Communication circuit based on RS422 signal

Abstract

The utility model discloses a communication circuit based on RS422 signals, relates to the technical field of communication, and comprises a power supply unit, the power supply unit provides power for a main control unit, a voltage stabilization unit and a communication unit, the communication unit comprises an RS422 interface, the RS422 interface receives the RS422 signals and sends the RS422 signals to the main control unit, the main control unit sends instruction signals after receiving the RS422 signals, and the main control unit sends the instruction signals to the voltage stabilization unit. A command signal is received and executed by the motor driving unit, the voltage stabilizing unit comprises a first single-chip microcomputer, a third pin of the first single-chip microcomputer receives voltage output by the power supply unit, input voltage is stabilized into needed output voltage through the first single-chip microcomputer arranged by the voltage stabilizing unit, and the output voltage is output through a first filter capacitor and a second filter capacitor. The voltage output by the power supply unit and the voltage output after voltage stabilization of the first single-chip microcomputer are filtered, voltage fluctuation is reduced, voltage stability is improved, communication signals are not prone to being affected, and then the transmission distance is increased.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, specifically to a communication circuit based on RS422 signals. Background Technology

[0002] RS-422 is a differential serial communication standard widely used in long-distance data transmission and industrial control systems. Its main advantages include strong anti-interference capabilities, transmission distances up to 1200 meters, and support for multi-point connections. RS-422 signals are transmitted via differential signals, reducing the impact of noise on data and making it suitable for environments with high electromagnetic interference. This standard is commonly used in industrial automation, data acquisition systems, remote monitoring, and connections between communication devices. Due to its reliability and efficiency, RS-422 has been widely adopted in modern communications, especially in applications requiring stable and high-speed data transmission.

[0003] However, existing communication circuits experience significant fluctuations in the received input voltage, making it difficult to maintain stability. This results in easily affected communication signals and reduced transmission distance. Therefore, it is necessary to provide a communication circuit based on RS422 signals to solve the aforementioned problems. Utility Model Content

[0004] To solve the above-mentioned technical problems, a communication circuit based on RS422 signals is provided. This technical solution solves the problem mentioned in the background art that the existing communication circuits have large fluctuations when receiving input voltage, making it difficult to maintain stability, which leads to the communication signal being easily affected and the transmission distance being reduced.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A communication circuit based on RS422 signals, comprising:

[0007] A power supply unit provides power to the main control unit, voltage regulator unit, and communication unit.

[0008] The communication unit includes an RS422 interface, which receives RS422 signals and sends the RS422 signals to the main control unit.

[0009] The main control unit receives an RS422 signal and then issues a command signal, which is received and executed by the motor drive unit.

[0010] The voltage regulation unit includes a first microcontroller. The third pin of the first microcontroller receives the voltage output from the power supply unit, and the fourth pin of the first microcontroller outputs a stable voltage. The fourth pin of the first microcontroller is electrically connected to a first filter capacitor, which is used to filter the stable voltage. A second filter capacitor is connected in series with the third pin of the first microcontroller, which is used to filter the voltage output from the power supply unit. The first filter capacitor, the second filter capacitor, and the first pin of the first microcontroller are all grounded.

[0011] Optionally, the main control unit includes a main control microcontroller, and the 29th, 30th, 31st and 32nd pins of the main control microcontroller are electrically connected to the 2nd, 1st, 5th and 6th pins of the third microcontroller, respectively.

[0012] Optionally, pins 81, 82, 83, and 84 of the main control microcontroller are connected in series with resistors 7, 11, 10, and 8. Resistors 7, 11, 10, and 8 are electrically connected to the anodes of LED 3, LED 5, LED 1, and LED 2, respectively. The cathodes of LED 3, LED 5, LED 1, and LED 2 are all grounded.

[0013] Optionally, the 77th, 78th, 79th and 80th pins of the main control microcontroller are electrically connected to the 4th, 1st, 6th and 3rd pins of the first DIP switch, respectively.

[0014] Optionally, the communication unit includes a fourth microcontroller. The twelfth and eleventh pins of the fourth microcontroller receive RS422 signal A and B signals respectively through the tenth and eleventh diodes. The fourth microcontroller converts the received RS422 signal A and B signals into TTL level RX signals and connects the TTL level RX signals to the main control microcontroller through the fifth pin and the sixty-second pin of the main control microcontroller.

[0015] Optionally, the 61st pin of the main control microcontroller is electrically connected to the 2nd pin of the fourth microcontroller to convert the RS422 signal into Y and Z output signals. The 4th pin of the fourth microcontroller is electrically connected to the collector of the second transistor. The base of the second transistor is connected in series with a 13th resistor. The end of the 13th resistor away from the second transistor is electrically connected to the 51st pin of the main control microcontroller.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] In the RS422 signal-based communication circuit proposed in this solution, the first microcontroller, set by the voltage stabilization unit, stabilizes the input voltage to the required output voltage. The voltage output by the power supply unit and the voltage output by the first microcontroller after voltage stabilization are filtered by the first filter capacitor and the second filter capacitor to reduce voltage fluctuations, improve voltage stability, make the communication signal less susceptible to interference, and thus increase the transmission distance. Attached Figure Description

[0018] Figure 1 and Figure 2 The circuit diagram of the main control unit of this utility model;

[0019] Figure 3 This is a circuit diagram of the voltage regulator unit of this utility model;

[0020] Figure 4 This is a circuit diagram of the communication unit of this utility model; Detailed Implementation

[0021] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0022] Reference Figure 1 - Figure 4 As shown, a communication circuit based on RS422 signals includes:

[0023] The power supply unit provides power to the main control unit, voltage regulator unit, and communication unit.

[0024] The communication unit includes an RS422 interface, which receives RS422 signals and sends RS422 signals to the main control unit.

[0025] The main control unit receives the RS422 signal and then sends a command signal, which is received and executed by the motor drive unit.

[0026] The voltage regulation unit includes a first microcontroller U1B. The third pin VCC of the first microcontroller U1B receives the voltage output from the power supply unit, and the fourth pin VOUT of the first microcontroller U1B outputs a stable voltage. The fourth pin VOUT of the first microcontroller U1B is electrically connected to the first filter capacitor C1B, which is used to filter the stable voltage. The third pin VCC of the first microcontroller U1B is connected in series with a second filter capacitor C2B, which is used to filter the voltage output from the power supply unit. The first filter capacitor C1B, the second filter capacitor C2B, and the first pin DGND of the first microcontroller U1B are all grounded.

[0027] Furthermore, the main control unit includes a main control microcontroller U2B. The 29th pin P1.7, 30th pin P1.6, 31st pin P1.5, and 32nd pin P1.4 of the main control microcontroller U2B are electrically connected to the 2nd pin SO, 1st pin CS, 5th pin SI, and 6th pin SCK of the third microcontroller U3B, respectively.

[0028] Furthermore, pins 81 (P5.7), 82 (P5.6), 83 (P5.5), and 84 (P5.4) of the main control microcontroller U2B are connected in series with resistors R7B (seventh), R11B (eleventh), R10B (tenth), and R8B (eighth). These resistors are electrically connected to the anodes (1) of the third LED (D3B), fifth LED (D5B), first LED (D1B), and second LED (D2B), respectively. The cathodes (2) of the third LED (D3B), fifth LED (D5B), first LED (D1B), and second LED (D2B) are all grounded (DGND). Pins 77 (P6.3), 78 (P6.2), 79 (P6.1), and 80 (P6.0) of the main control microcontroller U2B are electrically connected to pins 4 (fourth), 1 (first), 6 (sixth), and 3 (third) of the first DIP switch BK1, respectively.

[0029] The communication unit includes a fourth microcontroller U4B. Pins A (12th) and B (11th) of the fourth microcontroller U4B receive RS422 signals A and B respectively via diodes XD11 (10th) and XD10 (11th). The fourth microcontroller U4B converts the received RS422 signals A and B into TTL level RX signals, and then connects these TTL level RX signals to the main microcontroller U2B via pin DI (5th) and pin P0.0 (62nd). The 61st pin P0.1 of the main control microcontroller U2B is electrically connected to the 2nd pin RO of the fourth microcontroller U4B, converting the RS422 signal into Y and Z output signals. The 4th pin DE of the fourth microcontroller U4B is electrically connected to the collector 1 of the second transistor Q2B. The base 2 of the second transistor Q2B is connected in series with the 13th resistor R13B. The end of the 13th resistor R13B away from the second transistor Q2B is electrically connected to the 51st pin P3.3 of the main control microcontroller U2B.

[0030] Specifically, refer to Figure 1 and Figure 2As shown, the core of the main control unit uses a 100-pin C8051F020 microcontroller U2B. Power-on reset is achieved through a resistor-capacitor network consisting of resistor R4B, resistor R5B, capacitor C6B, and compensation capacitor C7B. The third microcontroller U3B (25045) communicates with the main control microcontroller U2B via pins SI, SO, CS, and SCK to store and retrieve data, and to implement power-down protection for control parameters.

[0031] Reference Figure 3 As shown, the first microcontroller U1B in the voltage regulator unit uses an ASM1117 (3.3). The ASM1117 can stabilize the input voltage to the required output voltage. Common output voltages include 1.2V, 1.5V, 1.8V, 3.3V, and 5V. This regulator has a low voltage drop, allowing it to operate normally with a small input-output voltage difference, thereby improving efficiency and reducing power consumption. The ASM1117 has built-in overcurrent and overheat protection functions to ensure safe operation of the device under abnormal conditions. Furthermore, the ASM1117 requires fewer external components, making circuit design simpler and suitable for various applications.

[0032] Reference Figure 4 As shown, the communication unit uses MAX489 as the fourth microcontroller U4B (communication interface chip). The send enable control signal is connected to the fourth pin DE of the fourth microcontroller U4B through the thirteenth resistor R13B, the second reverse capacitor Q2B, and the twelfth resistor R12B in a reverse circuit to realize the send enable control.

[0033] Working principle and workflow: The communication unit receives external communication signals (RS422 signals) and converts them into TTL level RX signals. Then, the TTL level RX signals are connected to the main control microcontroller U2B. During the process of receiving and sending signals, the main control microcontroller U2B outputs and receives voltages. The output and received voltages are input into the first microcontroller U1B of the voltage regulation unit for voltage regulation.

[0034] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A communication circuit based on RS422 signals, characterized in that, include: A power supply unit provides power to the main control unit, voltage regulator unit, and communication unit. The communication unit includes an RS422 interface, which receives RS422 signals and sends the RS422 signals to the main control unit. The main control unit receives an RS422 signal and then issues a command signal, which is received and executed by the motor drive unit. The voltage regulation unit includes a first microcontroller. The third pin of the first microcontroller receives the voltage output from the power supply unit, and the fourth pin of the first microcontroller outputs a stable voltage. The fourth pin of the first microcontroller is electrically connected to a first filter capacitor, which is used to filter the stable voltage. A second filter capacitor is connected in series with the third pin of the first microcontroller, which is used to filter the voltage output from the power supply unit. The first filter capacitor, the second filter capacitor, and the first pin of the first microcontroller are all grounded.

2. The communication circuit based on RS422 signal according to claim 1, characterized in that, The main control unit includes a main control microcontroller, and the 29th, 30th, 31st and 32nd pins of the main control microcontroller are electrically connected to the 2nd, 1st, 5th and 6th pins of the third microcontroller, respectively.

3. A communication circuit based on RS422 signals according to claim 2, characterized in that, The 81st, 82nd, 83rd and 84th pins of the main control microcontroller are connected in series with the 7th, 11th, 10th and 8th resistors. The 7th, 11th, 10th and 8th resistors are electrically connected to the anodes of the 3rd, 5th, 1st and 2nd LEDs, respectively. The cathodes of the 3rd, 5th, 1st and 2nd LEDs are all grounded.

4. A communication circuit based on RS422 signals according to claim 3, characterized in that, The 77th, 78th, 79th and 80th pins of the main control microcontroller are electrically connected to the 4th, 1st, 6th and 3rd pins of the first DIP switch, respectively.

5. A communication circuit based on RS422 signals according to claim 1, characterized in that, The communication unit includes a fourth microcontroller. The twelfth and eleventh pins of the fourth microcontroller receive RS422 signal A and B signals respectively through the tenth and eleventh diodes. The fourth microcontroller converts the received RS422 signal A and B signals into TTL level RX signals and connects the TTL level RX signals to the main control microcontroller through the fifth pin and the sixty-second pin of the main control microcontroller.

6. A communication circuit based on RS422 signals according to claim 2, characterized in that, The 61st pin of the main control microcontroller is electrically connected to the 2nd pin of the 4th microcontroller, converting the RS422 signal into Y and Z output signals. The 4th pin of the 4th microcontroller is electrically connected to the collector of the 2nd transistor. The base of the 2nd transistor is connected in series with the 13th resistor. The end of the 13th resistor away from the 2nd transistor is electrically connected to the 51st pin of the main control microcontroller.

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