An M-Bus master-slave communication data monitoring circuit, device, and smart meter

Abstract

This utility model relates to an M-Bus master-slave communication data monitoring circuit, device, and smart meter, including an M-Bus to UART communication circuit and a UART to USB communication circuit. The M-Bus to UART communication circuit includes an M-Bus interface chip, an M-Bus signal input interface, and an adjustment circuit. The M-Bus bus is connected to the M-Bus signal input interface, which is connected to the M-Bus interface chip via the adjustment circuit. The UART to USB communication circuit includes a signal conversion chip and a USB interface. The data signal input and data signal output terminals of the M-Bus interface chip are connected to the signal conversion chip, which is connected to the USB interface. By setting up a two-stage conversion circuit, M-Bus communication data can be converted into a data format recognizable by the USB interface in real time, thereby achieving seamless connection with terminal devices such as PCs.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, specifically to an M-Bus master-slave communication data monitoring circuit, device, and smart meter. Background Technology

[0002] With the development of smart grids and energy management systems, M-Bus (Meter-Bus), a communication protocol specifically designed for metering devices, is widely used in water meters, gas meters, heat meters, and smart meters. This protocol features low power consumption, long-distance transmission capability, and good anti-interference performance. It supports a master-slave communication structure, enabling centralized data acquisition and management of multiple metering devices on the same bus, thus playing a crucial role in automatic meter reading systems and building automation systems.

[0003] However, in practical applications, M-Bus systems still face numerous technical challenges. Because the M-Bus interface is not a standard interface for general-purpose computing devices, traditional M-Bus devices struggle to directly interact with PCs or mobile terminals, typically requiring dedicated master controllers or conversion equipment. This leads to complex and costly debugging and maintenance processes. Furthermore, existing M-Bus systems lack real-time monitoring capabilities for communication data frames. Once communication anomalies occur, it's difficult to quickly pinpoint the root cause, impacting system stability and fault response efficiency. Simultaneously, addressing the diverse needs of different application scenarios by reducing hardware costs and simplifying cabling while ensuring communication reliability remains a key issue hindering the further adoption of M-Bus technology. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides an M-Bus master-slave communication data monitoring circuit, including an M-Bus to UART communication circuit and a UART to USB communication circuit. The M-Bus to UART communication circuit includes an M-Bus interface chip, an M-Bus signal input interface, and an adjustment circuit. The M-Bus bus is connected to the M-Bus signal input interface, which is connected to the M-Bus interface chip via the adjustment circuit. The M-Bus interface chip is used to convert M-Bus bus communication to UART communication. The UART to USB communication circuit includes a signal conversion chip and a USB interface. The data signal input and data signal output terminals of the M-Bus interface chip are connected to the signal conversion chip, which is connected to the USB interface. The signal conversion chip is used to convert UART communication to USB communication, enabling communication with terminal devices via USB and thus monitoring the M-Bus bus signal.

[0005] Based on the above scheme, the adjustment circuit includes a first dual Schottky diode, a thermistor, a first bidirectional TVS diode, and a second dual Schottky diode. The first end of the M-Bus signal input interface is connected to the first end of the first bidirectional TVS diode via the thermistor. The second end of the M-Bus signal input interface is connected to the second end of the first bidirectional TVS diode. The second end of the M-Bus signal input interface is also connected to the third end of the second dual Schottky diode. The first end of the second dual Schottky diode is connected to the data signal output terminal of the M-Bus interface chip via a first resistor. The second end of the second dual Schottky diode is connected to the bus signal input terminal of the M-Bus interface chip. The thermistor is also connected to the third end of the first dual Schottky diode. The first end of the first dual Schottky diode is grounded. The second end of the first dual Schottky diode is connected to the bus signal input terminal of the M-Bus interface chip.

[0006] Based on the above scheme, the UART to USB communication circuit further includes a second bidirectional TVS diode, a third bidirectional TVS diode, and a fourth bidirectional TVS diode. The UD+ terminal of the signal conversion chip is connected to the D+ terminal of the USB interface, and the UD- terminal of the signal conversion chip is connected to the D- terminal of the USB interface. The D- terminal of the USB interface is grounded through the second bidirectional TVS diode, and the D+ terminal of the USB interface is grounded through the fourth bidirectional TVS diode. The third bidirectional TVS diode is connected between the D- terminal and the D+ terminal of the USB interface.

[0007] Furthermore, the M-Bus to UART communication circuit also includes a bus current value adjustment resistor and a holding capacitor. The output current of the VDO terminal of the M-Bus interface chip is adjusted by setting the resistance value of the bus current value adjustment resistor. The holding capacitor is an aluminum electrolytic capacitor used to suppress voltage fluctuations during communication.

[0008] On the other hand, this application also provides an M-Bus master-slave communication data monitoring device, including the aforementioned M-Bus master-slave communication data monitoring circuit, connected between a device with a USB interface and the M-BUS bus, for monitoring M-BUS bus data.

[0009] This utility model also provides a smart meter that uses the aforementioned M-Bus master-slave communication data monitoring circuit or device to acquire electricity usage data.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0011] 1. By setting up a two-stage conversion structure of M-Bus to UART communication circuit and UART to USB communication circuit, M-Bus communication data can be converted into a data format that the USB interface can recognize in real time, thereby achieving seamless connection with terminal devices such as PCs;

[0012] 2. The adjustment circuit not only improves the stability of signal transmission, but also effectively prevents problems such as voltage fluctuations, electrostatic interference and overcurrent damage, ensuring the reliability of M-Bus communication in complex industrial environments. Attached Figure Description

[0013] Figure 1 This is an overall structural diagram of the present invention;

[0014] Figure 2 This is the circuit diagram of the M-Bus to UART communication circuit of this utility model;

[0015] Figure 3 This is the circuit diagram for the UART to USB communication converter of this utility model. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings:

[0017] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0018] Example 1

[0019] This embodiment provides the following technical solution: an M-Bus master-slave communication data monitoring circuit, see reference. Figure 1 It includes an M-Bus to UART communication circuit and a UART to USB communication circuit, which are used to convert signals on the M-Bus bus to USB communication signals and vice versa, so that M-Bus interface devices can be easily monitored and maintained using PCs and other devices.

[0020] The M-Bus to UART communication circuit includes an M-Bus signal input interface, an M-Bus interface chip, and an adjustment circuit. The M-Bus bus is connected to the M-Bus signal input interface, and the M-Bus signal input interface is connected to the M-Bus interface chip through the adjustment circuit. The M-Bus interface chip is used to convert M-Bus bus communication to UART communication.

[0021] Specifically, such as Figure 2 As shown, the M-Bus to UART communication circuit includes an M-Bus signal input interface JH1, an M-BUS interface chip, and an adjustment circuit. The adjustment circuit includes a first dual Schottky diode DH1, a thermistor RH1, a first bidirectional TVS diode DH2, and a second dual Schottky diode DH3. The first terminal of JH1 is connected to the third terminal of DH1 via RH1. RH1 is also connected to the first terminal of DH2. The first terminal of DH1 is connected to MGND. The second terminal of DH1 is connected to the second terminal of DH3 and the bus signal input terminal Vin of UH1. The second terminal of DH3 is also connected to Vin. The first terminal of DH3 has two paths: one path connects to the data signal output terminal TXD of UH1 via the first resistor RH2, and the other path connects to MGND via the second resistor RH3. RH1 plays a protective role in the circuit; when the external current signal is abnormal, the thermistor enters a high-resistance state to protect the circuit from damage. DH1 and DH3 enable unidirectional conduction control of the bus current, ensuring that the current flows only from the bus to the input terminal Vin of chip UH1. The dual Schottky diodes, in conjunction with the TVS diode, can limit the level of the signal input to UH1 to prevent damage to the chip due to excessive voltage.

[0022] The UART to USB communication circuit includes a signal conversion chip and a USB interface. The data signal input terminal RXD and data signal output terminal TXD of the M-Bus interface chip are connected to the signal conversion chip, which is connected to the USB interface. The signal conversion chip is used to convert UART communication to USB communication, and communicate with the terminal device via USB.

[0023] Specifically, such as Figure 3 As shown, the UART-to-USB communication circuit also includes a second bidirectional TVS diode D1, a third bidirectional TVS diode D2, and a fourth bidirectional TVS diode D3. The UD+ terminal of the signal conversion chip UC1 is connected to the D+ terminal of the USB interface J1, and the UD- terminal of UC1 is connected to the D- terminal of J1. The D- terminal of J1 is grounded through D1, and the D+ terminal of J1 is grounded through D3. A D2 connects the D- and D+ terminals of J1. The bidirectional TVS diodes provide protection; when an external signal voltage is abnormal, regardless of which voltage segment is abnormal, the bidirectional TVS diodes can quickly respond and absorb the excessive voltage, thus protecting the circuit from damage.

[0024] In practice, the M-Bus bus is connected through the JH1 port, and after passing through the second Schottky diode, it enters the M-Bus interface chip UH1. UH1 converts the M-Bus bus communication into UART communication, and then through UC1, the UART communication is converted into USB communication. Through USB, it communicates with terminal devices such as PCs to monitor and maintain the M-Bus signal.

[0025] Example 2

[0026] Based on Embodiment 1, in order to operate stably under complex environmental conditions and have better anti-interference and stability, this utility model designs the circuit to make it more adaptable.

[0027] The M-Bus to UART communication circuit also includes a bus current adjustment resistor RH5 and a holding capacitor EH1. The output current of the VDO terminal of UH1 is adjusted by setting the resistance value of RH5, thereby meeting the load requirements of the subsequent circuit. EH1 is an aluminum electrolytic capacitor. A large-capacity aluminum electrolytic capacitor can better cope with transient changes in power supply and play a role in stabilizing voltage, so that the bus voltage remains unchanged when the bus current is modulated to transmit data.

[0028] The M-Bus to UART communication circuit also includes CH1 and RH4. CH1 is a surface-mount ceramic capacitor, with one end connected to MGND and the other end connected to the receiving demodulation capacitor terminal RXC of UH1. RH4 is a surface-mount resistor, with one end connected to M+5V and the other end connected to the data signal output terminal TXD of UH1, pulling the data signal output terminal TXD up to M+5V.

[0029] The UART to USB communication circuit also includes a first capacitor C1 and a second capacitor C2. C1 and C2 are surface-mount ceramic capacitors. C1 is connected between the VCC terminal of UC1 and MGND, and C2 is connected between the +5V terminal of J1 and MGND. C1 and C2 are used to filter out high-frequency AC signals to reduce the impact of ripple on the chip.

[0030] Based on the same concept, this application also provides an M-Bus master-slave communication data monitoring device, including the aforementioned M-Bus master-slave communication data monitoring circuit, connected between a device with a USB interface and the M-BUS bus, for monitoring M-BUS bus data. This device can be used to connect multiple devices, such as water meters, gas meters, and heat meters, to achieve centralized data acquisition system monitoring through a bus structure.

[0031] This invention also provides a smart meter that uses the aforementioned M-Bus master-slave communication data monitoring circuit or device to acquire electricity usage data. The M-Bus-based smart meter can upload the collected data to a cloud platform via the M-Bus master-slave communication data monitoring circuit or device for further system stability analysis, thus meeting the development needs of smart grids.

[0032] The foregoing has shown and described the basic principles and main features of this utility model. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments. Therefore, the embodiments should be regarded as exemplary and non-limiting. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims within this utility model.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A data monitoring circuit for communication between a master and a slave in an M-Bus system, characterized in that The system includes an M-Bus to UART communication circuit and a UART to USB communication circuit. The M-Bus to UART communication circuit includes an M-Bus interface chip, an M-Bus signal input interface, and an adjustment circuit. The M-Bus bus is connected to the M-Bus signal input interface, and the M-Bus signal input interface is connected to the M-Bus interface chip through the adjustment circuit. The M-Bus interface chip is used to convert M-Bus bus communication to UART communication. The UART to USB communication circuit includes a signal conversion chip and a USB interface. The data signal input and data signal output terminals of the M-Bus interface chip are connected to the signal conversion chip, and the signal conversion chip is connected to the USB interface. The signal conversion chip is used to convert UART communication to USB communication, enabling communication with terminal devices via USB and realizing the monitoring of M-Bus bus signals.

2. A kind of M-Bus master-slave machine communication data monitoring circuit according to claim 1, wherein, The adjustment circuit includes a first dual Schottky diode, a thermistor, a first bidirectional TVS diode, and a second dual Schottky diode. The first end of the M-Bus signal input interface is connected to the first end of the first bidirectional TVS diode via the thermistor. The second end of the M-Bus signal input interface is connected to the second end of the first bidirectional TVS diode. The second end of the M-Bus signal input interface is also connected to the third end of the second dual Schottky diode. The first end of the second dual Schottky diode is connected to the data signal output terminal of the M-Bus interface chip via a first resistor. The second end of the second dual Schottky diode is connected to the bus signal input terminal of the M-Bus interface chip. The thermistor is also connected to the third end of the first dual Schottky diode. The first end of the first dual Schottky diode is grounded. The second end of the first dual Schottky diode is connected to the bus signal input terminal of the M-Bus interface chip.

3. A data monitoring circuit for communication between a master and slave device according to claim 2, characterized in that The UART to USB communication circuit further includes a second bidirectional TVS diode, a third bidirectional TVS diode, and a fourth bidirectional TVS diode. The UD+ terminal of the signal conversion chip is connected to the D+ terminal of the USB interface, and the UD- terminal of the signal conversion chip is connected to the D- terminal of the USB interface. The D- terminal of the USB interface is grounded through the second bidirectional TVS diode, and the D+ terminal of the USB interface is grounded through the fourth bidirectional TVS diode. The third bidirectional TVS diode is connected between the D- terminal and the D+ terminal of the USB interface.

4. The M-Bus master-slave communication data monitoring circuit according to claim 2, characterized in that, The M-Bus to UART communication circuit also includes a bus current adjustment resistor and a holding capacitor. The output current of the VDO terminal of the M-Bus interface chip is adjusted by setting the resistance value of the bus current adjustment resistor. The holding capacitor is an aluminum electrolytic capacitor used to suppress voltage fluctuations during communication.

5. A master-slave communication data monitoring device for M-Bus, characterized in that, Includes the M-Bus master-slave communication data monitoring circuit as described in any one of claims 1-4, connected between a device with a USB interface and the M-BUS bus, for monitoring M-BUS bus data.

6. A smart meter, characterized in that, Power usage data is obtained using the M-Bus master-slave communication data monitoring circuit or device as described in any one of claims 1-5.

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