Host data acquisition circuit

Abstract

The utility model relates to the technical field of field bus control, in particular to a host data acquisition circuit, which comprises a front-end protection circuit, a communication circuit, an isolation optocoupler circuit and a sampling circuit which are sequentially connected, the sampling circuit is connected with a square wave oscillation circuit and a single chip microcomputer chip, the square wave oscillation circuit is used for generating square wave signals, and the single chip microcomputer chip is connected with the communication circuit. Host signals are sent to the sampling circuit in cooperation with the front-end protection circuit, the communication circuit and the isolation optocoupler circuit and finally provided to the single-chip microcomputer to obtain needed data signals, and the whole circuit is simple in structure and low in use cost.

Description

Technical Field

[0001] The utility model relates to the technical field of fieldbus control, in particular to a host data acquisition circuit. Background Technique

[0002] In modern times, the interlocking control of inverters and controllers (such as PLCs and industrial computers) through communication buses is a mainstream application, and the ModBus Rtu communication protocol is more widely adopted. In an electric control system, an inverter is a slave device, and the protocol needs to be fully compatible with the controller's protocol to operate properly.

[0003] However, in the actual replacement process, especially in the communication connection with the controller, it is often encountered that the correct host communication parameter settings cannot be obtained, and a lot of energy is spent in the trial-and-error process, and even ends in failure. At present, the data acquisition circuit structure for host communication parameters is complex and the use cost is high. Summary of the Invention

[0004] In order to solve the problems of the existing acquisition circuit with complex structure and high cost, the utility model provides a host data acquisition circuit, which has a simple structure and low cost.

[0005] Its technical solution is as follows: A host data acquisition circuit, characterized in that it includes a front-end protection circuit, a communication circuit, an isolation optocoupler circuit, and a sampling circuit connected in sequence. The sampling circuit is connected to a square-wave oscillation circuit and a microcontroller chip. The front-end protection circuit includes a common-mode inductor L6. One pin of the common-mode inductor L6 is connected to one end of a resistor R29 and one end of a varistor SA and serves as a host signal input terminal. The second pin is connected to one end of a resistor R30 and the other end of the varistor SA and serves as another host signal input terminal. The third pin of the common-mode inductor L6 is connected to the cathode of a voltage regulator diode ZD1, one end of a resistor R26, the other end of the resistor R30, and the 6th pin of a communication chip IC3 in the communication circuit. The fourth pin of the common-mode inductor L6 is connected to the cathode of a voltage regulator diode ZD2, one end of a resistor R25, the other end of the resistor R29, and the 7th pin of the communication chip IC3 in the communication circuit. The other end of the resistor R25 and the 5th pin of the communication chip IC3 are both connected to the IG12V power supply. The other end of the resistor R26 and the 8th pin of the communication chip IC3 are both connected to the IP5V power supply. The isolation optocoupler circuit includes optocouplers PC1, PC2, and PC3. The 4th pin of the optocoupler PC1 is connected to the IP5V power supply. The 3rd pin is connected to the 2nd and 3rd pins of the communication chip IC3 and one end of a resistor R24. The other end of the resistor R24 is connected to the IG12V power supply. The 4th pin of the optocoupler PC2 is connected to the IG12V power supply. The 5th pin is connected to one end of a resistor R22 and the 4th pin of the communication chip IC3. The 6th pin is connected to the other end of the resistor R22 and the IP5V power supply. The 1st pin of the optocoupler PC3 is connected to the IP5V power supply through a resistor R23. The 2nd pin is left floating. The 3rd pin is connected to the 1st pin of the communication chip IC3. The 1st pin of the optocoupler PC1 is connected to one end of a resistor R19. The 2nd pin is connected to the sampling and holding circuit. The 1st pin of the optocoupler PC2 is connected to one end of a resistor R16. The 2nd pin is left floating. The 3rd pin is connected to the sampling and holding circuit. The 4th pin of the optocoupler PC3 is grounded. The 5th pin is connected to one end of a resistor R15 and one end of a resistor R20. The other end of the resistor R16, the other end of the resistor R19, the other end of the resistor R20, and the 6th pin of the optocoupler PC3 are all connected to DVCC. The other end of the resistor R15 is connected to the sampling and holding circuit. The sampling and holding circuit includes a first register and a second register. The square-wave oscillation circuit includes a square-wave generator. The output terminal of the 3rd pin of the square-wave generator is connected to the SCK pins of the first register and the second register. The SDK pin of the first register is connected to the isolation optocoupler circuit.

[0006] After adopting the present utility model, a square-wave signal is generated by the square-wave oscillation circuit, and the host signal is sent to the sampling circuit in cooperation with the front-end protection circuit, the communication circuit, and the isolation optocoupler circuit, and finally provided to the microcontroller to obtain the required data signal. The whole circuit structure is simple and the use cost is low. Description of the Drawings

[0007] Figure 1 This is the block schematic diagram of the present utility model;

[0008] Figure 2 This is the circuit schematic diagram of the present utility model;

[0009] Figure 3 This is a square wave oscillation circuit. Specific embodiments

[0010] See Figure 1 , Figure 2 , Figure 3As shown in the figure, a host data acquisition circuit includes a front-end protection circuit, a communication circuit, an isolation optocoupler circuit, and a sample-and-hold circuit connected in sequence. The sample-and-hold circuit is connected to a square-wave oscillation circuit and a microcontroller chip. The front-end protection circuit includes a common-mode inductor L6. One end of the 1st pin of the common-mode inductor L6 is connected to one end of a resistor R29 and one end of a varistor SA, and the 2nd pin is connected to one end of a resistor R30 and the other end of the varistor SA. The 3rd pin of the common-mode inductor L6 is connected to the cathode of a zener diode ZD1, one end of a resistor R26, the other end of the resistor R30, and the 6th pin of a communication chip IC3 in the communication circuit. The 4th pin of the common-mode inductor L6 is connected to the cathode of a zener diode ZD2, one end of a resistor R25, the other end of the resistor R29, and the 7th pin of the communication chip IC3 in the communication circuit. The communication chip IC3 uses the SN75176BDR model and can achieve two-way data communication. The other end of the resistor R25 and the 5th pin of the communication chip IC3 are both connected to the IG12V power supply, and the other end of the resistor R26 and the 8th pin of the communication chip IC3 are both connected to the IP5V power supply. The isolation optocoupler circuit includes an optocoupler PC1 (model TLP181), an optocoupler PC2 (model TLP719), and an optocoupler PC3 (model TLP719). The 4th pin of the optocoupler PC1 is connected to the IP5V power supply, and the 3rd pin is connected to the 2nd and 3rd pins of the communication chip IC3 and one end of a resistor R24. The other end of the resistor R24 is connected to the IG12V power supply. The 4th pin of the optocoupler PC2 is connected to the IG12V power supply, the 5th pin is connected to one end of a resistor R22 and the 4th pin of the communication chip IC3, and the 6th pin is connected to the other end of the resistor R22 and the IP5V power supply. The 1st pin of the optocoupler PC3 is connected to the IP5V power supply through a resistor R23, the 2nd pin is left floating, and the 3rd pin is connected to the 1st pin of the communication chip IC3. The 1st pin of the optocoupler PC1 is connected to one end of a resistor R19, and the 2nd pin is connected to the sample-and-hold circuit. The 1st pin of the optocoupler PC2 is connected to one end of a resistor R16, the 2nd pin is left floating, and the 3rd pin is connected to the sample-and-hold circuit. The 4th pin of the optocoupler PC3 is grounded, and the 5th pin is connected to one end of a resistor R15 and one end of a resistor R20. The other end of the resistor R16, the other end of the resistor R19, the other end of the resistor R20, and the 6th pin of the optocoupler PC3 are all connected to DVCC. The other end of the resistor R15 is connected to the sample-and-hold circuit. The sample-and-hold circuit includes a first register and a second register. The square-wave oscillation circuit includes a square-wave generator. The output end of the 3rd pin of the square-wave generator is connected to the SCK pins of the first register and the second register. The SDK pin of the first register is connected to the isolation optocoupler circuit.

[0011] Figure 2 The power supply circuit is also given in the figure, which is implemented by two voltage regulators of the UPC78L05T model. The interface CN2 is used to connect to the host.

Claims

1. A host data acquisition circuit, characterized in that, It includes a front-end protection circuit, a communication circuit, an isolation optocoupler circuit, and a sampling circuit connected in sequence. The sampling circuit is connected to a square-wave oscillation circuit and a microcontroller chip. The front-end protection circuit includes a common-mode inductor L6. Pin 1 of the common-mode inductor L6 is connected to one end of a resistor R29 and one end of a varistor SA and serves as a main host signal input terminal. Pin 2 is connected to one end of a resistor R30 and the other end of the varistor SA and serves as another main host signal input terminal. Pin 3 of the common-mode inductor L6 is connected to the cathode of a voltage regulator diode ZD1, one end of a resistor R26, the other end of the resistor R30, and pin 6 of a communication chip IC3 in the communication circuit. Pin 4 of the common-mode inductor L6 is connected to the cathode of a voltage regulator diode ZD2, one end of a resistor R25, the other end of the resistor R29, and pin 7 of the communication chip IC3 in the communication circuit. The other end of the resistor R25 and pin 5 of the communication chip IC3 are both connected to the IG12V power supply. The other end of the resistor R26 and pin 8 of the communication chip IC3 are both connected to the IP5V power supply. The isolation optocoupler circuit includes optocouplers PC1, PC2, and PC3. Pin 4 of the optocoupler PC1 is connected to the IP5V power supply. Pin 3 is connected to pins 2 and 3 of the communication chip IC3 and one end of a resistor R24. The other end of the resistor R24 is connected to the IG12V power supply. Pin 4 of the optocoupler PC2 is connected to the IG12V power supply. Pin 5 is connected to one end of a resistor R22 and pin 4 of the communication chip IC3. Pin 6 is connected to the other end of the resistor R22 and the IP5V power supply. Pin 1 of the optocoupler PC3 is connected to the IP5V power supply through a resistor R23. Pin 2 is left floating. Pin 3 is connected to pin 1 of the communication chip IC3. Pin 1 of the optocoupler PC1 is connected to one end of a resistor R19. Pin 2 is connected to the sampling circuit. Pin 1 of the optocoupler PC2 is connected to one end of a resistor R16. Pin 2 is left floating. Pin 3 is connected to the sampling circuit. Pin 4 of the optocoupler PC3 is grounded. Pin 5 is connected to one end of a resistor R15 and one end of a resistor R20. The other end of the resistor R16, the other end of the resistor R19, the other end of the resistor R20, and pin 6 of the optocoupler PC3 are all connected to DVCC. The other end of the resistor R15 is connected to the sampling circuit. The sampling circuit includes a first register and a second register. The square-wave oscillation circuit includes a square-wave generator. The output terminal of pin 3 of the square-wave generator is connected to the SCK pins of the first register and the second register. The SDK pin of the first register is connected to the isolation optocoupler circuit.

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