Smart meter and control method

Abstract

The application discloses an intelligent electric meter and a control method, relates to the technical field of electric energy meters, and relates to an intelligent electric meter connected with a master station, which comprises a control module, a first isolation calibration module, a second isolation calibration module and a communication module; the communication module is connected with the master station; the first isolation calibration module is connected with the communication module and the control module respectively, the first isolation calibration module is used for isolating and sending a first communication signal output by the master station to the control module, and the first isolation calibration module performs bit width calibration on the first communication signal; the second isolation calibration module is connected with the communication module and the control module respectively, the second isolation calibration module is used for isolating and sending a second communication signal output by the control module to the master station, and the second isolation calibration module is also used for performing bit width calibration on the second communication signal. The application solves the problem that the anti-interference ability of 115200bps communication realized by using isolation high-speed communication devices such as capacity coupling, magnetic coupling and high-speed optical coupling is weak in the prior art, and the isolation high-speed communication devices are damaged.

Description

Technical Field

[0001] This application relates to the field of electricity meter technology, and more particularly to smart meters and control methods. Background Technology

[0002] With the popularization of smart electricity, the functions of electricity meters are becoming increasingly complex, requiring the storage and transmission of more and more data. Communication speeds are gradually shifting from 9600bps to 115200bps to improve the overall system efficiency and performance. Regardless of whether it's module communication or RS485 communication, electrical isolation from internal circuitry is necessary. Therefore, isolating high-speed communication devices is crucial for achieving 115200bps communication.

[0003] Currently, there are mainly isolated high-speed communication devices such as capacitive couplers, magnetic couplers, and high-speed optocouplers. The isolation communication principle of these devices determines the high degree of integration inside the devices. Therefore, compared with ordinary optocouplers, their anti-interference ability is greatly weakened. Whether it is the module interface or the RS485 interface, it is very easy to introduce external interference, which can damage the isolated high-speed communication devices. Summary of the Invention

[0004] This application provides a smart meter and a control method to at least solve the problem in related technologies where the anti-interference capability of 115200bps communication based on isolated high-speed communication devices such as capacitive couplers, magnetic couplers, and high-speed optocouplers is weak, leading to damage to the isolated high-speed communication devices.

[0005] This application provides a smart meter, which is connected to a master station. The smart meter includes: a control module, a first isolation calibration module, a second isolation calibration module, and a communication module.

[0006] The communication module is connected to the main station;

[0007] The first isolation calibration module is connected to the communication module and the control module respectively. The first isolation calibration module is used to isolate and send the first communication signal output by the master station to the control module. The first isolation calibration module is also used to perform bit width calibration on the first communication signal.

[0008] The second isolation calibration module is connected to the communication module and the control module respectively. The second isolation calibration module is used to isolate and send the second communication signal output by the control module to the master station. The second isolation calibration module is also used to perform bit width calibration on the second communication signal.

[0009] This application utilizes a control module to perform isolation and bit width self-calibration during communication with the main station, based on a first isolation calibration module and a second isolation calibration module. Compared to traditional optocouplers, which suffer from bit width imbalance between high and low levels during 115200bps communication due to excessively high communication speeds, causing communication failures, this application performs real-time bit width calibration based on the current bit width status, achieving bit width balance between high and low levels. This significantly improves transmission stability. Furthermore, achieving 115200bps communication using ordinary optocouplers does not compromise anti-interference performance compared to circuits composed of isolated high-speed communication devices such as capacitive couplers, magnetic couplers, and high-speed optocouplers.

[0010] In some optional embodiments, the first isolation calibration module includes:

[0011] A first isolation communication circuit is connected to the master station and is used to isolate and output the first communication signal.

[0012] A first adjustment circuit is connected to the first isolation communication circuit and the control module respectively, and is used to receive a first communication signal, adjust the waveform of the first communication signal and output it to the control module.

[0013] The control module is also used to receive the first communication signal and output a first calibration signal when it detects that the first bit width deviation data of the first communication signal is greater than the first preset bit width deviation threshold.

[0014] A first calibration circuit is connected to both the first adjustment circuit and the control module. The first calibration circuit is used to receive the first calibration signal and perform bit width calibration on the first adjustment circuit.

[0015] In some optional embodiments, the second isolation calibration module includes:

[0016] A second isolation communication circuit, which is connected to the control module, is used to isolate and output the second communication signal.

[0017] The second adjustment circuit is connected to the second isolation communication circuit and the master station respectively, and is used to receive the second communication signal, adjust the waveform of the second communication signal and output it to the master station.

[0018] The master station receives the second communication signal and outputs calibration data when it detects that the second bit width deviation data of the second communication signal is greater than the second preset bit width deviation threshold.

[0019] The control module is also used to receive the calibration data and output a second calibration signal;

[0020] An isolation calibration control circuit, connected to the control module, is used to receive the second calibration signal and output it in isolation.

[0021] The second calibration circuit is connected to both the second adjustment circuit and the isolation calibration control circuit. The second calibration circuit is used to isolate the reception of the second calibration signal and to perform bit width calibration on the second adjustment circuit.

[0022] In some optional embodiments, the first calibration circuit is used to receive a first calibration signal and control the first impedance corresponding to the first calibration signal to be connected to the first adjustment circuit, so as to perform bit width calibration on the first adjustment circuit.

[0023] In some optional embodiments, the first calibration circuit includes:

[0024] A first selection unit is connected to the control module;

[0025] A plurality of first resistors, the first end of which is connected to the first selection unit, and the second end of which is connected to the first adjustment circuit, wherein the resistance values ​​of the plurality of first resistors are different;

[0026] The first selection unit is used to receive the first calibration signal and control the target first resistor corresponding to the first calibration signal to be connected to the ground terminal and the first adjustment circuit respectively.

[0027] In some optional embodiments, the isolation calibration control circuit includes:

[0028] An optocoupler unit, wherein the first end of the optocoupler unit is connected to the control module, and the second end of the optocoupler unit is connected to the second calibration circuit.

[0029] In some optional embodiments, the second calibration circuit is used to receive a second calibration signal and control the second impedance corresponding to the second calibration signal to be connected to the second adjustment circuit, so as to perform bit width calibration on the second adjustment circuit.

[0030] In some optional embodiments, the second calibration circuit includes:

[0031] The second selection unit is connected to the isolation calibration control circuit.

[0032] A plurality of second resistors, the first end of which is connected to the second selection unit, and the second end of which is connected to the second adjustment circuit, wherein the resistance values ​​of the plurality of second resistors are different;

[0033] The second selection unit is used to receive the second calibration signal and control the target second resistor corresponding to the second calibration signal to be connected to the ground terminal and the second adjustment circuit respectively.

[0034] This application also provides a control method for a smart meter, which is applied to the smart meter described above, and includes:

[0035] When a calibration command is received from the first isolation calibration module, the first bit width deviation data of the calibration command from the first isolation calibration module is confirmed, and it is detected whether the first bit width deviation data is greater than the first preset bit width deviation threshold.

[0036] If it is confirmed that the first bit width deviation data is greater than the first preset bit width deviation threshold, control the first isolation calibration module to perform calibration corresponding to the first bit width deviation data;

[0037] and / or;

[0038] Upon receiving a calibration command from the second isolation calibration module, a test signal is output;

[0039] The system receives the second bit width deviation data and controls the second isolation calibration module to perform calibration corresponding to the second bit width deviation data, wherein the second bit width deviation data is the second bit width deviation data output by the master station based on the test signal.

[0040] In some alternative implementations,

[0041] Check whether the received command is a calibration command from the first isolation calibration module;

[0042] If the command is not from the first isolation calibration module, then check if the command is from the second isolation calibration module.

[0043] If it is not a calibration command from the second isolation calibration module, then it is confirmed as the second bit width deviation data. Attached Figure Description

[0044] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1A structural diagram of a smart meter provided in an embodiment of this application;

[0046] Figure 2 This is a structural diagram of another smart meter provided in an embodiment of this application;

[0047] Figure 3 A structural diagram of another smart meter provided in the embodiments of this application;

[0048] Figure 4 This is a flowchart illustrating a control method for a smart meter provided in an embodiment of this application. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0050] It should be noted that, in the description of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. The terms "first," "second," etc., in this application are used to distinguish similar objects and are not used to describe a specific order or sequence.

[0051] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] The specific application environment architecture or specific hardware architecture on which the control method of smart meters depends is described here.

[0053] With the popularization of smart electricity, the functions of electricity meters are becoming increasingly complex, requiring the storage and transmission of more and more data. Communication speeds are gradually shifting from 9600bps to 115200bps to improve the overall system efficiency and performance. Regardless of whether it's module communication or RS485 communication, electrical isolation from internal circuitry is necessary. Therefore, isolating high-speed communication devices is crucial for achieving 115200bps communication.

[0054] Currently, there are mainly isolated high-speed communication devices such as capacitive couplers, magnetic couplers, and high-speed optocouplers. The isolation communication principle of these devices determines the high degree of integration inside the devices. However, compared with ordinary optocouplers, their anti-interference ability is greatly weakened. Whether it is the module interface or the RS485 interface, it is very easy to introduce external interference, which can damage the isolated high-speed communication devices.

[0055] Embodiments of this application provide a smart meter, such as Figure 1 The smart meter is connected to the master station and includes: a control module 30, a first isolation calibration module 10, a second isolation calibration module 20, and a communication module 40.

[0056] The communication module 40 is connected to the main station;

[0057] The first isolation calibration module 10 is connected to the communication module 40 and the control module 30 respectively. The first isolation calibration module 10 is used to isolate and send the first communication signal output by the master station to the control module 30. The first isolation calibration module 10 is also used to perform bit width calibration on the first communication signal.

[0058] The second isolation calibration module 20 is connected to the communication module 40 and the control module 30 respectively. The second isolation calibration module 20 is used to isolate and send the second communication signal output by the control module 30 to the main station. The second isolation calibration module 20 is also used to perform bit width calibration on the second communication signal.

[0059] Specifically, refer to Figure 1 The smart meter also includes a communication module 40, which is connected to the first isolation calibration module 10, the second isolation calibration module 20, and the master station. The communication module 40 converts the first communication signal sent by the master station and sends it to the first isolation calibration module 10, and converts the second communication signal sent by the second isolation calibration module 20 and sends it to the master station. Specifically, the communication module 40 can perform module communication or RS485 communication. The communication module 40 converts command frames or data frames sent by the master station from RS485 communication signals to CMOS signals. The communication module 40 also converts CMOS signals sent by the control module to RS485 communication signals. Thus, signal conversion between the master station and the control module 30 is achieved through the communication module 40.

[0060] For example, refer to Figure 3The communication module 40 is an RS485 communication module, specifically including a control chip U3, a thermistor RT1, a third capacitor C3, a twentieth resistor R20, a first transient suppression diode D1, a second transient suppression diode D2, and a third transient suppression diode D3. The first transient suppression diode D1, the second transient suppression diode D2, and the third transient suppression diode D3 are used for electrostatic discharge (ESD) protection. P1 and P2 are connected to the master station. The control chip U3 converts the RS485 communication signal into a CMOS signal and outputs it through pin 1. Pin 4 of the control chip U3 is used to input the output data of the control module 30, including response frames or test frames. Additionally, through the third optocoupler OC3, the tenth resistor R10, and the eleventh resistor R11, the control module 30 isolates and controls the control chip U3 to receive or transmit data.

[0061] Specifically, the master station is the master station system. The control module 30 is a computing MCU. The first isolation calibration module 10 is used to isolate and transmit the first communication signal sent by the master station to the control module 30, and to perform self-calibration during the transmission of the first communication signal. During calibration, the control module 30 confirms the first bit width data based on the received first communication signal, and determines whether bit width calibration is needed based on the first bit width data. If bit width calibration is not needed, no operation is performed; if bit width calibration is needed, the control module 10 is controlled to perform bit width calibration.

[0062] Specifically, the second isolation calibration module 20 is used to isolate and transmit the second communication signal sent by the control module 30 to the master station, and to perform self-calibration during the transmission of the second communication signal. During calibration, the master station confirms the second bit-width data based on the second communication signal sent by the control module 30 to the master station, and determines whether bit-width calibration is required based on the second bit-width data. If bit-width calibration is not required, no operation is performed. If bit-width calibration is required, a calibration command is sent to the control module 30, and the control module 30 controls the second isolation calibration module 20 to perform bit-width calibration based on the calibration command.

[0063] Optionally, the first isolation calibration module 10 and the second isolation calibration module 20 are modules that adjust waveforms based on control signals and perform isolated transmission, respectively.

[0064] This application utilizes the control module 30 to perform isolation and bit width self-calibration based on the first isolation calibration module 10 and the second isolation calibration module 20 during communication with the main station. Compared to traditional ordinary optocouplers, which suffer from bit width imbalance between high and low levels due to excessively high communication speeds during 115200bps communication, causing communication failures, this application performs real-time bit width calibration based on the current bit width status, achieving bit width balance between high and low levels. This significantly improves transmission stability, enabling 115200bps communication through ordinary optocouplers. Furthermore, compared to circuits composed of isolated high-speed communication devices such as capacitive couplers, magnetic couplers, and high-speed optocouplers, the anti-interference performance is not weakened.

[0065] Furthermore, for example, assuming that under normal circumstances the low-level bit width is 1s and the high-level bit width is also 1s, due to the communication rate exceeding the upper limit of a normal optocoupler, the optocoupler output low level may become 1.9s and the high level may become 0.1s. Through the shaping circuit, the low level may become 1.1s and the high level may become 0.9s. Due to the discreteness of the optocoupler, the low and high levels of the optocoupler output may also be 1.8s, 0.2s, 1.7s, or 0.3s, and the output of the shaping circuit will also change accordingly. Therefore, the smart meter in this application separately adjusts the shaping circuit to make the high and low levels of the shaped output as close to 1s as possible. Theoretically, it can correctly identify even if it receives a value of 1s ± 0.4s. By adjusting it to 1s ± 0.1s through the first isolation calibration module 10 and the second isolation calibration module 20, the probability of the receiver correctly identifying the value is even higher.

[0066] In some alternative implementations, such as Figure 2 and Figure 3 As shown, the first isolation calibration module 10 includes:

[0067] A first isolation communication circuit 11 is connected to the master station and is used to isolate and output the first communication signal.

[0068] Specifically, the first isolation communication circuit 11 is used to isolate the communication module 40 from the control module 30, thereby improving anti-interference capability. The first isolation communication circuit 11 also performs level conversion, that is, converting the 5V level to a 3.3V level. It is worth noting that due to the 115200bps communication rate limitation, the first communication signal changes from a rectangular wave to a triangular wave.

[0069] For example, the first isolation communication circuit 11 includes a first optocoupler OC1 and a sixth resistor, wherein the first reference voltage V485 is 5V, the second reference voltage VCC is 3.3V, and after isolation and level conversion by the first optocoupler OC1, the output is through pin 3 of the first optocoupler OC1.

[0070] The first adjustment circuit 12 is connected to the first isolation communication circuit 11 and the control module 30 respectively, and is used to receive the first communication signal, adjust the waveform of the first communication signal and output it to the control module.

[0071] Specifically, the first adjustment circuit 12 is a shaping circuit, that is, it is used to convert the triangular wave into a rectangular wave and then transmit it to the control module 30.

[0072] For example, the first adjustment circuit 12 includes a first transistor Q1, a third resistor R3 and a fifth resistor R5. A triangular wave signal is input through pin 2 of the third resistor R3. After being converted by the first transistor Q1, a rectangular wave signal is output from pin 2 of the first transistor Q1 and input to the control module 30.

[0073] The control module 30 is also used to receive the first communication signal and output a first calibration signal when it detects that the first bit width deviation data of the first communication signal is greater than the first preset bit width deviation threshold.

[0074] Specifically, the first communication signal includes a calibration command from the first adjustment circuit 12. The first low-level bit width deviation data is specifically the first low-level bit width deviation time of the calibration command from the first adjustment circuit 12. The control module 30 receives the first communication signal and detects the first low-level bit width deviation time between the first low-level bit width time of the first communication signal and a first preset low-level bit width time. If the detected first low-level bit width deviation time is greater than the first preset bit width deviation threshold, the control module 30 outputs a first calibration signal and a first response frame to the master station. The path to the master station can be through the second isolation calibration module. At this time, the master station continues to send the first communication signal, and this cycle continues until the control module 30 responds to the master station that calibration is not required.

[0075] In addition to time detection via low level, time detection via high level can also be included.

[0076] If the detected first low-level bit width deviation time is less than or equal to the first preset bit width deviation threshold, no calibration is required.

[0077] The first calibration circuit 13 is connected to the first adjustment circuit 12 and the control module 30 respectively. The first calibration circuit 13 is used to receive the first calibration signal and perform bit width calibration on the first adjustment circuit 12.

[0078] Specifically, the first calibration circuit 13 adjusts the first adjustment circuit 12 based on the first calibration signal to perform bit width calibration on the first adjustment circuit.

[0079] It is worth noting that the first communication signal refers to the data sent by the master station to the control module 30.

[0080] In some alternative implementations, such as Figure 2 As shown, the second isolation calibration module 20 includes:

[0081] The second isolation communication circuit 21 is connected to the control module 30 and is used to isolate and output the second communication signal.

[0082] Specifically, the second isolation communication circuit 21 is used to isolate the communication module 40 from the control module 30, thereby improving anti-interference capability. The second isolation communication circuit 21 also performs level conversion, converting the 3.3V level to a 5V level. It is worth noting that due to the 115200bps communication rate limitation, the second communication signal changes from a rectangular wave to a triangular wave.

[0083] For example, the second isolation communication circuit 21 includes a second optocoupler OC2 and a twelfth resistor R12. The response frame or test frame of the control module is input to pin 2 of the second optocoupler OC2, and the second optocoupler OC2 outputs the CMOS signal from pin 3 after electrical isolation and level conversion.

[0084] The second adjustment circuit 22 is connected to the second isolation communication circuit 21 and the master station respectively, and is used to receive the second communication signal, adjust the waveform of the second communication signal and output it to the master station.

[0085] Specifically, the second adjustment circuit 22 is a shaping circuit, that is, it is used to convert the triangular wave into a rectangular wave and then transmit it to the main station.

[0086] For example, the second adjustment circuit 22 includes a second transistor Q2, a fourth resistor R4 and a thirteenth resistor R13. The triangular wave signal is input to pin 2 of the second adjustment circuit 22, and after being converted by the second transistor Q2, it is output from pin 2 of the second transistor Q2.

[0087] The master station receives the second communication signal and outputs calibration data when it detects that the second bit width deviation data of the second communication signal is greater than the second preset bit width deviation threshold.

[0088] Specifically, the master station outputs a calibration command to the second adjustment circuit 22, and the control module outputs a second communication signal based on the calibration command. The second communication signal includes a test frame output by the control module 30, and the second bit-width deviation data is specifically the second low-level bit-width deviation time of the test frame. The master station receives the second communication signal and detects the second low-level bit-width deviation time between the second low-level bit-width time of the second communication signal and a second preset low-level bit-width time. If the detected second low-level bit-width deviation time is greater than the second preset bit-width deviation threshold, calibration data is output; if the detected second low-level bit-width deviation time is less than or equal to the second preset bit-width deviation threshold, no calibration is required, and no calibration data is output. After calibrating the second adjustment circuit 22, the control module 30 outputs a second response frame. The master station continues to detect whether calibration is still required based on the second response frame, repeating this process until the test frame received by the master station no longer requires calibration.

[0089] The control module 30 is also used to receive the calibration data and output a second calibration signal;

[0090] An isolation calibration control circuit 23 is connected to the control module 30 and is used to receive the second calibration signal and output it in isolation.

[0091] Specifically, since the control module 30 adjusts the isolated second adjustment circuit, the second calibration signal output by the control module 30 also needs to be isolated from the control module 30, thereby improving anti-interference capability.

[0092] The second calibration circuit 24 is connected to the second adjustment circuit 22 and the isolation calibration control circuit 23 respectively. The second calibration circuit 24 is used to isolate the reception of the second calibration signal and perform bit width calibration for the second adjustment circuit.

[0093] Specifically, the second calibration circuit 24 adjusts the second adjustment circuit 22 based on the second calibration signal to perform bit width calibration on the second adjustment circuit.

[0094] It is worth noting that the second communication signal refers to the data sent by the control module 30 to the master station.

[0095] In some alternative implementations, such as Figure 2 As shown, the first calibration circuit 13 is used to receive the first calibration signal and control the first impedance corresponding to the first calibration signal to be connected to the first adjustment circuit, so as to perform bit width calibration on the first adjustment circuit.

[0096] Specifically, the first calibration circuit 13 receives the first calibration signal and connects the first impedance corresponding to the first calibration signal to the first adjustment circuit, thereby adjusting the bit width of the output waveform of the first adjustment circuit.

[0097] In some alternative implementations, such as Figure 3 As shown, the first calibration circuit 13 includes:

[0098] The first selection unit U1 is connected to the control module 30;

[0099] Multiple first resistors R1 are provided, with their first ends connected to the first selection unit U1 and their second ends connected to the first adjustment circuit 12. The resistance values ​​of the multiple first resistors are different.

[0100] The first selection unit U1 is used to receive the first calibration signal and control the target first resistor R1 corresponding to the first calibration signal to be connected to the ground terminal and the first adjustment circuit 12 respectively.

[0101] Specifically, when it is necessary to increase the low-level bit width time, the control module 30 controls the switching of a matching resistor with a larger resistance value to increase the voltage at pin 2 of the third resistor R3 of the first adjustment circuit 12 to GND. When it is necessary to decrease the low-level bit width time, the control module 30 controls the switching of a matching resistor with a smaller resistance value to decrease the voltage at pin 2 of the third resistor R3 to GND.

[0102] For example, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 serve as protection resistors. The first calibration signal is received through the three pins (pin A, pin B, and pin C) of the first selection unit U1. Based on the first calibration signal, one of the pins X0 to X7 is selected to be connected to pin X (pin 3) of the first selection unit U1, thereby activating the matching resistor on the corresponding pin and achieving the purpose of switching the matching resistor.

[0103] Optionally, the control module 30 sends a first calibration signal via three output terminals using binary code. Specifically, it can send eight combinations: 000, 001, 010, 011, 100, 101, 110, and 111. There can be eight first resistors R1: R1-1, R1-2, R1-3, R1-4, R1-5, R1-6, R1-7, and R1-8. The resistance values ​​of each first resistor are different, and they can be ordered from smallest to largest resistance value. Each first resistor R1 corresponds to a binary code. Upon receiving any of the eight combinations, the first selection unit U1 controls the target first resistor corresponding to the binary code to connect to the ground terminal and the first adjustment circuit 12, respectively.

[0104] For example, if the first selection unit U1 receives a first calibration signal of 010, the third first resistor is connected to the ground terminal and the first adjustment circuit 12 respectively.

[0105] In some alternative implementations, such as Figure 3 As shown, the isolation calibration control circuit 23 includes:

[0106] Optical coupler unit 23a, the first end of which is connected to the control module 30, and the second end of which is connected to the second calibration circuit 24.

[0107] Specifically, the second calibration signal is isolated by the optocoupler unit 23a, thereby adjusting the isolated second adjustment circuit 22.

[0108] For example, refer to Figure 3 Optical coupler unit 23a consists of multiple optical couplers.

[0109] In some alternative embodiments, the second calibration circuit 24 is used to receive the second calibration signal and control the second impedance corresponding to the second calibration signal to be connected to the second adjustment circuit 22, so as to perform bit width calibration for the second adjustment circuit.

[0110] Specifically, the second calibration circuit 24 receives the isolated second calibration signal and connects the second impedance corresponding to the second calibration signal to the second adjustment circuit, thereby adjusting the bit width of the output waveform of the second adjustment circuit.

[0111] In some alternative embodiments, the second calibration circuit 24 includes:

[0112] The second selection unit U2 is connected to the isolation calibration control circuit 23;

[0113] Multiple second resistors R2 are provided, with the first end of each second resistor R2 connected to the second selection unit U2 and the second end of each second resistor R2 connected to the second adjustment circuit 22. The resistance values ​​of the multiple second resistors are different.

[0114] The second selection unit U2 is used to receive the second calibration signal and control the target second resistor R2 corresponding to the second calibration signal to be connected to the ground terminal and the second adjustment circuit 22 respectively.

[0115] Specifically, when it is necessary to increase the low-level bit width time, the control module 30 controls the switching of a matching resistor with a larger resistance value to increase the voltage at pin 2 of the fourth resistor R4 of the second adjustment circuit 22 to GND. When it is necessary to decrease the low-level bit width time, the control module 30 controls the switching of a matching resistor with a smaller resistance value to decrease the voltage at pin 2 of the fourth resistor R4 to GND.

[0116] Optionally, the control module 30 sends a second calibration signal via three output terminals using binary code. Specifically, it can send eight combinations: 000, 001, 010, 011, 100, 101, 110, and 111. There can be eight second resistors R2: R2-1, R2-2, R2-3, R2-4, R2-5, R2-6, R2-7, and R2-8. The resistance values ​​of each second resistor are different, and they can be ordered from smallest to largest resistance value. Each second resistor R2 corresponds to a binary code. Upon receiving any of the eight combinations, the second selection unit U2 controls the target second resistor corresponding to the binary code to connect to the ground terminal and the second adjustment circuit 22.

[0117] For example, if the second selection unit U2 receives a second calibration signal of 010, the third second resistor is connected to the ground terminal and the second adjustment circuit 22 respectively.

[0118] For example, the fourteenth resistor R14, the fifteenth resistor R15, and the sixteenth resistor R16 serve as protection resistors. The second calibration signal is received through the three pins (pin A, pin B, and pin C) of the second selection unit U2. Based on the second calibration signal, one of the pins X0 to X7 is selected to be connected to pin X (pin 3) of the second selection unit U2, thereby activating the matching resistor on the corresponding pin and achieving the purpose of switching the matching resistor.

[0119] Embodiments of this application provide a control method for a smart meter, such as... Figure 4 As shown, the method is described in detail, taking into account the execution flow of the control method for smart meters.

[0120] Step 1: Upon receiving the calibration command from the first isolation calibration module, confirm the first bit width deviation data of the calibration command from the first isolation calibration module, and check whether the first bit width deviation data is greater than the first preset bit width deviation threshold.

[0121] Step 2: If it is confirmed that the first width deviation data is greater than the first preset width deviation threshold, control the first isolation calibration module to perform calibration corresponding to the first width deviation data;

[0122] and / or;

[0123] Step 3: Upon receiving the calibration command from the second isolation calibration module, output a test signal;

[0124] Step 4: Receive the second bit width deviation data and control the second isolation calibration module to perform calibration corresponding to the second bit width deviation data, wherein the second bit width deviation data is the second bit width deviation data output by the master station based on the test signal.

[0125] Specifically, refer to Figure 4 The first low-level bit width deviation data is specifically the first low-level bit width deviation time. The control module 30 receives the calibration command from the first isolation calibration module and detects the first low-level bit width deviation time between the first low-level bit width time of the calibration command from the first isolation calibration module and the first preset low-level bit width time. If the first low-level bit width deviation time is detected to be greater than the first preset bit width deviation threshold, the first calibration signal is output. If the first low-level bit width deviation time is detected to be less than or equal to the first preset bit width deviation threshold, no calibration is required.

[0126] Specifically, the test signal is a test frame, and the second bit-width deviation data is specifically the second low-level bit-width deviation time. The master station receives the test frame and detects the second low-level bit-width deviation time between the second low-level bit-width time of the response frame and the second preset low-level bit-width time. If the detected second low-level bit-width deviation time is greater than the second preset bit-width deviation threshold, calibration data is output. If the detected second low-level bit-width deviation time is less than or equal to the second preset bit-width deviation threshold, no calibration is required, and therefore no calibration data is output.

[0127] In some optional embodiments, the control method for the smart meter further includes:

[0128] Step (1): Check whether the received command is a calibration command from the first isolation calibration module;

[0129] Step (2): If it is not a calibration command from the first isolation calibration module, then check if the command is a calibration command from the second isolation calibration module;

[0130] Step (3): If it is not a calibration command from the second isolation calibration module, then it is confirmed as the second bit width deviation data.

[0131] Specifically, refer to Figure 4 First, check if the data sent by the master station is a calibration command from the first isolation calibration module. If it is, proceed to step one. If it is not, continue to check if it is a calibration command from the second isolation calibration module and proceed to step three. If it is not, confirm it as the second bit width deviation data and proceed to step four.

[0132] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method.

Claims

1. A smart meter, characterized in that, The smart meter is connected to the master station, and the smart meter includes: a control module, a first isolation calibration module, a second isolation calibration module, and a communication module; The communication module is connected to the main station; The first isolation calibration module is connected to the communication module and the control module respectively. The first isolation calibration module is used to isolate and send the first communication signal output by the master station to the control module. The first isolation calibration module is also used to perform bit width calibration on the first communication signal. The second isolation calibration module is connected to the communication module and the control module respectively. The second isolation calibration module is used to isolate and send the second communication signal output by the control module to the main station. The second isolation calibration module is also used to perform bit width calibration on the second communication signal. The first isolation calibration module includes: A first isolation communication circuit is connected to the master station and is used to isolate and output the first communication signal. A first adjustment circuit is connected to the first isolation communication circuit and the control module respectively, and is used to receive a first communication signal, adjust the waveform of the first communication signal and output it to the control module. The control module is also used to receive the first communication signal and output a first calibration signal when it detects that the first bit width deviation data of the first communication signal is greater than the first preset bit width deviation threshold. A first calibration circuit is connected to both the first adjustment circuit and the control module. The first calibration circuit is used to receive the first calibration signal and perform bit width calibration on the first adjustment circuit.

2. The smart meter according to claim 1, characterized in that, The second isolation calibration module includes: A second isolation communication circuit, which is connected to the control module, is used to isolate and output the second communication signal. The second adjustment circuit is connected to the second isolation communication circuit and the master station respectively, and is used to receive the second communication signal, adjust the waveform of the second communication signal and output it to the master station. The master station receives the second communication signal and outputs calibration data when it detects that the second bit width deviation data of the second communication signal is greater than the second preset bit width deviation threshold. The control module is also used to receive the calibration data and output a second calibration signal; An isolation calibration control circuit, connected to the control module, is used to receive the second calibration signal and output it in isolation. The second calibration circuit is connected to both the second adjustment circuit and the isolation calibration control circuit. The second calibration circuit is used to isolate the reception of the second calibration signal and to perform bit width calibration on the second adjustment circuit.

3. The smart meter according to claim 1, characterized in that, The first calibration circuit is used to receive the first calibration signal and control the first impedance corresponding to the first calibration signal to be connected to the first adjustment circuit, so as to perform bit width calibration on the first adjustment circuit.

4. The smart meter according to claim 3, characterized in that, The first calibration circuit includes: A first selection unit is connected to the control module; A plurality of first resistors, the first end of which is connected to the first selection unit, and the second end of which is connected to the first adjustment circuit, wherein the resistance values ​​of the plurality of first resistors are different; The first selection unit is used to receive the first calibration signal and control the target first resistor corresponding to the first calibration signal to be connected to the ground terminal and the first adjustment circuit respectively.

5. The smart meter according to claim 2, characterized in that, The isolation calibration control circuit includes: An optocoupler unit, wherein the first end of the optocoupler unit is connected to the control module, and the second end of the optocoupler unit is connected to the second calibration circuit.

6. The smart meter according to claim 2, characterized in that, The second calibration circuit is used to receive the second calibration signal and control the second impedance corresponding to the second calibration signal to be connected to the second adjustment circuit, so as to perform bit width calibration on the second adjustment circuit.

7. The smart meter according to claim 6, characterized in that, The second calibration circuit includes: The second selection unit is connected to the isolation calibration control circuit. A plurality of second resistors, the first end of which is connected to the second selection unit, and the second end of which is connected to the second adjustment circuit, wherein the resistance values ​​of the plurality of second resistors are different; The second selection unit is used to receive the second calibration signal and control the target second resistor corresponding to the second calibration signal to be connected to the ground terminal and the second adjustment circuit respectively.

8. A control method for a smart meter, characterized in that, The control method for the smart meter is applied to the smart meter as described in any one of claims 1 to 7, wherein the control method for the smart meter includes: When a calibration command is received from the first isolation calibration module, the first bit width deviation data of the calibration command from the first isolation calibration module is confirmed, and it is detected whether the first bit width deviation data is greater than the first preset bit width deviation threshold. If it is confirmed that the first bit width deviation data is greater than the first preset bit width deviation threshold, control the first isolation calibration module to perform calibration corresponding to the first bit width deviation data; and / or; Upon receiving a calibration command from the second isolation calibration module, a test signal is output; The system receives the second bit width deviation data and controls the second isolation calibration module to perform calibration corresponding to the second bit width deviation data, wherein the second bit width deviation data is the second bit width deviation data output by the master station based on the test signal.

9. The control method for a smart meter according to claim 8, characterized in that, The control method for the smart meter also includes: Check whether the received command is a calibration command from the first isolation calibration module; If the command is not from the first isolation calibration module, then check if the command is from the second isolation calibration module. If it is not a calibration command from the second isolation calibration module, then it is confirmed as the second bit width deviation data.

Images