MBUS slave enhancing system

Abstract

The invention discloses an MBUS (Meter Bus) slave enhancing system, which is suitable for a remote meter reading system of an instrument, and is particularly suitable for an MBUS bus environment with a large number of slaves and complex communication. The enhancement system comprises a main control unit, an MBUS communication interface module, a reset system, a four-way independent MBUS output module, a voltage monitoring module, a current protection module and an abnormity identification and reporting mechanism. And the main control unit communicates with the concentrator through an MBUS interface, analyzes an instruction and controls the states of the four output channels, and each channel can be connected with at most two slaves and supports independent switching and state monitoring. When short circuit, dynamic current interference or abnormal current occurs in a certain path, the system can automatically turn off the path and report abnormal information to the concentrator. The enhanced system supports segmented control and dynamic scheduling of communication loads, the communication stability and the meter reading success rate of the system are remarkably improved, and the enhanced system is particularly suitable for low-power-consumption application in a battery power supply scene. The device can be seamlessly accessed to the existing MBUS system, and has good compatibility.

Description

Technical Field

[0001] The invention relates to an MBUS slave enhancement system, and belongs to the field of remote meter reading. Background Art

[0002] MBUS (Meter-Bus) is a fieldbus protocol designed for remote meter reading and data collection. It is widely used in IoT metering devices such as smart water meters, electricity meters, gas meters, and heat meters. MBUS utilizes a master-slave architecture, with the MBUS concentrator acting as the master station controlling communications between multiple slave devices. It offers advantages such as low cost, low power consumption, and long-distance transmission.

[0003] In actual projects, MBUS bus usually adopts a multi-slave parallel structure, and all MBUS slaves share a set of communication lines through the bus for centralized reading. However, with the increase in the number of connected devices, the MBUS system has exposed the following problems in operation: (See the attached manual Figure 8-10 ) 1. Wide range of fault impact: Since all slave devices share a bus, once a slave device has a short circuit, dynamic current interference or device failure, it is easy to cause the entire bus communication to be paralyzed, resulting in the inability to read data from all devices; 2. The cumulative effect of interference signals is obvious: After aging or damage, the internal circuits of some slave devices generate irregular pulse signals or periodic dynamic currents. When multiple such devices are connected to the bus at the same time, they will cause superimposed interference to the return signal of normal devices, causing serious bit errors. 3. Difficulty in troubleshooting and high maintenance costs: On-site troubleshooting is generally conducted using a binary method. After the bus is divided into several sections and disconnected, each section can be read normally, but when connected together, all sections fail. This is the reason. This brings great difficulties to on-site maintenance work, dramatically increases the workload, greatly reduces work efficiency, increases maintenance costs, reduces corporate benefits, and is not conducive to the national call for energy conservation and emission reduction. 4. High energy consumption in battery-powered scenarios: All slave devices are connected in parallel for a long time. Especially in applications where the mains is lost and the system relies on batteries for operation, the overall current load of the system is large, which shortens the battery life.

[0004] 5. Excessive bus current variation: When the bus voltage remains unchanged, the bus current variation within 10 seconds should not exceed ±1%. Summary of the Invention

[0005] The object of the present invention is to provide an MBUS slave enhancement system that can effectively solve the above-mentioned problems.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: It includes a main control unit (MCU), which is used to control the operating status of the entire MBUS enhancement system, parse and execute data collection, data reporting, status reporting and other instructions issued by the MBUS concentrator; MBUS communication interface module, including MBUS interface chip MC8721C, which is connected to the MBUS bus through a rectifier bridge and protection circuit, and converts bus signals into communication signals recognizable by the MCU, supporting two-way communication between the MCU and the MBUS concentrator; The reset system uses the MAX809S chip to monitor the system's operating status in real time and output a reset signal to the MCU when the system is abnormal to prevent the system from entering a dead state. Multi-channel MBUS output module, including at least four independent output channels KZ1~KZ4, each of which is controlled by an independent MOS tube and can be connected to 1 to 2 MBUS slave devices respectively. Each channel can be independently turned on or off by the MCU; The voltage monitoring module connects a voltage sampling resistor R14 in series to each MBUS output. This module indirectly obtains load current information by detecting voltage changes and can identify static operating current, abnormal operating current, and short-circuit conditions. The current protection module includes a protection circuit consisting of a sampling resistor, MOS tube, and transistor. It can trigger automatic disconnection when the current increases abnormally or a short circuit occurs. It also supports MCU remote control of disconnection or recovery. The system abnormality identification and reporting module has an intelligent judgment function. The MCU can identify abnormal slaves based on monitoring data and automatically shut down. At the same time, it reports to the concentrator through the MBUS communication interface, and the concentrator uploads it to the background server.

[0007] Furthermore: the MBUS enhancement system defaults to all output channels being in the open state during initialization, and when no MBUS concentrator control instruction is received, the channels are in the transparent direct transmission state.

[0008] Furthermore: the voltage monitoring module is used to identify the abnormal voltage status of the MBUS slave in real time. When the voltage drops to a set threshold or fluctuates abnormally, the MCU issues a command to shut down the corresponding channel.

[0009] Furthermore: the MOS tube and the transistor in the current protection module form a locking circuit, which can close the channel when a short circuit or overcurrent abnormality is detected, and support the MCU to actively clear the locking state to reopen it.

[0010] Furthermore: Each MBUS output channel has electrical isolation and protection functions to prevent the entire bus communication from failing due to an abnormality in a slave device.

[0011] Furthermore: the input end of the MBUS communication interface module is provided with a protection circuit consisting of a rectifier bridge, a self-recovery fuse and a transient suppression diode, which is used for signal rectification, power supply protection and surge suppression.

[0012] Furthermore: the input end of the MBUS communication interface module is provided with a protection circuit consisting of a rectifier bridge, a self-recovery fuse and a transient suppression diode, which is used for signal rectification, power supply protection and surge suppression.

[0013] Furthermore: When there are multiple MBUS slave devices generating dynamic current, the MCU can identify the dynamic current waveform and isolate and shut down the channel to prevent the dynamic current from being superimposed on the normal device return current, resulting in communication errors or data loss.

[0014] Furthermore: it supports unit management of the entire MBUS bus through system algorithms, divides the entire line into several communication units, opens channels in sequence through timing management, realizes segmented communication, and improves bus communication efficiency.

[0015] Furthermore, in a battery-powered MBUS data acquisition system, the unitized management method can significantly reduce the average operating current of the system, extend the battery life, and reduce operating costs.

[0016] The beneficial effects are: The enhanced MBUS system features four independently controlled output channels, each capable of connecting to one or two MBUS slaves and individually controlled by the MCU for on / off switching. This radically changes the traditional "all-connected" architecture of the MBUS bus. If a device on a channel fails, it can be individually shut down without affecting communications with other slaves, significantly improving system stability and fault tolerance.

[0017] Built-in current and voltage sampling circuits and intelligent judgment algorithms can detect abnormal behavior such as dynamic current fluctuations and short circuits in slave devices in real time, and transmit this information back to the server via the MBUS concentrator. Maintenance personnel can directly identify the faulty channel or device through the system backend, avoiding tedious manual troubleshooting and significantly reducing manpower and time costs.

[0018] The system algorithm supports polling channels according to time strategies. By opening channels in batches and reading slave data in sections, the number of slaves connected instantly can be effectively controlled, the probability of interference current superposition can be reduced, the bit error rate can be reduced, and the communication success rate can be improved.

[0019] The enhanced system has a hardware-level overcurrent protection function, which can automatically lock the channel in the event of a short circuit or current abnormality, preventing faulty equipment from damaging the main control system, and can be remotely unlocked and restored through the MCU.

[0020] In an environment without mains power, the MBUS enhanced system reduces the instantaneous current total load by optimizing the slave activation strategy, extends the operating time of the battery-powered system, improves the system energy efficiency, and complies with the national energy conservation and emission reduction policy.

[0021] The enhanced system structure of the present invention is flexible in design, does not require changes to the MBUS concentrator hardware or software or communication protocol, has good system compatibility and field deployability, and can be directly connected to the existing MBUS system for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] For ease of explanation, the present invention is described in detail with reference to the following specific implementations and accompanying drawings.

[0023] Figure 1 A circuit diagram of the present invention; Figure 2 This is a circuit diagram of the main control unit of the present invention; Figure 3 This is a circuit diagram of the MBUS communication interface module of the present invention; Figure 4 This is a circuit diagram of the reset system of the present invention; Figure 5 This is a circuit diagram of the multi-channel MBUS output module, voltage monitoring module, and current protection module of the present invention; Figure 6 This is a schematic diagram of the on-site wiring of the MBUS device of the present invention; Figure 7 It is a four-way control flow diagram of the present invention; Figure 8 This is a current abnormal increase signal diagram of the prior art in the present invention; Figure 9 This is a current fluctuation signal diagram of the prior art in the present invention; Figure 10 This is a diagram of a high current pulse signal according to the prior art of the present invention. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0025] Furthermore, in the description of the present invention, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0026] See Figure 1-10 This is an embodiment of the MBUS slave enhancement system of the present invention. The system provides a controllable, relayed, and isolated communication bridge between an MBUS concentrator and multiple MBUS slaves. Its core purpose is to improve system communication stability and prevent slave failures from paralyzing the entire MBUS bus. This system is particularly suitable for scenarios with densely wired multiple meters, complex environments, and battery-powered systems.

[0027] The system mainly includes the following modules: main control unit (MCU), MBUS communication interface module, reset system, multi-channel MBUS output module, voltage monitoring module, current protection module, abnormality identification and reporting mechanism.

[0028] like Figure 2 As shown in the figure, the system's main control unit (MCU) uses the HC32L110C6PA, an ultra-low-power 32-bit microcontroller with a rich built-in GPIO interface and ADC sampling module, making it suitable for low-power communication and edge processing scenarios. The MCU's main functions include: communicating with the MBUS concentrator and parsing commands issued by it, such as data collection, status query, and fault control; controlling the on / off status of four MBUS slave output channels; sampling current and voltage data from each channel in real time and analyzing fault signals; isolating and controlling abnormal slave devices and recording fault status; and generating exception reporting packets and returning them to the concentrator via the MBUS interface.

[0029] By default, all output channels of the MCU are enabled and transparent forwarding is supported in the initial state. The slave data can be directly uploaded to the concentrator without additional configuration.

[0030] like Figure 3 As shown in the figure, the MBUS communication interface module of this system is the core communication component in the MBUS enhanced system. It is responsible for realizing the physical signal conversion and logical protocol connection between the MBUS concentrator and the main control unit (MCU), and is the signal "entrance" of the entire system.

[0031] The MBUS communication interface module mainly completes the following tasks: 1. Receives two-wire signals (power + data superposition) from the MBUS concentrator; 2. Performs pre-stage protection such as rectification, voltage limiting, and surge protection; 3. Converts physical signals into TTL-level serial data (UART) for the MCU to read and respond; 4. Converts the UART control signal output by the MCU into MBUS protocol signals and sends them to the concentrator.

[0032] The module mainly includes the following circuit units: MBUS interface chip (U3, model: MC8721C), rectifier bridge (D1, model: MB6S), self-recovery fuses (F1, F2, model: JK-nSMD005), transient suppression diode (TVS, D2, model: SMBJ36CA), filtering and coupling capacitors (such as C5, C6, C4); The MBUS interface chip (U3) rectifies the incoming MBUS two-wire (AC1, AC2) signal into a unidirectional voltage, ensuring that downstream circuits are unaffected by wiring polarity and enhancing access flexibility. Resettable fuses (F1, F2) provide current limiting and overload protection. If the input current exceeds a certain value, they automatically disconnect the circuit and automatically recover after the temperature drops, effectively protecting downstream chips from burnout. The transient suppression diode (D2) quickly absorbs and clamps surge voltages at the input, suppressing transients such as lightning strikes and strong electromagnetic interference, thereby improving the device's anti-interference capabilities and stability. Filter and coupling capacitors (such as C5, C6, and C4) smooth the rectified voltage, suppressing high-frequency interference and improving communication quality.

[0033] The MBUS interface chip (U3) is a dedicated chip for converting MBUS signals to TTL signals. Its main pins are described as follows: SC / STC: MBUS signal input terminal; TX / RX: UART interface output pin, connected to the MCU; VDD / GND: operating voltage and ground; VB / RIDD: MBUS power input and current limit pin.

[0034] The MBUS communication interface module in this invention is the core component that enables physical connection and protocol conversion between the MBUS booster and MBUS concentrator. This module is primarily based on the MC8721C communication interface chip and works with a rectifier protection circuit to receive, convert, and transmit MBUS signals, offering high compatibility and reliability.

[0035] After entering the interface chip MC8721C, the signal enters its built-in current modulation identification and level conversion circuit, which performs the following functions: Receiving direction (host computer → MCU): The command sent by the MBUS concentrator is transmitted to the bus through current modulation technology (i.e., adding a certain modulation frequency to the load current). The chip internally identifies the current change and converts it into a TTL serial signal of the standard UART protocol. The TTL signal is output from the chip's TX (Transmit) pin and connected to the MCU's RXD (Receive) pin. The MCU reads the data frame and further parses and processes it, such as determining whether it is a meter reading instruction, a control command, or a status query.

[0036] Transmit direction (MCU → host computer): The MCU outputs UART data to the MC8721C's RX pin via the TXD (transmit) pin. The chip converts the TTL signal into MBUS format, modulating the current load in a certain way to generate a return code signal on the bus. The concentrator recognizes and interprets this current return code signal to complete the response of a frame of data.

[0037] The function of the MBUS communication interface module is as follows: the MBUS concentrator is connected to the rectifier bridge D1 via a two-wire bus (positive and negative poles). The rectified signal is protected by self-resettable fuses F1 and F2, and surges are eliminated by transient suppression diode D2. After the signal enters the MC8721C, the chip completes the conversion of the MBUS physical layer signal to a UART logic signal. The converted UART signal is connected to the MCU serial port through TXD and RXD, realizing reliable communication between the concentrator and the enhanced system.

[0038] like Figure 4 As shown in the figure, the reset system of this system uses the MAX809S chip to monitor the MCU operating voltage and reset pin status: when the MCU crashes due to abnormal program or power jitter, the MAX809S detects the system abnormality and immediately outputs a low-level signal to the MCU reset pin, thus realizing automatic system recovery and avoiding communication interruption caused by MCU hanging.

[0039] like Figure 5 、 Figure 7 As shown in the figure, the four-channel MBUS output module of this system is the core functional module of the MBUS enhancement system of the present invention. Its function is to: after the communication signal from the MBUS concentrator is processed by the main control unit (MCU) of this enhancement system, it is sent to the connected MBUS slave devices through four independent output channels, and supports independent control, monitoring and fault isolation of each slave channel, thereby ensuring the stability and security of the entire bus communication.

[0040] The four-channel MBUS output module includes the following components: four MBUS output channels (KZ1, KZ2, KZ3, KZ4); four power MOS tubes (Q1, Q2, Q3, Q4); four control signal input ports (output by the MCU); load protection sampling resistors (R14, R4, R5); filtering and coupling capacitors (such as C7); and a locking device that works in conjunction with the current protection module.

[0041] Circuit connection method: The output of each MBUS channel (KZ1-KZ4) is controlled by an N-channel MOS transistor (model: NCE0103M); the source of each MOS transistor is connected to the positive terminal of the system VMBUS main power supply; the drain is connected to the corresponding output terminal KZx (x is 1-4), and then connected to the external MBUS slave; the gate is connected to the digital output pin (IO port) of the MCU, and the high and low levels output by the MCU control its conduction or shutdown; each channel is also connected in series with a sampling resistor (such as R14) for voltage / current monitoring.

[0042] According to the circuit connection mode of the MBUS output module, four independent channel control functions can be realized; that is, each MBUS output is controlled by a MOS tube, and the MCU independently controls the conduction and shutdown of the channel by controlling the gate level: Output high level: MOS tube is turned on, the channel is opened, and the corresponding slave is powered on and can communicate; Output low level: MOS tube is turned off, the channel is disconnected, the slave is powered off and cannot communicate.

[0043] Each channel supports up to two MBUS slave devices, with actual configuration based on load capacity and bus bandwidth to ensure stable communication. Upon initial power-up, the enhanced system defaults to enabling four channels. When the MBUS concentrator is not issuing commands, all slave devices transparently transmit communication signals, behaving like a traditional MBUS bus. In this mode, slave devices can respond to concentrator commands in real time, and the enhanced system does not actively intervene, acting only as a relay.

[0044] When the concentrator issues a command or the MCU detects an abnormal load, the MCU can immediately shut down a channel to achieve physical isolation. Channels can be dynamically opened according to time periods, logical polling, etc. for "segmented meter reading" or "low power mode" operation. Automatic recovery strategy is supported: when the fault is eliminated or the timeout is restored, the MCU can control the reopening of the channel.

[0045] Each channel's output is equipped with a sampling resistor to detect current anomalies. Once a short circuit or overcurrent occurs, the signal triggers the current protection module (Q5, Q7) to lock and disconnect the MOS tube, protecting the main control board and power supply circuit from reverse interference or breakdown by the faulty slave device. The MCU needs to determine the recovery conditions and send an "unlock" signal to restore normal operation.

[0046] like Figure 5 As shown, a voltage monitoring module is also set on the four-channel MBUS output module. The voltage monitoring module is based on the sampling resistor R14 connected in series with each output channel and is combined with the MCU's built-in ADC to achieve: The voltage drop data of each output is read in real time to indirectly calculate the load current value; it determines whether there are abnormal changes (such as sudden current surges, continuous current disturbances, etc.); when the current rise does not reach the point of short circuit but significantly deviates from the normal operating range, the MCU records the channel number and abnormality type to decide whether to issue a shutdown command.

[0047] like Figure 5 As shown, a current protection module is also provided on the four-way MBUS output module. In order to prevent the circuit from being damaged due to short circuit, the enhanced system also has an automatic locking mechanism: On the KZ output side, sampling resistors R4 and R5 are set to cooperate with MOS tube Q5 and transistor Q7. When an abnormally rapid increase in current is detected (such as a slave short circuit), Q7 is turned on, the gate of Q5 is pulled low, and the channel is locked. In the locked-off state, even if the MCU command is not issued, the channel cannot be restored to avoid further damage. Only when the MCU detection system returns to normal can a command be issued to restart the channel and release the lock.

[0048] Abnormal identification and reporting mechanism: The MBUS enhanced system can automatically identify the following abnormal conditions: 1. Slave short circuit; 2. Dynamic current disturbance (periodic opening and closing, causing return code interference); 3. Bus error caused by pulse superposition of multiple faulty devices; 4. Hidden fault where the entire line fails to communicate but local tests are normal.

[0049] After identification, the MCU generates an alarm information packet and uploads it to the concentrator via the MBUS communication module. The concentrator then uploads the information to the management backend server. Maintenance personnel can quickly locate the faulty device based on the prompts, avoiding large-scale disconnection testing.

[0050] The actual operation process of this system is as follows: 1. When powered on for the first time, the MCU initializes all channels to the open state; 2. When the concentrator issues a command for polling or centralized meter reading, the enhanced system accepts the command and dispatches a response; 3. If the concentrator does not issue a control command, the system maintains the default transparent pass-through mode; 4. When an abnormality occurs in a slave device, the enhanced system will immediately shut down the channel and report it; 5. The system can use the segmented control algorithm to open each group of slave channels in chronological order to control the instantaneous load of the bus; 6. Especially suitable for battery-powered scenarios, it can reduce current peaks and improve device life.

[0051] Through intelligent identification, independent on-off control and reporting mechanisms, the present invention significantly reduces the communication bit error rate and system downtime rate, significantly improves the stability and operation and maintenance efficiency of the MBUS system, and has extremely high industrial application value.

[0052] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An MBUS slave enhancement system, characterized by: It includes a main control unit, which is used to control the operating status of the entire MBUS concentrator, parse and execute the data collection, data reporting and status reporting instructions issued by the MBUS concentrator; MBUS communication interface module, including an interface chip MC8721C, which is connected to the MBUS bus through a rectifier bridge and a protection circuit, and converts MBUS bus signals into communication signals recognizable by the main control unit, supporting two-way communication between the main control unit and the MBUS concentrator; The reset system uses the MAX809S chip to monitor the system operation status in real time and output a reset signal to the main control unit when the system is abnormal; Multi-channel MBUS output module, including at least four independent output channels KZ1~KZ4, each of which is controlled by an independent MOS tube and can be connected to 1 to 2 MBUS slave devices respectively. Each channel can be independently turned on or off by the main control unit; The voltage monitoring module connects a voltage sampling resistor R14 in series to each MBUS output. This module indirectly obtains load current information by detecting voltage changes and can identify static operating current, abnormal operating current, and short-circuit conditions. The current protection module includes a protection circuit composed of a sampling resistor, a MOS tube, and a triode, which can trigger automatic disconnection when the current increases abnormally or a short circuit occurs, and supports remote control disconnection or recovery by the main control unit; The system abnormality identification and reporting module, the main control unit has an intelligent judgment function, can identify abnormal slaves based on monitoring data and automatically shut down, and at the same time report to the MBUS concentrator through the MBUS communication interface module, and the MBUS concentrator uploads it to the background server.

2. The MBUS slave enhancement system according to claim 1, characterized in that: The enhanced system defaults to all output channels being in an open state during initialization, and when no control instruction from the MBUS concentrator is received, the channels are in a transparent direct transmission state.

3. The MBUS slave enhancement system according to claim 1, wherein: The voltage monitoring module is used to identify the abnormal voltage status of the MBUS slave in real time. When the voltage drops to a set threshold or fluctuates abnormally, the main control unit issues an instruction to shut down the corresponding channel.

4. The MBUS slave enhancement system according to claim 1, wherein: The MOS tube and the transistor in the current protection module form a locking circuit, which can close the channel when a short circuit or overcurrent abnormality is detected, and support the main control unit to actively clear the locking state and reopen it.

5. The MBUS slave enhancement system according to claim 1, characterized in that: Each MBUS output channel has electrical isolation and protection functions.

6. The MBUS slave enhancement system according to claim 1, characterized in that: The input end of the MBUS communication interface module is provided with a protection circuit consisting of a rectifier bridge, a self-recovery fuse and a transient suppression diode.

7. The MBUS slave enhancement system according to claim 1, characterized in that: When multiple MBUS slave devices generate dynamic current, the main control unit can identify the dynamic current waveform and isolate and shut down the channel.

8. The MBUS slave enhancement system according to claim 1, wherein: It supports unit management of the entire MBUS bus through system algorithms, divides the entire line into several communication units, and opens channels in sequence through timing management to achieve segmented communication.

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