Discrete magnitude signal output power-on control circuit

Abstract

The utility model relates to the technical field of discrete magnitude signals, in particular to a discrete magnitude signal output power-on control circuit, which comprises a power supply, a controller, a discrete magnitude output interface module, a voltage detection repositor and a bidirectional bus transceiver. The power supply end of the voltage detection reset device is connected with a power supply, the reset end of the voltage detection reset device is connected with the direction control end of the bidirectional bus transceiver, the enabling output end and the data bus A end of the bidirectional bus transceiver are connected with the controller, and the data bus B end of the bidirectional bus transceiver is connected with the discrete magnitude output interface module. The voltage of the power supply is monitored in real time through the voltage detection restorer, the signal transmission state is controlled by combining the bidirectional bus transceiver, the bidirectional bus transceiver is set to be in an input state when the power supply is not stable, a discrete magnitude signal output path is forcibly disconnected, misoperation in the starting stage of the controller is avoided, and the reliability of the controller is improved. The method has the advantage of improving the safety and reliability of the power-on process of the system.

Description

Technical Field

[0001] This utility model relates to the field of discrete signal technology, specifically to a discrete signal output power-on control circuit. Background Technology

[0002] In fields such as industrial control, aerospace, and weaponry, the reliability of discrete signal outputs is crucial. Discrete signals control the start-up and shutdown of critical equipment (such as valves, motors, circuit breakers, engine igniters, and leads). The reliability of discrete signal outputs is a core element in these fields, especially since the power-on process directly affects the safety and stability of the system during startup.

[0003] During the power-on process of the discrete signal output system, the following problems may exist: (1) The surge current at the moment of power-on may cause the logic device (such as PLC output module, relay) to be falsely triggered; (2) When the controller (FPGA, MCU, PLC, etc.) starts, the program is not fully loaded, which may cause the output port status to be uncertain; (3) Multiple discrete signal outputs act at the same time, which may cause equipment abnormality due to timing conflicts.

[0004] Therefore, it is particularly important to ensure the reliability of discrete signal output power-on by designing a discrete signal output power-on control circuit. Utility Model Content

[0005] The purpose of this invention is to provide a discrete signal output power-on control circuit. This circuit solves the problem of erroneous output of discrete signals during the power-on process. It ensures that the signal output is prohibited before the power supply voltage stabilizes through hardware control, thereby improving the safety and stability of the system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A discrete signal output power-on control circuit includes a power supply, a controller, a discrete output interface module, a voltage detection reset device, and a bidirectional bus transceiver; the power supply terminal of the voltage detection reset device is connected to the power supply, its reset terminal is connected to the direction control terminal of the bidirectional bus transceiver, the enable output terminal and data bus A terminal of the bidirectional bus transceiver are connected to the controller, and the data bus B terminal of the bidirectional bus transceiver is connected to the discrete output interface module.

[0008] During power-on, the voltage detection reset device detects the power supply voltage. When the power supply voltage does not reach the set threshold, the voltage detection reset device outputs a low-level signal. The low-level signal controls the bidirectional bus transceiver to be in input mode, and discrete signals cannot be output. When the power supply voltage reaches the set threshold and stabilizes, the voltage detection reset device outputs a high-level signal. The high-level signal switches the bidirectional bus transceiver to output mode. If the bidirectional bus transceiver output enable is valid, discrete signals can be output.

[0009] Furthermore, a pull-down resistor is connected between the voltage detection reset unit and the bidirectional bus transceiver.

[0010] Furthermore, the controller's output is connected to the data bus A terminal of the bidirectional bus transceiver via a current-limiting resistor and a pull-down resistor. The current-limiting resistor serves the purpose of preventing damage when the bidirectional bus transceiver is in input mode. When the bidirectional bus transceiver is in input mode, the transceiver pin connected to the controller's output pin is also set to output mode upon power-up. Directly connecting these two output pins could damage the circuit. Connecting a current-limiting resistor in series between the two output pins avoids this problem.

[0011] Furthermore, a pull-down resistor is connected to the data bus B terminal of the bidirectional bus transceiver.

[0012] Furthermore, the enable output of the bidirectional bus transceiver is connected to the power supply via a pull-up circuit.

[0013] This invention monitors the power supply voltage in real time through a voltage detection reset device, and combines it with the bidirectional bus transmit and receive control signal transmission status. When the power supply is unstable, it forcibly disconnects the discrete signal output path, avoiding malfunctions of the controller during the startup phase. This has the advantage of improving the safety and reliability of the system during power-on. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the circuit structure of this utility model.

[0015] The diagram shows the following labels: U1, controller; U2, voltage detection resetter; U3, bidirectional bus transceiver; U4, discrete output interface module; R1, first pull-down resistor; R2, second pull-down resistor; R3, third pull-down resistor; R4, current limiting resistor; R5, pull-up resistor. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0017] This embodiment discloses a discrete signal output power-on control circuit, which solves the problem of erroneous output of discrete signals during power-on. It includes a power supply, a controller U1, a discrete output interface module U4, a voltage detection reset unit U2, and a bidirectional bus transceiver U3. The power supply provides power to all components of the controller U1, voltage detection reset unit U2, and bidirectional bus transceiver U3. Specifically, the power supply is connected to the VDD pins of the controller U1, voltage detection reset unit U2, and bidirectional bus transceiver U3. The reset pin of the voltage detection reset unit U2... The RESET pin is connected to the direction control pin (DIR) of the bidirectional bus transceiver U3 via a pull-down resistor R3; the data bus A terminal of the bidirectional bus transceiver U3 is connected to the data terminal DATA of the controller U1 via a current-limiting resistor R4 and a pull-down resistor R1; the enable output pin (OE) of the bidirectional bus transceiver U3 is connected to the IO pin of the controller U1 and to the power supply via a pull-up resistor R5; the data bus B terminal of the bidirectional bus transceiver U3 is connected to the discrete output interface module U4 via a pull-down resistor R2.

[0018] The voltage detection reset unit U2 detects the output supply voltage of the power supply and monitors the power supply voltage (VDD) in real time. When the voltage is lower than the threshold or unstable, it outputs a low-level reset signal; after the voltage stabilizes, it switches to a high-level signal after a delay of 100-200ms. When the bidirectional bus transceiver receives a low-level signal from the voltage detection reset unit U3, the signal is transmitted from terminal B to terminal A, i.e., from the external device to the controller U1, and discrete output is prohibited; when a high-level signal is received, the signal is transmitted from terminal A to terminal B, i.e., from the controller U1 to the external device, and output control signals are allowed; the bidirectional bus transceiver U3 is equivalent to a hardware switch, which forcibly isolates the output signal during power-on.

[0019] The controller U1 is a commonly used microcontroller, MCU, FPGM, etc.

[0020] The discrete output interface module U4 is an optocoupler, relay, etc.

[0021] During power-up, the power supply VDD starts rising from 0V. When VDD reaches the minimum operating voltage (e.g., 1.0V) of the voltage detection reset unit U2, it starts working. The detection circuit then detects the power supply VDD. Before VDD reaches the chip's set detection threshold of 3.0V, the reset signal output by the voltage detection reset unit U2 is low. The reset signal is connected to circuit ground via pull-down resistor R3 to ensure it is low before the voltage detection reset unit operates. When VDD reaches the chip's set detection threshold of 3.0V, the voltage detection reset unit U2 starts counting, and the reset signal remains low for 100-200ms before going high. The reset signal output by the voltage detection reset unit U2 is connected to the direction control pin (DIR) of the bidirectional bus transceiver U3. When the direction control pin (DIR) is low, the signal flow of the bidirectional bus transceiver U3 is from pin B to pin A, and the bidirectional bus transceiver U3 is in input mode. Because the bidirectional bus transceiver U3 is in input mode, the discrete output interface module U4 cannot output signals. This ensures that the discrete output circuit cannot output signals during power-on, thus avoiding potential equipment malfunctions caused by incorrect power-on output.

[0022] After the power supply voltage of the controller and other circuits reaches the rated operating voltage, the startup program is fully loaded, and the output port status is determined and the operation is normal. Only then will the output of the voltage detection reset unit U2 become high, and the DIR pin of the bidirectional bus transceiver U3 will be high. The bidirectional bus transceiver U3 will switch to the output state. At this time, if the discrete output enable signal OE output by the controller U1 is low, the bidirectional bus transceiver U3 can output discrete signals to the discrete output interface module U4.

[0023] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A discrete signal output power-on control circuit, comprising a power supply, a controller, and a discrete output interface module; characterized in that: It also includes a voltage detection reset unit and a bidirectional bus transceiver; the power supply terminal of the voltage detection reset unit is connected to the power supply, its reset terminal is connected to the direction control terminal of the bidirectional bus transceiver, the enable output terminal and data bus A terminal of the bidirectional bus transceiver are connected to the controller, and the data bus B terminal of the bidirectional bus transceiver is connected to the discrete quantity output interface module. During power-on, the voltage detection reset device detects the power supply voltage. When the power supply voltage does not reach the set threshold, the voltage detection reset device outputs a low-level signal. The low-level signal controls the bidirectional bus transceiver to be in input mode, and discrete signals cannot be output. When the power supply voltage reaches the set threshold and stabilizes, the voltage detection reset device outputs a high-level signal. The high-level signal causes the bidirectional bus transceiver to switch to output mode, and discrete signals can be output.

2. The discrete signal output power-on control circuit according to claim 1, characterized in that: A pull-down resistor is connected between the voltage detection reset device and the bidirectional bus transceiver.

3. The discrete signal output power-on control circuit according to claim 1, characterized in that: The output of the controller is connected to the data bus A terminal of the bidirectional bus transceiver via a current-limiting resistor and a pull-down resistor.

4. The discrete signal output power-on control circuit according to claim 1, characterized in that: The data bus B terminal of the bidirectional bus transceiver is connected to a pull-down resistor.

5. The discrete signal output power-on control circuit according to claim 1, characterized in that: The enable output of the bidirectional bus transceiver is connected to the power supply via a pull-up resistor.

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