Communication circuit and control system

Abstract

The application discloses a communication circuit and a control system, and belongs to the technical field of communication. The communication circuit is applied to the control system. The control system comprises a master control unit, a superior controlled device and a subordinate controlled device. The communication circuit comprises: a first communication module connected with the master control unit and the superior controlled device respectively, and forming a first communication link for transmitting data signals between the master control unit and the superior controlled device; a second communication module connected with the master control unit and the subordinate controlled device respectively, and forming a second communication link for transmitting data signals between the master control unit and the subordinate controlled device; and a third communication module connected with the master control unit and a man-machine interaction device respectively, and forming a third communication link for transmitting data signals between the master control unit and the man-machine interaction device. The application realizes the transmission of data signals through three independent communication links, avoids the situation of data transmission conflict, and improves the reliability of the communication circuit in the control system.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication circuit and control system. Background Technology

[0002] In a power system, a typical system may include a main control unit, upstream circuit breakers, and downstream circuit breakers. The main control unit needs to receive operating data from the upstream and downstream circuit breakers, monitor them, and send control data to them to control them. In addition, the main control unit can also send log data to a human-machine interface (HMI) device or perform debugging through the HMI device.

[0003] In related technologies, the communication links between the main control unit and the upper-level circuit breaker, lower-level circuit breaker, and human-machine interface device are not distinguished, which may lead to data transmission conflicts between the main control unit and the upper-level circuit breaker, lower-level circuit breaker, and human-machine interface device. Utility Model Content

[0004] The main objective of this application is to provide a communication circuit and control system that aims to at least partially solve the aforementioned technical problems.

[0005] To achieve the above objectives, in a first aspect, a communication circuit is provided for use in a control system, the control system comprising a main control unit, an upper-level controlled device, and a lower-level controlled device, the communication circuit comprising: The first communication module is connected to the main control unit and the upper-level controlled device respectively, forming a first communication link for transmitting data signals between the main control unit and the upper-level controlled device; The second communication module is connected to the main control unit and the lower-level controlled device respectively, forming a second communication link for transmitting data signals between the main control unit and the lower-level controlled device; The third communication module is connected to both the main control unit and the human-machine interaction device, forming a third communication link for transmitting data signals between the main control unit and the human-machine interaction device.

[0006] Optionally, the first communication module includes a first RS485 chip, the second communication module includes a second RS485 chip, and the third communication module includes a third RS485 chip. The first RS485 chip includes a first driver enable terminal, a first receiver enable terminal, a first receiver terminal, a first transmitter terminal, and a first differential signal positive terminal and a first differential signal negative terminal connected to the first serial port of the main control unit. The second RS485 chip includes a second driver enable terminal, a second receiver enable terminal, a second receiver terminal, a second transmitter terminal, and a second differential signal positive terminal and a second differential signal negative terminal connected to the second serial port of the main control unit. The third RS485 chip includes a third driver enable terminal, a third receiver enable terminal, a third receiver terminal, a third transmitter terminal, and a third differential signal positive terminal and a third differential signal negative terminal connected to the third serial port of the main control unit.

[0007] Optionally, the first RS485 chip further includes a power output terminal for outputting a first voltage, a communication mode selection terminal and a power input terminal connected to the power output terminal, the positive terminal of the first differential signal is connected to the power output terminal through a first resistor, and the negative terminal of the first differential signal is connected to the secondary ground through a second resistor.

[0008] Optionally, the first RS485 chip also includes a logic power supply terminal and a main power supply terminal connected to the second voltage, as well as a first ground terminal and a second ground terminal connected to the primary ground, and the first communication module also includes an anti-interference unit; The anti-interference unit is connected to the logic power terminal, the main power terminal, the first ground terminal, and the second ground terminal to absorb electromagnetic interference from the logic power terminal, the main power terminal, the first ground terminal, and the second ground terminal. The anti-interference unit includes a first ferrite bead, a second ferrite bead, a third ferrite bead, and a fourth ferrite bead, wherein: The first ferrite bead is connected between the logic power supply terminal and the second voltage; The second ferrite bead is connected between the main power supply terminal and the second voltage; The third magnetic bead is connected between the first grounding terminal and the original ground; The fourth ferrite bead is connected between the second grounding terminal and the primary ground.

[0009] Optionally, the first communication module further includes a voltage suppression unit; The voltage suppression unit is connected to the positive terminal and the negative terminal of the first differential signal to suppress the voltage spikes at the positive terminal and the negative terminal of the first differential signal. The voltage suppression unit includes a transient voltage suppression diode and a transient voltage suppressor; The transient voltage suppression diode includes a first terminal connected to the positive terminal of the first differential signal and a second terminal connected to the negative terminal of the first differential signal; The transient voltage suppressor includes a first terminal connected to the positive terminal of the first differential signal, a second terminal connected to the negative terminal of the first differential signal, and a third terminal connected to the secondary ground.

[0010] Optionally, the first communication module further includes a misconnection prevention unit; The anti-misconnection unit is connected to the positive terminal and the negative terminal of the first differential signal to prevent the positive terminal and the negative terminal of the first differential signal from being misconnected. The anti-misconnection unit includes a first thermistor and a second thermistor. The first thermistor is connected between the positive terminal of the first differential signal and the upper-level controlled device; The second thermistor is connected between the negative terminal of the first differential signal and the upstream controlled device.

[0011] Optionally, the first communication module further includes an anti-distortion unit; The anti-distortion unit is connected to the first serial port, the first driver enable terminal, the first receiver enable terminal, the first receiver terminal, and the first transmitter terminal respectively to prevent data signal distortion between the main control unit and the first RS485 chip; The anti-distortion unit includes a third resistor, a fourth resistor, and a fifth resistor; The third resistor is connected between the first serial port and the first driver enable terminal and the first receiver enable terminal; The fourth resistor is connected between the first serial port and the first receiving terminal; The fifth resistor is connected between the first serial port and the first transmitting end.

[0012] Optionally, the first communication module further includes a filtering unit; The filtering unit is connected to the first receiving end and the first transmitting end to filter the data signal between the main control unit and the first RS485 chip; The filter unit includes a first capacitor and a second capacitor; The first capacitor is connected between the first receiving end and the primary ground. The second capacitor is connected between the first transmitting end and the primary ground.

[0013] Optionally, the first communication module is connected to the upper-level controlled device through the first intermediate module, and the second communication module is connected to the lower-level controlled device through the second intermediate module.

[0014] Secondly, a control system is also proposed, including a main control unit, an upper-level controlled device, a lower-level controlled device, and a communication circuit as described above.

[0015] Through the above technical solution, this application includes at least the following beneficial technical effects: The above technical solution separates the communication links between the main control unit and the upper-level controlled device, the lower-level controlled device, and the human-machine interface device by setting up three communication modules to connect them respectively. It also separates the communication link between the main control unit and the human-machine interface device, so that the main control unit can transmit data signals to the upper-level controlled device, the lower-level controlled device, and the human-machine interface device through three independent communication links. This avoids data transmission conflicts between the main control unit and the upper-level circuit breaker, the lower-level circuit breaker, and the human-machine interface device, and improves the reliability of the communication circuit in the control system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the communication circuit in one embodiment of this application; Figure 2 This is a circuit schematic diagram of the first communication module in one embodiment of this application; Figure 3 This is a circuit schematic diagram of the second communication module in one embodiment of this application; Figure 4 This is a circuit schematic diagram of the third communication module in one embodiment of this application.

[0018] The realization of the objectives, functional features and advantages of the embodiments of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] In the embodiments of this application, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0021] Furthermore, in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0022] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0023] Based on the problems in the background technology, this application proposes a communication circuit and control system.

[0024] Firstly, such as Figure 1 As shown, this application embodiment provides a communication circuit applied to a control system. The control system may include a main control unit, an upper-level controlled device, and a lower-level controlled device. It is understood that the control system can be an industrial control system for controlling micro-circuit breakers, frame-type products, molded housing products, and industrial control products. The main control unit can be a Microcontroller Unit (MCU). In this control system, the lower-level controlled device can assist the upper-level controlled device in realizing system functions. The upper-level and lower-level controlled devices can be the same type of industrial product. For example, in a power system, the upper-level controlled device can be an upper-level circuit breaker, and the lower-level controlled device can be a lower-level circuit breaker; the upper-level circuit breaker is the main circuit breaker, and the lower-level circuit breaker is the auxiliary circuit breaker. The auxiliary circuit breaker can assist the main circuit breaker in realizing the protection function of the power system.

[0025] In this embodiment, the communication circuit may include a first communication module, a second communication module, and a third communication module. The first communication module is connected to both the main control unit and the upper-level controlled device, forming a first communication link for transmitting data signals between the main control unit and the upper-level controlled device. The second communication module is connected to both the main control unit and the lower-level controlled device, forming a second communication link for transmitting data signals between the main control unit and the lower-level controlled device. The third communication module is connected to both the main control unit and the human-machine interface device, forming a third communication link for transmitting data signals between the main control unit and the human-machine interface device.

[0026] It should be noted that the data signals between the main control unit and the upper-level controlled device can include upper-level control data signals sent by the main control unit to the upper-level controlled device, and operating status data signals sent by the upper-level controlled device to the main control unit; the data signals between the main control unit and the lower-level controlled device can include lower-level control data signals sent by the main control unit to the upper-level controlled device, and operating status data signals sent by the upper-level controlled device to the main control unit; the data signals between the main control unit and the human-machine interface device can include log data signals sent by the main control unit to the human-machine interface device, and debugging data signals sent by the human-machine interface device to the main control unit. The first communication module, the second communication module, and the third communication module can be implemented using the same type of interface chip, or they can be implemented using different types of interface chips. Therefore, this embodiment separates the communication links between the main control unit and the upper-level controlled device and the lower-level controlled device, and also separates the communication link between the main control unit and the human-machine interaction device. This allows the main control unit to transmit data signals through three independent communication links with the upper-level controlled device, the lower-level controlled device, and the human-machine interaction device, avoiding data transmission conflicts between the main control unit and the upper-level circuit breaker, the lower-level circuit breaker, and the human-machine interaction device, and improving the reliability of the communication circuit in the control system.

[0027] The specific implementation methods that the communication circuit may adopt will be described next.

[0028] In some embodiments, such as Figures 2 to 4As shown, the first communication module may include a first RS485 chip U1, the second communication module may include a second RS485 chip U2, and the third communication module may include a third RS485 chip U3. The first RS485 chip U1 may include a first driver enable terminal, a first receiver enable terminal, a first receiver terminal, a first transmitter terminal connected to a first serial port of the main control unit, and a first differential signal positive terminal and a first differential signal negative terminal connected to an upper-level controlled device. The second RS485 chip U2 may include a second driver enable terminal, a second receiver enable terminal, a second receiver terminal, a second transmitter terminal connected to a second serial port of the main control unit, and a second differential signal positive terminal and a second differential signal negative terminal connected to a lower-level controlled device. The third RS485 chip U3 may include a third driver enable terminal, a third receiver enable terminal, a third receiver terminal, a third transmitter terminal connected to a third serial port of the main control unit, and a third differential signal positive terminal and a third differential signal negative terminal connected to an upper-level controlled device.

[0029] In this embodiment, all three communication modules of the communication circuit can be implemented using isolated RS485 chips, and the three RS485 chips are connected to different UART (Universal Asynchronous Receiver / Transmitter) serial ports of the main control MCU. The main control MCU's UART serial port can include an enable control terminal, a data transmitter terminal, and a data receiver terminal. The RS485 chip's enable terminal can include a driver enable terminal (DE) and a receiver enable terminal (RE). The driver enable terminal (DE) and receiver enable terminal (RE) of an RS485 chip are connected to the enable control terminal of a UART serial port to receive the enable control signals 485_DE_INVERTER / 485_DE_4G / 485_DE_DEBUG sent by the main control MCU. The receiver terminal (RO) of an RS485 chip is connected to the data transmitter terminal of a UART serial port to receive the serial data signals 485_RX_INVERTER / 485_RX_4G / 485_RX_DEBUG sent by the main control MCU. The transmitter terminal (DI) of an RS485 chip is connected to the data receiver terminal of a UART serial port to send serial data signals 485_TX_INVERTER / 485_TX_4G / 485_TX_DEBUG to the main control MCU. The differential signal positive terminal A and differential signal negative terminal B of the three RS485 chips are respectively connected to the upper-level controlled device, the lower-level controlled device, and the human-machine interaction module to receive differential data signals RS485_A and RS485_B sent by the upper-level controlled device, the lower-level controlled device, or the human-machine interaction module, or to send differential data signals RS485_A and RS485_B to the upper-level controlled device, the lower-level controlled device, and the human-machine interaction module.

[0030] In some embodiments, such as Figure 2 As shown, the first RS485 chip U1 may further include a power output terminal VISO-OUT that outputs a first voltage VCC1, a communication mode selection terminal SEL connected to the power output terminal VISO-OUT, and a power input terminal VISO-IN. The positive terminal of the first differential signal is connected to the power output terminal VISO-OUT through a first resistor R1, and the negative terminal of the first differential signal is connected to the secondary ground 485GND through a second resistor R2. In this embodiment, the serial data signal side of the RS485 chip is the primary side, and the differential data signal side of the RS485 chip is the secondary side. The first RS485 chip U1, the second RS485 chip U2, and the third RS485 chip U3 can power the secondary components through the first voltage VCC1 output from the power output terminal VISO-OUT, eliminating the need for the system power supply to power the secondary components. It should be noted that, as Figures 2 to 4 As shown, the secondary-side self-powered schemes of the second RS485 chip U2 and the third RS485 chip U3 are the same as those of the first RS485 chip U1. In the secondary-side self-powered scheme of the RS485 chip, the power output terminal VISO-OUT of the RS485 chip outputs a first voltage VCC1 to the communication mode selection terminal SEL and the power input terminal VISO-IN to power the secondary-side components of the RS485 chip; the differential signal positive terminal A of the RS485 chip is connected to the power output terminal VISO-OUT through a pull-up resistor, which can pull the data signal of the differential signal positive terminal A high, keeping the data signal of the differential signal positive terminal A under control; the differential signal negative terminal B of the RS485 chip is connected to the secondary-side ground 485GND through a pull-down resistor, which can pull the data signal of the differential signal negative terminal B low, keeping the data signal of the differential signal negative terminal B under control. For example, the magnitude of the first voltage VCC1 can be 3.3V. In addition, the secondary side of the RS485 chip may also include two secondary ground terminals GND2, both of which are connected to the secondary ground 485GND.

[0031] In some embodiments, the first RS485 chip U1 may further include a logic power supply terminal VDDL and a main power supply terminal VDDP connected to the second voltage VCC2, and a first ground terminal and a second ground terminal connected to the primary ground GND. Wherein, as Figures 2 to 4As shown, the second voltage VCC2 on the primary side of the RS485 chip is provided by the system power supply. The first ground terminal and the second ground terminal are the ground terminals GND1 on the primary side of the RS485 chip, and both the first ground terminal and the second ground terminal are connected to the primary ground GND. For example, the value of the second voltage VCC2 can be 3.3V. In addition, the primary ground GND and the secondary ground 485GND are connected in parallel through a grounding resistor and a capacitor CX, so that the entire communication circuit shares a common ground. The grounding resistor can include multiple resistors connected in series; for example, the grounding resistor in this embodiment can include three resistors connected in series.

[0032] It should be noted that the first receiving end of the first RS485 chip U1 is also connected to the second voltage VCC2 through the sixth resistor R6, and the first transmitting end is also connected to the second voltage VCC2 through the seventh resistor R7. The first driver enable end and the first receiver enable end are also connected to the primary ground GND through the eighth resistor R8. Among them, the sixth resistor R6 and the seventh resistor R7 are pull-up resistors, which can pull the serial data signals 485_RX_INVERTER and 485_TX_INVERTER high to keep the data signals under control; the eighth resistor R8 is a pull-down resistor, which can pull the enable control signal 485_DE_INVERTER low to keep the enable control signal 485_DE_INVERTER under control. Similarly, the data transmission signals 485_RX_4G, 485_TX_4G, 485_RX_DEBGU, and 485_TX_DEBUG on the primary side of the second RS485 chip U2 and the third RS485 chip U3 are pulled high through the seventeenth resistor R17, the eighteenth resistor R18, the twenty-eighth resistor R28, and the twenty-ninth resistor R29, respectively; the enable control signals 485_DE_4G and 485_DE_DEBUG on the primary side of the second RS485 chip U2 and the third RS485 chip U3 are pulled low through the nineteenth resistor R19 and the thirtieth resistor R30, respectively.

[0033] In this embodiment, the first communication module may further include an anti-interference unit; the anti-interference unit is connected to the logic power supply terminal VDDL, the main power supply terminal VDDP, the first ground terminal, and the second ground terminal to absorb electromagnetic interference from the logic power supply terminal VDDL, the main power supply terminal VDDP, the first ground terminal, and the second ground terminal. It is understood that the anti-interference unit can absorb electromagnetic interference caused by ground plane instability, ensuring the stability of the primary-side power supply of the RS485 chip U1.

[0034] In one specific embodiment of the anti-interference unit, such as Figure 2As shown, the anti-interference unit may include a first ferrite bead L1, a second ferrite bead L2, a third ferrite bead L3, and a fourth ferrite bead L4. Specifically: the first ferrite bead L1 is connected between the logic power supply terminal VDDL and the second voltage VCC2; the second ferrite bead L2 is connected between the main power supply terminal VDDP and the second voltage VCC2; the third ferrite bead L3 is connected between the first ground terminal and the primary ground GND; and the fourth ferrite bead L4 is connected between the second ground terminal and the primary ground GND. In this embodiment, the anti-interference unit can be implemented using multiple ferrite beads, such as... Figure 3 and Figure 4 As shown, the same anti-interference unit can also be set on the original side of the second RS485 chip U2 and the third RS485 chip U3.

[0035] In some embodiments, the first communication module may further include a voltage suppression unit; the voltage suppression unit is connected to the positive terminal and the negative terminal of the first differential signal to suppress voltage spikes at the positive and negative terminals of the first differential signal. In this embodiment, the voltage suppression unit can absorb voltage spikes at the positive terminal A and the negative terminal B of the differential signal and achieve ESD protection (Electrostatic Discharge Protection), thereby improving the reliability of the communication module.

[0036] In one specific embodiment of the voltage suppression unit, such as Figure 2 As shown, the voltage suppression unit may include a transient voltage suppression diode D1 and a transient voltage suppressor D2. The transient voltage suppression diode D1 includes a first terminal connected to the positive terminal of the first differential signal and a second terminal connected to the negative terminal of the first differential signal. The transient voltage suppressor D2 includes a first terminal connected to the positive terminal of the first differential signal, a second terminal connected to the negative terminal of the first differential signal, and a third terminal connected to the secondary ground 485GND. In this embodiment, the transient voltage suppression diode D1 can be a high-power TVS (Transient Voltage Suppressor), which can absorb instantaneous energy during electrostatic discharge testing of the positive terminal A and the negative terminal B of the differential signal. The transient voltage suppressor D2 can be a dual-channel ESD protection device, capable of clamping voltage spikes on the positive terminal A and the negative terminal B of the differential signal. It is understood that, as Figure 3 and Figure 4 As shown, voltage suppression units based on the same principle can also be set at the positive terminal A and negative terminal B of the differential signal of the second RS485 chip U2 and the third RS485 chip U3 to absorb the peak voltage of the positive terminal A and the negative terminal B of the differential signal and to achieve ESD protection.

[0037] In some embodiments, the first communication module may further include a misconnection prevention unit; the misconnection prevention unit is connected to the positive terminal and the negative terminal of the first differential signal to prevent misconnection of the positive terminal and the negative terminal of the first differential signal. In this embodiment, the misconnection prevention unit can disconnect the positive terminal A and the negative terminal B of the differential signal from the external device when misconnection occurs, thereby achieving the misconnection prevention function.

[0038] In one specific implementation of the anti-misconnection unit, such as Figure 2 As shown, the anti-misconnection unit may include a first thermistor F1 and a second thermistor F2; the first thermistor F1 is connected between the positive terminal of the first differential signal and the upper-level controlled device; the second thermistor F2 is connected between the negative terminal of the first differential signal and the upper-level controlled device. In this embodiment, as... Figure 3 and Figure 4 As shown, the differential signal positive terminal A and differential signal negative terminal B of the second RS485 chip U2 and the third RS485 chip U3 can also be equipped with the same principle of misconnection protection unit. This misconnection protection unit can be implemented using two thermistors (PTCs). When the differential signal positive terminal A and differential signal negative terminal B of the RS485 chip are connected to the wrong power supply, the current at these terminals exceeds the rated trigger current of the thermistor PTC. The internal temperature of the PTC rises rapidly, and its resistance jumps to a high-resistance state, limiting the fault current at the differential signal positive terminal A and differential signal negative terminal B to a safe range, thus achieving misconnection protection for the RS485 chip. In addition, during the process of connecting the positive terminal A of the differential signal and the negative terminal B of the differential signal to the upper-level controlled device, the lower-level controlled device, or the human-machine interaction device, the PTC will gently limit the peak surge current during hot-plugging, ensuring that the communication between the RS485 chip and the upper-level controlled device, the lower-level controlled device, or the human-machine interaction device can be established normally, thus achieving the hot-plugging protection function.

[0039] In some embodiments, the first communication module may further include an anti-distortion unit; the anti-distortion unit is connected to the first serial port, the first driver enable terminal, the first receiver enable terminal, the first receiver terminal, and the first transmitter terminal respectively, to prevent data signal distortion between the main control unit and the first RS485 chip. In this embodiment, the anti-distortion unit can avoid data signal distortion between the main control unit and the RS485 chip, thereby improving the accuracy of data transmission.

[0040] In one specific implementation of the anti-distortion unit, such as Figure 2As shown, the anti-distortion unit may include a third resistor R3, a fourth resistor R4, and a fifth resistor R5; the third resistor R3 is connected between the first serial port and the first driver enable terminal and the first receiver enable terminal; the fourth resistor R4 is connected between the first serial port and the first receiver terminal; and the fifth resistor R5 is connected between the first serial port and the first transmitter terminal. In this embodiment, as... Figure 3 and Figure 4 As shown, the same anti-distortion unit can also be set on the original side of the second RS485 chip U2 and the third RS485 chip U3. In this design, the RS485 chip's driver enable terminal DE and receiver enable terminal RE are both connected to the UART serial port's enable control terminal. The resistor between the RS485 chip's driver enable terminal DE and receiver enable terminal RE and the UART serial port's enable control terminal can prevent distortion of the enable control signals 485_DE_INVERTER / 485_DE_4G / 485_DE_DEBUG. The resistor between the RS485 chip's receiver terminal RO and the UART serial port's data transmitter terminal can prevent distortion of the serial data signals 485_RX_INVERTER / 485_RX_4G / 485_RX_DEBUG. The resistor between the RS485 chip's transmitter terminal DI and the UART serial port's data receiver terminal can prevent distortion of the serial data signals 485_TX_INVERTER / 485_TX_4G / 485_TX_DEBUG.

[0041] In some embodiments, the first communication module may further include a filtering unit; the filtering unit is connected to the first receiving end and the first transmitting end to filter the data signal between the main control unit and the first RS485 chip. In this embodiment, the filtering unit can suppress noise interference in the data signal between the main control MCU and the RS485 chip, ensuring the accuracy and stability of the data signal and improving the reliability of the communication circuit.

[0042] In one specific implementation of the filtering unit, such as Figure 2 As shown, the filtering unit may include a first capacitor C1 and a second capacitor C2; the first capacitor C1 is connected between the first receiving end and the primary ground GND; the second capacitor C2 is connected between the first transmitting end DI and the primary ground GND. In this embodiment, the first capacitor and the second capacitor may be high-frequency filtering capacitors, such as... Figure 3 and Figure 4As shown, the primary side of the second RS485 chip U2 and the third RS485 chip U3 can also be equipped with filtering units based on the same principle. The capacitor between the receiving end RO and the primary side ground GND is used to filter the serial data signals 485_RX_INVERTER / 485_RX_4G / 485_RX_DEBUG, and the capacitor between the transmitting end DI and the primary side ground GND is used to filter the serial data signals 485_TX_INVERTER / 485_TX_4G / 485_TX_DEBUG.

[0043] In another specific embodiment of the filtering unit, the filtering unit may further include a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, and an eighth capacitor C8; the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are the primary-side power supply terminal energy storage capacitors of the first RS485 chip U1; the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 are the secondary-side power supply terminal energy storage capacitors of the first RS485 chip U1.

[0044] In some embodiments, the first communication module can be connected to the upper-level controlled device through a first intermediate module, and the second communication module can be connected to the lower-level controlled device through a second intermediate module. It should be noted that in the control system, control data signals can be sent to the drive module of the controlled device, which then controls the controlled device based on the control data signals; operating status data signals can be collected by the monitoring module of the controlled device and output to the RS485 chip; furthermore, the RS485 chip and the intermediate module can be connected via wired or wireless connection. Thus, different controlled devices and communication modules can be indirectly connected through different intermediate modules, realizing diverse communication circuits. In this embodiment, the first intermediate module can be a wired module, and the second intermediate module can be a wireless module; for example, the first intermediate module can be an inverter, and the second intermediate module can be a 4G communication stick.

[0045] Secondly, this application also provides a control system, which includes a main control unit, an upper-level controlled device, a lower-level controlled device, and a communication circuit as described above. The specific structure of the communication circuit is as described in the above embodiments. Since this communication circuit adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0046] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A communication circuit applied to a control system, the control system comprising a main control unit, an upper-level controlled device, and a lower-level controlled device, characterized in that, The communication circuit includes: The first communication module is connected to the main control unit and the upper-level controlled device respectively, forming a first communication link for transmitting data signals between the main control unit and the upper-level controlled device; The second communication module is connected to the main control unit and the lower-level controlled device respectively, forming a second communication link for transmitting data signals between the main control unit and the lower-level controlled device; The third communication module is connected to both the main control unit and the human-machine interaction device to form a third communication link for transmitting data signals between the main control unit and the human-machine interaction device.

2. The communication circuit according to claim 1, characterized in that, The first communication module includes a first RS485 chip, the second communication module includes a second RS485 chip, and the third communication module includes a third RS485 chip; The first RS485 chip includes a first driver enable terminal, a first receiver enable terminal, a first receiver terminal, a first transmitter terminal, and a first differential signal positive terminal and a first differential signal negative terminal connected to the first serial port of the main control unit; The second RS485 chip includes a second driver enable terminal, a second receiver enable terminal, a second receiver terminal, a second transmitter terminal, and a second differential signal positive terminal and a second differential signal negative terminal connected to the second serial port of the main control unit; The third RS485 chip includes a third driver enable terminal, a third receiver enable terminal, a third receiver terminal, a third transmitter terminal, and a third differential signal positive terminal and a third differential signal negative terminal connected to the third serial port of the main control unit.

3. The communication circuit according to claim 2, characterized in that, The first RS485 chip also includes a power output terminal for outputting a first voltage, a communication mode selection terminal and a power input terminal connected to the power output terminal, the positive terminal of the first differential signal is connected to the power output terminal through a first resistor, and the negative terminal of the first differential signal is connected to the secondary ground through a second resistor.

4. The communication circuit according to claim 2, characterized in that, The first RS485 chip also includes a logic power supply terminal and a main power supply terminal connected to the second voltage, as well as a first ground terminal and a second ground terminal connected to the original ground. The first communication module also includes an anti-interference unit. The anti-interference unit is connected to the logic power terminal, the main power terminal, the first ground terminal and the second ground terminal to absorb electromagnetic interference from the logic power terminal, the main power terminal, the first ground terminal and the second ground terminal; The anti-interference unit includes a first magnetic bead, a second magnetic bead, a third magnetic bead, and a fourth magnetic bead, wherein: The first ferrite bead is connected between the logic power supply terminal and the second voltage; The second ferrite bead is connected between the main power supply terminal and the second voltage. The third magnetic bead is connected between the first grounding terminal and the original ground; The fourth magnetic bead is connected between the second grounding terminal and the original ground.

5. The communication circuit according to claim 2, characterized in that, The first communication module further includes a voltage suppression unit; The voltage suppression unit is connected to the positive terminal and the negative terminal of the first differential signal to suppress the voltage spikes at the positive terminal and the negative terminal of the first differential signal. The voltage suppression unit includes a transient voltage suppression diode and a transient voltage suppressor; The transient voltage suppression diode includes a first terminal connected to the positive terminal of the first differential signal and a second terminal connected to the negative terminal of the first differential signal; The transient voltage suppressor includes a first terminal connected to the positive terminal of the first differential signal, a second terminal connected to the negative terminal of the first differential signal, and a third terminal connected to the secondary ground.

6. The communication circuit according to claim 2, characterized in that, The first communication module also includes a misconnection prevention unit; The anti-misconnection unit is connected to the positive terminal and the negative terminal of the first differential signal to prevent the positive terminal and the negative terminal of the first differential signal from being misconnected. The anti-misconnection unit includes a first thermistor and a second thermistor. The first thermistor is connected between the positive terminal of the first differential signal and the upper-level controlled device; The second thermistor is connected between the negative terminal of the first differential signal and the upper-level controlled device.

7. The communication circuit according to claim 2, characterized in that, The first communication module also includes an anti-distortion unit; The anti-distortion unit is connected to the first serial port, the first driver enable terminal, the first receiver enable terminal, the first receiver terminal, and the first transmitter terminal respectively to prevent data signal distortion between the main control unit and the first RS485 chip; The anti-distortion unit includes a third resistor, a fourth resistor, and a fifth resistor; The third resistor is connected between the first serial port and the first driver enable terminal and the first receiver enable terminal. The fourth resistor is connected between the first serial port and the first receiving end; The fifth resistor is connected between the first serial port and the first transmitting end.

8. The communication circuit according to claim 2, characterized in that, The first communication module further includes a filtering unit; The filtering unit is connected to the first receiving end and the first transmitting end to filter the data signal between the main control unit and the first RS485 chip. The filtering unit includes a first capacitor and a second capacitor; The first capacitor is connected between the first receiving end and the original ground. The second capacitor is connected between the first transmitting end and the original ground.

9. The communication circuit according to claim 1, characterized in that, The first communication module is connected to the upper-level controlled device through a first intermediate module, and the second communication module is connected to the lower-level controlled device through a second intermediate module.

10. A control system, characterized in that, It includes a main control unit, an upper-level controlled device, a lower-level controlled device, and a communication circuit as described in any one of claims 1 to 9.

Images