Dual-signal identification switching unit and compatible dual-signal safety barrier

Abstract

The utility model discloses a kind of dual signal identification switching unit and compatible safety barrier of dual signal, including identification switching unit;First acquisition module, it includes with the first signal input terminal of thermistor sensor connection, first signal input terminal is also connected with constant current source, the output end of first signal input terminal is connected with difference amplifier, the output end of difference amplifier is connected with first relay;Second acquisition module, it includes with the second signal input terminal of temperature transmitter connection, second signal input terminal is also connected with sampling resistance, the output end of sampling resistance is connected with second relay;Wherein, the on-off state of first relay and second relay is opposite.The compatible safety barrier of dual signal, by setting signal identification switching unit, different signals can be connected on different terminals of the same device when using, only in the pre-processing link of signal using different circuit, all subsequent signal processing share a circuit.

Description

Technical Field

[0001] This utility model relates to the technical field of isolation safety barriers, and in particular to a dual-signal identification switching unit and a dual-signal compatible safety barrier. Background Technology

[0002] In industrial automation control systems, safety barriers serve as key intermediate devices connecting temperature detection equipment in hazardous areas (intrinsically safe end) with PLC / DCS control systems in non-hazardous areas (non-intrinsically safe end). They must simultaneously achieve reliable signal transmission and intrinsically safe explosion protection to ensure the safety of the production process and the accuracy of data acquisition.

[0003] However, existing safety barriers generally suffer from poor signal compatibility: most products can only adapt to a single type of temperature signal. That is, safety barriers specifically designed for processing RTD signals are not compatible with 4mA to 20mA signals, and vice versa. This means that if two types of temperature detection devices are present in an industrial setting, multiple safety barriers of different types need to be configured. This not only increases equipment procurement costs and control cabinet installation space, but also increases the complexity of subsequent operation and maintenance. Staff need to calibrate and troubleshoot different safety barriers separately, which can easily lead to low maintenance efficiency due to the mixing of equipment types. Utility Model Content

[0004] In view of the incompatibility issues of existing dual-signal compatible safety barriers, this utility model is proposed.

[0005] Therefore, one objective of this invention is to provide a dual-signal identification and switching unit.

[0006] To address the aforementioned technical problem of insufficient compatibility, this utility model provides the following technical solution: a dual-signal identification and switching unit, comprising an identification and switching microcontroller; a first acquisition module, which includes a first signal input terminal connected to a thermistor sensor, the first signal input terminal also being connected to a constant current source, the output terminal of the first signal input terminal being connected to a differential amplifier, the output terminal of the differential amplifier being connected to a first relay, and the control terminal of the first relay being connected to a GPIO pin of the identification and switching microcontroller; and a second acquisition module, which includes a second signal input terminal connected to a temperature transmitter, the second signal input terminal also being connected to a sampling resistor, the output terminal of the sampling resistor being connected to a second relay, and the control terminal of the second relay being connected to a GPIO pin of the identification and switching microcontroller; wherein the on / off states of the first relay and the second relay are opposite.

[0007] In a preferred embodiment of the dual-signal identification switching unit of this utility model, the output pin of the constant current source is directly connected to the first signal input terminal, and the first signal input terminal is directly connected to the inverting input pin of the differential amplifier; the first acquisition module is further provided with a zero-adjustment circuit, which is located between the thermal resistance sensor and the differential amplifier, the input terminal of the zero-adjustment circuit is connected to the first signal input terminal, and the output pin of the zero-adjustment circuit is connected to the non-inverting input pin of the differential amplifier.

[0008] In a preferred embodiment of the dual-signal identification and switching unit of this utility model, the two output terminals of the temperature transmitter are respectively connected to two second signal input terminals; and a high-frequency filter capacitor is connected in parallel across the sampling resistor.

[0009] In a preferred embodiment of the dual-signal identification and switching unit of this utility model, the constant current source outputs a 1mA excitation current to the thermal resistance sensor to generate a first signal; the signal generated by the temperature transmitter is divided by the sampling resistor to generate a second signal.

[0010] In a preferred embodiment of the dual signal identification and switching unit of this utility model, the signal input pin of the identification and switching microcontroller is simultaneously connected to the first signal input terminal and the second signal input terminal, and the GPIO pin of the identification and switching microcontroller is simultaneously connected to the first relay and the second relay.

[0011] Another objective of this invention is to provide a safety barrier compatible with dual signals.

[0012] This utility model also provides the following technical solution: a safety barrier compatible with dual signals, including the above-mentioned dual signal identification and switching unit, and further including a signal isolation unit connected to the output terminal of the identification and switching microcontroller, the output terminal of the signal isolation unit being connected to a signal processing unit, and the output terminal of the signal processing unit being connected to a signal output unit.

[0013] As a preferred embodiment of the dual-signal compatible safety barrier of this utility model, the signal isolation unit includes an input filter capacitor connected to the identification switching microcontroller, a current-limiting resistor connected to the input filter capacitor, an isolation chip connected to the current-limiting resistor, and an output filter capacitor connected to the isolation chip; the output filter capacitor of the signal isolation unit is directly connected to the analog input pin of the analog-to-digital converter.

[0014] As a preferred embodiment of the dual-signal compatible safety barrier of this utility model, the signal processing unit includes an analog-to-digital converter electrically connected to the signal isolation unit, a calibration microcontroller electrically connected to the analog-to-digital converter, and the output terminal of the calibration microcontroller electrically connected to the signal output unit.

[0015] As a preferred embodiment of the dual-signal compatible safety barrier of this utility model, the signal output unit includes an operational amplifier and a filter circuit connected to the signal processing unit; the output pin of the calibration microcontroller is connected to the non-inverting input pin of the operational amplifier.

[0016] As a preferred embodiment of the dual-signal compatible safety barrier of this utility model, the first signal and the second signal of the first signal input terminal and the second signal input terminal are ultimately output through the signal output unit.

[0017] The beneficial effects of this utility model are: This invention, by setting up a signal identification and switching unit and two paths, allows different signals to be connected to different terminals of the same device. Different circuits are used only in the signal preprocessing stage, while all subsequent signal processing shares a single circuit, reducing the number of components and circuit complexity. Furthermore, by incorporating an identification and switching microcontroller, signal characteristics are automatically detected and path switching is completed, eliminating the need for manual adjustments and additional modifications to the temperature detection equipment. This significantly reduces the number of safety barriers required in the field, lowering maintenance complexity and labor costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the dual-signal recognition and switching unit of this utility model.

[0020] Figure 2 This is an overall schematic diagram of the dual-signal recognition and switching unit of this utility model.

[0021] Figure 3 This is a schematic diagram of the signal isolation unit of the dual-signal compatible safety barrier of this utility model.

[0022] Figure 4 This is a schematic diagram of the signal processing unit of the dual-signal compatible safety barrier of this utility model.

[0023] Figure 5 This is a schematic diagram of the signal output unit of the dual-signal compatible safety barrier of this utility model.

[0024] Figure 6 This is an overall schematic diagram of the dual-signal compatible safety barrier of this utility model. Detailed Implementation

[0025] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0028] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.

[0029] Example 1

[0030] Reference Figure 1 and Figure 2 This is the first embodiment of the present invention, providing a dual-signal compatible safety barrier, including an identification and switching microcontroller 100; a first acquisition module 200, which includes a first signal input terminal 201 connected to a thermistor sensor R, a constant current source 202 connected to the first signal input terminal 201, a differential amplifier 203 connected to the output terminal of the first signal input terminal 201, a first relay 204 connected to the output terminal of the differential amplifier 203, and a control terminal of the first relay 204 connected to the GPIO pin of the identification and switching microcontroller 100; and a second acquisition module 300, which includes a second signal input terminal 301 connected to a temperature transmitter W, a sampling resistor 302 connected to the second signal input terminal 301, a second relay 303 connected to the output terminal of the sampling resistor 302, and a control terminal of the second relay 303 connected to the GPIO pin of the identification and switching microcontroller 100.

[0031] The first relay 204 and the second relay 303 have opposite on / off states. To provide a stable power supply to the control unit and other chips, a power supply module (not shown in the figure) is provided. This module uses a low-dropout linear regulator to stabilize the voltage. One side of the power supply module is connected to a 24VDC non-intrinsically safe power supply, while the other side provides isolated 5V intrinsically safe power supplies to the signal acquisition module, isolation module, and field sensors. A power isolation module (not shown in the figure) is also provided between the power supply module and each signal unit. Filter capacitors are added to the input and output terminals of the power isolation module for input filtering, ensuring stable and reliable power after isolation. Simultaneously, a polarity protection diode is added to the input terminal of the power isolation module to prevent reverse power connection damage to the circuit. This diode identifies whether the GPIO pin connection of the microcontroller 100 is used to output control signals, thereby controlling the on / off state of the first relay 204 and the second relay 303.

[0032] Among them, the identification and switching microcontroller 100 is a microcontroller, which controls the on / off state of the first relay 204 or the second relay 303. The thermal resistance sensor R can be a three-wire thermal resistance sensor. In this case, the first signal input terminal 201 also has three terminals. The positive terminal of the thermal resistance sensor R is connected to one terminal of the first signal input terminal 201, the negative terminal of the thermal resistance sensor R is connected to the negative terminal of another terminal 201, and the compensation terminal of the thermal resistance sensor R is connected to the third terminal of the first signal input terminal 201. The output of the constant current source 202 is... The pin is directly connected to the first pin of the first signal input terminal 201, and the return pin of the constant current source 202 is directly connected to the second pin of the first signal input terminal 201, forming a current loop. The control terminal of the constant current source 202 is connected to the GPIO pin, i.e., the control pin, of the identification and switching microcontroller 100. Since the temperature transmitter W outputs two signals, positive and negative, the second signal input terminal 301 is also provided with two. The positive pin of the temperature transmitter W is connected to the first second signal input terminal 301, and the negative pin of the temperature transmitter W is connected to the second second signal input terminal 301.

[0033] During dual-signal input identification, the RTD temperature signal is connected to the first signal input terminal 201 of the first acquisition module 200 through a 3-wire terminal, and the 4mA~20mA temperature analog signal of the temperature transmitter W is connected to the second signal input terminal 301 of the second acquisition module through a 2-wire terminal. The RTD temperature signal and the temperature analog signal of the temperature transmitter W are not input signals simultaneously.

[0034] When an input signal is received, if the signal characteristics of a variable impedance matching low voltage are detected, which are consistent with the characteristics of a resistance temperature detector (RTD) signal, such as 0.1V at 0℃, then the input signal is determined to be the first signal. The microcontroller 100 is then identified and switched to control the first relay 204 to turn on, while simultaneously controlling the second relay 303 to turn off.

[0035] If the signal characteristics of a low impedance signal with a fixed voltage range of 1V to 5V are detected, which are consistent with the characteristics of a 4mA to 20mA signal after conversion by a sampling resistor, then the input signal is determined to be the second signal. The microcontroller 100 is then identified to control the second relay 303 to turn on, while simultaneously controlling the first relay 204 to turn off.

[0036] The identification and switching microcontroller 100 first determines whether the specific signal input is a temperature signal from a resistance temperature detector (RTD) or an analog temperature signal from a temperature transmitter (W). The identification and switching microcontroller 100 then samples the voltage values ​​of the first signal input terminal 201 and the second signal input terminal 301 in real time through an analog-to-digital converter, and controls the on / off state of the first relay 204 and the second relay 303 according to different signal inputs.

[0037] During operation, the RTD sensor R uses a 3-wire system, with pins corresponding to signal +, signal -, and compensation pins. The temperature transmitter W uses a 2-wire system, with pins corresponding to current + and current -. The first signal input terminal 201 and the second signal input terminal 301 are different terminals on the same device, meaning the RTD sensor R and the temperature transmitter W are connected to different terminals of this device. Only one signal input terminal (201) and the second signal input terminal (301) can be input at a time; both cannot be input simultaneously. Before the signal enters the identification and switching microcontroller 100, an analog-to-digital converter (ADC) is provided to convert the signal into a corresponding analog quantity for the identification and switching microcontroller 100 to recognize. Based on the detected signal, the identification and switching microcontroller 100 automatically determines whether it is a temperature signal from the RTD or a temperature analog signal from the temperature transmitter W. For example, the identification and switching microcontroller 100 can be an STM32F103 model, used for outputting control commands and signal detection. After the determination is completed, it automatically controls the corresponding path to be connected and the other path to be disconnected. For example, if the microcontroller 100 identifies a resistance temperature detector (RTD) signal, it then controls the first relay 204 to remain on while the second relay 303 is off. The signal is ultimately output through the signal output unit 600.

[0038] Example 2

[0039] Reference Figure 1 and Figure 2 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the first acquisition module 200 is further provided with a zero-adjustment circuit 205. The zero-adjustment circuit 205 is disposed between the thermal resistance sensor R and the differential amplifier 203. The input terminal of the zero-adjustment circuit 205 is connected to the first signal input terminal 201, and the output pin of the zero-adjustment circuit 205 is connected to the non-inverting input pin of the differential amplifier 203.

[0040] The constant current source 202 is based on the operational amplifier LM358 and is controlled by the identification and switching microcontroller 100. It outputs excitation current to the RTD. The identification and switching microcontroller 100 controls the constant current source 202 to output 1mA excitation current to the RTD, so that the RTD generates a voltage. At this time, the identification and switching microcontroller 100 detects the voltage across the RTD. For example, if the RTD generates a voltage of 0.1V at 0℃, it determines that the signal input is a RTD signal based on the characteristics of variable impedance and low voltage. Then, the identification and switching microcontroller 100 controls the first relay 204 of the first acquisition module 100 to be connected and the second relay 303 of the second acquisition module 300 to be disconnected.

[0041] The first signal generated by the RTD sensor is input into the zero-adjustment circuit 205 of the first acquisition module 100. The zero-adjustment circuit 205 includes a multi-turn potentiometer and a fixed resistor to fine-tune the signal at zero point, correct for device temperature drift, signal offset caused by installation errors, etc., and finally outputs the corrected RTD first signal. The RTD first signal enters the differential amplifier 203. A voltage divider circuit can also be set to fine-tune the signal to ensure measurement accuracy. It is then sent to the differential amplifier 203, where the differential amplification principle cancels the resistance loss of the 3-wire lead, and at the same time converts the resistance signal into a variable voltage signal, thus completing the preprocessing of the signal from the first acquisition module 200.

[0042] The two output terminals of the temperature transmitter W are respectively connected to the two second signal input terminals 301.

[0043] A high-frequency filter capacitor 304 is connected in parallel across the sampling resistor 302. The output terminal of the sampling resistor 302 is connected to the input pin of the second relay 303. The control terminal of the second relay 303 is connected to the GPIO pin of the identification switching microcontroller 100.

[0044] The microcontroller 100 identifies and switches the voltage of the first signal input terminal 201 and the second signal input terminal 301 at the same time, determines whether the input electrical signal is a resistance temperature detector (RTD) signal or a temperature transmitter W analog signal, and controls the on / off state of the corresponding first relay 204 or second relay 303.

[0045] Among them, the sampling resistor 302 is a 250Ω high-precision sampling resistor; for example, the sampling resistor 302 is a VishayDFR0500 with an accuracy of 0.1%, connected in series in the 4mA~20mA signal loop. The temperature transmitter W's temperature analog signal is divided by the sampling resistor 302 to generate a 1V~5V voltage, which also serves as a current-to-voltage conversion, with 4mA corresponding to 1V and 20mA corresponding to 5V. When the identification and switching microcontroller 100 detects the fixed voltage range + low impedance characteristics, it determines that it is a signal input from the temperature transmitter W. Then, the identification and switching microcontroller 100 controls the first relay 204 of the first acquisition module 200 to disconnect, and the second relay 303 of the second acquisition module 300 to connect.

[0046] After the temperature transmitter W signal is input, it enters the second acquisition module 300. When it is divided by the sampling resistor 302, it is converted into a voltage signal of 1V to 5V. At the same time, the high-frequency filter capacitor 304 in parallel filters out the industrial high-frequency interference carried in the current signal and outputs a stable voltage signal.

[0047] The remaining structure is the same as that in Example 1.

[0048] Example 3

[0049] Reference Figures 3-6 This is the third embodiment of the present invention. This embodiment also provides a dual-signal compatible safety barrier, including the dual-signal identification and switching unit mentioned above, and also including a signal isolation unit 400 connected to the output terminal of the identification and switching microcontroller 100. The output terminal of the signal isolation unit 400 is connected to a signal processing unit 500, and the output terminal of the signal processing unit 500 is connected to a signal output unit 600.

[0050] The signal isolation unit 400 filters out high-frequency interference between the signals before and after isolation. Resistors are connected in series on the input and output signal lines for current limiting and impedance matching. The signal processing unit 500 performs analog-to-digital conversion on different signals, transforming them into signals of the same format for output by the signal output unit 600, enabling various devices to read them.

[0051] refer to Figure 3 The signal isolation unit 400 includes an input filter capacitor 401 electrically connected to the signal identification and switching microcontroller 100, a current-limiting resistor 402 electrically connected to the input filter capacitor 401, an isolation chip 403 electrically connected to the current-limiting resistor 402, and an output filter capacitor 404 electrically connected to the isolation chip 403. Filter capacitors are added to the input and output terminals of the signal isolation chip 403 to filter out high-frequency interference in the signals before and after isolation. Simultaneously, the current-limiting resistor 402 is connected in series on the input and output signal lines to perform current limiting and impedance matching.

[0052] The positive pin of the output filter capacitor 404 of the signal isolation unit 400 is directly connected to the analog input pin of the analog-to-digital converter 501. The ground reference of the signal isolation unit 400 is connected to the analog ground pin of the analog-to-digital converter 501. The data output pin of the analog-to-digital converter 501 is connected to the parallel data input pin of the calibration microcontroller 502. The conversion completion pin of the analog-to-digital converter 501 is connected to the external interrupt pin of the calibration microcontroller 502.

[0053] refer to Figure 4 The signal processing unit 500 includes an analog-to-digital converter 501 electrically connected to the signal isolation unit 400, and a calibration microcontroller 502 electrically connected to the analog-to-digital converter 501. The output of the calibration microcontroller 502 is electrically connected to the signal output unit 600. The analog-to-digital converter 501 converts the analog signal into a digital signal, which is then calibrated by the calibration microcontroller 502 to eliminate errors before being output.

[0054] refer to Figure 5 Both the first acquisition module 200 and the second acquisition module 300 are electrically connected to the signal output unit 600. The signal output unit 600 includes an operational amplifier 601 and a filter circuit 602 connected to the signal identification and switching unit 200. The operational amplifier 601 is connected to the output terminal of the signal isolation unit 400. The feedback resistor and input resistor of the operational amplifier 601 form a high-precision current-to-voltage conversion circuit. The calibrated signal is input to the signal output unit 600, and the high-precision conversion circuit composed of the feedback resistor and input resistor of the operational amplifier 601 converts the voltage signal into a standard current signal of 4mA to 20mA. An LC oscillation filter circuit 602 composed of an inductor and a capacitor is added to the voltage output terminal. After the current signal is filtered to remove high-frequency noise, it is output to the PLC or DCS control system, completing the dual-signal compatibility processing.

[0055] The remaining structure is the same as that in Example 2.

[0056] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise changed, and the nature or number or position of discrete elements may be altered or changed. Therefore, all such modifications are intended to be included within the scope of this utility model. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. Therefore, this utility model is not limited to the particular embodiments but extends to a variety of modifications that still fall within the scope of the appended claims.

[0057] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the present invention as currently considered, or those features that are not relevant to the implementation of the present invention) may be omitted.

[0058] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A dual-signal identification and switching unit, characterized in that: include, Identify and switch microcontrollers (100); The first acquisition module (200) includes a first signal input terminal (201) connected to a resistance temperature detector (R), a constant current source (202) connected to the first signal input terminal (201), a differential amplifier (203) connected to the output of the first signal input terminal (201), a first relay (204) connected to the output of the differential amplifier (203), and a control terminal of the first relay (204) connected to the GPIO pin of the identification switching microcontroller (100); and, The second acquisition module (300) includes a second signal input terminal (301) connected to the temperature transmitter (W), the second signal input terminal (301) is also connected to a sampling resistor (302), the output terminal of the sampling resistor (302) is connected to a second relay (303), and the control terminal of the second relay (303) is connected to the GPIO pin of the identification switching microcontroller (100). The first relay (204) and the second relay (303) have opposite on / off states.

2. The dual-signal identification and switching unit according to claim 1, characterized in that: The output pin of the constant current source (202) is directly connected to the first signal input terminal (201), and the first signal input terminal (201) is directly connected to the inverting input pin of the differential amplifier (203); The first acquisition module (200) is also provided with a zero-adjustment circuit (205), which is located between the resistance temperature detector (R) and the differential amplifier (203). The input terminal of the zero-adjustment circuit (205) is connected to the first signal input terminal (201), and the output pin of the zero-adjustment circuit (205) is connected to the non-inverting input pin of the differential amplifier (203).

3. The dual-signal identification and switching unit according to claim 1 or 2, characterized in that: The two output terminals of the temperature transmitter (W) are respectively connected to two second signal input terminals (301); A high-frequency filter capacitor (304) is connected in parallel across the sampling resistor (302).

4. The dual-signal identification and switching unit according to claim 3, characterized in that: The constant current source (202) outputs a 1mA excitation current to the resistance temperature detector (R) to generate a first signal; The signal generated by the temperature transmitter (W) is divided by the sampling resistor (302) to generate a second signal.

5. The dual-signal identification and switching unit according to any one of claims 1, 2, and 4, characterized in that: The signal input pins of the identification switching microcontroller (100) are simultaneously connected to the first signal input terminal (201) and the second signal input terminal (301), and the GPIO pins of the identification switching microcontroller (100) are simultaneously connected to the first relay (204) and the second relay (303).

6. A dual-signal compatible safety barrier, comprising the dual-signal identification and switching unit as described in any one of claims 1 to 5, characterized in that: It also includes, A signal isolation unit (400) is connected to the output terminal of the identification switching microcontroller (100). The output terminal of the signal isolation unit (400) is connected to a signal processing unit (500). The output terminal of the signal processing unit (500) is connected to a signal output unit (600).

7. The dual-signal compatible safety barrier according to claim 6, characterized in that: The signal isolation unit (400) includes an input filter capacitor (401) connected to the identification switching microcontroller (100), a current limiting resistor (402) connected to the input filter capacitor (401), an isolation chip (403) connected to the current limiting resistor (402), and an output filter capacitor (404) connected to the isolation chip (403). The output filter capacitor (404) of the signal isolation unit (400) is directly connected to the analog input pin of the analog-to-digital converter (501).

8. The dual-signal compatible safety barrier according to claim 7, characterized in that: The signal processing unit (500) includes an analog-to-digital converter (501) electrically connected to the signal isolation unit (400), a calibration microcontroller (502) electrically connected to the analog-to-digital converter (501), and the output terminal of the calibration microcontroller (502) electrically connected to the signal output unit (600).

9. The dual-signal compatible safety barrier according to any one of claims 6 to 8, characterized in that: The signal output unit (600) includes an operational amplifier (601) and a filter circuit (602) connected to the signal processing unit (500). The output pin of the calibration microcontroller (502) is connected to the non-inverting input pin of the operational amplifier (601).

10. The dual-signal compatible safety barrier according to claim 9, characterized in that: The first signal and the second signal of the first signal input terminal (201) and the second signal input terminal (301) are ultimately output through the signal output unit (600).

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