATA pin of the wireless transmission module.

7. The RTU device with unified interface supporting modular design according to claim 5, characterized in that: The data storage module includes an SD card and an EEPROM memory chip. The communication interfaces of the SD card and the EEPROM memory chip both support the SPI communication protocol. Therefore, the control interface of the data storage module includes a MOSI interface, a MISO interface, a CLK interface, and a CS interface. The MOSI interface, the MISO interface, the CLK interface, and the CS interface are all connected to the control interface of the control board. The encryption chip used in the data encryption module supports the I2C communication interface. The control interface of the data encryption module includes an SDA interface, an SCL interface, and an RST interface. The SDA interface, the SCL interface, and the RST interface are all connected to the control interface of the control board.

8. The RTU device with unified interface supporting modular design according to claim 7, characterized in that: The power supply module includes an automatic power switching circuit and a buck-boost adjustable output circuit. The mains and the battery are connected to the automatic power switching circuit, and the automatic power switching circuit outputs a voltage of 3.3V; the automatic power switching circuit is connected to the buck-boost adjustable output circuit, and the buck-boost adjustable output circuit outputs the required adjustable voltage; the battery is connected to the solar panel; The automatic power switching circuit includes a diode D8 and a diode D9, the mains as an input power supply Vin is connected to the positive electrode of the diode D8, the battery as a battery backup power supply Vbat is connected to the positive electrode of the diode D9, the negative electrodes of the diode D8 and the diode D9 are both connected to the output power supply Vout, the gate of the switch tube Q5 is connected to the input power supply Vin through a resistor R25, the input power supply Vin is grounded through a resistor R28, the drain of the switch tube Q5 is connected to the battery backup power supply Vbat, and the source of the switch tube Q5 is connected to the output power supply Vout; when the input power supply Vin is powered, the switch tube Q5 is turned off through the resistors R25 and R28, and the input power supply Vin is output to the output power supply Vout through the diode D8; when the input power supply Vin is not powered, the diode D9 is a Schottky diode that provides a conduction voltage for the source of the switch tube Q5, the switch tube Q5 is turned on through the resistors R25 and R28, and the battery backup power supply Vbat is output to the output power supply Vout through the switch tube Q5; The buck-boost adjustable output circuit is an adjustable buck-boost circuit with a switch, and the buck-boost adjustable output circuit includes a boost power supply chip, and the boost power supply chip is connected to the output voltage through the Boost boost circuit and the self-recovery fuse F5. The Boost boost circuit includes a diode D10, an inductor L3 and a capacitor C18. The VIN pin and the SHDN pin of the boost power supply chip are connected in parallel and are respectively connected to the output power Vout of the power automatic switching circuit and the BstVEN pin of the control board and one end of the inductor L3 through the switch tube circuit II. , the other end of the inductor L3 is connected to the positive electrode of the diode D10, the positive electrode of the diode D10 is connected to the SW pin of the boost power chip, the negative electrode of the diode D10 is respectively connected to one end of the resettable fuse F5 and one end of the capacitor C18, and the other end of the capacitor C18 is connected to the GND pin of the boost power chip; the input voltage feedback pin of the boost power chip is connected to one end of the resettable fuse F5 through the resistor R32, and the DAC drive signal is connected to the input voltage feedback pin of the boost power chip through the voltage divider circuit.

9. The RTU device with unified interface supporting modular design according to claim 8, characterized in that: The data acquisition module includes an acquisition board, on which an acquisition interface and a communication interface are provided, the acquisition interface includes an RS485 interface, an RS232 interface, a switch input interface, a switch output interface, an analog input interface, and an analog output interface, the communication interface includes a first CAN interface, an I2C interface, and a TTL interface, and the power supply interface of the acquisition board is connected to the power supply interface of the power supply module; The RS485 interface is connected to the RS485 acquisition circuit, and the RS485 acquisition circuit includes a TTL to RS485 level conversion chip, the RE pin of the TTL to RS485 level conversion chip is connected to the output end of the power supply module through a resistor R11, the DE pin of the TTL to RS485 level conversion chip is grounded through a resistor R19, the VCC pin of the TTL to RS485 level conversion chip is respectively connected to the output end of the power supply module and one end of a capacitor C10, the other end of the capacitor C10 is grounded, and the B / Z pin of the TTL to RS485 level conversion chip is respectively connected to one end of the resistor R19, the positive pole of the TVS protection tube D3, and one end of the self-recovery fuse F3 The other end of the resistor R19 and the negative electrode of the TVS protection tube D3 are grounded, and the other end of the resettable fuse F3 is connected to one end of the resistor R12; the A / Y pins of the TTL to RS485 level conversion chip are respectively connected to one end of the resistor R21, the positive electrode of the TVS protection tube D7, and one end of the resettable fuse F4, the other end of the resistor R21 is connected to the output end of the power supply module, the negative electrode of the TVS protection tube D7 is grounded, the other end of the resettable fuse F4 is connected to one end of the resistor R18, the other end of the resistor R12 is connected to the other end of the resistor R18 through the resistor R13, and the other end of the resistor R12 and the other end of the resistor R18 jointly output the RS485 differential signal; The analog quantity input interface is connected to a 4-20mA current analog quantity acquisition circuit, which includes a sampling resistor R14, a first-order RC resistor-capacitor filter and a TVS protection transistor D5 are connected in parallel to the sampling resistor R14, one end of the sampling resistor R14 is grounded, and the other end is connected to the analog quantity input interface to be collected; The switch input interface and the switch output interface all use an isolation protection circuit. The switch input interface is connected to one end of the resistor R17 and the negative electrode of the TVS protection tube D6 through a diode D4, the positive electrode of the TVS protection tube D6 is grounded, and the other end of the resistor R17 is connected to the positive electrode of the optocoupler control end of the optocoupler isolation chip; the collector of the output end of the optocoupler isolation chip is connected to one end of the resistor R16 and the signal acquisition end, respectively, the other end of the resistor R16 is connected to a 3.3V power supply, and the negative end of the optocoupler control end and the emitter of the output end of the optocoupler isolation chip are both grounded; The control signal of the switching output interface is connected to the source of the field effect tube Q3 through the resistor R15, the source of the field effect tube Q3 is grounded through the resistor R20, the drain of the field effect tube Q3 is connected to the switching output interface through the resettable fuse F2, the gate of the field effect tube Q3 is grounded, and a diode is anti-parallel connected between the gate and the drain of the field effect tube Q3; the control signal of the switching output interface controls the conduction of the field effect tube Q3 after current limiting and voltage division through the resistors R15 and R20, thereby controlling the output signal of the switching output interface DO_1.

10. The RTU device with unified interface supporting modular design according to claim 9, characterized in that: The switch tube circuit I and the switch tube circuit II include a first switch tube and a first triode, the drain of the first switch tube is connected to the input pin of the power chip or the boost power chip as an output end, the source of the first switch tube is connected to the input power supply, the source of the first switch tube is connected to the gate of the first switch tube through a first resistor, a diode is connected in anti-parallel between the source and the drain of the first switch tube, the gate of the first second switch tube is connected to the collector of the first triode, the base of the first triode is connected to one end of the second resistor, the other end of the second resistor is connected to the control board, the base of the first triode is grounded through a third resistor, and the emitter of the first triode is grounded; The second filter circuit is a switching power supply step-down circuit, and the second filter circuit includes a resistor R24, a resistor R26 and a capacitor C12. The output end of the power chip is connected to the voltage feedback pin of the power chip through the resistor R24, and the voltage feedback pin is grounded through the resistor R26. The output voltage is divided by the resistor R24 ​​and the resistor R26, and then fed back to the voltage feedback pin. According to the feedback voltage, the power chip dynamically controls the output voltage; the output end of the power chip is connected to one end of the capacitor C12, and the other end of the capacitor C12 is grounded; The control board is provided with an LPUART interface, a USART interface, a UART interface, an I2C1 interface, an SPI1 interface, a second CAN interface, an ADC interface, a DAC interface, an LCD interface, a KEY interface and a GPIO interface. The LPUART interface, the USART interface and the UART interface are all used for serial communication at a TTL level. The I2C1 interface is connected to an encryption chip, the SPI1 interface is connected to a data storage chip and a clock chip, the second CAN interface is used to collect data of related signals, the ADC interface is connected to a power supply module, the DAC driving signal of a buck-boost adjustable output circuit is connected to the DAC interface, the LCD interface and the KEY interface are both connected to a data display module, and the GPIO interface is respectively connected to a first RST interface of a wireless transmission module, a CS interface of a storage chip and an RST interface of an encryption chip.

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