Neutral and live wire communication circuits, modules, and indoor / outdoor unit communication systems

Abstract

This utility model discloses a live-wire communication circuit, module, and indoor / outdoor unit communication system. The circuit includes: a simulated indoor unit module, a simulated outdoor unit module, and a waveform shaping module. The simulated indoor unit module includes power line communication ports S2, TXD1, and RXD1, as well as a simulated indoor unit relay circuit. The simulated outdoor unit module includes power line communication ports S3, TXD2, and RXD2, as well as a simulated outdoor unit relay circuit. The waveform shaping module includes a first OR logic gate and a second OR logic gate. One input of the first OR logic gate is connected to the RXD1 port, its output is connected to the TXD2 port, and its other input is used to receive a high-level signal. One input of the second OR logic gate is connected to the RXD2 port, its output is connected to the TXD1 port, and its other input is used to receive a high-level signal. This utility model solves the shortcomings of existing indoor / outdoor units where excessively long communication lines cause signal attenuation and unstable communication quality, greatly improving application reliability.

Description

Technical Field

[0001] This utility model belongs to the field of electronic circuit technology, specifically relating to a neutral and live wire communication circuit, module, and internal / external unit communication system. Background Technology

[0002] Live-neutral wire communication (L / N) is a highly efficient and reliable communication protocol. Its working principle utilizes the specific roles of the live and neutral wires in the circuit to achieve data transmission. In L / N communication circuits, the live wire (L) and neutral wire (N) not only provide power but also transmit data signals through voltage changes between them. L / N communication is suitable for various communication scenarios, including industrial automation, smart homes, and the Internet of Things (IoT). For example, the communication between the indoor and outdoor units (master and slave units) of a variable frequency air conditioner uses L / N communication.

[0003] However, existing neutral and live wire communication circuits are also significantly limited in some application scenarios and exhibit the following defects: taking the communication between the indoor and outdoor units of a variable frequency air conditioner as an example, when the indoor and outdoor units are placed far apart, the line is long and the line resistance increases accordingly, resulting in communication signal attenuation and unstable communication quality. Summary of the Invention

[0004] This utility model provides a live-wire communication circuit, module, and indoor / outdoor unit communication system, solving the problems of signal attenuation and unstable communication quality caused by long distances between the outdoor unit (master) and the indoor unit (slave). The technical solution adopted by this utility model is as follows:

[0005] In a first aspect, this utility model provides a neutral-live wire communication circuit, comprising:

[0006] The analog indoor unit module includes: a power line communication port S2 for connecting to the outdoor unit via a power line; TXD1 and RXD1 ports for connecting to the waveform processing module; and an analog indoor unit relay circuit for signal relay processing between the power line communication port S2 and the TXD1 and RXD1 ports.

[0007] The simulated outdoor unit module includes: a powerline communication port S3 for connecting to the indoor unit via a powerline; TXD2 and RXD2 ports for connecting to the waveform processing module; and a simulated outdoor unit relay circuit for signal relay processing between the powerline communication port S3 and the RXD2 ports.

[0008] The waveform shaping module includes a first OR logic gate and a second OR logic gate. One input of the first OR logic gate is connected to the RXD1 port, and its output is connected to the TXD2 port. The other input is connected to a high-level signal when the analog indoor unit module receives a level signal from the outdoor unit, so that the TXD2 port maintains a stable high level. One input of the second OR logic gate is connected to the RXD2 port, and its output is connected to the TXD1 port. The other input is connected to a high-level signal when the analog outdoor unit module receives a level signal from the indoor unit, so that the TXD1 port maintains a stable high level.

[0009] As a specific technical solution, the waveform shaping module also includes a main chip, which provides the high-level signal for the first OR logic gate and the second OR logic gate.

[0010] As a specific technical solution, the analog indoor unit relay circuit includes optocoupler PC5, optocoupler PC6, NPN transistor Q5, NPN transistor Q6, resistors R6, R7, R8, R9, and R10; the first terminal of optocoupler PC5 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q5, the third terminal is connected to the first terminal of optocoupler PC6, and the fourth terminal is connected to the power line communication port S2; the base (B) of NPN transistor Q5 is connected to the TX via resistor R6. At port D1, the emitter (E) of NPN transistor Q5 is grounded; terminals 2 and 3 of optocoupler PC6 are grounded, a resistor R10 is connected between terminals 1 and 2, and terminal 2 serves as the AC neutral terminal AC_N; terminal 4 is connected to the base (B) of NPN transistor Q6 and simultaneously connected to the DC power supply via resistor R9; the emitter (E) of NPN transistor Q6 is connected to port RXD1 via resistor R7, and the emitter (E) of NPN transistor Q6 is connected to the DC power supply via resistor R8; the collector (C) of NPN transistor Q6 is grounded.

[0011] As a specific technical solution, the analog outdoor unit relay circuit includes optocoupler PC7, optocoupler PC8, NPN transistor Q3, NPN transistor Q4, resistors R11, R12, R13, R14, and R15; the first terminal of optocoupler PC7 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q3, the third terminal is connected to the first terminal of optocoupler PC8, and the fourth terminal is connected to an AC-DC communication level; the base (B) of NPN transistor Q3 is connected to the... The TXD2 port is connected to the ground of the emitter (E) of NPN transistor Q3; a resistor R15 is connected between the first and second terminals of optocoupler PC8, the second terminal is connected to the power line communication port S3, the third terminal is grounded, and the fourth terminal is connected to the base (B) of NPN transistor Q4 and simultaneously connected to a DC power supply via resistor R13; the emitter (E) of NPN transistor Q4 is connected to the RXD2 port via resistor R14, the emitter (E) of NPN transistor Q4 is connected to a DC power supply via resistor R12, and the collector (C) of NPN transistor Q4 is grounded.

[0012] Secondly, this utility model provides a neutral-live wire communication module, including a PCB board and a housing. The neutral-live wire communication circuit mentioned above is disposed on the PCB board, and the PCB board is disposed in the housing. The power line communication port S2 and the power line communication port S3 are disposed on the housing.

[0013] Thirdly, this utility model provides an indoor / outdoor unit communication system, including an indoor unit, an outdoor unit, and the aforementioned live / neutral wire communication circuit; the outdoor unit includes an outdoor unit communication circuit, which has a power line communication port S1, and the power line communication port S1 is connected to the power line communication port S2 via a power line; the indoor unit includes an indoor unit communication circuit, which has a power line communication port S4, and the power line communication port S4 is connected to the power line communication port S3 via a power line.

[0014] As a specific technical solution, the outdoor unit communication circuit includes optocoupler PC1, optocoupler PC2, NPN transistor Q1, NPN transistor Q2, resistors R1, R2, R3, R4, and R5; the first terminal of optocoupler PC1 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q1, the third terminal is connected to the first terminal of optocoupler PC2, and the fourth terminal is connected to an AC-DC communication level; the base (B) of NPN transistor Q1 is connected to the transistor T of the outdoor unit communication circuit via resistor R1. The emitter (E) of NPN transistor Q1 is grounded at the XD port; the third terminal of optocoupler PC2 is grounded, a resistor R5 is connected between the first and second terminals, and the second terminal is connected to the power line communication port S1; the fourth terminal is connected to the base (B) of NPN transistor Q2 and simultaneously connected to the DC power supply via resistor R4; the emitter (E) of NPN transistor Q2 is connected to the RXD port of the outdoor unit communication circuit via resistor R2, the emitter (E) of NPN transistor Q2 is connected to the DC power supply via resistor R3, and the collector (C) of NPN transistor Q2 is grounded.

[0015] As a specific technical solution, the indoor unit communication circuit includes optocoupler PC3, optocoupler PC4, NPN transistor Q7, NPN transistor Q8, resistors R16, R17, R18, R19, and R20; the first terminal of optocoupler PC3 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q7, the third terminal is connected to the first terminal of optocoupler PC4, and the fourth terminal is connected to the power line communication port S4; the base (B) of NPN transistor Q7 is connected to the indoor unit communication circuit via resistor R16. The TXD port of the NPN transistor Q7 is grounded, and the emitter of the NPN transistor Q7 is grounded. The third terminal of the optocoupler PC4 is grounded, and a resistor R20 is connected between the first and second terminals. The second terminal serves as the AC neutral terminal AC_N. The fourth terminal is connected to the base of the NPN transistor Q8 and is also connected to the DC power supply via a resistor R18. The emitter of the NPN transistor Q8 is connected to the RXD port of the indoor communication circuit via a resistor R19. The emitter of the NPN transistor Q8 is connected to the DC power supply via a resistor R17, and the collector of the NPN transistor Q8 is grounded.

[0016] The beneficial effects of this utility model include: by using an innovative neutral and live wire communication circuit to connect the indoor unit and the outdoor unit, the neutral and live wire communication signals are amplified and relayed, which makes up for the shortcomings of communication signal attenuation and unstable communication quality caused by excessive distance and long communication lines between the indoor and outdoor units, and greatly improves the reliability of the application. Attached Figure Description

[0017] To more clearly illustrate the embodiments of this utility model, the accompanying drawings used in the description of the embodiments or the prior art will be briefly described below.

[0018] Figure 1 This is a block diagram of the neutral and live wire communication circuit provided in this embodiment of the utility model.

[0019] Figure 2 This is a circuit diagram of the live and neutral wire communication circuit provided in this embodiment of the utility model.

[0020] Figure 3 This is a comparative circuit diagram of the live and neutral wire communication circuit provided in this embodiment of the present invention.

[0021] Figure 4 This is a block diagram of the internal and external communication system provided in this embodiment of the utility model.

[0022] Figure 5 This is a circuit diagram of the internal and external communication system provided in this embodiment of the utility model.

[0023] Figure 6 This is a circuit diagram of the external unit and the simulated internal unit module in the internal-external unit communication system provided in this embodiment of the utility model.

[0024] Figure 7This is a circuit diagram simulating the external unit module and the internal unit in the internal and external unit communication system provided by this utility model embodiment. Detailed Implementation

[0025] To make the technical solution of the present invention clearer and its technical advantages more apparent, the technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present invention.

[0026] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. For ease of explanation, the orientations are defined in conjunction with the drawings. These orientation definitions are merely for the purpose of clearly describing the relative positional relationships and are not intended to limit the actual orientation of the product or device during production, use, or sale. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Moreover, in the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0027] The neutral-live wire communication circuit, module, and indoor / outdoor unit communication system provided in this embodiment are illustrated using long-distance communication between the indoor and outdoor units of an air conditioner as an example. It can also be applied to other similar indoor / outdoor unit communication or master-slave unit communication. This embodiment is based on a bidirectional symmetrical neutral-live wire communication structure, achieving bidirectional signal interaction through the neutral-live wire communication circuit between the indoor and outdoor units. The symmetrically designed transceiver circuit and waveform processing module work together to effectively suppress interference and improve signal integrity, ensuring stable and efficient data transmission between the indoor and outdoor units.

[0028] like Figure 1 As shown, as a basic implementation method, the live-wire communication circuit provided in this embodiment includes an analog indoor unit module (hereinafter referred to as analog indoor unit), an analog outdoor unit module (analog outdoor unit), and a waveform processing module.

[0029] Combination Figure 1 and Figure 2As shown, the analog indoor unit module includes a power line communication port S2, a TXD1 port, and an RXD1 port, as well as an analog indoor unit relay circuit. The power line communication port S2 is used to connect to the outdoor unit via a power line; the TXD1 and RXD1 ports are used to connect to the waveform processing module; and the analog indoor unit relay circuit is used to perform signal relay processing between the power line communication port S2 and the TXD1 and RXD1 ports.

[0030] Combination Figure 1 and Figure 2 As shown, the simulated outdoor unit module includes a powerline communication port S3, a TXD2 port, and an RXD2 port, as well as a simulated outdoor unit relay circuit. The powerline communication port S3 is used to connect to the indoor unit via a powerline; the TXD2 and RXD2 ports are used to connect to the waveform processing module; and the simulated outdoor unit relay circuit is used to perform signal relay processing between the powerline communication port S3 and the RXD2 port.

[0031] Combination Figure 1 and Figure 2 As shown, the waveform shaping module includes a first OR logic gate (i.e., Figure 2 The "OR logic gate 1" and the second OR logic gate (i.e. Figure 2 The first OR logic gate ("OR gate 2") has one input connected to the RXD1 port and its output connected to the TXD2 port. Its other input is connected to a high-level signal when the analog indoor unit module receives a level signal from the outdoor unit, thus maintaining a stable high level at the TXD2 port. The second OR logic gate has one input connected to the RXD2 port and its output connected to the TXD1 port. Its other input is connected to a high-level signal when the analog outdoor unit module receives a level signal from the indoor unit, thus maintaining a stable high level at the TXD1 port.

[0032] In this embodiment, the waveform shaping module also includes a main chip, which provides the high-level signal for the first OR logic gate and the second OR logic gate.

[0033] like Figure 2As shown, in a specific implementation, the analog indoor unit relay circuit includes optocoupler PC5, optocoupler PC6, NPN transistor Q5, NPN transistor Q6, resistors R6, R7, R8, R9, and R10; the first terminal of optocoupler PC5 is connected to the DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q5, the third terminal is connected to the first terminal of optocoupler PC6, and the fourth terminal is connected to the power line communication port S2; the base (B) of NPN transistor Q5 is connected to the TX via resistor R6. At port D1, the emitter (E) of NPN transistor Q5 is grounded; terminals 2 and 3 of optocoupler PC6 are grounded, a resistor R10 is connected between terminals 1 and 2, and terminal 2 serves as the AC neutral terminal AC_N; terminal 4 is connected to the base (B) of NPN transistor Q6 and simultaneously connected to the DC power supply via resistor R9; the emitter (E) of NPN transistor Q6 is connected to port RXD1 via resistor R7, and the emitter (E) of NPN transistor Q6 is connected to the DC power supply via resistor R8; the collector (C) of NPN transistor Q6 is grounded.

[0034] like Figure 2 As shown, in a specific implementation, the analog outdoor unit relay circuit includes optocoupler PC7, optocoupler PC8, NPN transistor Q3, NPN transistor Q4, resistors R11, R12, R13, R14, and R15; the first terminal of optocoupler PC7 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q3, the third terminal is connected to the first terminal of optocoupler PC8, and the fourth terminal is connected to an AC-DC communication level; the base (B) of NPN transistor Q3 is connected to the... The TXD2 port is connected to the ground of the emitter (E) of NPN transistor Q3; a resistor R15 is connected between the first and second terminals of optocoupler PC8, the second terminal is connected to the power line communication port S3, the third terminal is grounded, and the fourth terminal is connected to the base (B) of NPN transistor Q4 and simultaneously connected to a DC power supply via resistor R13; the emitter (E) of NPN transistor Q4 is connected to the RXD2 port via resistor R14, the emitter (E) of NPN transistor Q4 is connected to a DC power supply via resistor R12, and the collector (C) of NPN transistor Q4 is grounded.

[0035] In the above embodiments, the waveform shaping module is a collaborative architecture of OR logic gate circuits and the main chip's dynamic threshold GPIO. Through hardware logic shaping and software adjustable level adaptation, it achieves signal optimization, ensures the consistency of the timing of the zero and live wire carrier waveforms during transmission, and enhances anti-interference capabilities.

[0036] To illustrate the aforementioned beneficial effects, this embodiment provides a comparative example. See [link to example]. Figure 3As shown, if the TXD1 port of the analog indoor unit module is directly connected to the RXD2 port of the analog outdoor unit module, and simultaneously the RXD1 port of the analog indoor unit module is directly connected to the TXD2 port of the analog outdoor unit module, based on the principle of live-neutral wire communication, RXD1, RXD2 and TXD1, TXD2 will receive uncertain voltage levels. In this case, the system will cyclically forward the original signals from the indoor and outdoor units. When the transmission cable exceeds the critical length, the signal level is easily affected by the cable parameters during long-distance transmission, leading to indeterminate voltage levels and consequently causing communication abnormalities between the indoor and outdoor units.

[0037] The signal path in this embodiment is as follows:

[0038] (1) Signal path from outdoor unit to indoor unit: After the digital level signal sent by the outdoor unit is transmitted through the power line S, the analog indoor unit module receives the level signal sent by the outdoor unit. This signal is ORed with the high-level signal output by the main chip through logic gate 1, so that the TXD2 port of the analog indoor unit module maintains a stable high level. The NPN transistor Q3 and the optocoupler PC7 form a composite conduction circuit, triggering the optocoupler PC8 to conduct. The DC power supply (e.g., +5V voltage) is grounded through resistor R13 and the secondary terminal of optocoupler PC8, and the NPN transistor Q4 enters the cut-off state. The RXD2 of the analog indoor unit module receives a valid high level. In this way, the signal link realizes the complete communication signal transmission from the outdoor unit to the indoor unit, and the communication circuit is normal.

[0039] (2) Signal path from indoor unit to outdoor unit: A symmetrical design architecture is adopted, and the same logic processing mechanism is used to ensure the reliability of bidirectional communication.

[0040] This embodiment also provides a live-neutral communication module, including a PCB board and a housing. The live-neutral communication circuit described above is disposed on the PCB board, and the PCB board is disposed in the housing. The power line communication port S2 and the power line communication port S3 are disposed on the housing.

[0041] Combination Figure 4 and Figure 5 As shown, this embodiment also provides an indoor / outdoor unit communication system, including an indoor unit, an outdoor unit, and the live / neutral wire communication circuit described above; the outdoor unit includes an outdoor unit communication circuit, which has a power line communication port S1, and the power line communication port S1 is connected to the power line communication port S2 of the simulated indoor unit module via a power line; the indoor unit includes an indoor unit communication circuit, which has a power line communication port S4, and the power line communication port S4 is connected to the power line communication port S3 of the simulated outdoor unit module via a power line.

[0042] Combination Figure 5 and Figure 6As shown, in one specific implementation, the outdoor unit communication circuit includes optocoupler PC1, optocoupler PC2, NPN transistor Q1, NPN transistor Q2, resistors R1, R2, R3, R4, and R5; the first terminal of optocoupler PC1 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q1, the third terminal is connected to the first terminal of optocoupler PC2, and the fourth terminal is connected to an AC-DC communication level; the base (B) of NPN transistor Q1 is connected to the outdoor unit communication circuit via resistor R1. The TXD port of the circuit is connected to the ground of the emitter of NPN transistor Q1; the third terminal of optocoupler PC2 is grounded, a resistor R5 is connected between the first and second terminals, and the second terminal is connected to the power line communication port S1; the fourth terminal is connected to the base of NPN transistor Q2 and connected to the DC power supply via resistor R4; the emitter of NPN transistor Q2 is connected to the RXD port of the outdoor unit communication circuit via resistor R2, the emitter of NPN transistor Q2 is connected to the DC power supply via resistor R3, and the collector of NPN transistor Q2 is grounded.

[0043] The communication process between the outdoor unit and the analog indoor unit module is described below:

[0044] High-level transmission: When the outdoor unit sends a high level, Q1 saturates and conducts, driving PC1 and PC2 to conduct, activating the power line S to establish a forward transmission path. At this time, optocoupler PC5 and NPN transistor Q5 form a combined conduction state, injecting a high level into the simulated indoor unit's TXD1. Optocoupler PC6 conducts, grounding the DC power supply (e.g., +5V power supply) through resistor R9 and the secondary winding of optocoupler PC6. Transistor Q6 is cut off, and the simulated indoor unit's RXD1 port receives a high level.

[0045] Low-level transmission: When the outdoor unit sends a low level, the NPN transistor Q1 is cut off, simultaneously cutting off the PC1-PC2 and PC5-Q5 path signals, causing the power line S signal transmission to fail. At this time, the optocoupler PC6 is cut off, triggering the NPN transistor Q6 to conduct. The DC power supply (e.g., +5V power supply) is grounded through resistor R8 and NPN transistor Q6, and the collector pull-up network quickly pulls the RXD1 port down to a low level.

[0046] Combination Figure 5 and Figure 7As shown, in one specific implementation, the indoor unit communication circuit includes optocoupler PC3, optocoupler PC4, NPN transistor Q7, NPN transistor Q8, resistors R16, R17, R18, R19, and R20; the first terminal of optocoupler PC3 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q7, the third terminal is connected to the first terminal of optocoupler PC4, and the fourth terminal is connected to the power line communication port S4; the base (B) of NPN transistor Q7 is connected to the indoor unit communication circuit via resistor R16. At the TXD port of the circuit, the emitter (E) of NPN transistor Q7 is grounded; the third terminal of optocoupler PC4 is grounded, a resistor R20 is connected between the first and second terminals, and the second terminal serves as the AC neutral terminal AC_N; the fourth terminal is connected to the base (B) of NPN transistor Q8 and simultaneously connected to the DC power supply via resistor R18; the emitter (E) of NPN transistor Q8 is connected to the RXD port of the indoor unit communication circuit via resistor R19, the emitter (E) of NPN transistor Q8 is connected to the DC power supply via resistor R17, and the collector (C) of NPN transistor Q8 is grounded.

[0047] The communication process from the simulated outdoor unit module to the indoor unit is similar to the process from the outdoor unit to the simulated indoor unit, as explained below:

[0048] High-level transmission: When the analog outdoor unit sends a high level, Q3 saturates and conducts, driving PC7 and PC8 to conduct synchronously, activating bus S to establish a forward transmission path. At this time, optocoupler PC3 and transistor Q7 form a composite conduction circuit, injecting a high level into the indoor unit's TXD. Optocoupler PC4 conducts, grounding +5V through R18 and the secondary winding of PC4. Transistor Q8 is cut off, and the indoor unit's RXD receives a high level.

[0049] Low-level transmission: When the analog outdoor unit sends a low level, transistor Q3 is cut off, simultaneously cutting off the PC7-PC8 and PC3-Q7 path signals, causing the bus S signal transmission to fail. At this time, PC4 is cut off, triggering Q8 to conduct. +5V is grounded through R17 and Q8, and RXD is quickly pulled down to a low level through the collector pull-up network.

[0050] The beneficial effects of this utility model include: Through an innovative neutral-live wire communication circuit connected to the neutral-live wire communication loop of the indoor and outdoor units, it receives communication data from both units and forwards it to either unit. The communication signal is forwarded in real time, without affecting the accuracy or delay of the communication data. Simultaneously, the neutral-live wire communication circuit generates a communication level; after amplification via a relay, the signal strength is increased, effectively eliminating excessive signal loss and signal attenuation caused by excessively long communication cables, thus improving the stability and reliability of signal transmission. Furthermore, the waveform shaping module circuit ensures that the communication loop is in a stable state when receiving communication data, guaranteeing reliable data reception.

[0051] The above are preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A zero firewire communication circuit, characterized by, include: The analog indoor unit module includes: a power line communication port S2 for connecting to the outdoor unit via a power line; TXD1 and RXD1 ports for connecting to the waveform processing module; and an analog indoor unit relay circuit for signal relay processing between the power line communication port S2 and the TXD1 and RXD1 ports. The simulated outdoor unit module includes: a powerline communication port S3 for connecting to the indoor unit via a powerline; TXD2 and RXD2 ports for connecting to the waveform processing module; and a simulated outdoor unit relay circuit for signal relay processing between the powerline communication port S3 and the RXD2 ports. The waveform shaping module includes a first OR logic gate and a second OR logic gate. One input of the first OR logic gate is connected to the RXD1 port, and its output is connected to the TXD2 port. The other input is connected to a high-level signal when the analog indoor unit module receives a level signal from the outdoor unit, so that the TXD2 port maintains a stable high level. One input of the second OR logic gate is connected to the RXD2 port, and its output is connected to the TXD1 port. The other input is connected to a high-level signal when the analog outdoor unit module receives a level signal from the indoor unit, so that the TXD1 port maintains a stable high level.

2. The zero-fire line communication circuit of claim 1, wherein, The waveform shaping module also includes a main chip, which provides the high-level signal for the first OR logic gate and the second OR logic gate.

3. The neutral-live wire communication circuit according to claim 1, characterized in that, The analog indoor unit relay circuit includes optocoupler PC5, optocoupler PC6, NPN transistor Q5, NPN transistor Q6, resistors R6, R7, R8, R9, and R10. Terminal 1 of optocoupler PC5 is connected to a DC power supply, terminal 2 is connected to the collector (C) of NPN transistor Q5, terminal 3 is connected to terminal 1 of optocoupler PC6, and terminal 4 is connected to the power line communication port S2. The base (B) of NPN transistor Q5 is connected to the TXD1 port via resistor R6. The emitter (E) of NPN transistor Q5 is grounded; terminals 2 and 3 of optocoupler PC6 are grounded, a resistor R10 is connected between terminals 1 and 2, and terminal 2 serves as the AC neutral terminal AC_N; terminal 4 is connected to the base (B) of NPN transistor Q6 and simultaneously connected to a DC power supply via resistor R9; the emitter (E) of NPN transistor Q6 is connected to the RXD1 port via resistor R7, and the emitter (E) of NPN transistor Q6 is connected to a DC power supply via resistor R8; the collector (C) of NPN transistor Q6 is grounded.

4. The neutral-live wire communication circuit according to claim 1, characterized in that, The analog outdoor relay circuit includes optocoupler PC7, optocoupler PC8, NPN transistor Q3, NPN transistor Q4, resistors R11, R12, R13, R14, and R15. Terminal 1 of optocoupler PC7 is connected to a DC power supply, terminal 2 is connected to the collector (C) of NPN transistor Q3, terminal 3 is connected to terminal 1 of optocoupler PC8, and terminal 4 is connected to an AC-DC communication level. The base (B) of NPN transistor Q3 is connected to TXD2 via resistor R11. The NPN transistor Q3's emitter (E) is grounded; a resistor R15 is connected between terminals 1 and 2 of the optocoupler PC8, terminal 2 is connected to the power line communication port S3, terminal 3 is grounded, and terminal 4 is connected to the base (B) of the NPN transistor Q4 and simultaneously connected to the DC power supply via resistor R13; the emitter (E) of the NPN transistor Q4 is connected to the RXD2 port via resistor R14, the emitter (E) of the NPN transistor Q4 is connected to the DC power supply via resistor R12, and the collector (C) of the NPN transistor Q4 is grounded.

5. A live-wire communication module, characterized in that, The device includes a PCB board and a housing. The live and neutral wire communication circuit according to any one of claims 1-4 is disposed on the PCB board, and the PCB board is disposed in the housing. The power line communication port S2 and the power line communication port S3 are disposed on the housing.

6. An indoor / outdoor communication system, characterized in that, The system includes an indoor unit, an outdoor unit, and the live / neutral wire communication circuit as described in any one of claims 1-4; the outdoor unit includes an outdoor unit communication circuit, which has a power line communication port S1, and the power line communication port S1 is connected to the power line communication port S2 via a power line; the indoor unit includes an indoor unit communication circuit, which has a power line communication port S4, and the power line communication port S4 is connected to the power line communication port S3 via a power line.

7. The internal / external communication system according to claim 6, characterized in that, The outdoor unit communication circuit includes optocoupler PC1, optocoupler PC2, NPN transistors Q1 and Q2, resistors R1, R2, R3, R4, and R5. Terminal 1 of optocoupler PC1 is connected to a DC power supply, terminal 2 is connected to the collector (C) of NPN transistor Q1, terminal 3 is connected to terminal 1 of optocoupler PC2, and terminal 4 is connected to an AC-DC communication level. The base (B) of NPN transistor Q1 is connected to the TXD port of the outdoor unit communication circuit via resistor R1. The emitter (E) of NPN transistor Q1 is grounded; the third terminal of optocoupler PC2 is grounded, a resistor R5 is connected between the first and second terminals, and the second terminal is connected to the power line communication port S1; the fourth terminal is connected to the base (B) of NPN transistor Q2 and simultaneously connected to a DC power supply via resistor R4; the emitter (E) of NPN transistor Q2 is connected to the RXD port of the outdoor unit communication circuit via resistor R2, the emitter (E) of NPN transistor Q2 is connected to a DC power supply via resistor R3, and the collector (C) of NPN transistor Q2 is grounded.

8. The internal / external communication system according to claim 6, characterized in that, The indoor unit communication circuit includes optocoupler PC3, optocoupler PC4, NPN transistor Q7, NPN transistor Q8, resistors R16, R17, R18, R19, and R20. The first terminal of optocoupler PC3 is connected to a DC power supply, the second terminal is connected to the collector (C) of NPN transistor Q7, the third terminal is connected to the first terminal of optocoupler PC4, and the fourth terminal is connected to the power line communication port S4. The base (B) of NPN transistor Q7 is connected to the TXD terminal of the indoor unit communication circuit via resistor R16. The emitter (E) of NPN transistor Q7 is grounded; the third terminal of optocoupler PC4 is grounded, a resistor R20 is connected between the first and second terminals, and the second terminal serves as the AC neutral terminal AC_N; the fourth terminal is connected to the base (B) of NPN transistor Q8 and simultaneously connected to the DC power supply via resistor R18; the emitter (E) of NPN transistor Q8 is connected to the RXD port of the indoor unit communication circuit via resistor R19, the emitter (E) of NPN transistor Q8 is connected to the DC power supply via resistor R17, and the collector (C) of NPN transistor Q8 is grounded.

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