A method and device for calibrating an electric energy meter

Abstract

The present application relates to a kind of electric energy meter verification method and device, belong to electric energy meter verification technical field.The present application passes through the SCO communication link between the establishment verification platform and the electric energy meter to be verified, utilizes the SCO communication link to carry out the transmission of electric energy meter pulse signal, and SCO communication link and ACL communication link are independent link, do not interfere with each other, so in the process of verification, by SCO communication link to transmit electric energy meter pulse signal will not affect the ACL communication link of electric energy meter to be verified and the communication of other external devices, guarantee the normal operation of other services.Simultaneously, since the SCO communication link used in the process of verification of the present application is synchronous data transmission channel, so transmission delay is fixed, can satisfy electric energy meter pulse verification requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of electric energy meter verification method and device, belong to electric energy meter verification technical field. BACKGROUND

[0002] Prior art method "a kind of method and device for verifying electric energy meter based on low-power bluetooth communication" (Chinese patent application No.201911240531) proposes a kind of method for verifying electric energy meter based on bluetooth communication, the main feature of this method is that after the establishment of bluetooth connection between verification platform and the electric energy meter to be verified, the verification platform configures the verification parameters to the electric energy meter to be verified by using asynchronous data link transmission channel ACL (Asynchronous Connection-oriented Link), and issues start verification command, since the communication time delay is not fixed when transmitting data by bluetooth ACL link, continue to use ACL link to transmit the verification pulse data will greatly affect the accuracy of verification, in order to maintain the accuracy of verification, this method switches to private wireless communication mode to transmit the verification pulse data.This method adopts bluetooth wireless mode, avoids the connection operation required by the previous verification method based on pulse signal or infrared, improves the verification efficiency, and has been widely used.

[0003] But the existing calibration process is based on ACL communication mode, once jump to private wireless communication mode, other devices that have established connection with electric energy meter by bluetooth will interrupt bluetooth connection, and the normal data service communication function with electric energy meter needs to be disabled.Electric energy meter in field application, its bluetooth channel needs to be connected with circuit breaker, field detection terminal, fault analysis instrument and sensor for communication, starting the pulse verification of electric energy meter based on bluetooth will inevitably interrupt the normal execution of these devices. SUMMARY

[0004] The purpose of the present application is to provide an electric energy meter verification method and device to solve the problem that the electric energy meter to be verified cannot maintain communication with other devices through bluetooth due to the use of bluetooth asynchronous transmission in the current verification process.

[0005] The present application provides an electric energy meter verification method to solve the above technical problems, characterized in that the verification method comprises the following steps:

[0006] 1) Establish bluetooth connection between verification platform and the electric energy meter to be verified, and establish SCO communication link between verification platform and the electric energy meter to be verified after establishing connection;

[0007] 2) After establishing the SCO communication link, send start meter command from the verification platform to the electric energy meter to be verified;

[0008] 3) the electric energy meter to be tested collects electric energy meter pulse signals according to the start meter command and transmits the collected electric energy meter pulse signals to the testing table body through the SCO communication link;

[0009] 4) the testing table body restores the pulse signals received from the SCO communication link and realizes the testing of the electric energy meter to be tested according to the restoration result.

[0010] The application establishes the SCO communication link between the testing table body and the electric energy meter to be tested, uses the SCO communication link to transmit the electric energy meter pulse signals, and the SCO communication link and the ACL communication link are independent of each other and do not interfere with each other, so that the transmission of the electric energy meter pulse signals through the SCO communication link in the testing process does not affect the communication between the ACL communication link of the electric energy meter to be tested and other external devices, and the normal operation of other services is ensured. At the same time, since the SCO communication link used in the testing process of the application is a synchronous data transmission channel, the transmission delay is fixed, which can meet the electric energy meter pulse testing requirements.

[0011] Further, in the step 3), the electric energy meter to be tested encodes the corresponding pulse signals by using the PCM encoder according to the command type of the start meter command, each encoded byte represents the voltage amplitude of the signal, and the sampling and encoding data in the set time period are packaged by grouping and sent to the testing table body through the SCO communication link in the SCO time slot; in the step 4), the testing table body decodes and unpacks the data after receiving the data, and restores the voltage waveform of the pulse output pin of the electric energy meter to be tested based on the audio driver according to the decoding result.

[0012] The application uses the PCM encoder to sample and encode any one pulse signal at the electric energy meter to be tested end, and each encoded byte represents the voltage amplitude of the signal; the PCM decoder is used for decoding and outputting at the testing table body end, and the waveform of the pulse signal can be restored. In this way, the application can obtain the actual waveform of the electric energy meter pulse in the testing process.

[0013] Further, in the step 3), the electric energy meter to be tested collects the pulse signals according to the start meter command, and normalizes and encodes the sampling signals, each bit of each encoded byte representing the high or low level state of each pulse signal at the current time, and the sampling and encoding data in the set time period are packaged by grouping and sent to the testing table body through the SCO communication link; in the step 4), the testing table body decodes and outputs each bit information after receiving the data, and restores the state of each pulse signal of the electric energy meter to be tested by using the audio driver according to each bit information.

[0014] The application adopts a digitalized coding mode for the to-be-tested electric energy meter, and makes each bit of each coding byte represent the state of each pulse signal at the current time, so that the state of each pulse signal can be obtained each time, and the testing efficiency of each pulse signal is improved.

[0015] Further, the SCO communication link between the testing table body and the to-be-tested electric energy meter in step 1) has at least two, for simultaneously testing multiple pulse signals.

[0016] The SCO communication link established by the application has at least two, which can simultaneously transmit multiple pulse signal data, further improving the testing efficiency.

[0017] Further, the testing table body sends a start meter testing command to the to-be-tested electric energy meter through the ACL link in step 2).

[0018] Further, when the SCO communication link is used for pulse signal transmission, the first time slot of every 4 time slots is used for the testing table body to send a synchronization signal to the to-be-tested electric energy meter, the second time slot is used for the to-be-tested electric energy meter to send a pulse signal to the testing table body, and the remaining two time slots are idle.

[0019] The application reasonably allocates time slots according to the transmission mode of the SCO communication link, ensuring the stability and failure of transmission.

[0020] The application also provides an electric energy meter testing device, which comprises a testing table body, a first Bluetooth module arranged at the end of the testing table body, and a second Bluetooth module arranged at the end of the to-be-tested electric energy meter, a Bluetooth connection is established between the testing table body and the to-be-tested electric energy meter, an SCO communication link is further established between the first Bluetooth module and the second Bluetooth module, the second Bluetooth module is used to transmit the collected pulse signal of the to-be-tested electric energy meter to the first Bluetooth module through the SCO communication link, and the first Bluetooth module is used to restore the pulse signal received from the SCO communication link, and to realize testing of the to-be-tested electric energy meter according to the restoration result.

[0021] The application establishes an SCO communication link between the testing table body and the to-be-tested electric energy meter, and uses the SCO communication link for electric energy meter pulse signal transmission, and the SCO communication link and the ACL communication link are independent of each other and do not interfere with each other, so that the electric energy meter pulse signal transmission through the SCO communication link in the testing process does not affect the communication between the ACL communication link of the to-be-tested electric energy meter and other external devices, and ensures the normal operation of other services. At the same time, since the SCO communication link used in the testing process of the application is a synchronous data transmission channel, the transmission delay is fixed, which can meet the electric energy meter pulse testing requirements.

[0022] Further, the second Bluetooth module comprises a PCM encoder and a Bluetooth chip, the PCM encoder is connected with the pulse signal output end of the electric energy meter to be tested, samples and encodes the pulse signal output by the electric energy meter to be tested, and sends the sampling and encoding result to the Bluetooth chip, each encoding byte represents the voltage amplitude of the signal; the Bluetooth chip is used for grouping and packaging the sampling and encoding data in a set time period and sending the data to the first Bluetooth module.

[0023] The first Bluetooth module comprises a PCM decoder and a Bluetooth chip, the first Bluetooth module receives the data packet sent by the second Bluetooth module through the SCO communication link through the Bluetooth chip of the first Bluetooth module, and unpacks the data packet; the PCM decoder is used for decoding the decoded data, and the voltage waveform of the pulse output pin of the electric energy meter to be tested is restored based on the audio driver.

[0024] The PCM encoder is used for sampling and encoding any one pulse signal at the electric energy meter to be tested, and each encoding byte represents the voltage amplitude of the signal; the PCM decoder is used for decoding and outputting at the testing table body, and the waveform of the pulse signal can be restored. In this way, the actual waveform of the pulse of the electric energy meter can be obtained in the testing process.

[0025] Further, the second Bluetooth module comprises an encoder and a Bluetooth chip, the encoder is connected with the pulse signal output end of the electric energy meter to be tested, samples and encodes the pulse signal output by the electric energy meter to be tested, and sends the sampling and encoding result to the Bluetooth chip, each bit of each encoding byte represents the high-low level state of each pulse signal at the current time; the Bluetooth chip is used for grouping and packaging the sampling and encoding data in a set time period and sending the data to the first Bluetooth module.

[0026] The first Bluetooth module comprises a decoder and a Bluetooth chip, the first Bluetooth module receives the data packet sent by the second Bluetooth module through the SCO communication link through the Bluetooth chip of the first Bluetooth module, and unpacks the data packet; the decoder is used for decoding the decoded data and outputting each bit of information, and the state of each pulse signal of the electric energy meter to be tested is restored based on the audio driver.

[0027] The PCM encoder is used for sampling and encoding any one pulse signal at the electric energy meter to be tested, and each encoding byte represents the voltage amplitude of the signal; the PCM decoder is used for decoding and outputting at the testing table body, and the waveform of the pulse signal can be restored. In this way, the actual waveform of the pulse of the electric energy meter can be obtained in the testing process.

[0028] Further, there are at least two SCO communication links between the first Bluetooth module and the second Bluetooth module, which are used for simultaneously testing multiple pulse signals.

[0029] The established SCO communication link has at least two, which can simultaneously transmit multi-channel pulse signal data, further improving the efficiency of the test. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the flow chart of the electric energy meter testing method of the present application;

[0031] Figure 2 is the time slot allocation and PCM data transmission schematic diagram of the Bluetooth SCO link of the present application;

[0032] Figure 3 is the electric energy meter end testing pulse signal transmission schematic diagram in the electric energy meter testing device of the present application;

[0033] Figure 4 is the testing bench end testing pulse signal transmission schematic diagram in the electric energy meter testing device of the present application. DETAILED DESCRIPTION

[0034] The specific embodiments of the present application will be further described below in combination with the drawings.

[0035] Electric energy meter testing device embodiment

[0036] Bluetooth technology has two ways of transmission in application, voice call and data, and accordingly, in the underlying data transmission, Bluetooth supports two data transmission modes of circuit switching and packet switching. In the Bluetooth technology standard, the transmission of circuit switching is called SCO communication link, and the transmission of packet switching is called ACL communication link; the former mainly transmits strong real-time information such as voice, and the latter is mainly based on data packets. Voice and data can be transmitted separately or simultaneously. Bluetooth supports an asynchronous data channel, or three concurrent synchronous voice channels, or a channel that transmits asynchronous data and synchronous voice simultaneously. Each voice channel supports 64 kbps synchronous voice. Corresponding to the SCO communication link based on circuit switching, after the connection between the master device and the slave device is established, whether there is data transmission or not, the system will reserve fixed interval time slots for the master device and the slave device, and other slave devices cannot use the time slots on this connection to send data, as shown in Figure 2 , so the SCO communication link is applied to the transmission of synchronous conversation voice, and the clock deviation before the master and slave does not exceed ±10us.

[0037] Based on this, the application provides an electric energy meter calibration device, which comprises a calibration table body, a first Bluetooth module arranged at the end of the calibration table body, and a second Bluetooth module arranged at the end of an electric energy meter to be calibrated, an SCO communication link between the calibration table body and the electric energy meter to be calibrated is established through the first Bluetooth module and the second Bluetooth module, the transmission of the electric energy meter pulse signal is realized by using the SCO communication link, and the SCO communication link and the ACL communication link are independent links and do not interfere with each other, so that the transmission of the electric energy meter pulse signal through the SCO communication link does not affect the communication between the ACL communication link of the electric energy meter to be calibrated and other external devices during the calibration process, and the normal operation of other services is ensured.

[0038] Specifically, as shown in the figure, Figure 3 The second Bluetooth module arranged at the end of the electric energy meter comprises a PCM encoder and a Bluetooth chip, wherein the PCM encoder is connected with the pulse signal output terminal of the electric energy meter to realize the sampling and coding of the electric energy meter pulse signal; and the Bluetooth chip is provided with an asynchronous sending buffer, a synchronous sending buffer, a packet packer and an audio processing module. The electric energy meter judges the precision of electric energy measurement, clock and other functions by comparing the pulse generation interval time. During the calibration, the measurement of the power consumption in a period and the calculation of the number of accumulated output pulses of the electric energy meter by the standard equipment can detect the measurement precision of the electric energy meter. The pulses of the electric energy meter include active electric energy pulses, reactive electric energy pulses, second pulse output, demand cycle pulses, time period switching pulses, forward harmonic electric energy pulses and reverse harmonic electric energy pulses.

[0039] The electric energy meter outputs corresponding pulse signals to the electric energy meter pulse signal output terminal according to the command type, wherein the PCM encoder is used for sampling and coding at a set sampling frequency, 1 byte of data representing the voltage amplitude of the pulse signal is generated by coding, and the coded data is sent to the Bluetooth chip through the PCM interface; the Bluetooth chip puts the coded data output by the PCM encoder into the SCO synchronous sending buffer through the PCM interface, it is assumed that the PCM encoder is sampled and coded at 8KHz, it is sampled once every 125us and coded into 1 byte, 20 bytes of PCM coded data will be generated to the SCO synchronous sending buffer every 2.5ms, and the SCO synchronous sending buffer sends data to the packet packer every 2.5ms; the packet packer is used for packing the 20 bytes of data, and sending the packed data to the audio processing module after the packing is completed, and the audio processing module sends the data to the first Bluetooth module at the end of the detection table body on the corresponding time slot of the SCO.

[0040] As shown in the figure, Figure 4As shown, the first Bluetooth module arranged at the end of the testing platform body includes a PCM decoder and a Bluetooth chip. The Bluetooth chip in the first Bluetooth module and the Bluetooth chip in the second Bluetooth module have similar structures, including an asynchronous receiving buffer, a synchronous receiving buffer, a packet unpacker, and an audio processing module. The audio processing module is configured to receive data sent from the second Bluetooth module and send the received data to the packet unpacker. The packet unpacker is configured to unpack the data and place the data received through the SCO communication link into the synchronous receiving buffer and place the data received through the ACL communication link into the asynchronous receiving buffer. The data in the synchronous receiving buffer is transmitted to the PCM decoder through the PCM interface. The PCM decoder decodes the PCM data at a frequency of 8 kHz and outputs the decoded data to the PCM decoding output pin through an audio driver, restores the voltage waveform of the pulse output GPIO pin of the electric energy meter, and then outputs the signal to the corresponding type of pulse input signal line of the testing platform body through the multiplexer and the GPIO control of the Bluetooth chip. Since SCO is used for audio transmission, the chip design includes an audio driver, i.e., an audio analog signal is generated through DAC output. Therefore, the pulse voltage waveform can be output by borrowing this drive.

[0041] During the entire process, the voltage waveform on the pulse output GPIO pin of the electric energy meter is encoded, transmitted, and decoded by the testing platform. The time delay is fixed at 2.5 ms±10 us (±10 us is an uncertain window time caused by clock drift and jitter between the master and slave devices). The fixed time delay does not affect the calibration, the 8 kHz pulse resolution of the encoding and decoding meets the accuracy requirements of the highest 0.2S level electric meter pulse calibration.

[0042] The working process of the calibration device is as shown in Figure 1 The specific implementation steps are as follows.

[0043] 1. Establish a Bluetooth connection between the testing platform and the electric energy meter to be calibrated.

[0044] The testing platform initiates a connection establishment request to the second Bluetooth module arranged at the end of the electric energy meter to be calibrated through the first Bluetooth module according to the address of the electric energy meter to be calibrated. The second Bluetooth module receives the request and establishes a Bluetooth connection. Here, the established Bluetooth connection refers to the ACL communication link.

[0045] 2. Establish an SCO communication link between the testing platform and the electric energy meter to be calibrated.

[0046] After the connection is established, the test bench body is taken as a Bluetooth master device to initiate the establishment of an SCO communication link to the electric energy meter to be tested. The SCO link belongs to a synchronous transmission type of circuit switching. Circuit switching is that after the connection between the master device and the slave device is established, the system will reserve a fixed interval of time slots for the master device and the slave device regardless of whether data is sent or not. Other slave devices cannot use the time slots on the connection to send data. As shown in Figure 2 assuming that HV2 packet transmission is used, the underlying link is fixedly allocated to the master device for 625us (one time slot) every 2.5ms (four time slots) for the master device to send an SCO packet to the slave device. According to the standard, the next time slot is fixedly allocated to the slave device for the slave device to send an SCO packet to the master device. Other time slots are used for ACL communication link transmission of asynchronous packet data. The established SCO communication link can be multiple, for example, two or three, to facilitate the simultaneous transmission of multiple pulse signal data and further improve the testing efficiency.

[0047] In the present application, the test bench body Bluetooth only needs to send standard Bluetooth service data (for control) to the electric energy meter Bluetooth, and does not need to send synchronization data to the electric energy meter Bluetooth module. The electric energy meter Bluetooth needs to simultaneously receive and send standard Bluetooth service data and send synchronization pulse coding data to the test bench body Bluetooth module. From the perspective of underlying data communication, taking HV2 packet transmission as an example, once the SCO link is established, one time slot will be used to transmit the test bench body Bluetooth module data to the electric energy meter Bluetooth module (in the present application, the transmitted data is invalid data, which is only used for time synchronization) every four time slots, and one time slot will be used to transmit the synchronization pulse coding data of the electric energy meter end every four time slots.

[0048] 3. The test bench body sends a start metering command to the electric energy meter to be tested.

[0049] After the SCO communication link is established, the test bench body sends a start metering command to the electric energy meter to be tested through Bluetooth service (ACL communication link). After receiving the response of the electric energy meter to be tested, the test bench body starts the metering process.

[0050] 4. The electric energy meter to be tested collects electric energy meter pulse signals according to the start metering command and transmits the collected electric energy meter pulse signals to the test bench body through the SCO communication link.

[0051] Specifically, the electric energy meter outputs corresponding pulse signals to the electric energy meter pulse signal output terminal according to the command type, then the signals are encoded by the PCM encoder and transmitted to the SCO synchronous sending buffer of the Bluetooth chip through the PCM interface of the Bluetooth chip. 20 bytes of PCM encoded data will be generated to the SCO synchronous sending buffer every 2.5 ms. After the SCO synchronous sending buffer packs the data through the packet packer every 2.5 ms, the data is sent to the detection station body end Bluetooth module through the audio processing module on the SCO time slot from the main direction, that is, the packed pulse signals are sent to the first Bluetooth module through the SCO communication link.

[0052] 5. The detection station body restores the pulse signals received from the SCO communication link, and realizes the detection of the electric energy meter to be detected according to the restoration result.

[0053] The detection station body end Bluetooth module receives data through its audio processing module, and then unpacks the data through the packet unpacker and puts the data into the SCO synchronous receiving buffer. Then the data is transmitted to the PCM decoder through the PCM receiving. The PCM decoder decodes the PCM data at a frequency of 8KHz and outputs the voltage waveform of the electric energy meter pulse output GPIO pin through the audio drive to the PCM decoding output pin. The voltage waveform of the electric energy meter pulse output GPIO pin is restored, and then the signal is output to each type of pulse input signal line of the detection station body through the Bluetooth chip GPIO control by the multi-channel selector.

[0054] 6. After the detection is completed, the SCO communication link is cancelled.

[0055] After the detection is completed, the detection station body sends a stop meter detection command to the electric energy meter to be detected through the Bluetooth service. After receiving the response, the detection station body initiates the cancellation of the SCO communication link, and ends the electric energy meter detection process.

[0056] As other embodiments, the second Bluetooth module of the present application can also adopt a digital coding mode when performing pulse sampling coding, that is, the second Bluetooth module samples the multi-channel (in this case, up to 8 channels can be coded and transmitted) pulse signals of the electric energy meter at a sampling frequency of 8KHz, and after sampling, the data is normalized, with bit‘0’ representing low level and bit‘1’ representing high level, so that one byte can represent the state of 8 pulse signals at the current time through this coding mode; according to the sampling frequency of 8KHz, the 8 pulse signals are sampled every 125us and normalized to 1 byte, and 20 bytes of coded data are generated every 2.5ms to the SCO synchronous sending buffer, and the data is sent to the first Bluetooth module on the calibration platform through the SCO link. Similarly, the first Bluetooth module decodes the data according to the frequency of 8KHz, and every decoding takes out 1 byte of data, and the corresponding 8 bits are output to the corresponding GPIO, and through this mode, the 8 electric energy meter pulse signals are also restored. This coding mode can represent the state of multiple (up to 8) pulse signals at one time, compared with a coding representing the size of one pulse signal, greatly improving the coding efficiency and transmission efficiency.

[0057] Electric energy meter calibration method embodiment

[0058] The present application first establishes the Bluetooth connection between the calibration platform and the electric energy meter to be calibrated, and establishes the SCO communication link between the calibration platform and the electric energy meter to be calibrated after the connection is established; then after the SCO communication link is established, the calibration platform sends a start meter command to the electric energy meter to be calibrated; the electric energy meter to be calibrated collects the electric energy meter pulse signals according to the start meter command, and transmits the collected electric energy meter pulse signals to the calibration platform through the SCO communication link; finally, the calibration platform restores the pulse signals received from the SCO communication link, and realizes the calibration of the electric energy meter to be calibrated according to the restoration result. The specific implementation process of the method has been described in the embodiment of the device, which will not be repeated here.

Claims

1. A method for calibrating an electricity meter, characterized in that, The verification method includes the following steps: 1) Establish a Bluetooth connection between the calibration platform and the energy meter to be calibrated, and after establishing the connection, establish an SCO communication link between the calibration platform and the energy meter to be calibrated; 2) After the SCO communication link is established, the testing platform sends a start test command to the energy meter to be tested through the ACL link; 3) The energy meter to be tested acquires the energy meter pulse signal according to the start test command, and transmits the acquired energy meter pulse signal to the test bench through the SCO communication link; 4) The testing platform restores the pulse signal received from the SCO communication link and performs the testing of the energy meter to be tested based on the restoration result.

2. The method for verifying an electricity meter according to claim 1, characterized in that, In step 3), the energy meter to be tested uses a PCM encoder to sample and encode the corresponding pulse signal according to the command type of the start test command. Each encoded byte represents the voltage amplitude of the signal. The sampled and encoded data within a set time period is packaged into groups and sent to the testing platform through the SCO communication link in the SCO time slot. In step 4), after receiving the data, the testing platform unpacks and decodes the data, and restores the voltage waveform of the pulse output pin of the energy meter to be tested based on the decoding result and the audio driver.

3. The method for verifying an electricity meter according to claim 1, characterized in that, In step 3), the energy meter to be tested samples each pulse signal according to the start test command, and normalizes and encodes the sampled signals. Each bit of each encoded byte represents the high and low level state of each pulse signal at the current moment. The sampled encoded data within the set time period is packaged into groups and sent to the testing platform through the SCO communication link. In step 4), after receiving the data, the testing platform decodes the data and outputs each bit information. Based on each bit information, the state of each pulse signal of the energy meter to be tested is restored using an audio driver.

4. The method for verifying an electricity meter according to claim 1, characterized in that, In step 1), at least two SCO communication links are established between the calibration platform and the energy meter to be calibrated, which are used to perform calibration of multiple pulse signals simultaneously.

5. The method for verifying an electricity meter according to any one of claims 1-4, characterized in that, When using the SCO communication link for pulse signal transmission, the first time slot out of every four time slots is used for the calibration platform to send a synchronization signal to the energy meter to be calibrated, the second time slot is used for the energy meter to be calibrated to send a pulse signal to the calibration platform, and the SCO communication link is idle in the remaining two time slots.

6. An electricity meter calibration device, comprising a calibration platform, a first Bluetooth module disposed at one end of the calibration platform, and a second Bluetooth module disposed at the end of the electricity meter to be calibrated, wherein a Bluetooth connection is established between the calibration platform and the electricity meter to be calibrated, characterized in that, An SCO communication link is also established between the first Bluetooth module and the second Bluetooth module. The calibration platform sends a start calibration command to the energy meter to be calibrated through the ACL link. The second Bluetooth module is used to transmit the pulse signal of the energy meter to be calibrated collected to the first Bluetooth module through the SCO communication link. The first Bluetooth module is used to restore the pulse signal received from the SCO communication link and to calibrate the energy meter to be calibrated based on the restoration result.

7. The electricity meter calibration device according to claim 6, characterized in that, The second Bluetooth module includes a PCM encoder and a Bluetooth chip. The PCM encoder is used to connect to the pulse signal output terminal of the energy meter to be tested, sample and encode the pulse signal output by the energy meter to be tested, and send the sampling and encoding results to the Bluetooth chip. Each encoded byte represents the voltage amplitude of the signal. The Bluetooth chip is used to group and package the sampled and encoded data within a set time period and send it to the first Bluetooth module. The first Bluetooth module includes a PCM decoder and a Bluetooth chip. The first Bluetooth module receives data packets sent from the second Bluetooth module through its own Bluetooth chip via the SCO communication link and unpacks them. The PCM decoder is used to decode the unpacked encoded data and restore the voltage waveform of the pulse output pin of the energy meter to be tested based on the audio driver.

8. The electricity meter calibration device according to claim 6, characterized in that, The second Bluetooth module includes an encoder and a Bluetooth chip. The encoder is used to connect to the pulse signal output terminal of the energy meter to be tested, sample and encode the pulse signal output by the energy meter to be tested, and send the sampling and encoding results to the Bluetooth chip. Each bit of each encoded byte represents the high and low level state of each pulse signal at the current moment. The Bluetooth chip is used to group and package the sampled and encoded data within a set time period and send it to the first Bluetooth module. The first Bluetooth module includes a decoder and a Bluetooth chip. The first Bluetooth module receives data packets sent from the second Bluetooth module through its own Bluetooth chip via the SCO communication link and unpacks them. The decoder is used to decode the unpacked encoded data and output each bit information. Based on each bit information, the state of each pulse signal of the energy meter to be tested is restored using an audio driver.

9. The electricity meter calibration device according to any one of claims 6-8, characterized in that, At least two SCO communication links are also established between the first Bluetooth module and the second Bluetooth module for simultaneous verification of multiple pulse signals.

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