Interface circuit, interface system and electronic equipment

Abstract

The invention provides an interface circuit, an interface system and electronic equipment, and relates to the technical field of electronic circuits, and the circuit comprises a switch module which is electrically connected with a PLC and an anti-backflow module; the anti-backflow module is also electrically connected with the isolation module; the isolation module is further electrically connected with the PLC and the MCU. When the first control signal is received, the switch module enters a first conduction state; when the switch module enters a first conduction state and the isolation module obtains a first preset level signal from the PLC, the isolation module is conducted, and the switch module, the anti-backflow module and the isolation module form a first loop; when the second control signal is received, the switch module enters a second conduction state; and when the switch module enters a second conduction state and the isolation module obtains a second preset level signal from the PLC, the isolation module is conducted, and the switch module, the anti-backflow module and the isolation module form a second loop. The reliability of the interface circuit is improved, and the safety of the interface circuit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to an interface circuit, an interface system, and an electronic device. Background Art

[0002] Conventional programmable logic controller (PLC) interface circuits have active-low input and active-high input types. While commercially available interface circuits are compatible with both, there's a safety risk of optocoupler conduction when the common reference ground (COM) line is disconnected. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to overcome the deficiencies in the prior art and provide an interface circuit, an interface system, and an electronic device. The present invention provides the following technical solutions: In a first aspect, the present application provides an interface circuit, the circuit comprising: a switch module, an isolation module, and an anti-backflow module; the switch module is electrically connected to an editable logic controller and the anti-backflow module respectively; the anti-backflow module is also electrically connected to the isolation module; the isolation module is also electrically connected to the editable logic controller and a microcontroller respectively; The switch module is configured to enter a first conducting state upon receiving a first control signal; the isolation module is configured to be turned on when the switch module enters the first conducting state and the isolation module receives a first preset level signal from the editable logic controller, so that the switch module, the backflow prevention module, and the isolation module form a first loop; The switch module is further configured to enter a second conduction state upon receiving a second control signal; the isolation module is configured to be turned on when the switch module enters the second conduction state and the isolation module obtains a second preset level signal from the editable logic controller, so that the switch module, the backflow prevention module and the isolation module constitute a second loop.

[0004] In one embodiment, the isolation module includes: multiple isolation units, and the anti-backflow module includes: multiple anti-backflow units; the first end of each of the isolation units is electrically connected to one of the anti-backflow units, the second end of each of the isolation units is electrically connected to the editable logic controller, the third end of each of the isolation units is electrically connected to the microcontroller, and the fourth end of each of the isolation units is grounded; each of the anti-backflow units is also electrically connected to the switch module.

[0005] In one embodiment, the isolation unit includes: a bidirectional isolator; a first end of the bidirectional isolator is electrically connected to the anti-backflow unit, a second end of the bidirectional isolator is electrically connected to the editable logic controller, a third end of the bidirectional isolator is grounded, and a fourth end of the isolation unit is electrically connected to the microcontroller.

[0006] In one embodiment, the anti-backflow unit includes: a first diode and a second diode; the anode of the first diode is electrically connected to the switch module, and the cathode of the first diode is electrically connected to the first end of the isolation unit and the second end of the isolation unit respectively; the anode of the second diode is electrically connected to the first end of the isolation unit and the second end of the isolation unit respectively, and the cathode of the second diode is electrically connected to the switch module.

[0007] In one embodiment, the first end of the switch module is electrically connected to the power output end of the editable logic controller, the third end of the switch module is electrically connected to the common end of the editable logic controller, the second end of the switch module and the fourth end of the switch module are both open, the fifth end of the switch module is electrically connected to the anode of the first diode, and the sixth end of the switch module is electrically connected to the cathode of the second diode.

[0008] In one embodiment, the circuit also includes: a first current limiting resistor and a second current limiting resistor; the first end of the first current limiting resistor is electrically connected to the cathode of the first diode and the anode of the second diode, respectively; the first end of the second current limiting resistor is electrically connected to the first end of the isolation unit, and the second end of the second current limiting resistor is electrically connected to the second end of the isolation unit.

[0009] In one embodiment, the circuit further includes: a pull-up resistor and a third current-limiting resistor; the first end of the pull-up resistor is electrically connected to the external power supply, and the second end of the pull-up resistor is electrically connected to the third end of the isolation unit; the first end of the third current-limiting resistor is electrically connected to the fourth end of the isolation unit, and the second end of the current-limiting resistor is electrically connected to the microcontroller.

[0010] In one embodiment, the circuit further includes: a filter capacitor; a first end of the filter capacitor is electrically connected to the second end of the third current limiting resistor, and a second end of the filter capacitor is grounded.

[0011] In a second aspect, the present application provides an interface system, comprising: the interface circuit and an editable logic controller described in the first aspect, wherein the interface circuit is electrically connected to the editable logic controller.

[0012] In a third aspect, the present application provides an electronic device, comprising: the interface system and a host computer described in the second aspect; the host computer is electrically connected to the interface system.

[0013] The interface circuit, interface system and electronic device provided by the present application include: a switch module, an isolation module and an anti-backflow module; the switch module is electrically connected to an editable logic controller and the anti-backflow module respectively; the anti-backflow module is also electrically connected to the isolation module; the isolation module is also electrically connected to the editable logic controller and the microcontroller respectively; the present application increases the reliability of the interface circuit and improves the safety of the interface circuit by causing the switch module to enter a first conduction state when receiving a first control signal; when the switch module enters the first conduction state and the isolation module obtains a first preset level signal from the editable logic controller, the isolation module is turned on so that the switch module, the anti-backflow module and the isolation module constitute a first loop; when the second control signal is received, the switch module enters a second conduction state; when the switch module enters the second conduction state and the isolation module obtains a second preset level signal from the editable logic controller, the isolation module is turned on so that the switch module, the anti-backflow module and the isolation module constitute a second loop.

[0014] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without making any creative efforts.

[0016] Figure 1 A circuit schematic diagram of an interface circuit in the prior art is shown; Figure 2 A schematic structural diagram of an interface circuit provided in an embodiment of the present application is shown; Figure 3 Another structural diagram of the interface circuit provided in an embodiment of the present application is shown; Figure 4 A circuit schematic diagram of an interface circuit provided in an embodiment of the present application is shown; Figure 5 Another circuit schematic diagram of the interface circuit provided by an embodiment of the present application is shown; Figure 6Another circuit schematic diagram of the interface circuit provided in an embodiment of the present application is shown; Figure 7 A schematic structural diagram of an interface system provided in an embodiment of the present application is shown; Figure 8 A structural schematic diagram of an electronic device provided in an embodiment of the present application is shown.

[0017] Description of main component symbols: 100-interface circuit; 110-switch module; SW-switching switch; 120-anti-backflow module; 121-anti-backflow unit; D1-first diode; D2-second diode; 130-isolation module; 131-isolation unit; U1-bidirectional isolator; R1-first current-limiting resistor; R2-second current-limiting resistor; R3-third current-limiting resistor; RP-pull-up resistor; C1-filter capacitor; 200-programmable logic controller; 300-microcontroller; 700-interface system; 800-electronic equipment; 810-host computer. DETAILED DESCRIPTION

[0018] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by one skilled in the art to which this application belongs. The terms used in the template description herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] Example 1 Programmable Logic Controller (PLC) interface circuits serve as a bridge for connection and communication between the PLC and external devices. They are primarily used for signal conversion, isolation, and transmission, ensuring reliable data exchange and control between the PLC and external devices. Conventional PLC interface circuits are available in two types: active-low input and active-high input. While commercially available interface circuits are compatible with both, there is a safety risk of optocoupler conduction when the common reference ground is disconnected. For example, see 1, Figure 1 The following is a circuit diagram of a common interface circuit on the market that is compatible with both active-low and active-high input types. Figure 1 In the interface circuit shown in FIG. 1 , when the common terminal COM is disconnected, if the INPUT1 terminal of the editable logic controller 200 outputs a high level signal and the INPUT2 terminal outputs a low level signal, the following will be formed: Figure 1 The circuit indicated by the dotted line, at this time Figure 1 The optocoupler isolator in the circuit will be turned on, which may cause safety hazards. Figure 2 The embodiment of the present application provides an interface circuit 100, which includes: a switch module 110, an isolation module 130, and an anti-backflow module 120; the switch module 110 is electrically connected to an editable logic controller 200 and the anti-backflow module 120 respectively; the anti-backflow module 120 is also electrically connected to the isolation module 130; the isolation module 130 is also electrically connected to the editable logic controller 200 and a microcontroller unit 300 (MCU). The switch module 110 is configured to enter a first conducting state upon receiving a first control signal; the isolation module 130 is configured to be turned on when the switch module 110 enters the first conducting state and the isolation module 130 receives a first preset level signal from the editable logic controller 200, so that the switch module 110, the backflow prevention module 120, and the isolation module 130 form a first loop; The switch module 110 is further configured to enter a second conduction state upon receiving a second control signal; the isolation module 130 is configured to be turned on when the switch module 110 enters the second conduction state and the isolation module 130 obtains a second preset level signal from the editable logic controller 200, so that the switch module 110, the backflow prevention module 120 and the isolation module 130 form a second circuit.

[0022] In this embodiment, upon receiving the first control signal, the switch module 110 switches to a first conductive state, electrically connecting the common terminal of the editable logic controller 200 to the backflow prevention module 120 via the switch module 110. In this conductive state, if the isolation module 130 receives a first preset level signal from the signal output terminal of the editable logic controller 200, current flows from the signal output terminal of the editable logic controller 200, sequentially through the isolation module 130, the backflow prevention module 120, and the switch module 110, to the common terminal of the editable logic controller 200, thereby forming a first loop.

[0023] Upon receiving the second control signal, the switch module 110 switches to a second conductive state, electrically connecting the power output terminal of the editable logic controller 200 to the backflow prevention module 120 via the switch module 110. In this conductive state, if the isolation module 130 receives a second preset level signal from the signal output terminal of the editable logic controller 200, current flows from the power output terminal of the editable logic controller 200, sequentially through the switch module 110, the backflow prevention module 120, and the isolation module 130 to the signal output terminal of the editable logic controller 200, thereby forming a second loop.

[0024] It should be noted that the first preset level signal is a high level signal, and the second preset level signal is a low level signal. It can be understood that the interface circuit 100 provided in the present application is compatible with both high input validity and low input validity, while avoiding the safety hazard of forming a path when the common terminal is disconnected, thereby causing the isolation module 130 to be turned on.

[0025] In one embodiment, see Figure 3 , Figure 3 Another structural schematic diagram of the interface circuit 100 provided in an embodiment of the present application is shown, wherein the isolation module 130 includes: a plurality of isolation units 131, and the anti-backflow module 120 includes: a plurality of anti-backflow units 121; the first end of each of the isolation units 131 is electrically connected to one of the anti-backflow units 121, the second end of each of the isolation units 131 is electrically connected to the editable logic controller 200, the third end of each of the isolation units 131 is electrically connected to the microcontroller 300, and the fourth end of each of the isolation units 131 is grounded; each of the anti-backflow units 121 is also electrically connected to the switch module 110.

[0026] See Figure 3Taking two isolation units 131 as an example, any one of the isolation units 131 is used to be turned on when the switch module 110 enters the first conduction state and the isolation unit 131 receives a first preset level signal from the editable logic controller 200, so that the isolation unit 131, the anti-backflow unit 121 electrically connected to the isolation unit 131, and the switch module 110 form a first circuit; any one of the isolation units 131 is also used to be turned on when the switch module 110 enters the second conduction state and the isolation unit 131 receives a second preset level signal from the editable logic controller 200, so that the isolation unit 131, the anti-backflow unit 121 electrically connected to the isolation unit 131, and the switch module 110 form a second circuit.

[0027] It should be noted that Figure 3 In the figure, VCC represents the power output terminal of the editable logic controller 200, COM represents the common terminal, and INPUT1 and INPUT2 represent the signal output terminals of the editable logic controller 200. The signal output terminals INPUT1 and INPUT2 are electrically connected to different isolation units 131. It is understood that the number of isolation units 131 and the corresponding number of backflow prevention units 121 can be expanded to N, and the operating principle thereof can be analogously described above.

[0028] In one embodiment, please combine Figure 4 , Figure 4 A circuit schematic diagram of the interface circuit 100 provided in an embodiment of the present application is shown, wherein the isolation unit 131 includes: a bidirectional isolator U1; a first end of the bidirectional isolator U1 is electrically connected to the anti-backflow unit 121, a second end of the bidirectional isolator U1 is electrically connected to the editable logic controller 200, a third end of the bidirectional isolator U1 is grounded, and a fourth end of the isolation unit 131 is electrically connected to the microcontroller 300.

[0029] In this embodiment, the bidirectional isolator U1 can achieve bidirectional conduction. Specifically, when the switch module 110 receives the first control signal and enters the first conduction state and obtains the first preset level signal from the INPUT1 terminal of the editable logic controller 200, the bidirectional isolator U1 is turned on. At this time, the first circuit is as follows Figure 4 When the switch module 110 receives the second control signal and enters the second conduction state and obtains the second preset level signal from the INPUT1 terminal of the editable logic controller 200, the second circuit is turned on. Figure 5 Shown in the dotted line.

[0030] It should be noted that the switch module 110 includes: a switch SW, Figure 4The switch SW in is in the first conducting state, and the common terminal COM of the editable logic controller 200 is electrically connected to the anti-backflow module 120 through the switch SW. Figure 5 The switching unit in is in the second conducting state, and the power output terminal VCC of the editable logic controller 200 is electrically connected to the anti-backflow module 120 through the switching switch SW.

[0031] In one embodiment, the backflow prevention unit 121 includes: a first diode D1 and a second diode D2; the anode of the first diode D1 is electrically connected to the switch module 110, and the cathode of the first diode D1 is electrically connected to the first end of the isolation unit 131 and the second end of the isolation unit 131 respectively; the anode of the second diode D2 is electrically connected to the first end of the isolation unit 131 and the second end of the isolation unit 131 respectively, and the cathode of the second diode D2 is electrically connected to the switch module 110.

[0032] In this example, see Figure 4 and Figure 5 The first diode D1 is used to prevent current backflow in the second loop, and the second diode D2 is used to prevent current backflow in the first loop. Furthermore, when there are multiple bidirectional isolators U1, for example two, if the common terminal COM of the editable logic controller 200 is disconnected and the INPUT1 and INPUT2 terminals of the editable logic controller 200 respectively output signals of different preset levels, the anti-backflow module 120 can also prevent the bidirectional isolators U1 from conducting and causing safety hazards.

[0033] For example, see Figure 6 When the common terminal COM is disconnected, the INPUT1 terminal of the editable logic controller 200 outputs a high-level signal, and the INPUT2 terminal of the editable logic controller 200 outputs a low-level signal, a loop cannot be formed due to the unidirectional conduction characteristic of the second diode D2. Figure 6 As shown in the dotted line portion, the risk of the optical coupler being turned on in the interface circuit 100 compatible with high-efficiency and low-efficiency types in the prior art is avoided. In one embodiment, a first end of the switch module 110 is electrically connected to the power output end of the editable logic controller 200, a third end of the switch module 110 is electrically connected to the common end of the editable logic controller 200, a second end of the switch module 110 and a fourth end of the switch module 110 are both open, a fifth end of the switch module 110 is electrically connected to the anode of the first diode D1, and a sixth end of the switch module 110 is electrically connected to the cathode of the second diode D2.

[0034] In this embodiment, the switch module 110 includes a switch SW for receiving a first control signal or a second control signal from a user end, and enters a first conduction state when receiving the first control signal. In the first conduction state, the third end of the switch SW is electrically connected to the sixth end of the switch SW. Figure 4 In the second conducting state, the first terminal of the switch SW is electrically connected to the fifth terminal, as shown in FIG. Figure 5 shown.

[0035] In one embodiment, the circuit further includes: a first current-limiting resistor R1 and a second current-limiting resistor R2; a first end of the first current-limiting resistor R1 is electrically connected to the cathode of the first diode D1 and the anode of the second diode D2, respectively; a first end of the second current-limiting resistor R2 is electrically connected to the first end of the isolation unit 131, and a second end of the second current-limiting resistor R2 is electrically connected to the second end of the isolation unit 131.

[0036] See Figure 4 、 Figure 5 or Figure 6 The first current limiting resistor R1 and the second current limiting resistor R2 are used to limit the current flowing through the isolation unit 131 .

[0037] In one embodiment, the circuit further includes: a pull-up resistor RP and a third current-limiting resistor R3; a first end of the pull-up resistor RP is electrically connected to an external power supply, and a second end of the pull-up resistor RP is electrically connected to a third end of the isolation unit 131; a first end of the third current-limiting resistor R3 is electrically connected to a fourth end of the isolation unit 131, and a second end of the current-limiting resistor is electrically connected to the microcontroller 300.

[0038] The pull-up resistor RP is used to stabilize the fourth pin of the floating isolation unit 131 at a high level, so as to achieve a stable signal output of the isolation unit 131. The third current-limiting resistor R3 is used to limit the output current of the isolation unit 131.

[0039] In one embodiment, the circuit further includes: a filter capacitor C1; a first end of the filter capacitor C1 is electrically connected to the second end of the third current limiting resistor R3, and a second end of the filter capacitor C1 is grounded.

[0040] The filter capacitor C1 is used for output filtering of the isolation unit 131 to reduce or eliminate instantaneous, large-amplitude voltage or current mutations in the output signal.

[0041] The interface circuit provided by an embodiment of the present application includes: a switch module, an isolation module and an anti-backflow module; the switch module is electrically connected to an editable logic controller and the anti-backflow module respectively; the anti-backflow module is also electrically connected to the isolation module; the isolation module is also electrically connected to the editable logic controller and the microcontroller respectively; the present application increases the reliability of the interface circuit and improves the safety of the interface circuit by causing the switch module to enter a first conduction state when receiving a first control signal; when the switch module enters the first conduction state and the isolation module obtains a first preset level signal from the editable logic controller, the isolation module is turned on so that the switch module, the anti-backflow module and the isolation module constitute a first loop; when the second control signal is received, the switch module enters a second conduction state; when the switch module enters the second conduction state and the isolation module obtains a second preset level signal from the editable logic controller, the isolation module is turned on so that the switch module, the anti-backflow module and the isolation module constitute a second loop.

[0042] Example 2 Also, see Figure 7 , an embodiment of the present application further provides an interface system 700, comprising the interface circuit 100 and the editable logic controller 200 described in Example 1, wherein the interface circuit 100 is electrically connected to the editable logic controller 200.

[0043] Specifically, the interface circuit 100 includes: a switch module 110, an isolation module 130 and an anti-backflow module 120; the switch module 110 is electrically connected to the editable logic controller 200 and the anti-backflow module 120 respectively; the anti-backflow module 120 is also electrically connected to the isolation module 130; the isolation module 130 is also electrically connected to the editable logic controller 200 and the microcontroller 300 respectively; The switch module 110 is configured to enter a first conducting state upon receiving a first control signal; the isolation module 130 is configured to be turned on when the switch module 110 enters the first conducting state and the isolation module 130 receives a first preset level signal from the editable logic controller 200, so that the switch module 110, the backflow prevention module 120, and the isolation module 130 form a first loop; The switch module 110 is further configured to enter a second conduction state upon receiving a second control signal; the isolation module 130 is configured to be turned on when the switch module 110 enters the second conduction state and the isolation module 130 obtains a second preset level signal from the editable logic controller 200, so that the switch module 110, the backflow prevention module 120 and the isolation module 130 form a second circuit.

[0044] In one embodiment, the isolation module 130 includes: multiple isolation units 131, and the anti-backflow module 120 includes: multiple anti-backflow units 121; the first end of each of the isolation units 131 is electrically connected to one of the anti-backflow units 121, the second end of each of the isolation units 131 is electrically connected to the editable logic controller 200, the third end of each of the isolation units 131 is electrically connected to the microcontroller 300, and the fourth end of each of the isolation units 131 is grounded; each of the anti-backflow units 121 is also electrically connected to the switch module 110.

[0045] In one embodiment, the isolation unit 131 includes: a bidirectional isolator U1; a first end of the bidirectional isolator U1 is electrically connected to the anti-backflow unit 121, a second end of the bidirectional isolator U1 is electrically connected to the editable logic controller 200, a third end of the bidirectional isolator U1 is grounded, and a fourth end of the isolation unit 131 is electrically connected to the microcontroller 300.

[0046] In one embodiment, the backflow prevention unit 121 includes: a first diode D1 and a second diode D2; the anode of the first diode D1 is electrically connected to the switch module 110, and the cathode of the first diode D1 is electrically connected to the first end of the isolation unit 131 and the second end of the isolation unit 131 respectively; the anode of the second diode D2 is electrically connected to the first end of the isolation unit 131 and the second end of the isolation unit 131 respectively, and the cathode of the second diode D2 is electrically connected to the switch module 110.

[0047] In one embodiment, a first end of the switch module 110 is electrically connected to a power output end of the editable logic controller 200, a third end of the switch module 110 is electrically connected to a common end of the editable logic controller 200, a second end of the switch module 110 and a fourth end of the switch module 110 are both open, a fifth end of the switch module 110 is electrically connected to an anode of the first diode D1, and a sixth end of the switch module 110 is electrically connected to a cathode of the second diode D2.

[0048] In one embodiment, the circuit further includes: a first current limiting resistor R1 and a second current limiting resistor R2; the first end of the first current limiting resistor R1 is electrically connected to the cathode of the first diode D1 and the anode of the second diode D2, respectively; the first end of the second current limiting resistor R2 is electrically connected to the first end of the isolation unit 131, and the second end of the second current limiting resistor R2 is electrically connected to the second end of the isolation unit 131.

[0049] In one embodiment, the circuit further includes: a pull-up resistor RP and a third current-limiting resistor R3; a first end of the pull-up resistor RP is electrically connected to an external power supply, and a second end of the pull-up resistor RP is electrically connected to a third end of the isolation unit 131; a first end of the third current-limiting resistor R3 is electrically connected to a fourth end of the isolation unit 131, and a second end of the current-limiting resistor is electrically connected to the microcontroller 300.

[0050] In one embodiment, the circuit further includes: a filter capacitor C1; a first end of the filter capacitor C1 is electrically connected to the second end of the third current limiting resistor R3, and a second end of the filter capacitor C1 is grounded.

[0051] The interface system 700 provided in the embodiment of the present application can perform the functions of the interface circuit 100 provided in the above-mentioned embodiment 1, and will not be described again here to avoid repetition.

[0052] The interface system provided by the embodiment of the present application includes: the interface circuit and editable logic controller described in Example 1, wherein when a first control signal is received, the switch module enters a first conduction state; when the switch module enters the first conduction state and the editable logic controller of the isolation module obtains a first preset level signal, the isolation module is turned on so that the switch module, the anti-backflow module and the isolation module constitute a first loop; when a second control signal is received, the switch module enters a second conduction state; when the switch module enters the second conduction state and the isolation module obtains a second preset level signal from the editable logic controller, the isolation module is turned on so that the switch module, the anti-backflow module and the isolation module constitute a second loop, thereby increasing the reliability of the interface circuit and improving the safety of the interface circuit.

[0053] Example 3 Also, see Figure 8 , an embodiment of the present application further provides an electronic device 800, which includes: a host computer 810 and the interface system 700 described in Example 2; the host computer 810 is electrically connected to the interface system 700.

[0054] The electronic device 800 provided in the embodiment of the present application can perform the functions of the interface system 700 provided in the above-mentioned embodiment 2, and will not be described again here to avoid repetition.

[0055] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not limiting, and thus other examples of the exemplary embodiments may have different values.

[0056] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0057] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that variations and modifications are possible without departing from the scope of the present invention, and such variations and modifications are fully within the scope of protection of the present invention.

Claims

1. An interface circuit, characterized in that: The circuit includes: a switch module, an isolation module and an anti-backflow module; The switch module is electrically connected to the editable logic controller and the anti-backflow module respectively; The anti-backflow module is also electrically connected to the isolation module; The isolation module is also electrically connected to the editable logic controller and the microcontroller respectively; The switch module is configured to enter a first conducting state when receiving a first control signal; The isolation module is configured to be turned on when the switch module enters a first conduction state and the isolation module obtains a first preset level signal from the editable logic controller, so that the switch module, the backflow prevention module and the isolation module form a first loop; The switch module is further configured to enter a second conducting state when receiving a second control signal; The isolation module is used to be turned on when the switch module enters the second conduction state and the isolation module obtains a second preset level signal from the editable logic controller, so that the switch module, the anti-backflow module and the isolation module form a second loop.

2. The interface circuit according to claim 1, wherein: The isolation module includes: a plurality of isolation units, and the backflow prevention module includes: a plurality of backflow prevention units; The first end of each isolation unit is electrically connected to one of the backflow prevention units, the second end of each isolation unit is electrically connected to the editable logic controller, the third end of each isolation unit is electrically connected to the microcontroller, and the fourth end of each isolation unit is grounded. Each of the backflow prevention units is also electrically connected to the switch module.

3. The interface circuit according to claim 2, wherein: The isolation unit includes: a bidirectional isolator; The first end of the bidirectional isolator is electrically connected to the anti-backflow unit, the second end of the bidirectional isolator is electrically connected to the editable logic controller, the third end of the bidirectional isolator is grounded, and the fourth end of the isolation unit is electrically connected to the microcontroller.

4. The interface circuit according to claim 2, wherein: The anti-backflow unit includes: a first diode and a second diode; An anode of the first diode is electrically connected to the switch module, and a cathode of the first diode is electrically connected to a first end of the isolation unit and a second end of the isolation unit respectively; An anode of the second diode is electrically connected to the first end of the isolation unit and the second end of the isolation unit respectively, and a cathode of the second diode is electrically connected to the switch module.

5. The interface circuit according to claim 4, characterized in that: The first end of the switch module is electrically connected to the power output end of the editable logic controller, the third end of the switch module is electrically connected to the common end of the editable logic controller, the second end of the switch module and the fourth end of the switch module are both open, the fifth end of the switch module is electrically connected to the anode of the first diode, and the sixth end of the switch module is electrically connected to the cathode of the second diode.

6. The interface circuit according to claim 5, characterized in that: The circuit further includes: a first current limiting resistor and a second current limiting resistor; The first end of the first current limiting resistor is electrically connected to the cathode of the first diode and the anode of the second diode respectively; A first end of the second current limiting resistor is electrically connected to a first end of the isolation unit, and a second end of the second current limiting resistor is electrically connected to a second end of the isolation unit.

7. The interface circuit according to any one of claims 2 to 6, characterized in that: The circuit further comprises: a pull-up resistor and a third current-limiting resistor; The first end of the pull-up resistor is electrically connected to the external power supply, and the second end of the pull-up resistor is electrically connected to the third end of the isolation unit; The first end of the third current limiting resistor is electrically connected to the fourth end of the isolation unit, and the second end of the current limiting resistor is electrically connected to the microcontroller.

8. The interface circuit according to claim 7, wherein: The circuit further includes: a filter capacitor; The first end of the filter capacitor is electrically connected to the second end of the third current limiting resistor, and the second end of the filter capacitor is grounded.

9. An interface system, characterized in that: The system comprises: the interface circuit and the editable logic controller according to any one of claims 1 to 8, wherein the interface circuit is electrically connected to the editable logic controller.

10. An electronic device, characterized in that: include: The interface system and host computer according to claim 9; The host computer is electrically connected to the interface system.

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