An intrinsic safety explosion-proof IP68 waterproof multi-channel 485 pipe network telemetry terminal and implementation method

Abstract

The application discloses an intrinsic safety explosion-proof IP68 waterproof multi-channel 485 pipe network remote measuring terminal and an implementation method, belongs to the technical field of monitoring and measurement of intelligent water affairs, gas pipe networks and underground pipe corridors, and comprises an integrated explosion-proof sealing shell and a main control circuit unit, a three-way isolation RS485 communication unit, a sealed Bluetooth operation and maintenance unit, a data acquisition unit, a magnetic passive wake-up unit, an intrinsic safety explosion-proof power supply unit, a local storage unit and a 4G / NB-IoT wireless module arranged in the integrated explosion-proof sealing shell. The three-way independent isolation RS485 time-sharing acquisition, the shell cover-free magnetic passive wake-up, the sealed built-in Bluetooth opening-free debugging, the integrated power supply of the 3.7V low-voltage explosion-proof power battery, the full-shell IP68 airtight waterproof and the intrinsic safety explosion-proof are achieved, and the application is suitable for long-term maintenance-free monitoring of water accumulation, flammable and explosive pipe network wells.

Description

Technical Field

[0001] This invention relates to an intrinsically safe, explosion-proof, IP68 waterproof, multi-channel 485 pipeline remote telemetry terminal and its implementation method, belonging to the field of monitoring and measurement technology for smart water management, gas pipeline networks, and underground pipe corridors. Background Technology

[0002] In smart water management, gas pipeline networks, and underground integrated pipe gallery monitoring scenarios, buried pipelines, sealed valve wells, gas pipeline wells, and chemical pipeline wells are typical high-risk and harsh working environments. These types of wells generally have three major objective conditions: First, water easily accumulates inside the well, and long-term high humidity and condensation are required, requiring monitoring equipment to have waterproof capabilities for prolonged deep water immersion; second, pipeline leaks and sewage fermentation can easily produce flammable and explosive mixed gases, and if electrical equipment sparks, it can easily cause a deflagration accident, so the equipment must meet strict intrinsic safety and explosion-proof requirements; third, the well space is confined and small, opening the cover is cumbersome, disassembly, and wiring are difficult, and the opening process poses a high safety risk.

[0003] Existing pipeline telemetry RTU equipment still suffers from several insurmountable technical defects when applied to the aforementioned high-risk waterlogging pipeline wells. It cannot simultaneously meet the practical needs of multi-sensor access, explosion-proof safety, deep-water waterproofing, local downhole maintenance, and low power consumption with long battery life. The specific defects are as follows:

[0004] First, the multi-sensor interface adaptation capability is insufficient. Most conventional pipeline telemetry terminals on the market are only equipped with 1-2 RS485 communication interfaces, making it difficult to simultaneously connect to multiple Modbus protocol instruments such as electromagnetic flow meters, pressure transmitters, and water / combustible gas meters. Multiple instruments sharing the same RS485 bus can easily lead to device address conflicts and mutual interference of bus signals, resulting in poor system networking and expansion capabilities and failing to meet the needs of synchronous acquisition and monitoring of multiple parameters in pipeline networks.

[0005] Secondly, maintenance operations pose significant explosion-proof safety hazards. Traditional telemetry terminals have physical buttons and toggle switches on their housings, and some products even have exposed wiring harnesses for debugging. When performing on-site operations such as power-on setup, parameter modification, and Bluetooth pairing, the explosion-proof housing must be opened by loosening the bolts. Opening the housing directly damages its explosion-proof, airtight structure. In a confined space filled with flammable and explosive gases, opening the housing can easily generate electrical sparks, posing a significant safety risk of igniting the flammable gases.

[0006] Third, the power supply architecture is difficult to adapt to intrinsically safe explosion-proof and low-power requirements. Some existing terminals use external 12V power supply or external solar power supply, resulting in numerous openings in the casing, which easily leads to sealing failure and significantly reduces waterproof performance. A few telemetry terminals with built-in batteries mostly use 7.4V dual-series lithium batteries, requiring multiple stages of buck-boost conversion in the circuit, resulting in high power loss, high overall power consumption, and difficulty in controlling temperature rise, which does not meet the intrinsically safe explosion-proof low-voltage energy constraints. On the other hand, a few terminals using 3.7V single-cell lithium batteries lack explosion-proof potting, current limiting, temperature control, and other protective measures, making them prone to overheating during battery charging and discharging, posing safety hazards such as sparking and bulging.

[0007] Fourth, waterproof performance and intrinsically safe explosion-proof performance are incompatible. Currently, explosion-proof pipeline monitoring equipment generally only achieves an IP65 dustproof and waterproof rating, which cannot withstand long-term immersion in water; while existing IP68 high waterproof rating terminals often use a multi-component splicing structure for the casing, and the gaps between the splices cannot meet the airtightness requirements of intrinsically safe explosion-proof. The industry lacks integrated terminal products that can simultaneously achieve IP68 deep-water immersion waterproofing and intrinsically safe explosion-proof performance.

[0008] Fifth, on-site commissioning and maintenance in underground wells are difficult. Most underground pipeline wells lack external network signal coverage, and traditional RTUs only support remote configuration parameter distribution from the cloud; if the underground network is down, on-site commissioning cannot be carried out. To achieve local commissioning, an additional commissioning serial port needs to be opened, which further damages the explosion-proof and waterproof sealing structure of the casing, further amplifying the risks of on-site operations.

[0009] Sixth, faults can easily lead to complete machine failure, resulting in insufficient equipment reliability. Existing terminal 485 bus and sensor power supply mostly adopt a shared circuit design. When a single sensor experiences a short circuit or surge fault, it can easily cause communication interruption or power failure of the entire machine, resulting in the synchronous loss of all pipeline monitoring data. The lack of an independent fault isolation mechanism is not conducive to continuous and uninterrupted monitoring of high-risk pipelines.

[0010] Seventh, poor power consumption control and limited battery life. Traditional terminals mostly use a constant power supply design for Bluetooth, storage, and communication peripherals, resulting in high static current in sleep mode. In battery-powered scenarios where external power cannot be connected underground, the battery life of the equipment is short, requiring frequent underground battery replacements and a large workload for maintenance.

[0011] Eighth, the reliability of monitoring data is insufficient under complex operating conditions. There are interference factors such as large fluctuations in temperature and humidity, instantaneous pressure disturbances in the pipeline network, and vibration of the well cover in the mine. Existing equipment lacks a sound data fault tolerance and temperature compensation mechanism, which easily generates a large number of false alarms. At the same time, the underground network signal fluctuates frequently, and the local caching capacity is weak after the network is interrupted, which can easily cause the loss of pipeline monitoring data.

[0012] In summary, the industry currently lacks a pipeline telemetry terminal that can be adapted to water-filled, flammable, and explosive pipeline wells, integrating three independent isolated RS485 acquisition channels, hole-free magnetic wake-up, sealed cover-free Bluetooth local debugging, 3.7V intrinsically safe explosion-proof battery power supply, and IP68 deep-water waterproofing. There is a significant gap in product compatibility for high-risk underground pipeline monitoring scenarios, and targeted optimization of structure, circuitry, and software algorithms is urgently needed. Summary of the Invention

[0013] The technical problem to be solved by this invention is to address the above-mentioned shortcomings by providing an intrinsically safe, explosion-proof, IP68 waterproof, multi-channel RS485 pipeline telemetry terminal and its implementation method. This terminal achieves three-channel independent isolated RS485 time-sharing acquisition, passive wake-up via magnetic attraction without opening the casing, sealed built-in Bluetooth for hole-free debugging, integrated power supply with a 3.7V low-voltage explosion-proof power battery, and IP68 airtight waterproof + intrinsically safe explosion-proof casing, making it suitable for long-term maintenance-free monitoring of water-accumulating, flammable, and explosive pipeline wells.

[0014] To solve the above technical problems, the present invention adopts the following technical solution:

[0015] An intrinsically safe, explosion-proof, IP68 waterproof, multi-channel RS485 pipeline telemetry terminal includes an integrated explosion-proof sealed housing; and a main control circuit unit, a three-channel isolated RS485 communication unit, a sealed Bluetooth maintenance unit, a data acquisition unit, a magnetic passive wake-up unit, an intrinsically safe explosion-proof power supply unit, a local storage unit, and a 4G / NB-IoT wireless module, all housed within the integrated explosion-proof sealed housing.

[0016] The main control circuit unit is connected to three isolated RS485 communication units, a sealed Bluetooth maintenance unit, a data acquisition unit, a magnetic passive wake-up unit, a local storage unit, and a 4G / NB-IoT wireless module, respectively. The 4G / NB-IoT wireless module is connected to the cloud.

[0017] The intrinsically safe explosion-proof power supply unit uses a 3.7V explosion-proof lithium battery as input to provide multiple levels of intrinsically safe operating power to each unit; the integrated explosion-proof sealed housing is a one-piece injection molded, seamless sealed structure without any split seams. The housing has no physical buttons, DIP switches, or debugging openings, and has reserved IP68-level explosion-proof aviation sealed terminals for external sensors.

[0018] The three-channel isolated RS485 communication unit provides three electrically isolated RS485 communication channels. Each channel is equipped with independent surge protection and short-circuit current limiting protection, and the three channels support independent baud rate configuration, respectively adapting to electromagnetic flow meters, pressure level transmitters, combustible gas and water quality probes.

[0019] The magnetic passive wake-up unit adopts a passive dual-path magnetic trigger detection module. The external magnet is attached to the integrated explosion-proof sealed shell to generate a hardware wake-up interrupt, which is transmitted to the main control circuit unit. The sealed Bluetooth operation and maintenance unit is powered on under control and completely powered off when in sleep mode. After being woken up by magnetic attraction, it starts encrypted point-to-point Bluetooth communication.

[0020] Furthermore, the main control circuit unit includes chip U13, which is an STM32L151RET6. Pin 20 of chip U13 is connected to pin 4 of common anode LED indicator LED1, pin 21 of chip U13 is connected to pin 3 of common anode LED indicator LED1, pin 22 of chip U13 is connected to pin 1 of common anode LED indicator LED1, and pin 2 of common anode LED indicator LED1 is connected to one end of resistor R43. The other end of resistor R43 is connected to a 3.3V power supply.

[0021] Pin 4 of chip U13 is connected to one end of crystal oscillator Y1 and one end of capacitor C29. Pin 3 of chip U13 is connected to the other end of crystal oscillator Y1 and one end of capacitor C28. The other end of capacitor C28 and the other end of capacitor C29 are grounded. Pin 6 of chip U13 is connected to one end of crystal oscillator Y2 and one end of capacitor C31. Pin 5 of chip U13 is connected to the other end of crystal oscillator Y2 and one end of capacitor C30. The other end of capacitor C30 and the other end of capacitor C31 are grounded.

[0022] Pin 9 of the chip U13 is connected to the base of transistor Q20. The emitter of transistor Q20 is grounded. The collector of transistor Q20 is connected to one end of resistor R57 and the gate of MOSFET Q19. The other end of resistor R57 and the drain of MOSFET Q19 are connected to one end of resistor R58. The other end of resistor R58 is connected to pin 10 of chip U13, one end of diode D10 and one end of resistor R59. The other end of diode D10 and the other end of resistor R59 are grounded.

[0023] Furthermore, the three-channel isolated RS485 communication unit includes chips U2, U4, U5, and U8. Chips U2, U4, U5, and U8 are SP3485. Pin 1 of chip U2 is connected to pin 17 of chip U13. Pins 2 and 3 of chip U2 are connected to one end of resistor R19 and pin 15 of chip U13. The other end of resistor R19 is grounded. Pin 4 of chip U2 is connected to pin 16 of chip U13. Pin 6 of chip U2 is connected to one end of fuse F5, TVS diode array D1, and resistor R8. One end of chip U2 is connected to pin 1 of IP68 explosion-proof aviation sensor terminal CN1. Pin 7 of chip U2 is connected to one end of fuse F4, TVS diode array D1, the other end of resistor R8, and pin 2 of IP68 explosion-proof aviation sensor terminal CN1. Pin 8 of chip U2 is connected to one end of capacitor C12, and the other end of capacitor C12 is grounded. Pin 1 of chip U4 is connected to pin 52 of chip U13. Pins 2 and 3 of chip U4 are connected to one end of resistor R24 ​​and pin 50 of chip U13, and the other end of resistor R24 ​​is grounded. Pin 4 of chip U4 is connected to pin 50 of chip U13. Pin 51, pin 6 of chip U4 is connected to one end of fuse F7, TVS diode array D3, one end of resistor R23, and pin 1 of IP68 explosion-proof aviation sensor terminal CN2. Pin 7 of chip U4 is connected to one end of fuse F6, the other end of TVS diode array D3, resistor R23, and pin 2 of IP68 explosion-proof aviation sensor terminal CN2. Pin 8 of chip U4 is connected to one end of capacitor C15, and the other end of capacitor C15 is grounded. Pin 1 of chip U5 is connected to pin 54 of chip U13. Pins 2 and 3 of chip U5 are connected to resistor R27. Pin 4 of chip U5 is connected to pin 53 of chip U13. Pin 6 of chip U5 is connected to one end of fuse F9, one end of TVS diode array D4, one end of resistor R26, and pin 1 of IP68 explosion-proof aviation sensor terminal CN3. Pin 7 of chip U5 is connected to one end of fuse F8, one end of TVS diode array D4, the other end of resistor R26, and pin 2 of IP68 explosion-proof aviation sensor terminal CN3. Pin 8 of chip U5 is connected to one end of capacitor C18, and the other end of capacitor C18 is grounded.

[0024] Furthermore, pins 2 and 3 of chip U8 are connected to one end of resistor R31, and the other end of resistor R31 is grounded. Pin 1 of chip U8 is connected to pin 1 of chip U10. Pin 4 of chip U8 is connected to pin 12 of chip U10. The model of chip U10 is 74HC4052D. Pin 6 of chip U8 is connected to pin 5 of TVS diode array D5 and IP68 explosion-proof aviation sensor terminal CN1. Pin 7 of chip U8 is connected to pin 6 of TVS diode array D5 and IP68 explosion-proof aviation sensor terminal CN1. Pin 8 of chip U8 is connected to one end of capacitor C25 and connected to V485 power supply. The other end of capacitor C25 is grounded.

[0025] Furthermore, the sealed Bluetooth maintenance unit includes a chip U9, model BLE-SER-A-ANT. Pin 2 of chip U9 is connected to the drain (D) of MOSFET Q9. The gate (G) of MOSFET Q9 is connected to one end of resistor R15 and one end of resistor R14. The other end of resistor R15 and the source (S) of MOSFET Q9 are connected to a 3.3V power supply. The other end of resistor R14 is connected to the collector of transistor Q10. The emitter of transistor Q10 is grounded. The base of transistor Q10 is connected to pin 27 of chip U13. Pin 4 of chip U9 is connected to one end of resistor R35. The other end of resistor R35 is connected to pin 20 of chip U13. Pin 7 of chip U9 is connected to pin 5 of chip U10. Pin 8 of chip U9 is connected to pin 14 of chip U10. Chip U10 is model 74HC4052D.

[0026] Furthermore, the data acquisition unit includes a chip U12, model ADXL345BCCZ-RL7. Pin 1 of chip U12 is connected to 3.3V. Pin 6 of chip U12 is connected to one end of resistor R42, and the other end of resistor R42 is connected to 3.3V. Pin 7 of chip U12 is connected to one end of resistor R41, and the other end of resistor R41 is connected to 3.3V. Pin 8 of chip U12 is connected to pin 2 of chip U13. Pin 12 of chip U12 is connected to one end of resistor R45, and the other end of resistor R45 is grounded. Pin 13 of chip U12 is connected to one end of resistor R39 and pin 59 of chip U13. Pin 14 of chip U12 is connected to one end of resistor R38 and pin 58 of chip U13.

[0027] The data acquisition unit also includes chip U14, model AHT20_C2757850. Pin 2 of chip U14 is connected to one end of resistor R48 and one end of capacitor C32. The other end of resistor R48 is connected to VCC_MCU power supply, and the other end of capacitor C32 is grounded. Pin 3 of chip U14 is connected to one end of resistor R49 and pin 61 of chip U13. Pin 4 of chip U14 is connected to one end of resistor R50 and pin 62 of chip U13. The other ends of resistor R49 and resistor R50 are connected to VCC_MCU power supply.

[0028] Furthermore, the magnetic passive wake-up unit includes a magnetron S1 and a magnetron S2. One end of the magnetron S1 is connected to one end of a resistor R51 and pin 38 of the chip U13, and the other end of the resistor R51 is grounded. The other end of the reed magnetron S1 is connected to one end of a resistor R46, and the other end of the resistor R46 is connected to 3.3V. One end of the reed magnetron S2 is connected to one end of a resistor R52 and pin 28 of the chip U13, and the other end of the resistor R52 is grounded. The other end of the reed magnetron S2 is connected to one end of a resistor R47, and the other end of the resistor R47 is connected to 3.3V.

[0029] Furthermore, the local storage unit includes chip U11, model number MX25L2564GM21-08G. Pin 1 of chip U11 is connected to pin 33 of chip U13, pin 2 of chip U11 is connected to pin 35 of chip U13, pin 5 of chip U11 is connected to pin 36 of chip U13, pin 6 of chip U11 is connected to pin 34 of chip U13, pin 3 of chip U11 is connected to one end of resistor R32, and pin 7 of chip U11 is connected to one end of resistor R34. Resistor R34 is also connected to... One end is connected to pin 8 of chip U11 and one end of capacitor C27. The other end of capacitor C27 is grounded. Pin 8 of chip U11 and the other end of resistor R32 are connected to the drain of MOSFET Q13. The gate of MOSFET Q13 is connected to one end of resistor R33 and one end of resistor R36. The source of MOSFET Q13 and the other end of resistor R33 are connected to a 3.3V power supply. The other end of resistor R36 is connected to the collector of transistor Q15. The emitter of transistor Q15 is grounded. The base of transistor Q15 is connected to pin 37 of chip U13.

[0030] Furthermore, the intrinsically safe explosion-proof power supply unit includes a 12V boost circuit, a 4V boost circuit, a 3.3V circuit, and a 12V power control circuit. The 4V boost circuit uses an MT3608 chip to boost the voltage of a 3.7V lithium battery to generate a VCC_4V power supply. The 3.3V circuit uses an SPX3819M5-L-3-3 / TR to regulate and output 3.3V from the VCC_4V power supply. The 12V boost circuit uses an MT3608 chip to boost the voltage of the VCC_4V power supply to generate 12V, which is dedicated to powering external sensors.

[0031] The 12V control circuit includes transistor Q5. The base of transistor Q5 is connected to pin 14 of chip U13, the emitter of transistor Q5 is grounded, the collector of transistor Q5 is connected to one end of resistor R9, the other end of resistor R9 is connected to one end of resistor R2 and the gate (G) of MOSFET Q1, the other end of resistor R2 is connected to one end of fuse F1 and the source (S) of MOSFET Q1, the other end of fuse F1 is connected to the 12V power supply, and the drain (D) of MOSFET Q1 is connected to the IP68 explosion-proof aviation sensor terminal CN1. The 3-pin 12V control circuit also includes transistor Q6. The base of transistor Q6 is connected to pin 45 of chip U13, the emitter of transistor Q6 is grounded, the collector of transistor Q6 is connected to one end of resistor R11, the other end of resistor R11 is connected to one end of resistor R4 and the gate (G) of MOSFET Q3, the other end of resistor R4 is connected to one end of fuse F2 and the source (S) of MOSFET Q3, the other end of fuse F2 is connected to the 12V power supply, and the drain (D) of MOSFET Q3 is connected to the IP68 explosion-proof aviation sensor terminal. The CN2 circuit includes a 12V control circuit, specifically pin 3. The base of transistor Q4 is connected to pin 56 of chip U13. The emitter of transistor Q4 is grounded. The collector of transistor Q4 is connected to one end of resistor R12. The other end of resistor R12 is connected to one end of resistor R5 and the gate (G) of MOSFET Q4. The other end of resistor R5 is connected to one end of fuse F3 and the source (S) of MOSFET Q4. The other end of fuse F3 is connected to the 12V power supply. The drain (D) of MOSFET Q4 is connected to an IP68 explosion-proof aviation safety device. The sensor terminal CN3 is pin 3; the 12V control circuit also includes transistor Q7. The base of transistor Q7 is connected to pin 55 of chip U13. The emitter of transistor Q7 is grounded. The collector of transistor Q7 is connected to one end of resistor R10. The other end of resistor R10 is connected to one end of resistor R3 and the gate of MOSFET Q2. The other end of resistor R3 and the source of MOSFET Q2 are connected to a 3.3V power supply. The drain of MOSFET Q2 is connected to pins 8 of chip U2, pins 8 of chip U4, and pins 8 of chip U5.

[0032] A method for implementing an intrinsically safe, explosion-proof, IP68 waterproof, multi-channel 485 pipeline telemetry terminal includes the following steps:

[0033] Step 1: Power on the entire machine / RTC timer initialization control logic;

[0034] Step 11, System clock initialization logic: After the device is powered on or the RTC is woken up by a timer, the system master clock and the independent RTC timing clock are configured first; the RTC timing clock is kept independently powered, and there is no need to recalibrate the timing reference after waking up from sleep, ensuring the stability of the timing acquisition and delayed power-off timing sequence;

[0035] Step 12, Main control circuit unit IO port function configuration logic: uniformly configure the input and output attributes of three 485 transceiver control pins, Bluetooth power supply switch pins, sensor high voltage output control pins, storage power control pins, and magnetic wake-up interrupt pins; configure two magnetic detection ports as external interrupt trigger mode and enable dual-signal joint verification anti-shake logic;

[0036] Step 13, Multi-communication bus initialization logic:

[0037] The three 485 serial ports are independently allocated hardware resources and support multiple baud rate parameters of 9600bps, 19200bps, and 115200bps respectively.

[0038] Initialize the I2C communication bus and attach two types of sensors: internal temperature and humidity sensors and device attitude sensors.

[0039] Initialize the SPI communication bus and connect it to the local high-capacity storage chip;

[0040] Configure multiple signal switching channels to achieve time-division multiplexing and hardware isolation of Bluetooth serial port, debugging serial port, and three-channel acquisition 485 serial port;

[0041] Step 14, peripheral device power-on control logic: In the initial state of device power-on, the main control circuit unit issues a command to shut down the power supply to all peripheral devices, including the sealed Bluetooth maintenance unit, local storage unit, three-way isolated RS485 communication unit, and high-voltage output of the data acquisition unit; the whole machine only retains the main control circuit unit and the magnetic passive wake-up unit to maintain low power standby.

[0042] Step 15, Status Indicator Logic Definition: Divide the equipment operating status into four types of light indicators, corresponding to the four operating states of hibernation standby, data acquisition, wireless networking, and fault lockout, respectively. The indicator lights are off by default.

[0043] Step 16, Explosion-proof parameter loading and inspection startup logic: Read the device's fixed configuration parameters from local storage, including the 485 acquisition cycle for each channel, sensor calibration coefficient, alarm threshold, and automatic wake-up interval; pre-load the explosion-proof safety judgment thresholds, including the maximum safe temperature inside the enclosure, the upper limit of battery charging current, and the number of consecutive communication failure judgments; continuously start the safety inspection task in the background, cyclically collect battery current, internal temperature, and the operating status of each communication channel, and establish an explosion-proof real-time monitoring link;

[0044] Step 17, three-level power consumption mode parameter pre-storage logic: the main control circuit unit has built-in three types of power consumption switching judgment rules: deep sleep, timed acquisition, and Bluetooth operation and maintenance, and presets peripheral on / off control strategies and whole machine static current constraint standards for each mode.

[0045] Step 2: Three-way isolated RS485 time-division acquisition control logic;

[0046] After the device's RTC wakes up at a set time, it starts a multi-channel acquisition task, strictly following the time-sharing scheduling logic of single transmission and single reception, and transmission only after reception. The three communication channels operate independently and do not compete for bus resources.

[0047] Step 21, First-channel flow meter acquisition logic;

[0048] Turn on the power supply for this 485 communication channel and configure the high-speed baud rate to match the flow meter; output the transmit enable signal to send the standard Modbus read command; delay and close the transmit channel, switch to the data receive state and wait for the instrument to transmit back; complete the data verification, discard the single abnormal data directly, mark the instrument as offline fault if there are multiple consecutive valid data; after the acquisition is completed, cut off the power supply for this communication channel, release the bus resources, jump to the next acquisition process, and fix the high-frequency acquisition cycle.

[0049] Step S22, second channel pressure / level instrument acquisition logic;

[0050] Turn on the 485 communication power supply for this channel and configure the communication rate to match the transmitter; continuously read multiple sets of raw pressure and level monitoring values; retrieve the internal temperature data to perform temperature drift compensation and remove instantaneous extreme values ​​through the mean algorithm; add timestamps to valid data and store them in a temporary buffer; after the acquisition ends, turn off the communication for this channel and jump to the third acquisition process, using a low-frequency steady-state acquisition cycle.

[0051] Step 23, third-channel gas / water quality probe acquisition logic;

[0052] Turn on the 485 communication power supply and configure low-speed fault-tolerant communication parameters; issue a read command, set an ultra-long data reception waiting window, and automatically resend the command if there is no response; if there is no data returned multiple times, the probe is determined to be offline; if normal data is returned, mark the abnormal points that exceed the limit; after the data acquisition is completed, disconnect the communication power supply and adopt a long interval acquisition cycle.

[0053] Step 24: Collect data and unify the caching logic;

[0054] Integrate all monitoring data from three 485 channels, internal environmental data, and equipment attitude data, along with equipment number, timestamp, and fault marker to generate a complete data package; the data is synchronously stored in the running memory and local storage, and then a wireless upload task is initiated;

[0055] Step 3, 4G / NB-IoT wireless module network interruption resume control logic;

[0056] Step 31, 4G / NB-IoT wireless module power-on and link establishment logic: issue a command to turn on the power supply of the wireless module, initialize the wireless communication link, establish a long connection with the cloud platform, and periodically send heartbeat packets to maintain the online status of the base station;

[0057] Step 32, graded disconnection and reconnection control logic: distinguish between three disconnection scenarios: instantaneous packet loss, short-term weak signal, and long-term no signal, and extend the reconnection interval level by level to reduce the power consumption of continuous radio frequency transmission.

[0058] Step 33: Logic for offline caching and online retransmission;

[0059] When the network is disconnected, real-time uploading stops, and all data packets are stored in the local circular storage area in the order of collection, with each data packet carrying a unique time identifier. After the network is restored, offline cached data is read in chronological order and re-uploaded to the cloud one by one. After the upload is completed, the corresponding cached data is cleared to prevent duplicate uploads and data overflow.

[0060] Step 34, Cloud-based two-way command interaction logic: Real-time reception of remote commands from the cloud, supporting remote modification of acquisition parameters, remote wake-up, and remote fault reset, realizing two-way data transmission between the cloud and the terminal;

[0061] Step 35, power-off logic for peripheral devices after upload: After all real-time data and offline cache have been transmitted, the power supply to the wireless module is turned off, and the device returns to low-power standby mode;

[0062] Step 4: Magnetic activation of Bluetooth operation and maintenance linkage control logic;

[0063] Step 41, Magnetic passive wake-up unit signal verification logic: During deep sleep, only two magnetic interrupt detections are retained; after external magnetic triggering of two synchronous interrupt signals, valid wake-up is determined. Single triggering and instantaneous level transitions are directly filtered to avoid accidental Bluetooth activation by underground magnetic fields and vibrations.

[0064] Step 42, Power-on and channel switching logic of the sealed Bluetooth maintenance unit: After confirming a valid wake-up signal, a command is issued to power on the Bluetooth maintenance unit; multiple signal channels are switched to connect the communication link between the Bluetooth maintenance unit and the main control circuit unit; Bluetooth starts encrypted point-to-point broadcast to reject unauthorized devices from accessing the network, and the indicator light is switched to maintenance status.

[0065] Step 43, Bluetooth local interaction processing logic: After the handheld device establishes an encrypted connection, it responds to operation commands in four categories:

[0066] Read all local historical monitoring data and fault logs; modify the 485 baud rate, acquisition period, alarm threshold, and sensor calibration parameters of each channel in the three isolated RS485 communication unit, and permanently write the modifications to local storage; perform sensor zero-point and temperature drift calibration operations; retrieve the real-time fault status of the entire unit.

[0067] Step 44, Bluetooth timeout automatic sleep logic: After a fixed period of no interaction, the Bluetooth communication port is locked; after the magnetic removal, a countdown starts, and when the countdown ends, the Bluetooth power supply is completely turned off, the Bluetooth communication channel is disconnected, the indicator light goes out, and the device returns to the timed data collection standby state.

[0068] Step 5, three-level ultra-low power sleep control logic;

[0069] Step 51, Automatic Working Condition Classification Switching Logic: The main control circuit unit identifies the currently running task in real time and automatically switches between three power consumption modes:

[0070] Operating mode: Any task can be run, including data acquisition, wireless upload, or Bluetooth maintenance, while all peripherals remain powered.

[0071] Timed standby mode: After one round of data acquisition and upload is completed, the high voltage output, three isolated RS485 communication units, and 4G / NB-IoT wireless module are turned off, and only the RTC timer of the main control circuit unit is retained to wait for timed wake-up;

[0072] Deep sleep mode: No timed tasks, no magnetic wake-up signal, cut off power to all peripherals, only maintain RTC and magnetic interrupt detection, and the whole machine maintains a microampere-level static current;

[0073] Step 52, RTC timed wake-up loop logic: During the sleep process, the main control circuit unit RTC independently times the time. After reaching the preset acquisition interval, a wake-up interrupt is generated. After the main control receives the interrupt, the entire acquisition and upload process is restarted. After one round of tasks is completed, it falls back to the low power state, and the loop realizes long-term unattended monitoring.

[0074] Step 53, wake up the anti-shake filtering logic: after the magnetic interrupt is triggered, the level is checked twice after a delay. Only when the signal is stable and valid will the whole machine be woken up to avoid frequent start-stop of peripherals and consumption of battery power.

[0075] Step 6, Explosion-proof safety closed-loop control logic;

[0076] Step 61, Multi-dimensional safety cycle inspection logic: The background resident inspection task continuously reads four types of safety parameters: internal temperature, battery charging and discharging current, number of failures of three-way 485 communication, and abnormal status of wireless module.

[0077] Step 62, Over-temperature power-off interlocking control logic;

[0078] When the internal temperature of the enclosure exceeds the safety threshold, a high-temperature explosion risk is identified.

[0079] The high-voltage circuit of the sensor and the power supply of all peripherals are shut off in sequence, the whole machine is locked by power failure, and the fault indicator light stays on.

[0080] Simultaneously record high-temperature faults and store them locally, then attempt to push high-temperature alarms to the cloud;

[0081] The temperature must be continuously monitored. The device can only be restarted for data collection after the temperature drops back to a safe range and the device is manually reset using a magnetic clamp. Powering on the device is permanently prohibited until the fault is cleared.

[0082] Step 63, fault classification and isolation control logic;

[0083] When a single-channel 485 continuous communication failure occurs, only the high-voltage power supply to that sensor is cut off, while the other two acquisition channels operate normally.

[0084] When the battery overcurrent or charging current exceeds the standard, the power supply to the whole machine will be cut off and a short circuit / overcharge alarm will be uploaded.

[0085] All faults are permanently stored with timestamps, and fault records can be read locally via Bluetooth for troubleshooting and tracing.

[0086] Step 7, Data calibration and fault-tolerant control logic;

[0087] Step 71, Sensor temperature drift compensation logic: Each time pressure and water quality data are read, the internal temperature is retrieved synchronously, and the compensation algorithm is called to correct the sampling zero-point offset caused by high and low temperatures, thereby improving measurement accuracy;

[0088] Step 72, vibration filtering and mean-tolerance logic;

[0089] The pressure and liquid level channels employ a multi-point averaging algorithm to eliminate instantaneous extreme values ​​and suppress water flow impact fluctuations in the pipeline network;

[0090] Read equipment posture data, identify periods of severe vibration and tilt, and directly filter abnormal sample values ​​in the interval to avoid false alarms triggered by manhole cover disturbance;

[0091] Step 73, Logic for handling abnormal data in a tiered manner;

[0092] For minor exceedances in a single sample: the sample is automatically filtered and discarded, and no alarm data packet is generated.

[0093] Multiple consecutive sampling exceeding limits: Determine the actual fault in the pipeline network, generate alarm data, upload it to the cloud, and archive it locally;

[0094] Step 8: Local storage partition read / write control logic;

[0095] Step 81, Controlled power-on logic for the storage module: Power is turned on to the storage chip only in three scenarios: data acquisition, Bluetooth reading, and offline retransmission; power is completely turned off during other sleep periods to reduce overall power consumption and casing temperature rise;

[0096] Step 82, Storage Partition Management Logic: Divide the storage space into three independent logical partitions:

[0097] Parameter partitioning: Permanently stores fixed configurations such as baud rate, calibration coefficient, and alarm threshold, which are not lost when power is off;

[0098] Data cache partition: A circular storage mechanism for network outage monitoring data packets, with a capacity limit set to prevent data overwriting;

[0099] Fault log partitioning: Independently stores various alarm records, and retains them long-term for operation and maintenance traceability;

[0100] Step 83, read-write protection mutual exclusion logic;

[0101] Data acquisition and writing, Bluetooth reading, and online retransmission adopt a multi-task mutual exclusion mechanism to avoid data corruption caused by synchronous reading and writing;

[0102] Write protection is enabled in the device's core parameter partition to prevent arbitrary erasure and overwriting, thus preventing the loss of calibration configuration due to accidental operation.

[0103] The present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0104] This invention discloses an intrinsically safe, explosion-proof, IP68 waterproof, multi-channel 485 pipeline telemetry terminal. Addressing the harsh working conditions of buried water accumulation and flammable / explosive pipeline wells, it overcomes the shortcomings of existing telemetry terminals, such as insufficient multi-channel instrument access, high risk of explosion during maintenance by opening the cover, difficulty in simultaneously ensuring waterproofing and explosion protection, high power consumption, inability to conduct local debugging during network outages in wells, and easy failure of the entire unit due to single-channel faults. It possesses the following beneficial effects:

[0105] 1. Multi-channel independent isolation communication, strong anti-interference, and faults do not affect each other;

[0106] Three fully isolated RS485 communication channels are configured, each with independent surge and short-circuit current limiting protection. Each channel can be independently configured with a baud rate to adapt to electromagnetic flowmeters, pressure / level transmitters, combustible gas probes, and water quality probes. In the event of a short circuit or surge failure on a single bus, only that bus will fail, without interfering with the other two channels. This design is suitable for environments with strong electromagnetic interference, such as downhole motor frequency converters. The hardware implements transmit / receive separation and time-sharing scheduling, effectively solving the address conflicts, packet crosstalk, and packet loss problems caused by traditional single-bus multi-instrument parallel connections, thus improving the reliability of synchronous multi-parameter acquisition in pipeline networks.

[0107] 2. Sealed operation and maintenance without opening the cover eliminates explosion-proof safety hazards during underground operation and maintenance;

[0108] Employing a passive magnetic-controlled magnetic wake-up and controlled power-on Bluetooth maintenance architecture, the casing has no physical buttons or debugging openings, fully preserving the IP68 waterproof and intrinsically safe explosion-proof airtight structure. The magnetic unit consumes zero power in sleep mode, and Bluetooth is completely powered off under normal conditions, only activating encrypted point-to-point Bluetooth communication upon magnetic triggering. Parameter modification, sensor calibration, historical data retrieval, and fault log retrieval can be completed in a network-disconnected environment underground without disassembling the casing, completely avoiding the risk of electrical sparks igniting flammable gases inside the well, a risk associated with traditional terminal debugging methods.

[0109] 3. Intrinsically safe graded power supply with multiple protections, meeting explosion-proof requirements for high-risk environments;

[0110] Powered by a 3.7V explosion-proof battery, it features multiple intrinsically safe protections including current limiting, voltage limiting, temperature control, and short-circuit self-locking, meeting the ExicIIAT3Gc intrinsically safe explosion-proof standard. It includes a 55℃ over-temperature power-off interlock and battery charging current limiting protection, enabling hardware power-off interlocking in case of overcurrent or over-temperature faults. Each sensor's 12V output has independent short-circuit protection, ensuring that a single sensor short circuit will not cause a complete power outage. In sleep mode, all high-voltage circuits can be disconnected, and there are no long-term energized high-voltage components inside the casing, mitigating the risks of sparking, overheating, spontaneous combustion, and explosion at the power supply level.

[0111] 4. Graded ultra-low power consumption control, long battery life, suitable for long-term maintenance-free operation;

[0112] The software features three power consumption modes: normal operation, timed data acquisition and wake-up, and deep sleep. Deep sleep consumes ≤6μA of current. All peripherals support controlled power-on and power-off during sleep. The 485, Bluetooth, 4G, and local storage modules are all powered off during non-working periods, retaining only the RTC timing and magnetic wake-up detection. The RTC achieves a 15-minute timed wake-up for data acquisition, significantly reducing the overall static power consumption and enabling years of maintenance-free battery-powered operation underground.

[0113] 5. Data fault tolerance calibration ensures accurate and reliable monitoring data under complex operating conditions;

[0114] Built-in multi-point mean filtering and temperature compensation calibration algorithms can eliminate sampling errors caused by changes in underground temperature and humidity, line loss, instantaneous fluctuations in the pipeline network, and vibration disturbances of the manhole cover; it can distinguish between single disturbance anomalies and real pipeline faults, and filter false alarms; in the case of network outage, it locally caches all monitoring data in a large capacity, and after the network is restored, it retransmits the data in chronological order to avoid data loss caused by the weak signal environment underground and ensure the integrity of monitoring data.

[0115] 6. The integrated housing combines IP68 deep-water waterproofing with intrinsically safe explosion-proof performance;

[0116] The housing is integrally injection molded without any seams or exposed mechanical switches. Only IP68 explosion-proof aviation-grade sealed terminals are exposed externally, automatically locking in an airtight manner after insertion, allowing for long-term immersion in water up to 2 meters deep. This resolves the contradiction between the low waterproof rating of traditional explosion-proof equipment and the inability of high-level waterproof equipment to meet intrinsically safe airtight requirements, while also meeting the protection needs of water accumulation and flammable / explosive pipeline wells.

[0117] 7. Cloud-local two-way interaction, closed-loop fault management, and convenient operation and maintenance;

[0118] It supports remote parameter modification, remote wake-up, and remote fault reset via the cloud, as well as local Bluetooth debugging. The whole machine monitors temperature, current, and communication status in real time. After a fault occurs, it implements hardware and software interlocks, stores fault information locally, and reports alarms. The device is prohibited from starting until the fault is eliminated, forming an integrated explosion-proof closed-loop protection system for temperature, power supply, and communication, which facilitates fault tracing and troubleshooting by maintenance personnel. Attached Figure Description

[0119] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0120] Figure 1 This is a circuit diagram of the main control circuit unit in this invention;

[0121] Figure 2 This is a circuit diagram of the three-channel isolated RS485 communication unit in this invention;

[0122] Figure 3 This is a circuit diagram of the sealed Bluetooth maintenance unit in this invention;

[0123] Figure 4 This is a circuit diagram of the data acquisition unit in this invention;

[0124] Figure 5 This is a circuit diagram of the magnetic passive wake-up unit in this invention;

[0125] Figure 6 This is a circuit diagram of the intrinsically safe explosion-proof power supply unit in this invention;

[0126] Figure 7 This is a circuit diagram of the local storage unit in this invention. Detailed Implementation

[0127] An embodiment of an intrinsically safe, explosion-proof, IP68 waterproof, multi-channel RS485 pipeline telemetry terminal includes an integrated explosion-proof sealed housing, a main control circuit unit, a three-channel isolated RS485 communication unit, a sealed Bluetooth maintenance unit, a data acquisition unit, a magnetic passive wake-up unit, an intrinsically safe explosion-proof power supply unit, a local storage unit, and a 4G / NB-IoT wireless module. The main control circuit unit connects to the three-channel isolated RS485 communication unit, the sealed Bluetooth maintenance unit, the data acquisition unit, the magnetic passive wake-up unit, the local storage unit, and the 4G / NB-IoT wireless module. The 4G / NB-IoT wireless module connects to the cloud. The intrinsically safe explosion-proof power supply unit is used to power each unit.

[0128] The integrated explosion-proof sealed housing is injection molded from special ABS engineering plastic, with the outer wall treated with electrostatic anti-corrosion spraying, and has no gaps between the parts. The entire housing has passed ExicIIAT3Gc intrinsically safe explosion-proof certification and IP68 protection level certification, and can be immersed in water at a depth of 2m for long-term operation. The outer side of the housing is printed with magnetic positioning marks, and there are no physical buttons, DIP switches, or debugging openings. Only IP68-level explosion-proof aviation sealed terminals are reserved for external sensors, eliminating the risk of explosion caused by opening the cover from the physical structure.

[0129] The main control circuit unit is the core control hub of the whole machine, equipped with a low-power main control chip; it completes the initialization of system clock, various peripheral buses, and IO ports; schedules the operation of all functional units, performs multi-channel 485 time-division acquisition, data processing and filtering, fault judgment, power management, and explosion-proof logic control; drives status indicator lights to reflect the equipment's operating status, and relies on an independent RTC clock to achieve sleep timed wake-up.

[0130] The three-channel isolated RS485 communication unit provides three electrically isolated RS485 communication channels, which are respectively connected to the electromagnetic flowmeter, pressure level transmitter, and combustible gas / water quality probe. Each channel has independent lightning protection and current limiting protection, and supports independent baud rate configuration. It realizes asynchronous time-sharing acquisition of multiple instruments, and the failure of a single channel does not affect each other. It also provides a debugging signal channel to complete the serial port signal switching isolation.

[0131] The sealed Bluetooth maintenance unit enables local downhole maintenance without openings in the housing; it is powered on under controlled conditions and completely powered off during sleep; it enables encrypted Bluetooth communication after magnetic wake-up; it completes bidirectional data transmission between the mobile phone and the main controller, supporting the reading of historical data, modification of equipment parameters, sensor calibration, and retrieval of fault logs; it automatically powers off after timeout to avoid radio frequency interference and unnecessary power consumption.

[0132] The data acquisition unit collects internal temperature and humidity, as well as equipment vibration / attitude information. Temperature and humidity data are used for sensor temperature drift compensation and internal over-temperature explosion-proof determination. Attitude and vibration data identify manhole cover disturbances and equipment displacement, assist in filtering sampling anomalies, avoid false alarms, and provide raw detection signals for the whole machine's explosion-proof closed loop and data fault tolerance.

[0133] The magnetic passive wake-up unit adopts a passive dual-path magnetic trigger detection module; it does not increase sleep power consumption; the external magnet is attached to the shell to generate a hardware wake-up interrupt and transmits the wake-up signal to the main controller; the dual signal verification filters out false triggers caused by vibration and stray magnetic fields, and serves as the start trigger source for Bluetooth operation and maintenance.

[0134] The intrinsically safe explosion-proof power supply unit takes a 3.7V explosion-proof lithium battery as input and generates multiple operating power levels of 3.3V, 4V, and 12V; it provides intrinsically safe power supply to all modules of the whole machine; it has current limiting, voltage limiting, charging current limiting, and short circuit protection; the 12V output of each sensor can be independently controlled to switch on and off; it receives temperature signals to realize over-temperature power-off interlocking, meeting the ExicIIAT3Gc explosion-proof standard.

[0135] The local storage unit operates under controlled power-on conditions; it is divided into parameter area, data cache area, and fault log area; it saves device configuration and calibration parameters when power is off; it caches monitoring data packets when the network is disconnected and performs breakpoint retransmission after the network is restored; it stores fault alarm records and supports local reading of historical monitoring and fault data.

[0136] The 4G / NB-IoT wireless module establishes a wireless communication link between the terminal and the cloud platform; uploads monitoring data and fault alarms; enables remote parameter distribution, remote wake-up, and remote reset from the cloud; has a graded disconnection and reconnection mechanism; ensures data upload in the weak signal environment underground; and completes two-way interaction between the terminal and the cloud.

[0137] like Figure 1 As shown, the main control circuit unit includes chip U13, which is an STM32L151RET6. Pin 20 of chip U13 is connected to pin 4 of common anode LED indicator LED1, pin 21 of chip U13 is connected to pin 3 of common anode LED indicator LED1, pin 22 of chip U13 is connected to pin 1 of common anode LED indicator LED1, and pin 2 of common anode LED indicator LED1 is connected to one end of resistor R43. The other end of resistor R43 is connected to a 3.3V power supply.

[0138] Pin 4 of chip U13 is connected to one end of crystal oscillator Y1 and one end of capacitor C29. Pin 3 of chip U13 is connected to the other end of crystal oscillator Y1 and one end of capacitor C28. The other end of capacitor C28 and the other end of capacitor C29 are grounded. Pin 6 of chip U13 is connected to one end of crystal oscillator Y2 and one end of capacitor C31. Pin 5 of chip U13 is connected to the other end of crystal oscillator Y2 and one end of capacitor C30. The other end of capacitor C30 and the other end of capacitor C31 are grounded.

[0139] Pin 9 of the chip U13 is connected to the base of transistor Q20. The emitter of transistor Q20 is grounded. The collector of transistor Q20 is connected to one end of resistor R57 and the gate of MOSFET Q19. The other end of resistor R57 and the drain of MOSFET Q19 are connected to one end of resistor R58. The other end of resistor R58 is connected to pin 10 of chip U13, one end of diode D10 and one end of resistor R59. The other end of diode D10 and the other end of resistor R59 are grounded.

[0140] The core device of the main control circuit unit is the STM32L151RET6 main control chip U13, which is the core of the main machine's logic operation, peripheral scheduling, and explosion-proof safety control. It includes four parts: clock sub-circuit, status indicator sub-circuit, peripheral switch driver sub-circuit, and power supply filter and reset sub-circuit.

[0141] Clock sub-circuit: Pins 3 and 4 of chip U13 are connected to the main crystal oscillator Y1, with matching start-up capacitors C28 and C29 grounded; Pins 5 and 6 of chip U13 are connected to the RTC high-precision crystal oscillator Y2, with matching start-up capacitors C30 and C31 grounded; The two crystal oscillators work independently. The main crystal oscillator supports the whole machine's data acquisition and communication operations, while the RTC crystal oscillator continues to keep time during the device's deep sleep mode, ensuring the accuracy of timed acquisition, delayed sleep, and fault timing determination, and avoiding timing offsets caused by downhole temperature and humidity fluctuations.

[0142] Status indicator sub-circuit: Pins 20, 21, and 22 of chip U13 are connected to pins 4, 3, and 1 of common anode tri-color LED indicator LED1, respectively; pin 2 of LED1 is connected to a 3.3V power supply after being connected in series with current-limiting resistor R43; the main controller drives the LED to output red, green, and yellow lights by outputting different pin level combinations, distinguishing four operating conditions: device sleep, data acquisition, wireless networking, and fault lockout, so that the device operating status can be intuitively identified without opening the cover.

[0143] Peripheral switch driver sub-circuit: Pin 9 of chip U13 is connected to the base of transistor Q20, and the emitter of transistor Q20 is grounded; the collector of transistor Q20 is connected to the gate of MOSFET Q19 through resistor R57; the drain of MOSFET Q19 is connected to pin 10 of chip U13, diode D10, and resistor R59 after being connected in series with resistor R58, and the other end of diode D10 and resistor R59 is grounded; the main controller outputs high and low levels through pin 9 to control the on and off of transistor Q20 and MOSFET Q19, and cuts off the power supply to the subsequent peripherals in a time-division multiplexing manner to achieve graded ultra-low power sleep mode; diode D10 absorbs the reverse electromotive force of MOSFET to prevent pulse high voltage from damaging the main controller IO pin.

[0144] Power supply filtering and reset sub-circuit: The power supply circuit is equipped with a magnetic bead L2 and multiple sets of filter capacitors C33~C38 to form an LC filter network, which separates the power supply areas of digital circuits and analog circuits, and suppresses the interference of downhole electromagnetic noise on pressure and flow analog sampling; an independent reset interface H2 and an RC anti-jitter circuit are configured to eliminate the main control false reset and communication abnormality caused by power supply ripple and equipment vibration.

[0145] Overall scheduling logic: The main controller manages three RS485 time-sharing acquisition, magnetic wake-up interrupt signal recognition, Bluetooth module power-on / power-off control, temperature and vibration data sampling, Flash storage read and write, 4G / NB-IoT network transmission, and explosion-proof hardware power-off interlocking through GPIO, SPI, I2C, and multi-channel serial bus. It also has internally fixed average filtering, time-sharing and transceiver scheduling, multi-level fault judgment, and temperature control power-off control algorithms.

[0146] The main control circuit unit is adapted to an intrinsically safe, low-voltage, low-power architecture: it uses an STM32L series ultra-low-power MCU, with a deep sleep current of ≤6μA, and is natively matched to the 3.7V single-cell lithium battery intrinsically safe power supply standard; it avoids the defects of existing 7.4V dual-series lithium battery terminal multi-stage buck-boost circuits, such as high power consumption, large heat generation, and exceeding intrinsically safe energy limits; digital-analog power supply hardware isolation: ferrite beads + multi-stage capacitor filter network isolate digital circuit interference, solving the problems of traditional RTUs lacking independent filtering, electromagnetic interference from downhole frequency converters causing large fluctuations in sampling data, and frequent false alarms; independent RTC hardware timing: sleep mode The system provides continuous and stable timing, with no errors in timed data acquisition, sleep mode, or power-off logic. Existing equipment relies on a main crystal oscillator for timing, which stops working after sleep mode, causing disordered data acquisition cycles. It features a three-color LED transparent display, eliminating the need for indicator lights or button holes in the explosion-proof housing and fully preserving the IP68 airtight waterproof and intrinsically safe explosion-proof sealing structure. Traditional equipment exposes its operation and indicator structures, compromising the housing's sealing performance. Hardware-level power-off control allows for independent disconnection of power to 485 communication, Bluetooth, and storage peripherals, reducing internal temperature rise within the sealed housing and meeting ExicIIAT3 explosion-proof temperature rise constraints.

[0147] like Figure 2As shown, the three-channel isolated RS485 communication unit includes chips U2, U4, U5, and U8. Chips U2, U4, U5, and U8 are SP3485. Pin 1 of chip U2 is connected to pin 17 of chip U13. Pins 2 and 3 of chip U2 are connected to one end of resistor R19 and pin 15 of chip U13. The other end of resistor R19 is grounded. Pin 4 of chip U2 is connected to pin 16 of chip U13. Pin 6 of chip U2 is connected to one end of fuse F5, TVS diode array D1, and resistor R8. Pin 1 of IP68 explosion-proof aviation sensor terminal CN1 is connected to pin 7 of chip U2, which is connected to one end of fuse F4, TVS diode array D1, the other end of resistor R8, and pin 2 of IP68 explosion-proof aviation sensor terminal CN1. Pin 8 of chip U2 is connected to one end of capacitor C12, and the other end of capacitor C12 is grounded. Pin 1 of chip U4 is connected to pin 52 of chip U13. Pins 2 and 3 of chip U4 are connected to one end of resistor R24 ​​and pin 50 of chip U13, and the other end of resistor R24 ​​is grounded. Pin 4 of chip U4 is connected to pin 50 of chip U13. Pin 1 of chip U4, pin 6, is connected to one end of fuse F7, TVS diode array D3, one end of resistor R23, and pin 1 of IP68 explosion-proof aviation sensor terminal CN2. Pin 7 of chip U4 is connected to one end of fuse F6, the other end of TVS diode array D3, resistor R23, and pin 2 of IP68 explosion-proof aviation sensor terminal CN2. Pin 8 of chip U4 is connected to one end of capacitor C15, and the other end of capacitor C15 is grounded. Pin 1 of chip U5 is connected to pin 54 of chip U13. Pins 2 and 3 of chip U5 are connected to resistor R27. Pin 4 of chip U5 is connected to pin 53 of chip U13. Pin 6 of chip U5 is connected to one end of fuse F9, one end of TVS diode array D4, one end of resistor R26, and pin 1 of IP68 explosion-proof aviation sensor terminal CN3. Pin 7 of chip U5 is connected to one end of fuse F8, one end of TVS diode array D4, the other end of resistor R26, and pin 2 of IP68 explosion-proof aviation sensor terminal CN3. Pin 8 of chip U5 is connected to one end of capacitor C18, and the other end of capacitor C18 is grounded.

[0148] Pins 2 and 3 of chip U8 are connected to one end of resistor R31, and the other end of resistor R31 is grounded. Pin 1 of chip U8 is connected to pin 1 of chip U10. Pin 4 of chip U8 is connected to pin 12 of chip U10. The model of chip U10 is 74HC4052D. Pin 6 of chip U8 is connected to pin 5 of TVS diode array D5 and IP68 explosion-proof aviation sensor terminal CN1. Pin 7 of chip U8 is connected to pin 6 of TVS diode array D5 and IP68 explosion-proof aviation sensor terminal CN1. Pin 8 of chip U8 is connected to one end of capacitor C25 and connected to V485 power supply. The other end of capacitor C25 is grounded.

[0149] The three-way isolated RS485 communication unit includes three SP3485 transceiver chips U2, U4, and U5, an SP3485 chip U8 for debugging, and a 74HC4052D multi-channel analog switch chip U10. Chips U2, U4, and U5 correspond to three sets of IP68 explosion-proof aviation sensor terminals CN1, CN2, and CN3, respectively. The three buses are electrically isolated and equipped with independent lightning protection, current limiting, and terminal matching circuits.

[0150] Single-channel 485 standard circuit: Pins 1 (TXD), 2 / 3 (DE / RE transmit / receive enable), and 4 (RXD) of each SP3485 chip are independently connected to the dedicated IO pins of the main controller U13; the transmit / receive enable pin is grounded in series with resistors R19, R24, and R27 to stabilize the bus idle level; pins 6 and 7 of the chip are the A and B signal terminals of the 485 bus, which are connected in series with self-resetting fuses F4~F9, TVS diode array D1 / D3 / D4, and 120Ω terminating matching resistors R8 / R23 / R26 before being connected to the aviation terminal; the power supply pin of chip 8 is grounded in parallel with filter capacitors C12 / C15 / C18; the three 485 chips are uniformly powered by MOSFET Q2, and the main controller can synchronously or individually cut off the power supply of a single communication channel.

[0151] Three-channel differentiated hardware adaptation logic: Chip U2 corresponds to the CN1 channel for electromagnetic flowmeters, with hardware support for 115200bps high-speed baud rate and 500ms high-frequency polling transmission and reception; Chip U4 corresponds to the CN2 channel for pressure and level transmitters, with enhanced analog signal reception filtering and 1s low-frequency steady-state sampling; Chip U5 corresponds to the CN3 channel for combustible gas and SS water quality probes, with added fault-tolerant receiving circuit, 2s low-speed polling and support for abnormal data marking and storage.

[0152] Debugging channel and signal switching circuit: Chip U8 is a backup debugging 485 channel, and the bus end is equipped with TVS array D5 for surge protection; the serial port signal of U8 is connected to the multi-channel analog switch U10, and U10 switches between Bluetooth serial port, debugging 485, and three-channel acquisition 485 signals in a time-division manner to achieve hardware isolation of multiple serial ports and avoid bus contention and data packet crosstalk.

[0153] Three-way completely independent communication: Existing pipeline RTUs only have 1-2 channels sharing the 485 bus. When multiple sensors are connected in parallel, address conflicts and bus crosstalk are likely to occur. This solution has three independent opto-isolation channels, independent power supply, and independent surge protection. If a single bus is short-circuited or struck by lightning, only the fuse of that channel will blow, while the other two channels will continue to communicate normally. Faults will not cause the entire unit to shut down.

[0154] Hardware-level time-sharing isolation: Each channel is configured with independent transmit and receive buffers and independent enable pins. At the hardware level, "single transmit and single receive, transmit again after receiving" scheduling is implemented, which completely solves the shortcomings of traditional single bus relying solely on software time-sharing, data packet loss under strong interference, and serial number errors.

[0155] Triple intrinsically safe bus protection: self-resetting fuse current limiting, TVS array voltage limiting, 120Ω terminal impedance matching, strictly limiting the maximum energy of bus faults, in compliance with Exic intrinsically safe explosion-proof energy constraints; conventional 485 circuits are only equipped with simple TVS, and the instantaneous large current during short circuits can easily generate electric sparks, making them unsuitable for high-risk well chambers such as those for gas or sewage.

[0156] The hardware-adaptive sensor features for each channel are optimized: the drive circuits are optimized for flow meters, pressure transmitters and gas probes respectively, eliminating the need for a unified acquisition cycle and baud rate, and reducing the overall power consumption caused by high-frequency polling of low-speed probes; traditional equipment has completely identical hardware for three 485 channels, resulting in high power consumption and poor compatibility.

[0157] Controllable power-off of peripherals: When there is no data acquisition task, the power supply of a single or all 485 circuits can be cut off to eliminate static heating of the bus and reduce the safety hazards of explosion-proof enclosure.

[0158] like Figure 3 As shown, the sealed Bluetooth maintenance unit includes a chip U9, model BLE-SER-A-ANT. Pin 2 of chip U9 is connected to the drain (D) of MOSFET Q9. The gate (G) of MOSFET Q9 is connected to one end of resistor R15 and one end of resistor R14. The other end of resistor R15 and the source (S) of MOSFET Q9 are connected to a 3.3V power supply. The other end of resistor R14 is connected to the collector of transistor Q10. The emitter of transistor Q10 is grounded. The base of transistor Q10 is connected to pin 27 of chip U13. Pin 4 of chip U9 is connected to one end of resistor R35. The other end of resistor R35 is connected to pin 20 of chip U13. Pin 7 of chip U9 is connected to pin 5 of chip U10. Pin 8 of chip U9 is connected to pin 14 of chip U10. Chip U10 is model 74HC4052D.

[0159] The core component of the sealed Bluetooth maintenance unit is the BLE-SER-A-ANT type Bluetooth communication chip U9. It adopts a normal complete power-off and magnetic wake-up controlled power-on architecture. The housing has no debugging openings, enabling local parameter configuration and historical data reading in a sealed underground environment.

[0160] Bluetooth module controlled power supply circuit: Pin 27 of the main controller U13 is connected to the base of transistor Q10, and the emitter of transistor Q10 is grounded; the collector of transistor Q10 is connected to the gate of MOSFET Q9 through voltage divider resistor R14, and the source of MOSFET Q9 is connected to a 3.3V power supply through pull-up resistor R15. The drain outputs BLE_VCC to pin 2 of Bluetooth chip U9; when the device is in normal sleep mode, the main controller outputs a low level, transistor Q10 and MOSFET Q9 are cut off, the Bluetooth module is completely powered off, there is no radio frequency broadcast, and no static power consumption; after magnetic trigger wake-up, the main controller outputs a high level to turn on MOSFET Q9 and transistor Q10, and initializes the Bluetooth module for power-on.

[0161] Serial communication isolation switching circuit: Bluetooth chip U9 pins 7 (TXD) and 8 (RXD) are connected to the multi-channel analog switch U10, which is used by the main controller to switch the communication channel between Bluetooth and the main controller in a time-division manner. The Bluetooth RF signal is hardware isolated from the three 485 buses. Chip U9 pin 4 is connected in series with current limiting resistor R35 to the main controller LED status pin to provide real-time feedback on the Bluetooth data interaction status.

[0162] Timeout power-off linkage logic: After the magnetic Bluetooth is woken up, if there is no bidirectional data interaction for 30 seconds, the main controller will lock the communication port; after the magnetic tag is removed, the main controller will automatically turn off the MOS transistor Q9 after 60 seconds, cut off the Bluetooth power supply, and the device will return to deep sleep mode.

[0163] Maintenance without opening the cover, fully preserving the explosion-proof IP68 protection performance: Traditional terminal on-site debugging requires opening the cover or creating an external serial port opening. Opening the cover damages the explosion-proof airtight structure, and opening the port reduces the waterproof rating. The risk of electrical sparks during maintenance in underground water accumulation and flammable and explosive gas environments is extremely high. This solution has a completely sealed shell and Bluetooth debugging can be started by relying solely on external magnetic attraction.

[0164] Bluetooth module with zero static power consumption in sleep mode: It is completely powered off under normal conditions, with no RF standby power consumption, and is compatible with 3.7V small-capacity explosion-proof lithium batteries, requiring no maintenance for a long time; Existing devices are constantly powered by Bluetooth, with standby current reaching tens of milliamps, and battery life is only a few months.

[0165] Hardware isolation for serial port interference suppression: The Bluetooth radio frequency is isolated from the 485 acquisition bus by a 74HC4052 analog switch to avoid Bluetooth noise interference with flow and gas sampling accuracy; ordinary terminals share the serial port with Bluetooth and 485, which causes mutual interference and frequent sampling errors.

[0166] Encrypted point-to-point connection + timeout interlock: Encrypted broadcasting is only enabled after magnetic wake-up, preventing unfamiliar devices from tampering with device parameters; automatic power-off when there is no operation, eliminating long-term radio frequency interference to network monitoring; traditional Bluetooth devices broadcast permanently, making them vulnerable to unauthorized connection and threshold modification by external devices.

[0167] Offline full-function local debugging: In environments without external network access underground, historical stored data can be read offline, 485 baud rate can be modified, sensor coefficients can be calibrated, and over-limit alarm thresholds can be set; traditional RTUs only support remote configuration in the cloud, and cannot be debugged on-site after network outage underground.

[0168] like Figure 4As shown, the data acquisition unit includes chip U12, model ADXL345BCCZ-RL7. Pin 1 of chip U12 is connected to 3.3V. Pin 6 of chip U12 is connected to one end of resistor R42, and the other end of resistor R42 is connected to 3.3V. Pin 7 of chip U12 is connected to one end of resistor R41, and the other end of resistor R41 is connected to 3.3V. Pin 8 of chip U12 is connected to pin 2 of chip U13. Pin 12 of chip U12 is connected to one end of resistor R45, and the other end of resistor R45 is grounded. Pin 13 of chip U12 is connected to one end of resistor R39 and pin 59 of chip U13. Pin 14 of chip U12 is connected to one end of resistor R38 and pin 58 of chip U13.

[0169] The data acquisition unit also includes chip U14, model AHT20_C2757850. Pin 2 of chip U14 is connected to one end of resistor R48 and one end of capacitor C32. The other end of resistor R48 is connected to VCC_MCU power supply, and the other end of capacitor C32 is grounded. Pin 3 of chip U14 is connected to one end of resistor R49 and pin 61 of chip U13. Pin 4 of chip U14 is connected to one end of resistor R50 and pin 62 of chip U13. The other ends of resistor R49 and resistor R50 are connected to VCC_MCU power supply.

[0170] The data acquisition unit includes an ADXL345BCCZ-RL7 triaxial accelerometer chip U12 and an AHT20 temperature and humidity chip U14. Both are connected to chip U13 via I2C communication to collect real-time data on the internal environment and device attitude, providing basic parameters for explosion-proof protection and sampling data compensation.

[0171] Attitude acquisition sub-circuit (U12): Pin 1 of chip U12 is connected to a 3.3V power supply; pins 6 and 7 are connected in series with pull-up resistors R42 and R41 to 3.3V respectively; SDA and SCL communication pins 13 and 14 are connected to pins 59 and 58 of chip U13 through current-limiting resistors R39 and R38; INT1 interrupt pin 12 is connected in series with pull-down resistor R45 to ground; the chip acquires equipment vibration and tilt signals in real time to identify manhole cover disturbances and equipment displacement and trigger alarms, and at the same time uses vibration data to perform fault-tolerant filtering on the 485 instantaneous fluctuation sampling value.

[0172] Temperature and humidity acquisition sub-circuit (U14): The power supply pin 2 of chip U14 is connected in series with current limiting resistor R48 and filter capacitor C32 to VCC_MCU; SCL and SDA pins 3 and 4 are connected in series with pull-up resistor R49 and resistor R50 respectively to the main control U13 pins 61 and 62; the chip continuously acquires the temperature and humidity inside the shell, which is used by the main control to perform temperature drift compensation for pressure and water quality sensors, and when the temperature inside the shell exceeds 55℃, it triggers the intrinsically safe explosion-proof power supply unit to shut down and lock the whole machine, eliminating the high temperature explosion-proof hazard.

[0173] Dual-dimensional monitoring constructs an explosion-proof closed-loop control: Traditional pipeline terminals only collect external pipeline medium data, without monitoring the internal temperature and vibration of the casing, and cannot provide early warning of battery overheating or equipment tilting and displacement; this solution monitors the casing temperature rise in real time, and automatically cuts off the power supply to the whole machine when the temperature exceeds the limit, forming a hardware explosion-proof protection closed loop.

[0174] Standardized I2C resistor-capacitor circuit ensures stable and reliable sampling: The sensor bus is equipped with independent current limiting, pull-up, and filtering components, ensuring no data loss during I2C communication in high humidity and strong electromagnetic environments underground; Ordinary terminals simplify the sensor's peripheral circuitry, resulting in frequent fluctuations in temperature and humidity data and insufficient monitoring accuracy.

[0175] Attitude detection auxiliary data fault-tolerant filtering: When the equipment vibrates or tilts, instantaneous abnormal sampling values ​​are automatically removed to avoid false alarms caused by manhole cover disturbance or water flow impact; existing equipment lacks vibration recognition logic, and instantaneous data fluctuations are very likely to report false over-limit alarms.

[0176] Temperature compensation improves the accuracy of medium monitoring: After the main controller reads the internal temperature, it automatically corrects the temperature drift error of the pressure and SS water quality sensors, significantly reducing the measurement error under high and low temperature conditions; traditional terminals have no temperature compensation mechanism, and the measurement error exceeds the standard in extreme temperature and humidity environments.

[0177] The unified 3.3V low-voltage power supply complies with intrinsic safety standards: Both sensors operate at a safe low voltage of 3.3V and have no high-voltage heating elements; some existing terminals use 5V sensors, and the temperature rise exceeds the standard after adding a boost circuit, posing an explosion-proof safety hazard.

[0178] like Figure 5 As shown, the magnetic passive wake-up unit includes a magnetron S1 and a magnetron S2. One end of the magnetron S1 is connected to one end of a resistor R51 and pin 38 of the chip U13, and the other end of the resistor R51 is grounded. The other end of the reed magnetron S1 is connected to one end of a resistor R46, and the other end of the resistor R46 is connected to 3.3V. One end of the reed magnetron S2 is connected to one end of a resistor R52 and pin 28 of the chip U13, and the other end of the resistor R52 is grounded. The other end of the reed magnetron S2 is connected to one end of a resistor R47, and the other end of the resistor R47 is connected to 3.3V.

[0179] The magnetic passive wake-up unit includes two normally open reed magnetrons S1 and S2 (model MKA-14103), which are passive dual-path trigger detection circuits. There is no current consumption during the device's sleep phase, enabling the Bluetooth maintenance channel to be woken up without opening the cover.

[0180] The single-channel magnetron circuit structure is completely identical: one end of the reed magnetron is connected to a 3.3V power supply via 1kΩ pull-up resistors R46 and R47; the other end is grounded via 100kΩ pull-down resistors R51 and R52, and the KEY_MAG and KEY_BLE signals are led out and connected to pins 38 and 28 of the main control U13, respectively.

[0181] When there is no external magnetic attachment, the reed magnetron is physically disconnected, the main control IO pin is pulled down to a low level, and there is no wake-up interrupt signal; when the external magnet is attached to the magnetic marking on the housing, the reed magnetron is passively turned on, the IO pin is pulled up to a 3.3V high level, and a hardware wake-up interrupt is output to the main control.

[0182] The two magnetic control signals adopt dual verification logic, and a single reed magnetron mis-connection will not trigger the whole machine to wake up; hardware resistors and capacitors are combined with software delay anti-jitter to filter out instantaneous false triggers caused by well water flow vibration and stray magnetic field of motor.

[0183] After receiving the wake-up interrupt, the main controller sequentially performs the following actions: powering on the Bluetooth module, unlocking local storage read / write, and opening the local parameter debugging channel. After the magnetic tag detaches from the casing, the countdown automatically cuts off the Bluetooth power supply, and the entire device returns to deep sleep mode.

[0184] Passive triggering with zero power consumption: The reed magnetron is a purely mechanical passive switch with no conduction current in the sleep state and only microampere-level leakage current for the whole device; existing devices use Hall sensors and physical buttons, with Hall sensors continuously polling and buttons energized and voltage divided, which greatly increases standby power consumption.

[0185] No exposed mechanical structure, and the shell is completely sealed: there are no buttons, DIP switches, or touch windows. The shell is integrally injection molded without openings and can support long-term immersion in water up to 2m deep; there is no risk of mechanical friction and ignition in the underground combustible gas environment; traditional equipment has external operation buttons, and debugging requires opening the cover, which directly damages the explosion-proof sealing airtight layer.

[0186] Dual-channel magnetic redundancy prevents false wake-up: Two independent reed magnetron signals are verified, and the alternating magnetic field and water flow vibration in the well cannot trigger wake-up on their own; the single-channel magnetic attraction scheme is easily affected by external magnetic field interference, which frequently starts Bluetooth and accelerates battery consumption.

[0187] Sealed reed magnetrons are suitable for high-humidity well chambers: Glass-encapsulated reed magnetrons are waterproof and moisture-proof, eliminating the risk of oxidation and failure of metal contacts; traditional thin films and touch buttons are prone to leakage and malfunction in high-humidity condensation environments downhole.

[0188] Power-free, closed-loop operation and maintenance: No need to disassemble the casing or disconnect the sensor power supply. The entire operation is closed in a high-risk environment downhole, eliminating the risk of electric sparks igniting flammable gases in the well when the cover is opened.

[0189] like Figure 7As shown, the local storage unit includes chip U11, model number MX25L2564GM21-08G. Pin 1 of chip U11 is connected to pin 33 of chip U13, pin 2 of chip U11 is connected to pin 35 of chip U13, pin 5 of chip U11 is connected to pin 36 of chip U13, pin 6 of chip U11 is connected to pin 34 of chip U13, pin 3 of chip U11 is connected to one end of resistor R32, pin 7 of chip U11 is connected to one end of resistor R34, and the other end of resistor R34... One end is connected to pin 8 of chip U11 and one end of capacitor C27. The other end of capacitor C27 is grounded. Pin 8 of chip U11 and the other end of resistor R32 are connected to the drain of MOSFET Q13. The gate of MOSFET Q13 is connected to one end of resistor R33 and one end of resistor R36. The source of MOSFET Q13 and the other end of resistor R33 are connected to a 3.3V power supply. The other end of resistor R36 is connected to the collector of transistor Q15. The emitter of transistor Q15 is grounded. The base of transistor Q15 is connected to pin 37 of chip U13.

[0190] The core storage chip of the local storage unit is the MX25L2564GM21-08G SPIFlash chip U11, which is used for network outage caching of network monitoring data, permanent storage device calibration parameters, and fault logs. It adopts a controlled power-on architecture to reduce static power consumption.

[0191] SPI communication sub-circuit: Pins 1 (SPI_NSS), 2 (SPI_MISO), 5 (SPI_SCK), and 6 (SPI_MOSI) of chip U11 are connected to pins 33, 35, 36, and 34 of chip U13 respectively to realize high-speed data read and write; pin 3 is connected in series with pull-up resistor R32 as a write protection control terminal; pin 7 is configured with pull-up resistor R34 and filter capacitor C27 to stabilize the chip power supply level.

[0192] Controlled power switch circuit: MOSFET Q13 is the main power switch for the Flash chip. The 3.3V power supply provides Vflash power to U11 through the drain of MOSFET Q13. Pin 37 of chip U13 is connected to the base of transistor Q15. The collector of transistor Q15 is connected to the gate of MOSFET Q13 through voltage divider resistor R36. Resistor R33 is the gate pull-up resistor. When the device is in deep sleep mode, the main control outputs a low level to turn off MOSFET Q13, and the Flash chip is completely powered off, eliminating static leakage current.

[0193] Data storage and interaction logic: In the event of a 4G / NB-IoT network outage, the flow, pressure, liquid level, gas, and temperature / vibration data collected by the three channels of RS-485 are timestamped and stored in Flash; in Bluetooth local operation and maintenance mode, all historical cached data can be read; after the network is restored, the main controller retransmits the data in chronological order, with no data loss or duplicate uploads; the device sensor calibration coefficients, alarm thresholds, and collection cycles are permanently stored in Flash, and the parameters are not lost after the entire device is powered off.

[0194] Controlled power-on, hibernation, and power-off reduce power consumption and casing temperature rise: Traditional Flash chips are constantly powered, and during hibernation, they continuously consume power and generate heat; this solution only powers on briefly for data acquisition, cloud upload, and Bluetooth debugging, and is completely powered off at other times, improving battery life by more than 30%, reducing the number of heat sources inside the sealed casing, and meeting the explosion-proof temperature rise limit.

[0195] 256Mbit large-capacity offline cache, zero data loss: The large-capacity Flash supports complete storage of all monitoring data underground for several days without external network access, and orderly retransmission of interrupted data after network connection; traditional terminals have small storage capacity, and historical pipeline data is overwritten after a few hours of network outage, resulting in permanent loss of monitoring records.

[0196] Independent SPI bus communication, without occupying 485 acquisition resources: Storage read and write use an independent SPI hardware bus, which is physically isolated from three RS485 channels. Read and write operations will not interfere with the real-time acquisition of the sensor; traditional devices share a serial port or 485 bus for storage modules, which causes acquisition lag and data packet loss during read and write.

[0197] Low heat generation compatible with sealed explosion-proof housing: Flash only works for short periods and is dormant for long periods without being charged, reducing the number of components that continuously generate heat inside the sealed housing; traditional terminal storage chips are continuously charged 24 hours a day, and long-term heat accumulation exacerbates the explosion-proof safety risk.

[0198] Offline local data retrieval: With the help of a sealed Bluetooth maintenance unit, months of historical flow, pressure and gas monitoring data can be read on-site in environments without external network access, without relying on cloud backend queries; traditional terminals only support remote reading from the cloud, and historical records cannot be retrieved after network outages underground.

[0199] like Figure 6As shown, the intrinsically safe explosion-proof power supply unit includes a 12V boost circuit, a 4V boost circuit, a 3.3V circuit, and a 12V power control circuit. The 12V boost circuit includes chip U3, model MT3608. Pin 5 of chip U3 is connected to one end of capacitor C3 and one end of inductor L1, with the other end of capacitor C3 grounded. Pin 1 of chip U3 is connected to the other end of inductor L1 and one end of diode D9. The other end of diode D9 is connected to one end of resistor R1 and one end of capacitor C4, connected in parallel to 12V. The other end of capacitor C4... The circuit is grounded. The other end of resistor R1 is connected to pin 3 of chip U3 and one end of resistor R7. The other end of resistor R7 is grounded. Pin 4 of chip U3 is connected to the base of transistor Q21. The emitter of transistor Q21 is grounded. The collector of transistor Q21 is connected to one end of resistor R16. The other end of resistor R16 is connected to one end of resistor R17 and the gate of MOSFET Q14. The other end of resistor R17 and the source of MOSFET Q14 are connected to VCC-4V power supply. The drain of MOSFET Q14 is connected to pin 5 of chip U3.

[0200] The 4V boost circuit includes a chip U1, model MT3608. Pins 4 and 5 of chip U1 are connected to one end of capacitor C1 and one end of inductor L3, and connected to the VBAT power supply. The other end of capacitor C1 is grounded. The other end of inductor L3 is connected to pin 1 of chip U1 and one end of diode D6. The other end of diode D6 is connected to one end of resistor R13 and one end of capacitor C2, and connected to the VCC_4V power supply. The other end of capacitor C2 is grounded. The other end of resistor R13 is connected to pin 3 of chip U1 and one end of resistor R1. The other end of resistor R1 is grounded.

[0201] The 3.3V circuit includes chip U6, SPX3819M5-L-3-3 / TR. Pins 1 and 3 of chip U6 are connected to one end of capacitor C19 and one end of capacitor C20, respectively, and are connected to VCC_4V power supply. The other ends of capacitor C19 and C20 are grounded. Pin 4 of chip U6 is connected to one end of capacitor C26, and the other end of capacitor C26 is grounded. Pin 5 of chip U6 is connected to one end of capacitor C21 and one end of capacitor C22, respectively, and is connected to 3.3V power supply. The other ends of capacitor C21 and C22 are grounded.

[0202] The 3.3V circuit also includes a MOSFET Q12. The drain of MOSFET Q12 is connected to one end of fuse F11. The other end of fuse F11 is connected to one end of TVS diode U7 and connected to the VBAT power supply. The other end of TVS diode U7 is grounded. The gate of MOSFET Q12 is connected to one end of resistor R30. The other end of resistor R30 is grounded. The source of MOSFET Q12 is connected to one end of capacitor C23, pin 1 of interface CN5, and the drain of MOSFET Q11. The other end of capacitor C23 is grounded. The gate of MOSFET Q11 is connected to one end of resistor R29. The other end of resistor R29 is grounded. The source of MOSFET Q11 is connected to one end of capacitor C24 and the VCHG power supply. The other end of capacitor C24 is grounded.

[0203] The 12V control circuit includes transistor Q5. The base of transistor Q5 is connected to pin 14 of chip U13, the emitter of transistor Q5 is grounded, the collector of transistor Q5 is connected to one end of resistor R9, the other end of resistor R9 is connected to one end of resistor R2 and the gate (G) of MOSFET Q1, the other end of resistor R2 is connected to one end of fuse F1 and the source (S) of MOSFET Q1, the other end of fuse F1 is connected to the 12V power supply, and the drain (D) of MOSFET Q1 is connected to the IP68 explosion-proof aviation sensor terminal CN1. The 3-pin 12V control circuit also includes transistor Q6. The base of transistor Q6 is connected to pin 45 of chip U13, the emitter of transistor Q6 is grounded, the collector of transistor Q6 is connected to one end of resistor R11, the other end of resistor R11 is connected to one end of resistor R4 and the gate (G) of MOSFET Q3, the other end of resistor R4 is connected to one end of fuse F2 and the source (S) of MOSFET Q3, the other end of fuse F2 is connected to the 12V power supply, and the drain (D) of MOSFET Q3 is connected to the IP68 explosion-proof aviation sensor terminal. The CN2 circuit includes a 12V control circuit, specifically pin 3. The base of transistor Q4 is connected to pin 56 of chip U13. The emitter of transistor Q4 is grounded. The collector of transistor Q4 is connected to one end of resistor R12. The other end of resistor R12 is connected to one end of resistor R5 and the gate (G) of MOSFET Q4. The other end of resistor R5 is connected to one end of fuse F3 and the source (S) of MOSFET Q4. The other end of fuse F3 is connected to the 12V power supply. The drain (D) of MOSFET Q4 is connected to an IP68 explosion-proof aviation safety device. The sensor terminal CN3 is pin 3; the 12V control circuit also includes transistor Q7. The base of transistor Q7 is connected to pin 55 of chip U13. The emitter of transistor Q7 is grounded. The collector of transistor Q7 is connected to one end of resistor R10. The other end of resistor R10 is connected to one end of resistor R3 and the gate of MOSFET Q2. The other end of resistor R3 and the source of MOSFET Q2 are connected to a 3.3V power supply. The drain of MOSFET Q2 is connected to pins 8 of chip U2, pins 8 of chip U4, and pins 8 of chip U5.

[0204] The intrinsically safe explosion-proof power supply unit uses a 3.7V explosion-proof lithium battery VBAT as its sole input source. It integrates a 4V boost circuit, a 3.3V LDO intrinsically safe voltage regulator circuit, a 12V sensor boost circuit, and four independent 12V controlled output circuits. The entire link is equipped with multiple protections including current limiting, voltage limiting, temperature control, and short-circuit self-locking, meeting the ExicIIAT3Gc intrinsically safe explosion-proof standard.

[0205] 4V boost circuit (chip U1, MT3608): VBAT lithium battery input is connected to pins 4 and 5 of chip U1, along with input filter capacitor C1 and energy storage inductor L3; pin 1 of chip U1 outputs VCC_4V intermediate power supply after being connected in series with freewheeling diode D6, and the output terminal is connected in parallel with filter capacitor C2; resistors R13 and R1 form a voltage divider feedback loop to stabilize the output voltage; VCC_4V supplies power to low-voltage peripherals such as main control, Bluetooth, storage, temperature and vibration sensors, and the no-load boost power loss is extremely low.

[0206] 3.3V Intrinsically Safe Voltage Regulator Circuit (Chip U6, SPX3819M5-L-3-3 / TR): VCC_4V input to pins 1 and 3 of chip U6, with parallel filter capacitors C19 and C20 at the input; chip U6 pin 5 outputs a stable 3.3V low voltage, with filter capacitors C21 and C22 at the output; equipped with charging protection MOSFET Q11 and power protection MOSFET Q12; intrinsically safe current-limiting fuse F11 and TVS diode U7 are connected in series at the VBAT input to limit the maximum current of the circuit during a short circuit to prevent arcing; the battery charging circuit current is limited to ≤200mA to prevent overheating and battery bulging during charging.

[0207] 12V sensor boost circuit (chip U3, MT3608): VCC_4V powers chip U3. Energy storage inductor L1 and freewheeling diode D9 boost the voltage to generate 12V high voltage, which is dedicated to external sensors such as electromagnetic flowmeters and combustible gas transmitters. Transistor Q21 and MOSFET Q14 form a boost enable switch. When there is no data acquisition task, the main control cuts off the 12V high voltage output to eliminate the explosion-proof hazards of the underground live high voltage circuit.

[0208] Three independent 12V sensor controlled output circuits: The bases of transistors Q5, Q6, and Q4 are connected to pins 14, 45, and 56 of chip U13, respectively. The transistors turn on / off to drive MOSFETs Q1, Q3, and Q4, providing independent 12V power supply to the CN1, CN2, and CN3 aviation terminal interfaces. Each output is connected in series with self-resetting fuses F1, F2, and F3. If a single sensor is short-circuited, only the fuse of that output will blow, preventing high voltage from backflowing and damaging the low-voltage main control circuit. Transistor Q7 and MOSFET Q2 control the three 485 chip power rails, allowing for synchronous cutoff of the bus power supply.

[0209] Multiple explosion-proof protection linkage logic: The battery input terminal is equipped with a 100mA intrinsically safe dedicated current-limiting fuse; combined with the temperature and humidity signal of the data acquisition unit, the internal temperature is monitored in real time. When the temperature is >55℃, the main control cuts off the boost circuit and 12V output, and the whole machine is powered off and locked. Powering on is prohibited until the fault is eliminated; the charging circuit current is limited to within 200mA to prevent overheating during charging; all 12V high-voltage circuits are shut off in deep sleep mode, and there are no high-voltage live components inside the casing.

[0210] 3.7V Single-Cell Lithium Battery Integrated Intrinsically Safe Power Supply: Most explosion-proof terminals on the market use 7.4V dual-series lithium batteries, which have high power loss and excessive temperature rise due to multi-stage step-up and step-down circuits, exceeding the intrinsically safe energy limit; This solution uses a single 3.7V battery, with fewer step-up stages, lower overall power consumption, and controllable casing temperature rise, and has fully passed the ExicIIAT3 explosion-proof certification.

[0211] High and low voltage power rails can be controlled to cut off power: 12V high voltage for sensors and 3.3V low voltage for main control are independently powered. When there is no data acquisition task, the 12V high voltage circuit is completely shut off. There are no live high voltage cables underground, which greatly reduces the risk of short circuits and electrical sparks. Traditional equipment is constantly powered by 12V high voltage. If the cable is damaged and short circuits occur, it is easy to generate ignition sparks.

[0212] Independent short-circuit isolation protection for single-channel sensors: Each of the three 12V outputs is equipped with an independent fuse and power MOS switch. A short circuit in one sensor will not interrupt the monitoring of the other two instruments. In traditional equipment, multiple sensors share one 12V power supply. A short circuit in one channel will directly cut off the power to the entire machine and interrupt all pipeline monitoring data.

[0213] Temperature-controlled power-off hardware explosion-proof closed loop: Linked to the housing temperature and humidity acquisition signal, the whole machine is automatically powered off and locked when the temperature exceeds the limit, and cannot be powered on until the fault is cleared; traditional power supply circuits have no temperature control protection, and the battery is at high temperature for a risk of spontaneous combustion and ignition of gas in the well.

[0214] Intrinsically safe charging current limiting protection: The charging current is strictly limited to within 200mA, and overheating will not occur even with poor heat dissipation conditions in the sealed casing; Traditional equipment has a large charging current, and there is a risk of explosion if it is left to charge in the well for a long time; A dedicated current limiting fuse at the front end of the battery controls the short-circuit peak current within the intrinsically safe threshold.

[0215] IP68 explosion-proof aviation terminals provide unified external power supply: all 12V sensor power is led out only through sealed aviation plugs, which automatically lock in an airtight manner after plugging and unplugging, without damaging the waterproof and explosion-proof structure of the whole machine; traditional equipment has many openings for external power cables, and water can easily enter and short-circuit if the seal fails.

[0216] A method for implementing an intrinsically safe, explosion-proof, IP68 waterproof, multi-channel 485 pipeline telemetry terminal includes the following steps:

[0217] Step 1: Power on the entire machine / RTC timer initialization control logic;

[0218] Step 11, System clock initialization logic: After the device is powered on or the RTC is woken up by a timer, the system master clock and the independent RTC timing clock are configured first; the RTC timing clock is kept independently powered, and there is no need to recalibrate the timing reference after waking up from sleep, ensuring the stability of the timing acquisition and delayed power-off timing sequence.

[0219] Step 12, Main control circuit unit IO port function configuration logic: uniformly configure the input and output attributes of three 485 transceiver control pins, Bluetooth power supply switch pins, sensor high voltage output control pins, storage power control pins, and magnetic wake-up interrupt pins; configure two magnetic detection ports as external interrupt trigger mode and enable dual-signal joint verification anti-jitter logic.

[0220] Step 13, Multi-communication bus initialization logic:

[0221] The three 485 serial ports are independently allocated hardware resources and support multiple baud rate parameters of 9600bps, 19200bps, and 115200bps respectively.

[0222] Initialize the I2C communication bus and attach two types of sensors: internal temperature and humidity sensors and device attitude sensors.

[0223] Initialize the SPI communication bus and connect it to the local high-capacity storage chip;

[0224] Configure multiple signal switching channels to achieve time-division multiplexing and hardware isolation of Bluetooth serial port, debugging serial port, and three-channel acquisition 485 serial port.

[0225] Step 14, peripheral device power-on control logic: In the initial state of device power-on, the main control circuit unit issues a command to shut down the power supply to all peripheral devices, including the sealed Bluetooth maintenance unit, local storage unit, three-way isolated RS485 communication unit, and data acquisition unit high-voltage output; the whole machine only retains the main control circuit unit and magnetic passive wake-up unit to maintain low power standby.

[0226] Step 15, Status Indicator Logic Definition: Divide the equipment operating status into four types of indicator lights, corresponding to the four operating states of hibernation standby, data acquisition, wireless networking, and fault lockout, respectively. The indicator lights are off by default.

[0227] Step 16, Explosion-proof parameter loading and inspection startup logic: Read the device's fixed configuration parameters from local storage, including the 485 acquisition cycle for each channel, sensor calibration coefficient, alarm threshold, and automatic wake-up interval; pre-load the explosion-proof safety judgment thresholds, including the maximum safe temperature inside the enclosure, the upper limit of battery charging current, and the number of consecutive communication failure judgments; continuously start the safety inspection task in the background, cyclically collect battery current, internal temperature, and the operating status of each communication channel, and establish an explosion-proof real-time monitoring link.

[0228] Step 17, three-level power consumption mode parameter pre-storage logic: the main control circuit unit has built-in three types of power consumption switching judgment rules: deep sleep, timed acquisition, and Bluetooth operation and maintenance, and presets peripheral on / off control strategies and whole machine static current constraint standards for each mode.

[0229] Step 2: Three-way isolated RS485 time-division acquisition control logic;

[0230] After the device's RTC wakes up at a set time, it starts a multi-channel acquisition task, strictly following the time-sharing scheduling logic of single transmission and single reception, and transmission only after reception. The three communication channels operate independently and do not compete for bus resources.

[0231] Step 21, First-channel flow meter acquisition logic;

[0232] Turn on the power supply for this 485 communication channel and configure the high-speed baud rate to match the flow meter; output the transmit enable signal to send the standard Modbus read command; delay and close the transmit channel, switch to the data receive state and wait for the instrument to transmit back; complete the data verification, discard any single abnormal data, and mark the instrument as offline if there is no valid data for multiple consecutive times; after the acquisition is completed, cut off the power supply for this communication channel, release the bus resources, jump to the next acquisition process, and fix the high-frequency acquisition cycle.

[0233] Step S22, second channel pressure / level instrument acquisition logic;

[0234] Turn on the 485 communication power supply for this channel and configure the communication rate to match the transmitter; continuously read multiple sets of raw pressure and level monitoring values; retrieve the internal temperature data, perform temperature drift compensation, and remove instantaneous extreme values ​​through the mean algorithm; add timestamps to valid data and store them in a temporary buffer; after the acquisition ends, turn off the communication for this channel and jump to the third acquisition process, using a low-frequency steady-state acquisition cycle.

[0235] Step 23, third-channel gas / water quality probe acquisition logic;

[0236] Turn on the 485 communication power supply and configure low-speed fault-tolerant communication parameters; issue a read command, set an ultra-long data reception waiting window, and automatically resend the command if there is no response; if there is no data returned multiple times, the probe is considered offline; if normal data is returned, mark the abnormal points that exceed the limit; after the data acquisition is completed, disconnect the communication power supply and adopt a long interval acquisition cycle.

[0237] Step 24: Collect data and unify the caching logic;

[0238] The system integrates all monitoring data from three 485 channels, internal environmental data, and equipment attitude data, along with equipment number, timestamp, and fault marker to generate a complete data package. The data is then synchronously stored in the running memory and local storage, and a wireless upload task is initiated.

[0239] Step 3, 4G / NB-IoT wireless module network interruption resume control logic;

[0240] Step 31, 4G / NB-IoT wireless module power-on and link establishment logic: issue a command to turn on the power supply of the wireless module, initialize the wireless communication link, establish a long connection with the cloud platform, and periodically send heartbeat packets to maintain the online status of the base station.

[0241] Step 32, graded disconnection and reconnection control logic: distinguish between three disconnection scenarios: instantaneous packet loss, short-term weak signal, and long-term no signal, and extend the reconnection interval level by level to reduce the power consumption of continuous radio frequency transmission.

[0242] Step 33: Logic for offline caching and online retransmission;

[0243] When the network is disconnected, real-time uploading stops, and all data packets are stored in the local circular storage area in the order of collection, with each data packet carrying a unique timestamp. After the network is restored, offline cached data is read in chronological order and re-uploaded to the cloud one by one. After the upload is completed, the corresponding cached data is cleared to prevent duplicate uploads and data overflow.

[0244] Step 34, Cloud-based two-way command interaction logic: Real-time reception of remote commands from the cloud, supporting remote modification of acquisition parameters, remote wake-up, and remote fault reset, realizing two-way data transmission between the cloud and the terminal.

[0245] Step 35, power-off logic for peripheral devices after upload completion: After all real-time data and offline cache have been transmitted, the power supply to the wireless module is turned off, and the device returns to a low-power standby state.

[0246] Step 4: Magnetic activation of Bluetooth operation and maintenance linkage control logic;

[0247] Step 41, Magnetic passive wake-up unit signal verification logic: During deep sleep, only two magnetic interrupt detections are retained; after external magnetic triggering of two synchronous interrupt signals, valid wake-up is determined. Single-path triggering and instantaneous level transitions are directly filtered to avoid accidental Bluetooth activation by underground magnetic fields and vibrations.

[0248] Step 42, Power-on and channel switching logic of the sealed Bluetooth maintenance unit: After confirming a valid wake-up signal, a command is issued to power on the Bluetooth maintenance unit; multiple signal channels are switched to connect the communication link between the Bluetooth maintenance unit and the main control circuit unit; Bluetooth starts encrypted point-to-point broadcast to reject unauthorized devices from accessing the network, and the indicator light is switched to maintenance status.

[0249] Step 43, Bluetooth local interaction processing logic: After the handheld device establishes an encrypted connection, it responds to operation commands in four categories:

[0250] Read all local historical monitoring data and fault logs; modify the 485 baud rate, acquisition period, alarm threshold, and sensor calibration parameters of each channel in the three isolated RS485 communication unit, and permanently write the modifications to local storage; perform sensor zero-point and temperature drift calibration operations; retrieve the real-time fault status of the entire machine.

[0251] Step 44, Bluetooth timeout automatic sleep logic: After a fixed period of no interaction, the Bluetooth communication port is locked; after the magnetic removal, a countdown starts, and when the countdown ends, the Bluetooth power supply is completely turned off, the Bluetooth communication channel is disconnected, the indicator light goes out, and the device returns to the timed data collection standby state.

[0252] Step 5, three-level ultra-low power sleep control logic;

[0253] Step 51, Automatic Working Condition Classification Switching Logic: The main control circuit unit identifies the currently running task in real time and automatically switches between three power consumption modes:

[0254] Operating mode: Any task can be run, including data acquisition, wireless upload, or Bluetooth maintenance, while all peripherals remain powered.

[0255] Timed standby mode: After one round of data acquisition and upload is completed, the high voltage output, three isolated RS485 communication units, and 4G / NB-IoT wireless module are turned off, and only the RTC timer of the main control circuit unit is retained to wait for timed wake-up;

[0256] Deep sleep mode: No timed tasks, no magnetic wake-up signal, cut off power to all peripherals, only maintain RTC and magnetic interrupt detection, and the whole machine maintains a microampere-level static current.

[0257] Step 52, RTC timed wake-up loop logic: During the sleep process, the main control circuit unit RTC independently times the time. After reaching the preset acquisition interval, a wake-up interrupt is generated. After the main control receives the interrupt, the entire acquisition and upload process is restarted. After one round of tasks is completed, it falls back to a low power state, and the loop realizes long-term unattended monitoring.

[0258] Step 53, wake up the anti-shake filtering logic: after the magnetic interrupt is triggered, a second level check is performed. Only a stable and valid signal is used to wake up the whole machine, so as to avoid frequent start-stop of peripherals and consumption of battery power.

[0259] Step 6, Explosion-proof safety closed-loop control logic;

[0260] Step 61, Multi-dimensional safety cycle inspection logic: The background inspection task continuously reads four types of safety parameters: internal temperature, battery charging and discharging current, number of failures of three-way 485 communication, and abnormal status of wireless module.

[0261] Step 62, Over-temperature power-off interlocking control logic;

[0262] When the internal temperature of the enclosure exceeds the safety threshold, a high-temperature explosion risk is identified.

[0263] The high-voltage circuit of the sensor and the power supply of all peripherals are shut off in sequence, the whole machine is locked by power failure, and the fault indicator light stays on.

[0264] Simultaneously record high-temperature faults and store them locally, then attempt to push high-temperature alarms to the cloud;

[0265] The temperature must be continuously monitored. The device can only be restarted for data collection after the temperature drops to a safe range and the device is manually reset using a magnetic clamp. Powering on the device is permanently prohibited until the fault is eliminated.

[0266] Step 63, fault classification and isolation control logic;

[0267] When a single-channel 485 continuous communication failure occurs, only the high-voltage power supply to that sensor is cut off, while the other two acquisition channels operate normally.

[0268] When the battery overcurrent or charging current exceeds the standard, the power supply to the whole machine will be cut off and a short circuit / overcharge alarm will be uploaded.

[0269] All faults are permanently stored with timestamps, and fault records can be read locally via Bluetooth for troubleshooting and tracing.

[0270] Step 7, Data calibration and fault-tolerant control logic;

[0271] Step 71, Sensor Temperature Drift Compensation Logic: Each time pressure and water quality data are read, the internal temperature is retrieved synchronously, and the compensation algorithm is called to correct the sampling zero-point offset caused by high and low temperatures, thereby improving measurement accuracy.

[0272] Step 72, vibration filtering and mean-tolerance logic;

[0273] The pressure and liquid level channels employ a multi-point averaging algorithm to eliminate instantaneous extreme values ​​and suppress water flow impact fluctuations in the pipeline network;

[0274] Read equipment posture data, identify periods of severe vibration and tilt, and directly filter abnormal sample values ​​in the interval to avoid false alarms triggered by manhole cover disturbances.

[0275] Step 73, Logic for handling abnormal data in a tiered manner;

[0276] For minor exceedances in a single sample: the sample is automatically filtered and discarded, and no alarm data packet is generated.

[0277] Multiple consecutive sampling exceeding limits: Determine the actual fault in the pipeline network, generate alarm data, upload it to the cloud, and archive it locally.

[0278] Step 8: Local storage partition read / write control logic;

[0279] Step 81, Controlled power-on logic for the storage module: Power is turned on to the storage chip only in three scenarios: data acquisition, Bluetooth reading, and offline retransmission; power is completely turned off during other sleep periods to reduce overall power consumption and casing temperature rise.

[0280] Step 82, Storage Partition Management Logic: Divide the storage space into three independent logical partitions:

[0281] Parameter partitioning: Permanently stores fixed configurations such as baud rate, calibration coefficient, and alarm threshold, which are not lost when power is off;

[0282] Data cache partition: A circular storage mechanism for network outage monitoring data packets, with a capacity limit set to prevent data overwriting;

[0283] Fault log partition: Independently store various alarm records and retain them for long-term maintenance traceability.

[0284] Step 83, read-write protection mutual exclusion logic;

[0285] Data acquisition and writing, Bluetooth reading, and online retransmission adopt a multi-task mutual exclusion mechanism to avoid data corruption caused by synchronous reading and writing;

[0286] Write protection is enabled in the device's core parameter partition to prevent arbitrary erasure and overwriting, thus preventing the loss of calibration configuration due to accidental operation.

[0287] The description of this invention is given for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. An intrinsically safe, explosion-proof, IP68 waterproof, multi-channel 485 pipeline telemetry terminal, characterized in that: It includes an integrated explosion-proof sealed housing; and a main control circuit unit, a three-way isolated RS485 communication unit, a sealed Bluetooth maintenance unit, a data acquisition unit, a magnetic passive wake-up unit, an intrinsically safe explosion-proof power supply unit, a local storage unit, and a 4G / NB-IoT wireless module, all housed within the integrated explosion-proof sealed housing. The main control circuit unit is connected to three isolated RS485 communication units, a sealed Bluetooth maintenance unit, a data acquisition unit, a magnetic passive wake-up unit, a local storage unit, and a 4G / NB-IoT wireless module, respectively. The 4G / NB-IoT wireless module is connected to the cloud. The intrinsically safe explosion-proof power supply unit uses a 3.7V explosion-proof lithium battery as input to provide multiple levels of intrinsically safe operating power to each unit; the integrated explosion-proof sealed housing is a one-piece injection molded, seamless sealed structure without any split seams. The housing has no physical buttons, DIP switches, or debugging openings, and has reserved IP68-level explosion-proof aviation sealed terminals for external sensors. The three-channel isolated RS485 communication unit provides three electrically isolated RS485 communication channels. Each channel is equipped with independent surge protection and short-circuit current limiting protection, and the three channels support independent baud rate configuration, respectively adapting to electromagnetic flowmeters, pressure level transmitters, combustible gas and water quality probes. The magnetic passive wake-up unit adopts a passive dual-path magnetic trigger detection module. The external magnet is attached to the integrated explosion-proof sealed shell to generate a hardware wake-up interrupt, which is transmitted to the main control circuit unit. The sealed Bluetooth operation and maintenance unit is powered on under control and completely powered off when in sleep mode. After being woken up by magnetic attraction, it starts encrypted point-to-point Bluetooth communication.

2. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 1, characterized in that: The main control circuit unit includes chip U13, model STM32L151RET6. Pin 20 of chip U13 is connected to pin 4 of common anode LED indicator LED1, pin 21 of chip U13 is connected to pin 3 of common anode LED indicator LED1, pin 22 of chip U13 is connected to pin 1 of common anode LED indicator LED1, and pin 2 of common anode LED indicator LED1 is connected to one end of resistor R43. The other end of resistor R43 is connected to a 3.3V power supply. Pin 4 of chip U13 is connected to one end of crystal oscillator Y1 and one end of capacitor C29. Pin 3 of chip U13 is connected to the other end of crystal oscillator Y1 and one end of capacitor C28. The other end of capacitor C28 and the other end of capacitor C29 are grounded. Pin 6 of chip U13 is connected to one end of crystal oscillator Y2 and one end of capacitor C31. Pin 5 of chip U13 is connected to the other end of crystal oscillator Y2 and one end of capacitor C30. The other end of capacitor C30 and the other end of capacitor C31 are grounded. Pin 9 of the chip U13 is connected to the base of transistor Q20. The emitter of transistor Q20 is grounded. The collector of transistor Q20 is connected to one end of resistor R57 and the gate of MOSFET Q19. The other end of resistor R57 and the drain of MOSFET Q19 are connected to one end of resistor R58. The other end of resistor R58 is connected to pin 10 of chip U13, one end of diode D10 and one end of resistor R59. The other end of diode D10 and the other end of resistor R59 are grounded.

3. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 1, characterized in that: The three-way isolated RS485 communication unit includes chips U2, U4, U5, and U8. Chips U2, U4, U5, and U8 are of model SP3485. Pin 1 of chip U2 is connected to pin 17 of chip U13. Pins 2 and 3 of chip U2 are connected to one end of resistor R19 and pin 15 of chip U13. The other end of resistor R19 is grounded. Pin 4 of chip U2 is connected to pin 16 of chip U13. Pin 6 of chip U2 is connected to one end of fuse F5, TVS diode array D1, one end of resistor R8, and... Pin 1 of the IP68 explosion-proof aviation sensor terminal CN1 is connected to pin 7 of chip U2, which is connected to one end of fuse F4, TVS diode array D1, the other end of resistor R8, and pin 2 of IP68 explosion-proof aviation sensor terminal CN1. Pin 8 of chip U2 is connected to one end of capacitor C12, with the other end of capacitor C12 grounded. Pin 1 of chip U4 is connected to pin 52 of chip U13. Pins 2 and 3 of chip U4 are connected to one end of resistor R24 ​​and pin 50 of chip U13, with the other end of resistor R24 ​​grounded. Pin 4 of chip U4 is connected to pin 51 of chip U13. Pin 6 of chip U4 is connected to one end of fuse F7, TVS diode array D3, one end of resistor R23, and pin 1 of IP68 explosion-proof aviation sensor terminal CN2. Pin 7 of chip U4 is connected to one end of fuse F6, the other end of TVS diode array D3, resistor R23, and pin 2 of IP68 explosion-proof aviation sensor terminal CN2. Pin 8 of chip U4 is connected to one end of capacitor C15, and the other end of capacitor C15 is grounded. Pin 1 of chip U5 is connected to pin 54 of chip U13, and pins 2 and 3 of chip U5 are connected to one end of resistor R27. Pin 57 of chip U13 is connected to pin 53 of chip U13. Pin 6 of chip U5 is connected to one end of fuse F9, one end of TVS diode array D4, one end of resistor R26, and pin 1 of IP68 explosion-proof aviation sensor terminal CN3. Pin 7 of chip U5 is connected to one end of fuse F8, one end of TVS diode array D4, the other end of resistor R26, and pin 2 of IP68 explosion-proof aviation sensor terminal CN3. Pin 8 of chip U5 is connected to one end of capacitor C18, and the other end of capacitor C18 is grounded.

4. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 3, characterized in that: Pins 2 and 3 of chip U8 are connected to one end of resistor R31, and the other end of resistor R31 is grounded. Pin 1 of chip U8 is connected to pin 1 of chip U10. Pin 4 of chip U8 is connected to pin 12 of chip U10. The model of chip U10 is 74HC4052D. Pin 6 of chip U8 is connected to pin 5 of TVS diode array D5 and IP68 explosion-proof aviation sensor terminal CN1. Pin 7 of chip U8 is connected to pin 6 of TVS diode array D5 and IP68 explosion-proof aviation sensor terminal CN1. Pin 8 of chip U8 is connected to one end of capacitor C25 and connected to V485 power supply. The other end of capacitor C25 is grounded.

5. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 1, characterized in that: The sealed Bluetooth maintenance unit includes a chip U9, model BLE-SER-A-ANT. Pin 2 of chip U9 is connected to the drain (D) of MOSFET Q9. The gate (G) of MOSFET Q9 is connected to one end of resistor R15 and one end of resistor R14. The other end of resistor R15 and the source (S) of MOSFET Q9 are connected to a 3.3V power supply. The other end of resistor R14 is connected to the collector of transistor Q10. The emitter of transistor Q10 is grounded. The base of transistor Q10 is connected to pin 27 of chip U13. Pin 4 of chip U9 is connected to one end of resistor R35. The other end of resistor R35 is connected to pin 20 of chip U13. Pin 7 of chip U9 is connected to pin 5 of chip U10. Pin 8 of chip U9 is connected to pin 14 of chip U10. Chip U10 is model 74HC4052D.

6. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 1, characterized in that: The data acquisition unit includes chip U12, model ADXL345BCCZ-RL7. Pin 1 of chip U12 is connected to 3.3V. Pin 6 of chip U12 is connected to one end of resistor R42, and the other end of resistor R42 is connected to 3.3V. Pin 7 of chip U12 is connected to one end of resistor R41, and the other end of resistor R41 is connected to 3.3V. Pin 8 of chip U12 is connected to pin 2 of chip U13. Pin 12 of chip U12 is connected to one end of resistor R45, and the other end of resistor R45 is grounded. Pin 13 of chip U12 is connected to one end of resistor R39 and pin 59 of chip U13. Pin 14 of chip U12 is connected to one end of resistor R38 and pin 58 of chip U13. The data acquisition unit also includes chip U14, model AHT20_C2757850. Pin 2 of chip U14 is connected to one end of resistor R48 and one end of capacitor C32. The other end of resistor R48 is connected to VCC_MCU power supply, and the other end of capacitor C32 is grounded. Pin 3 of chip U14 is connected to one end of resistor R49 and pin 61 of chip U13. Pin 4 of chip U14 is connected to one end of resistor R50 and pin 62 of chip U13. The other ends of resistor R49 and resistor R50 are connected to VCC_MCU power supply.

7. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 1, characterized in that: The magnetic passive wake-up unit includes a magnetron S1 and a magnetron S2. One end of magnetron S1 is connected to one end of resistor R51 and pin 38 of chip U13, and the other end of resistor R51 is grounded. The other end of reed magnetron S1 is connected to one end of resistor R46, and the other end of resistor R46 is connected to 3.3V. One end of reed magnetron S2 is connected to one end of resistor R52 and pin 28 of chip U13, and the other end of resistor R52 is grounded. The other end of reed magnetron S2 is connected to one end of resistor R47, and the other end of resistor R47 is connected to 3.3V.

8. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 1, characterized in that: The local storage unit includes chip U11, model number MX25L2564GM21-08G. Pin 1 of chip U11 is connected to pin 33 of chip U13, pin 2 of chip U11 is connected to pin 35 of chip U13, pin 5 of chip U11 is connected to pin 36 of chip U13, pin 6 of chip U11 is connected to pin 34 of chip U13, pin 3 of chip U11 is connected to one end of resistor R32, pin 7 of chip U11 is connected to one end of resistor R34, and the other end of resistor R34 is connected to... Pin 8 of chip U11 is connected to one end of capacitor C27, and the other end of capacitor C27 is grounded. Pin 8 of chip U11 and the other end of resistor R32 are connected to the drain of MOSFET Q13. The gate of MOSFET Q13 is connected to one end of resistor R33 and one end of resistor R36. The source of MOSFET Q13 and the other end of resistor R33 are connected to a 3.3V power supply. The other end of resistor R36 is connected to the collector of transistor Q15. The emitter of transistor Q15 is grounded. The base of transistor Q15 is connected to pin 37 of chip U13.

9. The intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in claim 1, characterized in that: The intrinsically safe explosion-proof power supply unit includes a 12V boost circuit, a 4V boost circuit, a 3.3V circuit, and a 12V power control circuit. The 4V boost circuit uses an MT3608 chip to boost the voltage of a 3.7V lithium battery to generate a VCC_4V power supply. The 3.3V circuit uses an SPX3819M5-L-3-3 / TR to regulate and output 3.3V from the VCC_4V power supply. The 12V boost circuit uses an MT3608 chip to boost the voltage of the VCC_4V power supply to generate 12V, which is dedicated to powering external sensors. The 12V control circuit includes transistor Q5. The base of transistor Q5 is connected to pin 14 of chip U13, the emitter of transistor Q5 is grounded, the collector of transistor Q5 is connected to one end of resistor R9, the other end of resistor R9 is connected to one end of resistor R2 and the gate (G) of MOSFET Q1, the other end of resistor R2 is connected to one end of fuse F1 and the source (S) of MOSFET Q1, the other end of fuse F1 is connected to the 12V power supply, and the drain (D) of MOSFET Q1 is connected to the IP68 explosion-proof aviation sensor terminal CN1. The 3-pin 12V control circuit also includes transistor Q6. The base of transistor Q6 is connected to pin 45 of chip U13, the emitter of transistor Q6 is grounded, the collector of transistor Q6 is connected to one end of resistor R11, the other end of resistor R11 is connected to one end of resistor R4 and the gate (G) of MOSFET Q3, the other end of resistor R4 is connected to one end of fuse F2 and the source (S) of MOSFET Q3, the other end of fuse F2 is connected to the 12V power supply, and the drain (D) of MOSFET Q3 is connected to the IP68 explosion-proof aviation sensor terminal. The CN2 circuit includes a 12V control circuit, specifically pin 3. The base of transistor Q4 is connected to pin 56 of chip U13. The emitter of transistor Q4 is grounded. The collector of transistor Q4 is connected to one end of resistor R12. The other end of resistor R12 is connected to one end of resistor R5 and the gate (G) of MOSFET Q4. The other end of resistor R5 is connected to one end of fuse F3 and the source (S) of MOSFET Q4. The other end of fuse F3 is connected to the 12V power supply. The drain (D) of MOSFET Q4 is connected to an IP68 explosion-proof aviation safety device. The sensor terminal CN3 is pin 3; the 12V control circuit also includes transistor Q7. The base of transistor Q7 is connected to pin 55 of chip U13. The emitter of transistor Q7 is grounded. The collector of transistor Q7 is connected to one end of resistor R10. The other end of resistor R10 is connected to one end of resistor R3 and the gate of MOSFET Q2. The other end of resistor R3 and the source of MOSFET Q2 are connected to a 3.3V power supply. The drain of MOSFET Q2 is connected to pins 8 of chip U2, pins 8 of chip U4, and pins 8 of chip U5.

10. A method for implementing an intrinsically safe, explosion-proof, IP68 waterproof, multi-channel 485 pipeline telemetry terminal, characterized in that: The implementation method is based on the intrinsically safe explosion-proof IP68 waterproof multi-channel 485 pipeline telemetry terminal as described in any one of claims 1-9, and includes the following steps: Step 1: Power on the entire machine / RTC timer initialization control logic; Step 11, System clock initialization logic: After the device is powered on or the RTC is woken up by a timer, the system master clock and the independent RTC timing clock are configured first; the RTC timing clock is kept independently powered, and there is no need to recalibrate the timing reference after waking up from sleep, ensuring the stability of the timing acquisition and delayed power-off timing sequence; Step 12, Main control circuit unit IO port function configuration logic: uniformly configure the input and output attributes of three 485 transceiver control pins, Bluetooth power supply switch pins, sensor high voltage output control pins, storage power control pins, and magnetic wake-up interrupt pins; configure two magnetic detection ports as external interrupt trigger mode and enable dual-signal joint verification anti-shake logic; Step 13, Multi-communication bus initialization logic: The three 485 serial ports are independently allocated hardware resources and support multiple baud rate parameters of 9600bps, 19200bps, and 115200bps respectively. Initialize the I2C communication bus and attach two types of sensors: internal temperature and humidity sensors and device attitude sensors. Initialize the SPI communication bus and connect it to the local high-capacity storage chip; Configure multiple signal switching channels to achieve time-division multiplexing and hardware isolation of Bluetooth serial port, debugging serial port, and three-channel acquisition 485 serial port; Step 14, peripheral device power-on control logic: In the initial state of device power-on, the main control circuit unit issues a command to shut down the power supply to all peripheral devices, including the sealed Bluetooth maintenance unit, local storage unit, three-way isolated RS485 communication unit, and high-voltage output of the data acquisition unit; the whole machine only retains the main control circuit unit and the magnetic passive wake-up unit to maintain low power standby. Step 15, Status Indicator Logic Definition: Divide the equipment operating status into four types of light indicators, corresponding to the four operating states of hibernation standby, data acquisition, wireless networking, and fault lockout, respectively. The indicator lights are off by default. Step 16, Explosion-proof parameter loading and inspection startup logic: Read the device's fixed configuration parameters from local storage, including the 485 acquisition cycle for each channel, sensor calibration coefficient, alarm threshold, and automatic wake-up interval; pre-load the explosion-proof safety judgment thresholds, including the maximum safe temperature inside the enclosure, the upper limit of battery charging current, and the number of consecutive communication failure judgments; continuously start the safety inspection task in the background, cyclically collect battery current, internal temperature, and the operating status of each communication channel, and establish an explosion-proof real-time monitoring link; Step 17, three-level power consumption mode parameter pre-storage logic: the main control circuit unit has built-in three types of power consumption switching judgment rules: deep sleep, timed acquisition, and Bluetooth operation and maintenance, and presets peripheral on / off control strategies and whole machine static current constraint standards for each mode. Step 2: Three-way isolated RS485 time-division acquisition control logic; After the device's RTC wakes up at a set time, it starts a multi-channel acquisition task, strictly following the time-sharing scheduling logic of single transmission and single reception, and transmission only after reception. The three communication channels operate independently and do not compete for bus resources. Step 21, First-channel flow meter acquisition logic; Turn on the power supply for this 485 communication channel and configure the high-speed baud rate to match the flow meter; output the transmit enable signal to send the standard Modbus read command; delay and close the transmit channel, switch to the data receive state and wait for the instrument to transmit back; complete the data verification, discard the single abnormal data directly, mark the instrument as offline fault if there are multiple consecutive valid data; after the acquisition is completed, cut off the power supply for this communication channel, release the bus resources, jump to the next acquisition process, and fix the high-frequency acquisition cycle. Step S22, second channel pressure / level instrument acquisition logic; Turn on the 485 communication power supply for this channel and configure the communication rate to match the transmitter; continuously read multiple sets of raw pressure and level monitoring values; retrieve the internal temperature data to perform temperature drift compensation and remove instantaneous extreme values ​​through the mean algorithm; add timestamps to valid data and store them in a temporary buffer; after the acquisition ends, turn off the communication for this channel and jump to the third acquisition process, using a low-frequency steady-state acquisition cycle. Step 23, third-channel gas / water quality probe acquisition logic; Turn on the 485 communication power supply and configure low-speed fault-tolerant communication parameters; issue a read command, set an ultra-long data reception waiting window, and automatically resend the command if there is no response; if there is no data returned multiple times, the probe is determined to be offline; if normal data is returned, mark the abnormal points that exceed the limit; after the data acquisition is completed, disconnect the communication power supply and adopt a long interval acquisition cycle. Step 24: Collect data and unify the caching logic; Integrate all monitoring data from three 485 channels, internal environmental data, and equipment attitude data, along with equipment number, timestamp, and fault marker to generate a complete data package; the data is synchronously stored in the running memory and local storage, and then a wireless upload task is initiated; Step 3, 4G / NB-IoT wireless module network interruption resume control logic; Step 31, 4G / NB-IoT wireless module power-on and link establishment logic: issue a command to turn on the power supply of the wireless module, initialize the wireless communication link, establish a long connection with the cloud platform, and periodically send heartbeat packets to maintain the online status of the base station; Step 32, graded disconnection and reconnection control logic: distinguish between three disconnection scenarios: instantaneous packet loss, short-term weak signal, and long-term no signal, and extend the reconnection interval level by level to reduce the power consumption of continuous radio frequency transmission. Step 33: Logic for offline caching and online retransmission; When the network is disconnected, real-time uploading stops, and all data packets are stored in the local circular storage area in the order of collection, with each data packet carrying a unique time identifier. After the network is restored, offline cached data is read in chronological order and re-uploaded to the cloud one by one. After the upload is completed, the corresponding cached data is cleared to prevent duplicate uploads and data overflow. Step 34, Cloud-based two-way command interaction logic: Real-time reception of remote commands from the cloud, supporting remote modification of acquisition parameters, remote wake-up, and remote fault reset, realizing two-way data transmission between the cloud and the terminal; Step 35, power-off logic for peripheral devices after upload: After all real-time data and offline cache have been transmitted, the power supply to the wireless module is turned off, and the device returns to low-power standby mode; Step 4: Magnetic activation of Bluetooth operation and maintenance linkage control logic; Step 41, Magnetic passive wake-up unit signal verification logic: During deep sleep, only two magnetic interrupt detections are retained; after external magnetic triggering of two synchronous interrupt signals, valid wake-up is determined. Single triggering and instantaneous level jumps are directly filtered to avoid accidental Bluetooth activation by underground magnetic fields and vibrations. Step 42, Power-on and channel switching logic of the sealed Bluetooth maintenance unit: After confirming a valid wake-up signal, a command is issued to power on the Bluetooth maintenance unit; multiple signal channels are switched to connect the communication link between the Bluetooth maintenance unit and the main control circuit unit; Bluetooth starts encrypted point-to-point broadcast to reject unauthorized devices from accessing the network, and the indicator light is switched to maintenance status. Step 43, Bluetooth local interaction processing logic: After the handheld device establishes an encrypted connection, it responds to operation commands in four categories: Read all local historical monitoring data and fault logs; modify the 485 baud rate, acquisition period, alarm threshold, and sensor calibration parameters of each channel in the three isolated RS485 communication unit, and permanently write the modifications to local storage; perform sensor zero-point and temperature drift calibration operations; retrieve the real-time fault status of the entire unit. Step 44, Bluetooth timeout automatic sleep logic: After a fixed period of no interaction, the Bluetooth communication port is locked; after the magnetic removal, a countdown starts, and when the countdown ends, the Bluetooth power supply is completely turned off, the Bluetooth communication channel is disconnected, the indicator light goes out, and the device returns to the timed data collection standby state. Step 5, three-level ultra-low power sleep control logic; Step 51, Automatic Working Condition Classification Switching Logic: The main control circuit unit identifies the currently running task in real time and automatically switches between three power consumption modes: Operating mode: Any task can be run, including data acquisition, wireless upload, or Bluetooth maintenance, while all peripherals remain powered. Timed standby mode: After one round of data acquisition and upload is completed, the high voltage output, three isolated RS485 communication units, and 4G / NB-IoT wireless module are turned off, and only the RTC timer of the main control circuit unit is retained to wait for timed wake-up; Deep sleep mode: No timed tasks, no magnetic wake-up signal, cut off power to all peripherals, only maintain RTC and magnetic interrupt detection, and the whole machine maintains a microampere-level static current; Step 52, RTC timed wake-up loop logic: During the sleep process, the main control circuit unit RTC independently times the time. After reaching the preset acquisition interval, a wake-up interrupt is generated. After the main control receives the interrupt, the entire acquisition and upload process is restarted. After one round of tasks is completed, it falls back to the low power state, and the loop realizes long-term unattended monitoring. Step 53, wake up the anti-shake filtering logic: after the magnetic interrupt is triggered, the level is checked twice after a delay. Only when the signal is stable and valid will the whole machine be woken up to avoid frequent start-stop of peripherals and consumption of battery power. Step 6, Explosion-proof safety closed-loop control logic; Step 61, Multi-dimensional safety cycle inspection logic: The background resident inspection task continuously reads four types of safety parameters: internal temperature, battery charging and discharging current, number of failures of three-way 485 communication, and abnormal status of wireless module. Step 62, Over-temperature power-off interlocking control logic; When the internal temperature of the enclosure exceeds the safety threshold, a high-temperature explosion risk is identified. The high-voltage circuit of the sensor and the power supply of all peripherals are shut off in sequence, the whole machine is locked by power failure, and the fault indicator light stays on. Simultaneously record high-temperature faults and store them locally, then attempt to push high-temperature alarms to the cloud; The temperature must be continuously monitored. The device can only be restarted for data collection after the temperature drops back to a safe range and it is manually reset with a magnetic clamp. Powering on the device is permanently prohibited until the fault is eliminated. Step 63, fault classification and isolation control logic; When a single-channel 485 continuous communication failure occurs, only the high-voltage power supply to that sensor is cut off, while the other two acquisition channels operate normally. When the battery overcurrent or charging current exceeds the standard, the power supply to the whole machine will be cut off and a short circuit / overcharge alarm will be uploaded. All faults are permanently stored with timestamps, and fault records can be read locally via Bluetooth for troubleshooting and tracing. Step 7, Data calibration and fault-tolerant control logic; Step 71, Sensor temperature drift compensation logic: Each time pressure and water quality data are read, the internal temperature is retrieved synchronously, and the compensation algorithm is called to correct the sampling zero-point offset caused by high and low temperatures, thereby improving measurement accuracy; Step 72, vibration filtering and mean-tolerance logic; The pressure and liquid level channels employ a multi-point averaging algorithm to eliminate instantaneous extreme values ​​and suppress water flow impact fluctuations in the pipeline network; Read equipment posture data, identify periods of severe vibration and tilt, and directly filter abnormal sample values ​​in the interval to avoid false alarms triggered by manhole cover disturbance; Step 73, Logic for handling abnormal data in a tiered manner; For minor exceedances in a single sample: the sample is automatically filtered and discarded, and no alarm data packet is generated. Multiple consecutive sampling exceeding limits: Determine the actual fault in the pipeline network, generate alarm data, upload it to the cloud, and archive it locally; Step 8: Local storage partition read / write control logic; Step 81, Controlled power-on logic for the storage module: Power is turned on to the storage chip only in three scenarios: data acquisition, Bluetooth reading, and offline retransmission; power is completely turned off during other sleep periods to reduce overall power consumption and casing temperature rise; Step 82, Storage Partition Management Logic: Divide the storage space into three independent logical partitions: Parameter partitioning: Permanently stores fixed configurations such as baud rate, calibration coefficient, and alarm threshold, which are not lost when power is off; Data cache partition: A circular storage mechanism for network outage monitoring data packets, with a capacity limit set to prevent data overwriting; Fault log partitioning: Independently stores various alarm records, and retains them long-term for operation and maintenance traceability; Step 83, read-write protection mutual exclusion logic; Data acquisition and writing, Bluetooth reading, and online retransmission adopt a multi-task mutual exclusion mechanism to avoid data corruption caused by synchronous reading and writing; Write protection is enabled in the device's core parameter partition to prevent arbitrary erasure and overwriting, thus preventing the loss of calibration configuration due to accidental operation.

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