A gas meter electronic control system based on NDC non-contact coupling and a control method thereof

Abstract

The present application relates to the technical field of intelligent gas electronic control, in particular to a kind of electronic control system and control method of gas meter based on NDC non-contact coupling, through the two major parts of base meter electronic unit and detachable remote communication module electronic unit, realize contactless two-way data interaction using NDC non-contact radio frequency coupling data link, user NFC module normal power-off design, and the modular design of general NDC coupling interface to realize the reliability, sealing hardware structure, with strong anti-interference, flexible replacement, measurement level performance and low power consumption effect.

Description

Technical Field

[0001] This invention relates to the field of intelligent gas electronic control technology, specifically to an electronic control system and control method for a gas meter based on NDC non-contact coupling. Background Technology

[0002] With the development of technology and the arrival of the intelligent era, fully utilizing new-generation technologies such as intelligence, communication, and the Internet of Things to deeply integrate with traditional industries and create integrated designs has become the direction for upgrading and iterating across all sectors.

[0003] With the integration of intelligent technologies into the gas industry, modular operation and maintenance, low power consumption, and high reliability have become the core development directions for smart gas meter electronic systems. However, existing technologies still suffer from three prominent shortcomings: 1. Inter-board communication relies on physical connectors, making it difficult to balance reliability and sealing. Specifically: The existing split-type gas meters connect the base meter and the communication module through physical contacts such as pin headers and gold fingers. In humid, dusty, and highly corrosive installation environments, this can easily lead to malfunctions such as contact oxidation, poor contact, and water ingress short circuits. Furthermore, the housing needs to have a connector opening, which compromises the overall sealing performance of the meter body and fails to meet the requirements for explosion-proof and high protection levels.

[0004] 2. The NFC card reader module is designed to be constantly powered, resulting in significant power consumption and interference issues. Specifically: Gas meters with local NFC card reading functionality often have their card reading modules in a constant-power standby state. This continuously consumes power, reducing battery life. Furthermore, the NFC radio frequency unit, being in a standby state for extended periods, is prone to electromagnetic interference with the remote communication module, leading to packet loss and interruptions in remote data transmission. Current technologies mostly address interference through software time-sharing scheduling, but this method still carries the risk of accidental interruptions to remote communication during card reading, failing to guarantee the integrity of remote communication.

[0005] 3. Communication standards are fixed at the factory, resulting in high maintenance costs throughout the entire lifecycle. Specifically: The remote communication chip is directly soldered to the metering motherboard, and is locked to a single communication standard at the factory. When upgrading the network or adjusting the networking scheme in the later stage, the entire meter must be disassembled and the legal metering seal must be broken. After the modification, it needs to be re-tested and recalibrated, resulting in long operation and maintenance cycles and high costs. Therefore, gas operators need to stock multiple models of meters for different scenarios, resulting in great pressure on inventory management.

[0006] Based on the above reasons, this invention designs a gas meter electronic control system and its control method based on NDC non-contact coupling. It consists of two main parts: the base meter electronic unit and the detachable remote communication module electronic unit. It utilizes the NDC non-contact radio frequency coupling data link to achieve contactless bidirectional data interaction, thereby achieving a reliable and sealed hardware structure. At the same time, it has the effects of strong anti-interference, flexible replacement, metering-grade performance and low power consumption. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a gas meter electronic control system and control method based on NDC non-contact coupling. It consists of two main parts: a base meter electronic unit and a detachable remote communication module electronic unit. It utilizes the NDC non-contact radio frequency coupling data link to achieve contactless bidirectional data interaction, thereby achieving a reliable and sealed hardware structure. At the same time, it has the effects of strong anti-interference, flexible replacement, metering-grade performance and low power consumption.

[0008] To achieve the above objectives, this invention provides an electronic control system for gas meters based on NDC non-contact coupling, comprising a base meter electronic unit that communicates with each other and an independently sealed detachable remote communication module. The base meter electronic unit includes a main control MCU, a user-end NFC card reader module, an NDC tag unit, a metering acquisition module, a valve control drive module, a low-power power management module, a data storage module, and an electromagnetic compatibility protection module. The detachable remote communication module has a unified NDC radio frequency coupling interaction protocol and a mechanical mounting interface, and includes a module control unit, an NDC reader / writer unit, and a remote radio frequency unit. The main control MCU communicates bidirectionally with the metering acquisition module and the valve control drive module. The main control MCU communicates via I... 2 The C-bus communicates bidirectionally with the user-end NFC card reader module and NDC tag unit; the main control MCU communicates with the low-power power management module and data storage module; the module control unit communicates with the NDC reader / writer unit and the remote transmission RF unit respectively; and the electromagnetic compatibility protection module communicates with other modules of the base meter electronic unit and the detachable remote transmission communication module.

[0009] The NDC tag unit is embedded inside the gas meter housing, and the NDC reader unit is located inside the mating surface of the detachable remote communication module. There are no physical electrical contacts between the NDC reader unit and the detachable remote communication module, and a millimeter-level air gap is maintained after assembly.

[0010] The NDC reader unit uses the FM17622 NFC card reader chip, and the NDC tag unit uses the FM11NT083C dual-interface NFC tag chip. The NDC reader unit and the NDC tag unit establish a radio frequency communication link based on the ISO / IEC 14443 Type A protocol and follow the agreed-upon inter-board private data pass-through protocol to complete bidirectional data interaction.

[0011] The main control MCU has a built-in 2-channel I / O. 2 A dedicated metering-grade low-power MCU with a C-bus interface and multiple configurable I / O ports, and built-in linkage scheduling firmware. The linkage scheduling firmware includes a system identification unit, a power domain management unit, a billing mode switching unit, and a data encryption and verification unit responsible for system-wide task scheduling, mode switching, and data processing. The user-side NFC card reader module has a built-in hierarchical key verification unit that distinguishes between user cards and tool cards for different types of operation permissions. It includes an NFC radio frequency antenna, a card reader decoding chip, a hierarchical key verification unit, and a trigger detection circuit, and is connected to the main control I / O port and the main control MCU through an independent power supply domain. The core of the NDC tag unit is a dual-interface NFC tag chip and an onboard radio frequency antenna, and is connected to the main control MCU through an I / O port. 2 The C interface connects to the main control MCU; the metering acquisition module and valve control drive module interface with the gas metering sensor; the low power management module is an LDO array that supports the independent shutdown of idle module power and provides multiple independent power supply domains, and has a built-in battery voltage sampling circuit for real-time monitoring of lithium-ion battery status and low power triggering warning. The module control unit establishes a bidirectional data link with the gas base meter through the NDC reader unit; the core of the NDC reader unit is the NFC reader chip and the corresponding radio frequency antenna, which are aligned with the NDC tag unit after assembly.

[0012] The method for non-destructive replacement of remote transmission standards in a control system includes the following steps: S1-1, Original module removal: Without opening the base meter housing or damaging the legal metering seal, remove the original detachable remote communication module from the gas base meter installation position, disconnect the NDC contactless NFC radio frequency coupling data link, keep the main control MCU in the current payment mode, support switching to other payment modes, and turn off the remote transmission related logic. S1-2, New Module Adaptation and Installation: Replace with a new detachable remote communication module equipped with the target communication standard. The new module maintains the same mechanical mounting dimensions, NDC RF antenna position, and general data interaction protocol as the original module. Install the new module into the gas meter mounting position and re-establish the NDC contactless NFC RF coupling data link. S1-3, Automatic Standard Adaptation Operation: The main control MCU reads the communication standard identifier of the new module through the coupling link and completes the identity verification. It automatically loads the corresponding standard driver and communication protocol stack. It can switch to the corresponding standard postpaid operation mode without upgrading the underlying firmware of the base meter or re-measuring and verifying.

[0013] The target communication standards include, but are not limited to, NB-IoT public network and LoRa wireless networking. Communication modules of different standards share a unified mechanical interface and NDC radio frequency coupling communication standard.

[0014] The method for switching payment modes in a control system includes the following steps: 2-1, Initial configuration: After leaving the factory, the base meter works in local prepaid mode by default. The main control MCU disables the firmware logic related to remote communication. The user-end NFC card reader module is normally powered off, and only the metering acquisition, valve control drive and module detection circuit are kept in a low-power operation state. 2-2, Module access detection: The detachable remote communication module is assembled into the preset mounting position of the base meter. The NDC reader unit and the NDC tag unit establish a contactless NFC radio frequency coupling data link. The main control MCU periodically sends probe frames through the link to identify whether there is a legitimate communication module access. 2-3, Mutually Exclusive Collaborative Operation: In postpaid mode, during remote communication execution, the main control MCU locks the power supply path of the user-end NFC card reader module, prohibiting it from being powered on and activated, so there is no situation where card reading operation interrupts remote communication; only when the system is idle will the power supply permission of the user-end NFC card reader module be opened to respond to local card reading operations.

[0015] A control method for an electronic control system of a gas meter based on NDC non-contact coupling includes the following: When the S3-1 detachable remote communication module is installed at the corresponding position of the gas base meter, the NDC reader unit and the NDC tag unit establish an NDC contactless NFC radio frequency coupling data link through a 13.56MHz radio frequency field, and realize bidirectional data transparent transmission in accordance with the standard NFC data interaction protocol. After the main control MCU recognizes the legitimate module access, it supports the original payment mode or switches to a postpaid working mode that supports NFC local interaction combined with remote background management. S3-2, the user-end NFC card reader module adopts an independent and controllable power supply domain, with controllable power-on and power-off timing control logic, and is in a completely power-off mode under normal conditions; when the system performs NDC remote communication tasks, the main control MCU locks the power supply path of the user-end NFC card reader module to prevent it from being activated by power-on, thus eliminating the interference of the user-end NFC radio frequency signal to the NDC communication process at the hardware level, and there is no situation where the card reading operation interrupts the remote communication process; The S3-3's main control MCU has a built-in automatic standard identification unit. It reads the standard identification and identity verification information of the communication module through the NDC contactless NFC radio frequency coupling data link, and automatically loads the corresponding driver and communication protocol stack. It can adapt to different communication standards without upgrading the underlying firmware of the base table.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The NDC non-contact coupling method simultaneously improves reliability and sealing performance, exceeding conventional technical approaches in this field: The NDC inter-board communication solution based on NFC radio frequency coupling eliminates the need for physical electrical contacts and requires no openings in the base meter housing, ensuring overall sealing performance and explosion-proof rating. It completely avoids contact failures caused by connector oxidation, moisture, and dust ingress, and is suitable for complex gas meter installation environments. At the same time, it achieves electrical isolation between the metering core and the communication side, reducing interference from external surges and static electricity on the metering circuit.

[0017] 2. Hardware-level mutual exclusion control solves the problems of interference and interruption at their root: The user's NFC module is designed to be normally powered off, which greatly reduces standby power consumption; the power supply lockout mechanism during remote communication prevents the simultaneous operation of two radio frequencies from the hardware level, completely eliminating the risk of electromagnetic crosstalk, and there is no possibility of card reading operations interrupting remote communication, thus significantly improving the stability and integrity of remote communication.

[0018] 3. Non-destructive replacement of standard components significantly reduces the total lifecycle cost: Based on the modular design of the universal NDC coupling interface, the replacement of the remote transmission system does not require disassembling the base meter, breaking the metering seal, or recalibration. The network upgrade can be completed by simply replacing the external communication module, which significantly reduces the operation and maintenance cycle and cost. The same base meter can be adapted to multiple networking scenarios, and enterprises can keep only one model in stock, which greatly reduces inventory pressure.

[0019] 4. MCU main control adaptation, balancing metering-grade performance and low power consumption: It adopts Renesas metering-grade low-power MCU, which is natively adapted to gas metering and data acquisition scenarios. Its computing accuracy and anti-interference capability meet industry standards. With the help of a graded power consumption management mechanism, the average power consumption of the whole machine is controlled within the industry standard range of civil gas meters, thereby ensuring a 6-8 year maintenance-free battery life. Attached Figure Description

[0020] Figure 1 This is a block diagram of the overall architecture of the control system of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Main control MCU, 2. User terminal NFC card reader module, 3. NDC tag unit, 4. Metering acquisition module, 5. Valve control drive module, 6. Low power management module, 7. Data storage module, 8. Detachable remote communication module, 8-1 Module control unit, 8-2 NDC reader / writer unit, 8-3 Remote RF unit, 9. Electromagnetic compatibility protection module. Detailed Implementation

[0022] The present invention will now be further described with reference to the accompanying drawings.

[0023] NDC stands for Non-contact Data Coupling. The physical layer is based on the 13.56MHz NFC radio frequency coupling principle of the ISO / IEC 14443 Type A protocol and is used for contactless bidirectional data transmission between the base meter and the detachable module.

[0024] See Figure 1 This invention provides an electronic control system for gas meters based on NDC non-contact coupling, comprising a base meter electronic unit that communicates with each other and an independently sealed detachable remote communication module 8. The base meter electronic unit includes a main control MCU 1, a user-end NFC card reader module 2, an NDC tag unit 3, a metering acquisition module 4, a valve control drive module 5, a low-power power management module 6, a data storage module 7, and an electromagnetic compatibility protection module 9. The detachable remote communication module 8 has a unified NDC radio frequency coupling interaction protocol and a mechanical installation interface, and includes a module control unit 8-1, an NDC reader / writer unit 8-2, and a remote radio frequency unit 8-3. The main control MCU 1 communicates bidirectionally with the metering acquisition module 4 and the valve control drive module 5. The main control MCU 1 communicates via I... 2 The C-bus communicates bidirectionally with the user-end NFC card reader module 2 and NDC tag unit 3. The main control MCU1 communicates with the low-power power management module 6 and the data storage module 7. The data storage module 7 stores metering data, billing parameters, equipment operation logs and key information. The module control unit 8-1 communicates with the NDC reader / writer unit 8-2 and the remote transmission radio frequency unit 8-3 respectively. The electromagnetic compatibility protection module 9 communicates with other modules of the base meter electronic unit and the detachable remote transmission communication module 8.

[0025] The NDC tag unit 3 is embedded inside the gas meter housing, and the NDC reader / writer unit 8-2 is located inside the mating surface of the detachable remote communication module 8. There are no physical electrical contacts between the NDC reader / writer unit 8-2 and the detachable remote communication module 8, and a millimeter-level air gap is maintained after assembly. The NDC tag unit 3 serves as the NDC non-contact data coupling port on the meter side. Because it is embedded inside the meter housing, it can transmit data externally without requiring openings in the housing. It supports passive wake-up and password verification; modules that fail identity verification cannot establish communication.

[0026] The NDC reader unit 8-2 uses the FM17622 NFC card reader chip, and the NDC tag unit 3 uses the FM11NT083C dual-interface NFC tag chip. The NDC reader unit 8-2 and the NDC tag unit 3 establish a radio frequency communication link based on the ISO / IEC 14443 Type A protocol and follow the agreed-upon inter-board private data pass-through protocol to complete bidirectional data interaction.

[0027] The main control MCU1 has a built-in 2-channel I / O. 2A dedicated metering-grade low-power MCU with a C-bus interface and multiple configurable I / O ports, and built-in linkage scheduling firmware. The linkage scheduling firmware includes a system identification unit, a power domain management unit, a billing mode switching unit, and a data encryption and verification unit responsible for system-wide task scheduling, mode switching, and data processing. The user-end NFC card reader module 2 has a built-in hierarchical key verification unit that distinguishes between user cards and tool cards for different types of operation permissions. It includes an NFC radio frequency antenna, a card reader decoding chip, a hierarchical key verification unit, and a trigger detection circuit, and is connected to the main control MCU1 via an independent power supply domain. The core of the NDC tag unit 3 is a dual-interface NFC tag chip and an onboard radio frequency antenna, and is connected to the main control MCU1 via an I / O port. 2 The C interface connects to the main control MCU1; the metering acquisition module 4 and the valve control drive module 5 interface with the gas metering sensor to collect flow data in real time and upload it to the main control; it receives the main control command to execute the opening and closing of the gas valve and feeds back the valve status; the low power management module 6 is an LDO array that supports the separate shutdown of the power supply of idle modules and provides multiple independent power supply domains, and has a built-in battery voltage sampling circuit for real-time monitoring of lithium-ion battery status and low power triggering warning; The module control unit 8-1 establishes a bidirectional data link with the gas base meter through the NDC reader / writer unit 8-2; the core of the NDC reader / writer unit 8-2 is an NFC reader / writer chip and a corresponding radio frequency antenna, which are aligned with the NDC tag unit 3 after assembly.

[0028] The method for non-destructive replacement of remote transmission standards in a control system includes the following steps: S1-1, Original module removal: Without opening the base meter housing or damaging the legal metering seal, remove the original detachable remote communication module 8 from the gas base meter installation position, disconnect the NDC contactless NFC radio frequency coupling data link, keep the main control MCU1 in the current payment mode, support switching to other payment modes, and turn off the remote transmission related logic. S1-2, New module adaptation and installation: Replace with a new detachable remote communication module 8 equipped with the target communication standard. The new module maintains the same mechanical mounting dimensions, NDC RF antenna position and general data interaction protocol as the original module. Install the new module into the gas meter mounting position and re-establish the NDC contactless NFC RF coupling data link. S1-3, Automatic Standard Adaptation Operation: The main control MCU1 reads the communication standard identifier of the new module through the coupling link and completes the identity verification. It automatically loads the corresponding standard driver and communication protocol stack. It can switch to the corresponding standard postpaid operation mode without upgrading the underlying firmware of the base meter or re-measuring and verifying.

[0029] The target communication standards include, but are not limited to, NB-IoT public network and LoRa wireless networking. Communication modules of different standards share a unified mechanical interface and NDC radio frequency coupling communication standard.

[0030] The method for switching payment modes in a control system includes the following steps: 2-1 Initial Configuration: After leaving the factory, the base meter defaults to local prepaid mode. The main control MCU1 disables the firmware logic related to remote communication, and the user-end NFC card reader module 2 is normally powered off, only maintaining the metering acquisition, valve control drive and module detection circuit in a low-power operation state. When the detachable remote communication module 8 is not installed, the system defaults to NFC local prepaid mode. Local recharge and fee management can be completed by relying on the user-end NFC card reader module, or other payment modes can be selected through optical interface tools or NFC card reader module 2. 2-2, Module Access Detection: The detachable remote communication module 8 is installed in the preset mounting position of the base meter. The NDC reader / writer unit 8-2 establishes a contactless NFC radio frequency coupling data link with the NDC tag unit 3. The main control MCU1 periodically sends probe frames through the link to identify whether a legitimate communication module is connected. When no communication module is detected, the NDC tag unit 3 is in a passive sleep state. The module detection circuit is intermittently woken up for detection at second intervals. The rest of the time, it is in a deep sleep state, which can maintain the base meter's battery life for more than 6 years.

[0031] 2-3, Mutually Exclusive Collaborative Operation: In postpaid mode, during remote communication execution, the main control MCU1 locks the power supply path of the user-end NFC card reader module 2, prohibiting it from being powered on and activated, so there is no situation where card reading operation interrupts remote communication; only when the system is idle will the power supply permission of the user-end NFC card reader module 2 be opened to respond to local card reading operations.

[0032] A control method for an electronic control system of a gas meter based on NDC non-contact coupling includes the following: S3-1, when the detachable remote communication module 8 is installed at the corresponding position of the gas base meter, the NDC reader unit 8-2 and the NDC tag unit 3 establish an NDC contactless NFC radio frequency coupling data link through a 13.56MHz radio frequency field, and realize bidirectional data transparent transmission in accordance with the standard NFC data interaction protocol. After the main control MCU1 recognizes the legitimate module access, it supports the original payment mode or switches to the postpaid working mode that supports NFC local interaction + remote background management. S3-2, the user-side NFC card reader module 2 supports CPU card interaction, and has built-in CPU card data domain planning, read / write control and hierarchical encryption / decryption logic, which can complete the reading, writing and identity verification of data in the card; it adopts an independent and controllable power supply domain and has controllable power-on and power-off timing control logic, and is in a completely power-off mode under normal conditions; when the system performs NDC remote communication tasks, the main control MCU1 locks the power supply path of the user-side NFC card reader module 2 to prevent it from being powered on and activated, thus eliminating the interference of the user-side NFC radio frequency signal to the NDC communication process from the hardware level, and there is no situation where the card reading operation interrupts the remote communication process; The S3-3 main control MCU1 has a built-in automatic standard identification unit. It reads the standard identification and identity verification information of the communication module through the NDC contactless NFC radio frequency coupling data link, and automatically loads the corresponding driver and communication protocol stack. It can adapt to different communication standards without upgrading the underlying firmware of the base table.

[0033] The electronic control system in this embodiment is divided into two parts: the base electronic unit and the detachable remote communication module 8.

[0034] The specific workflow of this control system is as follows: (1) Local prepaid mode (when the communication module is not installed): After the system is powered on, it enters the local prepaid mode by default, and the main controller disables the remote transmission driver and related task scheduling; the user-side NFC card reader module 2 is normally in a completely powered-off state with zero power consumption; only the metering acquisition, valve control drive module 5 and NDC detection circuit maintain low-power operation.

[0035] When a user brings an NFC card or mobile phone close to the sensing area, and the long press triggers the detection circuit to capture a valid signal, the main controller turns on the power supply to the user-end NFC card reader module 2, activates the card reading function, performs key verification and data interaction, updates the locally stored data after completing the recharge and balance query, and controls the valve opening and closing according to the remaining gas volume; after the operation is completed, the main controller immediately disconnects the power supply to the user-end NFC card reader module 2 and returns to the low-power standby state.

[0036] (2) Postpaid mode (installation of remote communication module): Install the detachable remote communication module into the corresponding mounting position of the base meter, with the radio frequency antennas on both sides facing each other, to establish an NDC contactless NFC radio frequency coupling data link; the main controller can be switched to postpaid working mode.

[0037] In this mode, the remote radio frequency unit wakes up at preset intervals, acquires metering data, equipment status and local operation logs through the NDC coupling link, uploads them to the gas operation backend, and simultaneously receives and executes valve control, parameter calibration and clock synchronization commands issued by the backend.

[0038] During remote communication, the main control MUC1 actively locks the power supply trigger path of the user-end NFC module 2. Even if a card reading trigger signal is detected, the power supply will not be turned on, ensuring that the user-end NFC card reading module 2 is continuously powered off, thus avoiding radio frequency crosstalk at the source and ensuring that the card reading operation does not interrupt the remote communication, thus guaranteeing the integrity and stability of remote data transmission.

[0039] Only after the remote communication ends and the system returns to an idle state will the main control MUC1 grant power to the NFC module and respond to local card reading operations; the user's NFC card reading function retains local query and emergency recharge permissions, and the operation data is synchronized to local storage and uploaded to the cloud through the remote transmission module.

[0040] (3) Non-destructive replacement process for remote transmission system: When the communication standard needs to be changed, simply remove the original communication module from the base meter, disconnect the NDC coupling link, and the main controller MUC1 can maintain the current payment mode. The payment mode can be selected through the optical interface tool or NFC card tool. Replace it with a communication module of the same size that carries the target standard. After the card is installed, re-establish the NDC coupling link. After the main controller reads the standard identifier of the new module and completes the identity verification, it automatically loads the corresponding driver and protocol. The remote transmission standard switch can be completed without modifying the base meter hardware, breaking the meter seal, or re-verifying.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any circuit equivalent substitutions, control logic modifications, standard extensions, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0042] The above are merely preferred embodiments of the present invention, intended only to aid in understanding the method and core ideas of this application. The scope of protection of the present invention is not limited to the above embodiments; all technical solutions falling within the scope of the present invention's concept are within its protection. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

[0043] This invention comprehensively addresses the shortcomings of existing technologies, such as reliance on physical connectors for communication between smart gas meters, difficulty in balancing reliability and sealing, unavoidable power consumption and interference issues due to the constantly powered design, and high lifecycle maintenance costs caused by factory-fixed communication standards. Through NDC non-contact coupling identification and standard adaptive mechanism, power domain mutual exclusion anti-interference mechanism, hierarchical low-power management mechanism, and adaptive switching logic for payment modes, the following specific functions are achieved: 1. NDC contactless coupling identity recognition and standard adaptive mechanism: The base meter controller periodically sends probe frames via the NDC RF coupling link to identify the legitimacy and communication standard of the connected communication module. Upon successful identification, it automatically loads the corresponding driver and communication protocol stack, completing adaptation without requiring an upgrade to the base meter's underlying firmware. When no legitimate module is identified, the NDC tag unit enters passive sleep mode, maintaining extremely low standby power consumption. Regardless of whether a module is connected, the customer can select a payment mode according to their needs, which can be changed via commands issued from the platform.

[0044] 2. Power domain mutual exclusion anti-interference mechanism: The user-side NFC card reader module employs an independent and controllable power supply domain, remaining completely powered off and consuming zero power under normal conditions. During remote communication tasks, the main controller actively locks the power supply trigger path of the user-side NFC module, preventing its activation upon power-up. This eliminates electromagnetic crosstalk between NFC radio frequency signals and the remote transmission channel at the hardware level, and also eliminates the possibility of card reading operations interrupting the remote communication process, ensuring the integrity and stability of remote data transmission. The main controller only grants power to the NFC module and responds to local card reading operations when the system is in a non-remote communication idle state.

[0045] 3. Hierarchical low-power management mechanism: Standby mode: The user's NFC module is completely powered off, the remote transmission circuits are in sleep mode, and the overall current is maintained at the microamp level; Local card reading status: Only the NFC module is temporarily powered on, while the other modules work as needed and are powered off immediately after the operation is completed; Remote communication status: NFC module power is locked, remote transmission unit and NDC link are working, no additional power consumption is added; When the module is not connected: the NDC tag unit goes into passive sleep with zero power consumption, and the detection circuit wakes up intermittently at second intervals to ensure the base meter's battery life for more than 6 years.

[0046] 4. Adaptive switching logic for payment modes: Module not connected: Local prepaid mode, billing and control are entirely based on local storage balance; Module access identification passed: Postpaid mode can be switched, user's NFC local emergency operation permission is retained, billing and valve control can be uniformly managed by the remote backend, and metering data is regularly transmitted and reported remotely. Module Removal: The payment mode can be selected and the remote transmission logic can be turned off through the optical interface tool or NFC card tool to ensure that the meter can still be used normally when the network is disconnected or the module fails.

Claims

1. An electronic control system for a gas meter based on NDC non-contact coupling, characterized in that, The system includes a base meter electronic unit that communicates with each other and an independently sealed detachable remote communication module (8); the base meter electronic unit includes a main control MCU (1), a user terminal NFC card reader module (2), an NDC tag unit (3), a metering acquisition module (4), a valve-controlled drive module (5), a low-power power management module (6), a data storage module (7), and an electromagnetic compatibility protection module (9); the detachable remote communication module (8) has a unified NDC radio frequency coupling interaction protocol and a mechanical installation interface, and includes a module control unit (8-1), an NDC reader / writer unit (8-2), and a remote radio frequency unit (8-3); the main control MCU (1) communicates bidirectionally with the metering acquisition module (4) and the valve-controlled drive module (5), and the main control MCU (1) communicates with the metering acquisition module (4) and the valve-controlled drive module (5) through I 2 The C-bus communicates bidirectionally with the user-end NFC card reader module (2) and the NDC tag unit (3). The main control MCU (1) communicates with the low-power power management module (6) and the data storage module (7). The module control unit (8-1) communicates with the NDC reader unit (8-2) and the remote transmission radio frequency unit (8-3) respectively. The electromagnetic compatibility protection module (9) communicates with other modules of the base meter electronic unit and the detachable remote transmission communication module (8).

2. The gas meter electronic control system based on NDC non-contact coupling according to claim 1, characterized in that, The NDC tag unit (3) is embedded inside the gas meter housing, and the NDC reader unit (8-2) is located inside the mating surface of the detachable remote communication module (8). There are no physical electrical contacts between the NDC reader unit (8-2) and the detachable remote communication module (8), and a millimeter-level air gap is maintained after assembly.

3. The gas meter electronic control system based on NDC non-contact coupling according to claim 2, characterized in that, The NDC reader unit (8-2) uses the FM17622 NFC card reader chip, and the NDC tag unit (3) uses the FM11NT083C dual-interface NFC tag chip. The NDC reader unit (8-2) and the NDC tag unit (3) establish a radio frequency communication link based on the ISO / IEC 14443 Type A protocol and follow the agreed inter-board private data transparent transmission protocol to complete bidirectional data interaction.

4. The gas meter electronic control system based on NDC non-contact coupling according to claim 1, characterized in that, The main control MCU (1) has a built-in 2-channel I / O. 2 The dedicated metering-grade low-power MCU with a C-bus interface and multiple configurable I / O ports and built-in linkage scheduling firmware includes a system identification unit, a power domain management unit, a billing mode switching unit, and a data encryption and verification unit responsible for system task scheduling, mode switching, and data processing; the user terminal NFC card reader module (2) has a built-in hierarchical key verification unit that distinguishes between user cards and tool cards, which includes an NFC radio frequency antenna, a card reader decoding chip, a hierarchical key verification unit, and a trigger detection circuit, and is connected to the main control MCU (1) through an independent power supply domain connected to the main control I / O port; the core of the NDC tag unit (3) is a dual-interface NFC tag chip and an onboard radio frequency antenna, and is connected to the main control MCU (1) through an I-bus interface and multiple configurable I / O ports. 2 The C interface is connected to the main control MCU (1); the metering acquisition module (4) is connected to the gas metering sensor of the valve control drive module (5); the low power management module (6) is an LDO array that supports the separate shutdown of idle module power and provides multiple independent power supply domains, and has a built-in battery voltage sampling circuit for real-time monitoring of lithium-ion battery status and low power triggering early warning.

5. The gas meter electronic control system based on NDC non-contact coupling according to claim 1, characterized in that, The module control unit (8-1) establishes a bidirectional data link with the gas base meter through the NDC reader unit (8-2); the core of the NDC reader unit (8-2) is an NFC reader chip and a corresponding radio frequency antenna, which are aligned with the NDC tag unit (3) after assembly.

6. The gas meter electronic control system based on NDC non-contact coupling according to claim 1, characterized in that, The method for non-destructive replacement of the remote transmission system of the control system is characterized by comprising the following steps: S1-1, Original module disassembly: Without opening the base meter housing or damaging the legal metering seal, remove the original detachable remote communication module (8) from the gas base meter installation position, disconnect the NDC contactless NFC radio frequency coupling data link, and keep the main control MCU (1) in the current payment mode. It can support switching to other payment modes and close the remote transmission related logic. S1-2, New module adaptation and installation: Replace the new detachable remote communication module (8) with the target communication standard. The new module maintains the same mechanical installation dimensions, NDC RF antenna position and general data interaction protocol as the original module. Install the new module into the gas meter mounting position and re-establish the NDC contactless NFC RF coupling data link. S1-3, Automatic Adaptation Operation: The main control MCU (1) reads the communication standard identifier of the new module through the coupling link and completes the identity verification. It automatically loads the corresponding standard driver and communication protocol stack. It can switch to the corresponding standard postpaid operation mode without upgrading the underlying firmware of the base table or re-measuring and verifying.

7. The gas meter electronic control system based on NDC non-contact coupling according to claim 6, characterized in that, The target communication standards include, but are not limited to, NB-IoT public network and LoRa wireless networking. Communication modules of different standards share a unified mechanical interface and NDC radio frequency coupling communication standard.

8. The gas meter electronic control system based on NDC non-contact coupling according to claim 1, characterized in that, The payment mode switching method of the control system includes the following steps: 2-1, Initial state configuration: After the base meter leaves the factory, it works in local prepaid mode by default. The main control MCU (1) closes the firmware logic related to remote communication. The user terminal NFC card reader module (2) is normally powered off, and only the metering acquisition, valve control drive and module detection circuit are kept in low power operation state. 2-2, Module access detection: The detachable remote communication module (8) is assembled into the preset mounting position of the base table. The NDC reader unit (8-2) and the NDC tag unit (3) establish a contactless NFC radio frequency coupling data link. The main control MCU (1) periodically sends detection frames through the link to identify whether there is a legitimate communication module access. 2-3, Mutually exclusive collaborative operation: In the postpaid mode, during the remote communication execution, the main control MCU (1) locks the power supply path of the user terminal NFC card reader module (2) and prohibits it from being powered on and activated. There is no situation where the card reading operation interrupts the remote communication. Only when the system is idle will the power supply permission of the user terminal NFC card reader module (2) be opened to respond to the local card reading operation.

9. A control method for a gas meter electronic control system based on NDC non-contact coupling as described in claim 1, characterized in that, Includes the following: S3-1, when the detachable remote communication module (8) is installed at the corresponding position of the gas base meter, the NDC reader unit (8-2) and the NDC tag unit (3) establish an NDC contactless NFC radio frequency coupling data link through a 13.56MHz radio frequency field, and realize bidirectional data transmission in accordance with the standard NFC data interaction protocol. After the main control MCU (1) recognizes the access of the legitimate module, it supports the original payment mode or switches to the postpaid working mode that supports NFC local interaction + remote background management. S3-2, the user terminal NFC card reader module (2) adopts an independent controllable power supply domain and has controllable power-on and power-off timing control logic. Under normal conditions, it is in a completely power-off mode. When the system performs NDC remote communication tasks, the main control MCU (1) locks the power supply path of the user terminal NFC card reader module (2) to prevent it from being activated by power-on. This eliminates the interference of the user terminal NFC radio frequency signal to the NDC communication process from the hardware level, and there is no situation where the card reading operation interrupts the remote communication process. S3-3, the main control MCU (1) has a built-in automatic standard identification unit. It reads the standard identification and identity verification information of the communication module through the NDC contactless NFC radio frequency coupling data link, and automatically loads the corresponding driver and communication protocol stack. It can adapt to different communication standards without upgrading the underlying firmware of the base table.

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