Electric energy meter and compatible interface circuit, signal conversion circuit and meter reading device thereof

Abstract

The application is suitable for the field of power electronics, and particularly relates to an electric energy meter, a compatible interface circuit thereof, a signal conversion circuit and a meter reading device. The compatible interface circuit is matched with the signal conversion circuit, and is connected through the first positive terminal and the first negative terminal of the first wiring port and the second positive terminal and the second negative terminal of the second wiring port. The current is input on the second positive terminal, so that the high and low of the level signal output by the second negative terminal follow the high and low of the pulse signal output by the first pin. When the low or high level signal is input in communication, the current is input or not input on the second negative terminal, so that the input of the low or high level signal is formed at the second pin. The signal output is realized by relying on the first pin and the signal conversion circuit, and the data writing is realized by relying on the signal conversion circuit and the second pin, so that the pulse and clock calibration adjustment functions can be completed, and the corresponding functional interfaces need not be separately configured, thereby reducing the terminal quantity and wiring complexity.

Description

TECHNICAL FIELD

[0001] The present application is suitable for the field of power electronics, and in particular relates to an electric energy meter and a compatible interface circuit, a signal conversion circuit and a meter reading device thereof. BACKGROUND

[0002] In the field of power electronics, an electronic electric energy metering device usually has multiple auxiliary terminals, such as a pulse output terminal, a clock output terminal and an RS485 communication terminal. These terminals need to be designed with independent interfaces and corresponding circuits in the electric energy meter. The metering pulse output terminal is used for metering pulse output and metering calibration, the clock output terminal is used for clock pulse output and calibration, and the RS485 communication terminal is used for communication between an external communication device and the electric energy meter to read and set data of the electric energy meter.

[0003] Based on the specific functions of these terminals, the electric energy meter needs to communicate or operate through the corresponding terminals during the production stage. The electric energy meter production setting and calibration device needs to connect multiple groups of terminal connection lines. Too many terminal connection lines and complicated wiring increase the error rate and unreliability of trial wiring, which directly reduces the production efficiency.

[0004] Therefore, how to compatibly combine multiple terminals and realize function switching to reduce the number of terminals and the complexity of wiring under the condition of ensuring functions has become a problem to be solved. SUMMARY

[0005] Therefore, the embodiments of the present application provide an electric energy meter and a compatible interface circuit, a signal conversion circuit and a meter reading device thereof to solve the problem of how to compatibly combine multiple terminals and realize function switching to reduce the number of terminals and the complexity of wiring under the condition of ensuring functions.

[0006] In a first aspect, the embodiments of the present application provide a compatible interface circuit of an electric energy meter, which is applied to the electric energy meter and includes a pulse port circuit, a communication port circuit, a first voltage source and a first wiring port. A first positive terminal of the first wiring port is used to connect a second positive terminal of a second wiring port in a signal conversion circuit of a meter reading device, and a first negative terminal of the first wiring port is used to connect a second negative terminal of the second wiring port.

[0007] A first switch is arranged on the pulse port circuit. A control terminal of the first switch is used to connect a first pin of a control chip of the electric energy meter. An input terminal of the first switch is connected to the first positive terminal, and an output terminal of the first switch is connected to the first negative terminal.

[0008] The communication port is provided with a second switch, an input end of the second switch is used for connecting a second pin of the control chip, an input end of the second switch is also connected with the first voltage source, an output end of the second switch is grounded, an input side of a control end of the second switch is connected with the first negative terminal, and an output side of the control end of the second switch is connected with the first positive terminal.

[0009] The signal conversion circuit is controlled to input current on the second positive terminal, so that the high and low of the level signal output by the second negative terminal follow the high and low of the pulse signal output by the first pin, when a low level signal is input in communication, the signal conversion circuit is controlled to input current on the second negative terminal, so that a low level signal is formed at the second pin, and when a high level signal is input in communication, the signal conversion circuit is controlled not to input current on the second negative terminal, so that a high level signal is formed at the second pin.

[0010] In an embodiment, the compatible interface circuit further comprises a second voltage source and a third voltage source.

[0011] The first switch is a first optocoupler switch, an input end of the first switch corresponds to a positive electrode of a first photosensitive diode of the first optocoupler switch, an output end of the first switch corresponds to a negative electrode of the first photosensitive diode, and a control end of the first switch corresponds to a positive and negative electrode of a first light emitting diode of the first optocoupler switch, a positive electrode of the first light emitting diode is connected with the second voltage source through a first resistor, a negative electrode of the first light emitting diode is connected with an input end of an optocoupler control switch, and an output end of the optocoupler control switch is grounded.

[0012] The third voltage source is connected with a control end of the optocoupler control switch through a second resistor and a third resistor, a line for connecting the first pin is arranged between the second resistor and the third resistor, the optocoupler control switch is cut off when the first pin outputs a high level signal, and the optocoupler control switch is turned on when the first pin outputs a low level signal.

[0013] In an embodiment, the compatible interface circuit further comprises an indicator light circuit, the indicator light circuit is provided with a second light emitting diode and a fourth resistor, a positive electrode of the second light emitting diode is connected with the second voltage source through the fourth resistor, and a negative electrode of the second light emitting diode is connected with an input end of the optocoupler control switch.

[0014] In an embodiment, the second switch is a second optocoupler switch, the input end of the second switch corresponds to the positive electrode of a second photodiode of the second optocoupler switch, the output end of the second switch corresponds to the negative electrode of the second photodiode, the input of the control end of the second switch corresponds to the positive electrode of a third light-emitting diode of the second optocoupler switch, and the output side of the control end of the second switch corresponds to the negative electrode of the third light-emitting diode.

[0015] The first voltage source is connected to the positive electrode of the second photodiode through a fifth resistor, and a line for connecting the second pin is arranged between the fifth resistor and the second photodiode.

[0016] In an embodiment, the control of the signal conversion circuit inputs current on the second positive electrode end, so that the high and low of the level signal output by the second negative electrode end follow the high and low of the pulse signal output by the first pin, including:

[0017] The control of the signal conversion circuit inputs current on the second positive electrode end;

[0018] When the pulse signal output by the first pin is a low-level signal, the first switch is turned on, the second negative electrode end outputs current to drive the third switch connected to the second negative electrode end to be turned on, and a low-level signal is formed at the input end of the third switch;

[0019] When the pulse signal output by the first pin is a high-level signal, the first switch is turned off, so that the third switch is turned off and a high-level signal is formed at the input end of the third switch, realizing the following of the pulse signal output by the first pin.

[0020] In an embodiment, the control of the signal conversion circuit inputs current on the second negative electrode end when a low-level signal is input in communication, so that a low-level signal is formed at the input of the second pin, and the control of the signal conversion circuit does not input current on the second negative electrode end when a high-level signal is input in communication, so that a high-level signal is formed at the input of the second pin, including:

[0021] When a low-level signal is input in communication, the control of the signal conversion circuit inputs current on the second negative electrode end, flows into the input of the control end of the second switch through the first negative electrode end, and reaches the first positive electrode end and the second positive electrode end after passing through the output side of the control end of the second switch and grounding, so that the first switch is reversely turned off and the second switch is turned on to drive the second pin to ground, so that a low-level signal is formed at the input of the second pin;

[0022] The signal conversion circuit controls the signal conversion circuit not to input current on the second negative terminal when a communication input high level signal, so that the second switch is cut off, and the first voltage source forms an input of a high level signal at the second pin.

[0023] In a second aspect, the embodiments of the present application provide a signal conversion circuit of an electric energy meter, which is applied to a meter reading device and includes a signal following circuit, a signal control circuit, a fourth voltage source, a fifth voltage source and a second connection port. A second positive terminal of the second connection port is used for connecting a first positive terminal of a first connection port in a compatible interface circuit of the electric energy meter, and a second negative terminal of the second connection port is used for connecting a first negative terminal of the first connection port.

[0024] A third switch is arranged on the signal following circuit, a control terminal of the third switch is connected to the second negative terminal, an input terminal of the third switch is connected to the fourth voltage source, the input terminal of the third switch is further provided with a signal output interface, and an output terminal of the third switch is grounded. When the second negative terminal outputs current, the third switch is turned on to form a low level signal on the signal output interface. When the second negative terminal does not output current, the third switch is cut off to form a high level signal on the signal output interface.

[0025] A fourth switch is arranged on the signal control circuit, an input terminal and a control terminal of the fourth switch are connected to the fifth voltage source, the control terminal of the fourth switch is further connected to a signal input interface, and an output terminal of the fourth switch is connected to the second negative terminal. The fifth voltage source is further connected to the second positive terminal through a resistor. A grounding control circuit is further arranged between the resistor and the second positive terminal. When the signal input interface is a high level signal, the fourth switch and the grounding control circuit are cut off, and the fifth voltage source provides current to the second positive terminal. When the signal output interface is a low level, the fourth switch and the grounding control circuit are turned on, and the fifth voltage source provides current to the second negative terminal.

[0026] In an embodiment, the grounding control circuit includes a fifth switch, a sixth switch and a seventh switch. A control terminal of the fifth switch is connected to the fifth voltage source, an input terminal of the fifth switch is connected to the fourth voltage source, and an output terminal of the fifth switch is respectively connected to a control terminal of the sixth switch, an output terminal of the sixth switch and a control terminal of the seventh switch.

[0027] An input terminal of the sixth switch is connected to a circuit between the control terminal of the third switch and the output terminal of the fourth switch, and an output terminal of the sixth switch is grounded.

[0028] An input end of the seventh switch is connected to a line between the fifth voltage source and the second positive terminal, and an output end of the seventh switch is grounded.

[0029] In a third aspect, the embodiments of the present application provide an electric energy meter, which comprises a control chip and the compatible interface circuit according to the first aspect and the improvements thereof.

[0030] In a fourth aspect, the embodiments of the present application provide a meter reading device, which comprises the signal conversion circuit according to the second aspect and the improvements thereof.

[0031] Compared with the prior art, the embodiments of the present application have the beneficial effects that: the compatible interface circuit and the signal conversion circuit are matched for use, the compatible interface circuit is applied to the electric energy meter, the signal conversion circuit is applied to the meter reading device, the connection of the compatible interface circuit and the signal conversion circuit is formed through the first positive terminal of the first wiring port and the second positive terminal of the second wiring port, and the first negative terminal of the first wiring port and the second negative terminal of the second wiring port, the current input of the signal conversion circuit on the second positive terminal is controlled, so that the high and low of the level signal output from the second negative terminal follow the high and low of the pulse signal output from the first pin, when the low level signal is input in communication, the current input of the signal conversion circuit on the second negative terminal is controlled, so that the low level signal input is formed at the second pin, when the high level signal is input in communication, the current input of the signal conversion circuit on the second negative terminal is not controlled, so that the high level signal input is formed at the second pin, the signal output is realized relying on the first pin and the signal conversion circuit, the data writing is realized relying on the signal conversion circuit and the second pin, so that the pulse, clock calibration and adjustment functions can be completed, only one first wiring port and second wiring port are matched, and the pulse interface, clock interface and communication interface do not need to be separately configured, thereby reducing the terminal quantity and wiring complexity. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0033] Figure 1 is an application environment schematic diagram of an electric energy meter and a meter reading device provided by an embodiment of the present application;

[0034] Figure 2 is a structure schematic diagram of a compatible interface circuit of an electric energy meter provided by an embodiment of the present application;

[0035] Figure 3is a connection schematic diagram of a compatible interface circuit of an electric energy meter provided by Embodiment Two of the present application;

[0036] Figure 4 is a structural schematic diagram of a signal conversion circuit of an electric energy meter provided by Embodiment Three of the present application;

[0037] Figure 5 is a connection schematic diagram of a signal conversion circuit of an electric energy meter provided by Embodiment Three of the present application;

[0038] Figure 6 is a connection schematic diagram of a compatible interface circuit and a signal conversion circuit provided by Embodiment Four of the present application;

[0039] Wherein, 1, pulse port line, 2, communication port line, 3, first voltage source, 4, first wiring port, 5, control chip, 6, signal following line, 7, signal control line, 8, fourth voltage source, 9, fifth voltage source, 10, second wiring port, 11, ground control line, 101, first switch, 201, second switch, 401, first positive terminal, 402 first negative terminal, 501, first pin, 502, second pin, 601, third switch, 701, fourth switch, 1001, second positive terminal, 1002, second negative terminal. DETAILED DESCRIPTION

[0040] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular sequences of steps, techniques, etc., in order to provide a thorough understanding of the present embodiments. However, it will be apparent to those skilled in the art that the present embodiments can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, and circuits are omitted so as not to obscure the description of the present embodiments.

[0041] It should be understood that the term "comprises" when used in this specification and the appended claims indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0042] It should also be understood that the term "and / or" when used in this specification and the appended claims indicates that the associated listed items can be present one or more of the associated listed items, and that the combinations of the associated listed items are also included.

[0043] As used in the specification and the appended claims, the term "if' can be interpreted as meaning "when" or "once" or "in response to a determination" or "in response to detecting" depending on the context. Similarly, the phrase "if it is determined" or "if [a described condition or event] is detected" can be interpreted to mean "once it is determined" or "in response to a determination" or "once [the described condition or event] is detected" or "in response to detecting [a described condition or event]" depending on the context.

[0044] In addition, in the description of the present application and the appended claims, the terms "first", "second", "third", etc. are used only to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

[0045] In the present application, the reference "one embodiment" or "some embodiments" and the like means that the specific features, structures or characteristics described in connection with the embodiment are included in one or more embodiments of the present application. Therefore, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in further some embodiments" and the like appearing in different places in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "include", "contain", "have" and their variants mean "include but not limited to", unless otherwise specifically emphasized.

[0046] It should be understood that the size of the serial number of each step in the following embodiments does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0047] In order to illustrate the technical solutions of the present application, the following specific embodiments are described.

[0048] As Figure 1 shown, the present embodiment one provides an application environment schematic diagram of an electric energy meter and a meter reading device, a compatible charging interface circuit is configured in the electric energy meter, the compatible interface circuit is connected with a control chip in the electric energy meter through I / O (i.e. two ports of pulse signal port and communication signal port), so as to realize the output of signals in the control chip and the input of signals. The compatible interface circuit cooperates with a signal conversion circuit in the meter reading device to realize the communication between the meter reading device and the electric energy meter. The meter reading device can be equipped with corresponding computer functions, of course, the meter reading device can also be connected with corresponding PC or calibration platform to realize the sending and receiving of electric energy meter signals.

[0049] Referring to Figure 2Is a kind of compatible interface circuit structure schematic diagram of electric energy meter provided in embodiment two of the application, wherein the compatible interface circuit is applied to electric energy meter, comprising: pulse port circuit 1, communication port circuit 2, first voltage source 3 and first wiring port 4, the first positive terminal 401 of first wiring port 4 is used to connect the second positive terminal 1001 of second wiring port 10 in signal conversion circuit of meter reading device, the first negative terminal 402 of first wiring port 4 is used to connect the second negative terminal 1002 of second wiring port 10.

[0050] First switch 101 is provided on pulse port circuit 1, the control end of first switch 101 is used to connect the first pin 501 of control chip 5 of electric energy meter, the input end of first switch 101 is connected with first positive terminal 401, and the output end of first switch 101 is connected with first negative terminal 402.

[0051] Second switch 201 is provided on communication port circuit 2, the input end of second switch 201 is used to connect the second pin 502 of control chip 5, and the input end of second switch 201 is also connected with first voltage source 3, the output end of second switch 201 is grounded, and the input side of the control end of second switch 201 is connected with first negative terminal 402, and the output side of the control end of second switch 201 is connected with first positive terminal 401.

[0052] Control signal conversion circuit inputs current on second positive terminal 1001, so that the high and low of level signal output by second negative terminal 1002 follow the high and low of pulse signal output by first pin 501, that is, when first pin 501 outputs high level signal, first switch 101 is turned on, so that first positive terminal 401 and first negative terminal 402 are connected, so that the corresponding current is output at second negative terminal 1002, and then high level signal output can be realized by corresponding circuit, when first pin 501 outputs low level signal, first switch 101 is cut off, so that first positive terminal 401 and first negative terminal 402 are disconnected, whether second positive terminal 1001 has input current or not, no current output is provided at second negative terminal 1002, so as to realize low level signal output in combination with corresponding circuit. It should be known that, since second switch 201 has corresponding circuit connection between first positive terminal 401 and first negative terminal 401, in the process of realizing the above functions, unidirectional conduction element can be set or short-circuit mode is used to avoid current entering second switch 210.

[0053] When a low-level signal is inputted, the control signal conversion circuit inputs current on the second positive terminal 1002, so that a low-level signal is formed at the input of the second pin 502, i.e., the high-level signal formed by the first voltage source 3 by default is inputted at the second pin 502, current is inputted on the second positive terminal 1002, enters the control end of the second switch 201 through the input of the first negative terminal 402, and enters the first positive terminal 401 through the output of the control end of the second switch 201, so that the second switch 201 is turned on, thereby forming a pull-down to the first voltage source 3, so that the input at the second pin 502 becomes a low-level signal.

[0054] When a high-level signal is inputted, the control signal conversion circuit does not input current on the second positive terminal 1002, so that a high-level signal is formed at the input of the second pin 502, i.e., the high-level signal formed by the first voltage source 3 by default is inputted at the second pin 502, no current is inputted on the second positive terminal 1002, so that the second switch 201 is turned off and cannot form a pull-down to the first voltage source 3, so that the input at the second pin 502 becomes a high-level signal.

[0055] As shown in Figure 2 , it is a connection diagram of a compatible interface circuit of an electric energy meter provided by Embodiment Two of the present application, wherein Prot1 corresponds to the first wiring port 4, P+ corresponds to the first positive terminal 401, and P- corresponds to the first negative terminal 402.

[0056] In the connection relationship diagram of the compatible interface circuit, the first switch 101 is a first optocoupler switch OP1, the input end of the first switch corresponds to the positive electrode of the first photosensitive diode of the first optocoupler switch OP1, the output end of the first switch 101 corresponds to the negative electrode of the first photosensitive diode, and the control end of the first switch 101 corresponds to the positive and negative electrodes of the first light-emitting diode of the first optocoupler switch OP1.

[0057] The compatible interface circuit further comprises a second voltage source and a third voltage source, wherein the second voltage source is connected to the positive electrode of the first light-emitting diode in the first optocoupler switch OP1 through the first resistor R1, the negative electrode of the first light-emitting diode is connected to the input end of the optocoupler control switch Q1, and the output end of the optocoupler control switch Q1 is grounded. The third voltage source is connected to the control end of the optocoupler control switch Q1 through the second resistor R2 and the third resistor R3, and a line (i.e., PUSLE_P) for connecting the first pin 501 is arranged between the second resistor R2 and the third resistor R3.

[0058] When the first pin 501 outputs a high-level signal, the optocoupler control switch Q1 is turned off, and when the first pin 501 outputs a low-level signal, the optocoupler control switch Q1 is turned on.

[0059] As shown in Figure 3As shown, the compatible interface circuit also includes an indicator light circuit. The indicator light circuit is equipped with a second light-emitting diode D4 and a fourth resistor R4. The positive terminal of the second light-emitting diode D4 is connected to the second voltage source through the fourth resistor R4, and the negative terminal of the second light-emitting diode D4 is connected to the input terminal of the optocoupler control switch Q1.

[0060] like Figure 3 As shown, the second switch 201 is the second optocoupler switch OP2. The input terminal of the second switch 201 corresponds to the positive terminal of the second photodiode of the second optocoupler switch OP2, and the output terminal of the second switch 201 corresponds to the negative terminal of the second photodiode. The input of the control terminal of the second switch 201 corresponds to the positive terminal of the third light-emitting diode of the second optocoupler switch OP2, and the output terminal of the control terminal of the second switch 201 corresponds to the negative terminal of the third light-emitting diode. The first voltage source 3 is connected to the positive terminal of the second photodiode through the fifth resistor R5. A line (i.e., RS485_RXD) for connecting the second pin 502 is provided between the fifth resistor R5 and the second photodiode.

[0061] In one embodiment, the control signal conversion circuit receives current at the second positive terminal, causing the level signal output from the second negative terminal to follow the level of the pulse signal output from the first pin, including:

[0062] The control signal conversion circuit receives current at its second positive terminal.

[0063] When the pulse signal output from the first pin is a low-level signal, the first switch is turned on, and the output current from the second negative terminal drives the third switch connected to the second negative terminal to turn on, and a low-level signal is formed at the input terminal of the third switch.

[0064] When the pulse signal output from the first pin is a high-level signal, the first switch is turned off, causing the third switch to turn off and forming a high-level signal at the input of the third switch, thus enabling the pulse signal output from the first pin to follow.

[0065] In one embodiment, when a low-level communication input signal is received, the control signal conversion circuit inputs current to the second negative terminal, thereby creating a low-level signal input at the second pin; when a high-level communication input signal is received, the control signal conversion circuit does not input current to the second negative terminal, thereby creating a high-level signal input at the second pin, including:

[0066] When a low-level signal is input to the communication input, the control signal conversion circuit inputs current to the second negative terminal, which flows into the input of the control terminal of the second switch through the first negative terminal, and reaches the first and second positive terminals after passing through the output side of the control terminal of the second switch, and then grounds. This causes the first switch to be reverse-biased and the second switch to be turned on, thereby driving the second pin to be grounded, so that a low-level signal input is formed at the second pin.

[0067] The control signal conversion circuit does not input current on the second negative terminal when the communication input high level signal, so that the second switch is cut off, and the first voltage source forms the input of the high level signal at the second pin.

[0068] Referring to Figure 4 A structural schematic diagram of a signal conversion circuit of an electric energy meter is provided for Embodiment Three of the present application, and the signal conversion circuit is applied to a meter reading device. The signal conversion circuit comprises a signal following circuit 6, a signal control circuit 7, a fourth voltage source 8, a fifth voltage source 9, and a second connection port 10. The second positive terminal 1001 of the second connection port is used for connecting the first positive terminal 401 of the first connection port 4 in the compatible interface circuit of the electric energy meter, and the second negative terminal 1002 of the second connection port 10 is used for connecting the first negative terminal 402 of the first connection port 4.

[0069] The third switch 601 is arranged on the signal following circuit 6, the control terminal of the third switch 601 is connected to the second negative terminal 1002, the input terminal of the third switch 601 is connected to the fourth voltage source 8, the input terminal of the third switch 601 is further provided with a signal output interface, and the output terminal of the third switch 601 is grounded. When the second negative terminal 1002 outputs current, the third switch 601 is turned on, and a low level signal is formed on the signal output interface. When the second negative terminal 1002 does not output current, the third switch 601 is cut off, and a high level signal is formed on the signal output interface.

[0070] The fourth switch 701 is arranged on the signal control circuit 7, the input terminal and the control terminal of the fourth switch 701 are both connected to the fifth voltage source 9, the control terminal of the fourth switch 701 is further connected to the signal input interface, the output terminal of the fourth switch 701 is connected to the second negative terminal 1002, and the fifth voltage source 9 is further connected to the second positive terminal 1001 through a resistor. A grounding control circuit 11 is further arranged between the resistor and the second positive terminal 1001. When the signal input interface is a high level signal, the fourth switch 701 and the grounding control circuit 11 are cut off, and the fifth voltage source 9 provides current to the second positive terminal 1001. When the signal output interface is a low level, the fourth switch 701 and the grounding control circuit 11 are turned on, and the fifth voltage source 9 provides current to the second negative terminal 1002.

[0071] As Figure 5As shown in the figure, the third switch 601 is Q11, the fourth switch 701 is Q13, the ground control line 11 includes the fifth switch Q10, the sixth switch Q12 and the seventh switch Q14, the control end of the fifth switch Q10 is connected with the fifth voltage source 9, the input end of the fifth switch Q10 is connected with the fourth voltage source 8, the output end of the fifth switch Q10 is respectively connected with the control end of the sixth switch Q12, the output end of the sixth switch Q12 and the control end of the seventh switch Q14, the input end of the sixth switch Q12 is connected on the line between the control end of the third switch 601 and the output end of the fourth switch 701, the output end of the sixth switch Q12 is grounded, and the input end of the seventh switch Q14 is connected on the line between the fifth voltage source 9 and the second positive end 1001, and the output end of the seventh switch Q14 is grounded.

[0072] As shown in the figure, the third switch 601 is Q11, the fourth switch 701 is Q13, the ground control line 11 includes the fifth switch Q10, the sixth switch Q12 and the seventh switch Q14, the control end of the fifth switch Q10 is connected with the fifth voltage source 9, the input end of the fifth switch Q10 is connected with the fourth voltage source 8, the output end of the fifth switch Q10 is respectively connected with the control end of the sixth switch Q12, the output end of the sixth switch Q12 and the control end of the seventh switch Q14, the input end of the sixth switch Q12 is connected on the line between the control end of the third switch 601 and the output end of the fourth switch 701, the output end of the sixth switch Q12 is grounded, and the input end of the seventh switch Q14 is connected on the line between the fifth voltage source 9 and the second positive end 1001, and the output end of the seventh switch Q14 is grounded. Figure 6 As shown in the figure, the third switch 601 is Q11, the fourth switch 701 is Q13, the ground control line 11 includes the fifth switch Q10, the sixth switch Q12 and the seventh switch Q14, the control end of the fifth switch Q10 is connected with the fifth voltage source 9, the input end of the fifth switch Q10 is connected with the fourth voltage source 8, the output end of the fifth switch Q10 is respectively connected with the control end of the sixth switch Q12, the output end of the sixth switch Q12 and the control end of the seventh switch Q14, the input end of the sixth switch Q12 is connected on the line between the control end of the third switch 601 and the output end of the fourth switch 701, the output end of the sixth switch Q12 is grounded, and the input end of the seventh switch Q14 is connected on the line between the fifth voltage source 9 and the second positive end 1001, and the output end of the seventh switch Q14 is grounded. Figure 6 As shown in the figure, the third switch 601 is Q11, the fourth switch 701 is Q13, the ground control line 11 includes the fifth switch Q10, the sixth switch Q12 and the seventh switch Q14, the control end of the fifth switch Q10 is connected with the fifth voltage source 9, the input end of the fifth switch Q10 is connected with the fourth voltage source 8, the output end of the fifth switch Q10 is respectively connected with the control end of the sixth switch Q12, the output end of the sixth switch Q12 and the control end of the seventh switch Q14, the input end of the sixth switch Q12 is connected on the line between the control end of the third switch 601 and the output end of the fourth switch 701, the output end of the sixth switch Q12 is grounded, and the input end of the seventh switch Q14 is connected on the line between the fifth voltage source 9 and the second positive end 1001, and the output end of the seventh switch Q14 is grounded. Figure 6 As shown in the figure, the third switch 601 is Q11, the fourth switch 701 is Q13, the ground control line 11 includes the fifth switch Q10, the sixth switch Q12 and the seventh switch Q14, the control end of the fifth switch Q10 is connected with the fifth voltage source 9, the input end of the fifth switch Q10 is connected with the fourth voltage source 8, the output end of the fifth switch Q10 is respectively connected with the control end of the sixth switch Q12, the output end of the sixth switch Q12 and the control end of the seventh switch Q14, the input end of the sixth switch Q12 is connected on the line between the control end of the third switch 601 and the output end of the fourth switch 701, the output end of the sixth switch Q12 is grounded, and the input end of the seventh switch Q14 is connected on the line between the fifth voltage source 9 and the second positive end 1001, and the output end of the seventh switch Q14 is grounded.

[0073] As shown in the figure, the third switch 601 is Q11, the fourth switch 701 is Q13, the ground control line 11 includes the fifth switch Q10, the sixth switch Q12 and the seventh switch Q14, the control end of the fifth switch Q10 is connected with the fifth voltage source 9, the input end of the fifth switch Q10 is connected with the fourth voltage source 8, the output end of the fifth switch Q10 is respectively connected with the control end of the sixth switch Q12, the output end of the sixth switch Q12 and the control end of the seventh switch Q14, the input end of the sixth switch Q12 is connected on the line between the control end of the third switch 601 and the output end of the fourth switch 701, the output end of the sixth switch Q12 is grounded, and the input end of the seventh switch Q14 is connected on the line between the fifth voltage source 9 and the second positive end 1001, and the output end of the seventh switch Q14 is grounded.

[0074] The metering calibration platform calculates the metering calibration parameters according to the received metering pulses, and needs to be written into the electric energy meter through RS485 communication to correct the metering parameters. The PC machine or TXD port of the calibration platform on the right side of the figure sends a low-level effective signal, the transistors Q10, Q12, Q13 and Q14 are turned on, the current provided by the power supply Vex passes through the connection line between the E-C electrode of the transistor Q13, the 1 pin of the Port1 and Port2, the resistor R6, the 1-2 pin of the second optocoupler switch OP2, the resistor R7, the connection line between the 2 pin of the Port1 and Port2, the resistor R21 and the C-E electrode of the transistor Q14 to the ground. The 1-2 pin of the second optocoupler switch OP2 is turned on, and the 4-3 pin is also turned on, and RS485_RXD is pulled low to low level; when the TXD port of the PC machine or the calibration platform is pulled high, the transistors Q10, Q12, Q13 and Q14 are cut off, and the second optocoupler switch OP2 is also cut off, and RS485_RXD is pulled high to high level by the resistor R5; the high and low level signals sent by the TXD port of the PC machine or the calibration platform are transmitted to the RS485_RXD receiving port of the electric energy meter MCU for metering correction parameter writing operation. If the RS485_RXD receiving port of the electric energy meter MCU receives the completion, it needs to reply the confirmation command to the calibration platform, and the PUSLE_P port needs to be configured as a communication sending function on the firmware of the electric energy meter MCU to send the confirmation command to the port, and the signal transmission hardware mechanism is the same as the above-mentioned electric energy pulse output mechanism.

[0075] When the clock of the electric energy meter needs to be checked, the PC machine or the calibration platform sends a control command through the signal conversion circuit on the right side of the figure to inform the electric energy meter to set the PUSLE_P port as a clock pulse output, and the clock pulse is output to the calibration platform for clock correction parameter calculation, and the correction parameter is written into the electric energy meter MCU through the RS485 communication function. The hardware circuit mechanism of this process is similar to the above-mentioned electric energy pulse output metering calibration, and will not be described here.

[0076] When other pulse output calibration is needed, only the PC machine or the calibration platform needs to send a function switching command to the electric energy meter.

[0077] It should be known that the turning on of the transistor refers to that after a voltage higher than 0.7V is applied to the base electrode of the transistor, the C-E or E-C electrode presents a low voltage drop state. The calibration platform is used for the metering calibration and clock calibration of the electric energy meter.

[0078] The electric energy meter generally has a communication or pulse output auxiliary terminal designed on the surface of the shell. The electric meter signal output circuit part of the electric energy meter pulse port compatible with the communication port and clock port scheme needs to be designed into the electric energy meter as a part of the electric energy meter communication port circuit. The signal conversion circuit part of the present application is designed as a communication interface conversion tool which can be connected to the communication terminal of the electric energy meter on one side and to the TTL communication port of the PC or calibration table on the other side.

[0079] The present application combines software, uses a single-chip microcomputer, resistors, optocouplers, transistors, etc., and combines the previously required multiple sets of independent communication and calibration output terminals into one terminal, which can be used for function verification output and communication interaction, realizes more concise product auxiliary terminal design, improves production efficiency, and reduces cost.

[0080] The embodiment of the present application provides an electric energy meter, which comprises a control chip and a compatible interface circuit as described above.

[0081] The embodiment of the present application provides a meter reading device, which comprises a signal conversion circuit as described above.

[0082] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A compatible interface circuit for an electricity meter, characterized in that, The compatible interface circuit is applied to an energy meter and includes: a pulse port line, a communication port line, a first voltage source and a first connection port. The first positive terminal of the first connection port is used to connect to the second positive terminal of the second connection port in the signal conversion circuit of the meter reading device, and the first negative terminal of the first connection port is used to connect to the second negative terminal of the second connection port. A first switch is provided on the pulse port line. The control terminal of the first switch is used to connect to the first pin of the control chip of the energy meter. The input terminal of the first switch is connected to the first positive terminal, and the output terminal of the first switch is connected to the first negative terminal. A second switch is provided on the communication port line. The input terminal of the second switch is used to connect to the second pin of the control chip. The input terminal of the second switch is also connected to the first voltage source. The output terminal of the second switch is grounded. The input side of the control terminal of the second switch is connected to the first negative terminal, and the output side of the control terminal of the second switch is connected to the first positive terminal. The signal conversion circuit is controlled to input current to the second positive terminal, so that the level signal output from the second negative terminal follows the level of the pulse signal output from the first pin. When a low-level communication signal is input, the signal conversion circuit is controlled to input current to the second negative terminal, so that a low-level signal is input at the second pin. When a high-level communication signal is input, the signal conversion circuit is controlled not to input current to the second negative terminal, so that a high-level signal is input at the second pin.

2. The compatible interface circuit according to claim 1, characterized in that, The compatible interface circuit also includes a second voltage source and a third voltage source; The first switch is a first optocoupler switch. The input terminal of the first switch corresponds to the positive terminal of the first photodiode of the first optocoupler switch, the output terminal of the first switch corresponds to the negative terminal of the first photodiode, the control terminal of the first switch corresponds to the positive and negative terminals of the first light-emitting diode of the first optocoupler switch, the positive terminal of the first light-emitting diode is connected to the second voltage source through a first resistor, the negative terminal of the first light-emitting diode is connected to the input terminal of the optocoupler control switch, and the output terminal of the optocoupler control switch is grounded. The third voltage source is connected to the control terminal of the optocoupler control switch through the second resistor and the third resistor. A line for connecting the first pin is provided between the second resistor and the third resistor. When the first pin outputs a high-level signal, the optocoupler control switch is turned off. When the first pin outputs a low-level signal, the optocoupler control switch is turned on.

3. The compatible interface circuit according to claim 2, characterized in that, The compatible interface circuit also includes an indicator light circuit, on which a second light-emitting diode and a fourth resistor are provided. The positive terminal of the second light-emitting diode is connected to the second voltage source through the fourth resistor, and the negative terminal of the second light-emitting diode is connected to the input terminal of the optocoupler control switch.

4. The compatible interface circuit according to claim 1, characterized in that, The second switch is a second optocoupler switch. The input terminal of the second switch corresponds to the positive terminal of the second photodiode of the second optocoupler switch, and the output terminal of the second switch corresponds to the negative terminal of the second photodiode. The input of the control terminal of the second switch corresponds to the positive terminal of the third light-emitting diode of the second optocoupler switch, and the output terminal of the control terminal of the second switch corresponds to the negative terminal of the third light-emitting diode. The first voltage source is connected to the positive terminal of the second photodiode through a fifth resistor, and a line for connecting the second pin is provided between the fifth resistor and the second photodiode.

5. The compatible interface circuit according to claim 1, characterized in that, The control circuit that inputs current to the second positive terminal, such that the level signal output from the second negative terminal follows the level of the pulse signal output from the first pin, includes: The signal conversion circuit is controlled to input current at the second positive terminal; When the pulse signal output by the first pin is a low-level signal, the first switch is turned on, and the output current of the second negative terminal drives the third switch connected to the second negative terminal to turn on, and a low-level signal is formed at the input terminal of the third switch. When the pulse signal output by the first pin is a high-level signal, the first switch is turned off, causing the third switch to turn off and forming a high-level signal at the input of the third switch, thereby enabling the pulse signal output by the first pin to follow.

6. The compatible interface circuit according to claim 1, characterized in that, The method of controlling the signal conversion circuit to input current to the second negative terminal when a low-level communication input signal is received, so that a low-level signal input is formed at the second pin, and controlling the signal conversion circuit not to input current to the second negative terminal when a high-level communication input signal is received, so that a high-level signal input is formed at the second pin, includes: When a low-level signal is input to the communication input, the signal conversion circuit is controlled to input current to the second negative terminal. The current flows through the first negative terminal into the input of the control terminal of the second switch, and after passing through the output side of the control terminal of the second switch, it reaches the first positive terminal and the second positive terminal and is grounded. This causes the first switch to be reverse cut off and the second switch to be turned on, thereby driving the second pin to be grounded, so that a low-level signal input is formed at the second pin. When a high-level signal is input to the communication input, the signal conversion circuit is controlled not to input current to the second negative terminal, so that the second switch is turned off, and the first voltage source forms a high-level signal input at the second pin.

7. A signal conversion circuit for an electricity meter, characterized in that, The signal conversion circuit is applied to the meter reading device and includes: a signal following line, a signal control line, a fourth voltage source, a fifth voltage source, and a second terminal. The second positive terminal of the second terminal is used to connect to the first positive terminal of the first terminal in the compatible interface circuit of the energy meter, and the second negative terminal of the second terminal is used to connect to the first negative terminal of the first terminal. A third switch is provided on the signal following line. The control terminal of the third switch is connected to the second negative terminal, and the input terminal of the third switch is connected to a fourth voltage source. The input terminal of the third switch is also provided with a signal output interface, and the output terminal of the third switch is grounded. When the second negative terminal outputs current, the third switch is turned on, and a low-level signal is generated on the signal output interface. When the second negative terminal does not output current, the third switch is turned off, and a high-level signal is generated on the signal output interface. A fourth switch is provided on the signal control line. The input and control terminals of the fourth switch are both connected to the fifth voltage source. The control terminal of the fourth switch is also connected to the signal input interface. The output terminal of the fourth switch is connected to the second negative terminal. The fifth voltage source is also connected to the second positive terminal through a resistor. A grounding control line is also provided between the resistor and the second positive terminal. When the signal input interface is at a high level, the fourth switch and the grounding control line are cut off, and the fifth voltage source provides current to the second positive terminal. When the signal output interface is at a low level, the fourth switch and the grounding control line are connected, and the fifth voltage source provides current to the second negative terminal.

8. The signal conversion circuit according to claim 7, characterized in that, The grounding control line includes a fifth switch, a sixth switch, and a seventh switch. The control terminal of the fifth switch is connected to the fifth voltage source, the input terminal of the fifth switch is connected to the fourth voltage source, and the output terminal of the fifth switch is connected to the control terminal of the sixth switch, the output terminal of the sixth switch, and the control terminal of the seventh switch, respectively. The input terminal of the sixth switch is connected to the line between the control terminal of the third switch and the output terminal of the fourth switch, and the output terminal of the sixth switch is grounded. The input terminal of the seventh switch is connected to the line between the fifth voltage source and the second positive terminal, and the output terminal of the seventh switch is grounded.

9. An electricity meter, characterized in that, The electricity meter includes a control chip and a compatible interface circuit as described in any one of claims 1 to 6.

10. A meter reading device, characterized in that, The meter reading device includes the signal conversion circuit as described in any one of claims 7 to 8.

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