Input recognition circuit and industrial device

Abstract

The application discloses an input recognition circuit and industrial equipment. The input recognition circuit comprises a protection module, a switch module and a signal isolation module. The protection module is used for receiving an external signal and performing input protection on the input recognition circuit. The switch module is connected with the protection module and is used for switching a first conduction state according to the external signal. The signal isolation module is connected with the switch module and is used for switching a second conduction state according to the first conduction state. The recognition module is connected with the signal isolation module and is used for performing a logic recognition operation on the external signal according to the second conduction state and generating a logic value corresponding to the external signal. The application can recognize the logic state of the external signal according to the conduction state of the signal isolation module, avoiding the phenomenon of logic judgment error when the external signal is in an intermediate state level in the related art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of signal processing, and in particular to an input recognition circuit and an industrial device. BACKGROUND

[0002] At present, an input detection interface is arranged on an industrial device to determine the level state of an external input signal, so as to ensure the safety of internal control systems and other components of the industrial device.

[0003] In the related art, the working voltage of a control system includes 1.8V, 3.3V, 5V, etc., and the input signal provided externally is generally 8V, 12V, 24V, etc. The control system performs corresponding operations according to the level logic value of the input signal. In a digital circuit, the logic value corresponding to a high level (assuming that the high level is set to 24V) is "1", and the logic value corresponding to a low level (assuming that the low level is set to 0V) is "0". Therefore, when the input signal provided externally is an intermediate state level (for example, 8V), the control system is prone to misjudgment (for example, misjudging that the intermediate state level is a low level), thereby causing the control system to perform incorrect control logic. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes an input recognition circuit and an industrial device, which can recognize the logic state of an external signal according to the conduction state of a signal isolation module, thereby avoiding the phenomenon of logic judgment error when the external signal is an intermediate state level in the related art.

[0005] The input recognition circuit according to the first aspect of the present application comprises:

[0006] a protection module, configured to receive an external signal and perform input protection on the input recognition circuit;

[0007] a switch module, connected to the protection module, configured to switch a first conduction state according to the external signal;

[0008] a signal isolation module, connected to the switch module, configured to switch a second conduction state according to the first conduction state;

[0009] a recognition module, connected to the signal isolation module, configured to perform a logic recognition operation on the external signal according to the second conduction state, and generate a logic value corresponding to the external signal.

[0010] The input recognition circuit according to the embodiment of the present application has at least the following beneficial effects: different types of elements in the switch module are set to adjust the "high level" value requirement, when the external signal reaches the conduction threshold of the switch module, it indicates that the external signal reaches the "high level" value requirement. At this time, the switch module is switched to the conduction state, and the signal isolation module is triggered to switch to the conduction state, and the recognition module determines that the logic value of the external signal is logic "1" according to the conduction state of the signal isolation module. Conversely, it is determined that the logic value of the external signal is logic "0". As can be seen, the input recognition circuit provided by the embodiment of the present application can recognize the logic state of the external signal according to the preset "high level" value requirement, avoiding the phenomenon of logic judgment error when the external signal is in the intermediate state level in the related art.

[0011] According to some embodiments of the present application, the switch module comprises:

[0012] A first resistor, one end of the first resistor is connected with the protection module;

[0013] A control pressure flow element, a base of the control pressure flow element is connected with the other end of the first resistor, an emitter of the control pressure flow element is connected with the signal isolation module, and a collector of the control pressure flow element is grounded;

[0014] A voltage stabilizing tube, an anode of the voltage stabilizing tube is connected with the collector of the control pressure flow element, and a cathode of the voltage stabilizing tube is connected with the base of the control pressure flow element.

[0015] According to some embodiments of the present application, the control pressure flow element comprises any one of a MOS tube and a triode.

[0016] According to some embodiments of the present application, the signal isolation module comprises:

[0017] A second resistor, one end of the second resistor is connected with the protection module;

[0018] A light emitting diode, an anode of the light emitting diode is connected with the other end of the second resistor, and a cathode of the light emitting diode is connected with the emitter of the control pressure flow element;

[0019] A photosensitive triode, the photosensitive triode is coupled with the light emitting diode.

[0020] According to some embodiments of the present application, the protection module comprises:

[0021] A first diode, an anode of the first diode is used to receive the external signal, and a cathode of the first diode is connected with the switch module.

[0022] According to some embodiments of the present application, the protection module further comprises:

[0023] a first capacitor, one end of the first capacitor is connected with the cathode of the first diode, and the other end of the first capacitor is grounded;

[0024] an inductor, one end of the inductor is connected with one end of the first capacitor and the switch module respectively, and the other end of the inductor is connected with the signal isolation module;

[0025] a second capacitor, one end of the second capacitor is connected with the other end of the inductor, and the other end of the second capacitor is connected with the other end of the first capacitor.

[0026] According to some embodiments of the present application, the protection module further comprises:

[0027] a second diode, the anode of the second diode is connected with the other end of the first capacitor, and the cathode of the second diode is connected with the anode of the first diode.

[0028] The industrial equipment according to the second aspect of the embodiments of the present application comprises:

[0029] The input recognition circuit according to any one of the first aspect;

[0030] a control system, the control system is used for being connected with the recognition module, and the control system is used for performing corresponding operation according to the logic value.

[0031] Additional aspects and advantages of the present application will be given in part in the following description, become apparent from the following description, or be understood by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0032] The present application will be further described below in combination with the drawings and embodiments, wherein:

[0033] Figure 1 A module block diagram of the input recognition circuit according to the embodiments of the present application;

[0034] Figure 2 A circuit schematic diagram of the input recognition circuit according to the embodiments of the present application;

[0035] Figure 3 A module block diagram of the industrial equipment according to the embodiments of the present application.

[0036] Reference signs:

[0037] The protection module 100, the switch module 200, the signal isolation module 300, the recognition module 400, and the control system 500. DETAILED DESCRIPTION

[0038] Embodiments of the present application are described below in the detailed description and illustrated in the accompanying drawings by which like or similar elements, structures and / or functions have been given the same reference numerals and functionalities (which are known to those skilled in the art) are not described in detail. The embodiments described below are exemplary only and are not intended to be limiting of the present application.

[0039] In the description of the present application, if the orientation description, such as up, down, front, back, left, right, and the like, is described, the orientation or position relationship based on the orientation or position relationship shown in the drawings is described for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0040] In the description of the present application, if the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, more than, and the like are understood as not including the number, above, below, and the like are understood as including the number. If the first, second, and the like are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0041] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, and the like should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0042] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0043] Reference Figure 1The input recognition circuit provided by the embodiment of the present application comprises a protection module 100, a switch module 200, a signal isolation module 300 and a recognition module 400. The protection module 100 is configured to receive an external signal and perform input protection on the input recognition circuit. The switch module 200 is connected with the protection module 100, and the switch module 200 is configured to switch a first conduction state according to the external signal. The signal isolation module 300 is connected with the switch module 200, and the signal isolation module 300 is configured to switch a second conduction state according to the first conduction state. The recognition module 400 is connected with the signal isolation module 300, and the recognition module 400 is configured to perform a logic recognition operation on the external signal according to the second conduction state and generate a logic value corresponding to the external signal.

[0044] It can be understood that the input recognition circuit provided by the embodiment of the present application can be arranged in an input detection interface of an industrial device. The industrial device refers to a device used in the fields of machinery, rail transportation, aerospace, power system, etc., and used for digital control. The input recognition circuit comprises the protection module 100, the switch module 200, the signal isolation module 300 and the recognition module 400. The protection module 100 is configured to receive an external signal provided by an external linkage device, and perform input protection on a back-end module (including the switch module 200, the signal isolation module 300 and the recognition module 400) in the input recognition circuit and a control system connected with the recognition module 400 according to the external signal. For example, the protection module 100 can perform protection against static electricity, surge, reverse connection and electromagnetic interference.

[0045] It can be understood that the external signal flows to the switch module 200 through the protection module 100. When the voltage value of the external signal is greater than the sum of a first voltage drop and a second voltage drop, the switch module 200 is turned on, thereby triggering the signal isolation module 300 to be turned on. At this time, the recognition module 400 confirms that the logic value of the external signal is logic "1" according to the second conduction state being turned on. The first voltage drop is the sum of the voltage drops of the elements in the protection module 100, and the second voltage drop is the conduction voltage drop of the switch module 200. That is, the input recognition circuit provided by the embodiment of the present application takes the sum of the first voltage drop and the second voltage drop as a "comparison threshold value". According to the numerical requirement of the "high level" in actual application, the model of each component in the protection module 100 and / or the switch module 200 is adjusted to adjust the size of the "comparison threshold value". When the first conduction state of the switch module 200 is turned on, it indicates that the voltage value of the external signal meets the numerical requirement of the "high level", and therefore the recognition module 400 outputs the logic value of logic "1", so that the back-end control system performs corresponding logic control operation according to the logic value.

[0046] Similarly, when the voltage value of the external signal is less than the sum of the first voltage drop and the second voltage drop, the switch module 200 is turned off, and the signal isolation module 300 is turned off because the signal isolation module 300 cannot form a signal loop due to the turn-off of the switch module 200. At this time, the identification module 400 confirms that the logic value of the external signal is logic "0" according to the second conduction state being turned off, that is, the voltage value of the external signal does not meet the numerical requirement of the "high level" described above.

[0047] It can be understood that the signal isolation module 300 is used to signal isolate the external signal from the back-end system to protect the safety of the back-end system.

[0048] The input identification circuit provided by the embodiment of the present application adjusts the "high level" numerical requirement by setting different models of elements in the switch module 200. When the external signal reaches the conduction threshold of the switch module 200, it indicates that the external signal meets the "high level" numerical requirement. At this time, the switch module 200 is switched to the conduction state, and the signal isolation module 300 is triggered to switch to the conduction state, and the identification module 400 determines that the logic value of the external signal is logic "1" according to the conduction state of the signal isolation module 300. Conversely, it is determined that the logic value of the external signal is logic "0". Therefore, the input identification circuit provided by the embodiment of the present application can identify the logic state of the external signal according to the preset "high level" numerical requirement, and avoid the phenomenon of logic judgment error when the external signal is in the intermediate state level in the related art.

[0049] Reference Figure 2 In some embodiments, the protection module 100 includes a first diode D1, an anode of the first diode D1 is used to receive the external signal, and a cathode of the first diode D1 is connected with the switch module 200. Specifically, in order to avoid the reverse connection phenomenon when the external device is connected with the input detection interface, a reverse connection prevention unit is arranged in the protection module 100, and the reverse connection prevention unit includes the first diode D1. Normally, the anode of the first diode D1 is used to receive the VIN signal (i.e. the external signal) output by the external device, and when the external signal changes from the VIN signal to the negative voltage GND-IN signal, the first diode D1 is not conductive, at this time, the back-end circuit of the first diode D1 does not work, thereby ensuring the safety of the back-end circuit and the control system.

[0050] In some embodiments, the protection module 100 further comprises a first capacitor C1, an inductor L1 and a second capacitor C2. One end of the first capacitor C1 is connected with the cathode of the first diode D1, and the other end of the first capacitor C1 is grounded; one end of the inductor L1 is connected with the one end of the first capacitor C1 and the switch module 200 respectively, and the other end of the inductor L1 is connected with the signal isolation module 300; one end of the second capacitor C2 is connected with the other end of the inductor L1, and the other end of the second capacitor C2 is connected with the other end of the first capacitor C1. Specifically, the first capacitor C1, the inductor L1 and the second capacitor C2 constitute a "CLC" shaped filter circuit to perform signal filtering operation on the external signal, so as to prevent the electromagnetic interference signal in the external signal from affecting the subsequent operation. It can be understood that according to the actual application environment, "RC" shaped, "L" shaped and other filter circuits can also be set, and the embodiments of the present application are not limited specifically.

[0051] In some embodiments, the protection module 100 further comprises a second diode D2, the anode of the second diode D2 is connected with the other end of the first capacitor C1, and the cathode of the second diode D2 is connected with the anode of the first diode D1. Specifically, the protection module 100 further comprises the second diode D2 for realizing the anti-static and anti-surge functions. When the voltage between the two ends of the second diode D2 is greater than a certain value, the second diode D2 is reversely broken down, so that a conduction loop is formed instantaneously for the input recognition circuit. At this time, the large current between the two ends of the second diode D2 is led out, and the voltage between the two ends of the second diode D2 is clamped to a fixed voltage value, thereby protecting the rear-end circuit connected in parallel with the second diode D2. It can be understood that according to the actual application environment, the second diode D2 can also be replaced by other protection devices such as a pressure-sensitive resistor, and the embodiments of the present application are not limited specifically.

[0052] In some embodiments, the switch module 200 comprises a first resistor R1, a voltage-controlled current element Q1 and a voltage stabilizing tube D3. One end of the first resistor R1 is connected with the protection module 100; the base of the voltage-controlled current element Q1 is connected with the other end of the first resistor R1, the emitter of the voltage-controlled current element Q1 is connected with the signal isolation module 300, and the collector of the voltage-controlled current element Q1 is grounded. The anode of the voltage stabilizing tube D3 is connected with the collector of the voltage-controlled current element Q1, and the cathode of the voltage stabilizing tube D3 is connected with the base of the voltage-controlled current element Q1. Specifically, one end of the first resistor R1 is connected with the connection node of the first capacitor C1 and the inductor L1, and the voltage-controlled current element Q1 is any one of a MOS tube and a triode. Hereinafter, the voltage-controlled current element Q1 is taken as a triode for specific description.

[0053] It can be understood that, in combination with the above-described embodiments, the first voltage drop V1 = VL + VR2 + VD1, wherein VL represents the voltage drop of the inductor L1, for the convenience of engineering estimation, VL can be taken as 0V; VR2 represents the voltage drop of the second resistor R2, and the specific value of VR2 can be changed by adjusting the resistance value of the second resistor R2; VD1 represents the on-voltage drop of the first diode D1, for the convenience of engineering estimation, VD1 can be taken as 0.7V. The second voltage drop V2 = VQEB + VA, wherein VQEB represents the on-voltage between the emitter and the base of the voltage-controlled current element Q1, and VA represents the voltage value at the node where the first resistor R1 and the base of the voltage-controlled current element Q1 are connected. Therefore, when the external signal VIN-VD1-VR2-VQEB > VA, that is, VIN > V1 + V2, the signal isolation module 300 is turned on, and the identification module 400 outputs a logic value of logic “1”; otherwise, the signal isolation module 300 is turned off, and the identification module 400 outputs a logic value of logic “0”. It can be understood that the specific value of VA can be adjusted by selecting different parameter types of the voltage stabilizing tube D3.

[0054] With reference to Figure 2 In some embodiments, the signal isolation module 300 includes a second resistor R2, a light-emitting diode, and a photosensitive triode. One end of the second resistor R2 is connected with the protection module 100. The anode of the light-emitting diode is connected with the other end of the second resistor R2, and the cathode of the light-emitting diode is connected with the emitter of the voltage-controlled current. The photosensitive triode is coupled with the light-emitting diode. Specifically, one end of the second resistor R2 is connected with the connection node of the inductor L1 and the second capacitor C2, and the light-emitting diode and the photosensitive triode constitute a photoelectric coupler Q2. When the light-emitting diode is turned on, the light-emitting diode generates a light signal, and the photosensitive triode is turned on due to receiving the light signal, so as to realize the isolation of the input voltage and the output voltage of the photoelectric coupler Q2. It can be understood that the second resistor R2 is a current-limiting resistor, and the specific value thereof can be adaptively selected according to the actual application environment, which is not limited in the embodiments of the present application.

[0055] With reference to Figure 3 The embodiments of the present application also provide an industrial equipment, which comprises a control system 500 and an input identification circuit as described in any of the above embodiments. The control system is used to be connected with the identification module, and the control system is used to perform corresponding logical operations according to the logic “0” or the logic “1” output by the identification module.

[0056] It can be seen that the contents in the above-mentioned input identification circuit embodiments are all applicable to the embodiments of the present industrial equipment, the functions specifically realized by the embodiments of the present industrial equipment are the same as those of the above-mentioned input identification circuit embodiments, and the beneficial effects achieved by the embodiments of the present industrial equipment are also the same as those achieved by the above-mentioned input identification circuit embodiments.

[0057] The embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application. Furthermore, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. An input recognition circuit, characterized by, The input recognition circuit comprises: a protection module, configured to receive an external signal and to perform input protection on the input recognition circuit; a switch module, connected with the protection module, configured to switch a first conduction state according to the external signal; a signal isolation module, connected with the switch module, configured to switch a second conduction state according to the first conduction state; a recognition module, connected with the signal isolation module, configured to perform a logical recognition operation on the external signal according to the second conduction state and to generate a logical value corresponding to the external signal; wherein, when a voltage value of the external signal is greater than a sum of a first voltage drop and a second voltage drop, the first conduction state is conduction, the second conduction state is conduction, the first voltage drop is a sum of voltage drops of elements in the protection module, and the second voltage drop is a conduction voltage drop of the switch module, the sum of the first voltage drop and the second voltage drop is determined as a comparison threshold value, and types of elements in the protection module and / or the switch module are adjusted to adjust the size of the comparison threshold value.

2. The input recognition circuit according to claim 1, characterized by, The switch module comprises: a first resistor, one end of which is connected with the protection module; a control voltage flow element, a base of which is connected with the other end of the first resistor, an emitter of which is connected with the signal isolation module, and a collector of which is grounded; a voltage stabilizing tube, an anode of which is connected with the collector of the control voltage flow element, and a cathode of which is connected with the base of the control voltage flow element.

3. The input recognition circuit according to claim 2, characterized by The control voltage flow element comprises any one of a MOS tube and a triode.

4. The input recognition circuit according to claim 2, characterized by The signal isolation module comprises: a second resistor, one end of which is connected with the protection module; a light emitting diode, an anode of which is connected with the other end of the second resistor, and a cathode of which is connected with the emitter of the control voltage flow element; a light-sensitive triode, coupled with the light emitting diode.

5. The input recognition circuit according to any one of claims 1 to 4, characterized by, The protection module comprises: a first diode, an anode of which is configured to receive the external signal, and a cathode of which is connected with the switch module.

6. The input recognition circuit according to claim 5, characterized by The protection module further comprises: a first capacitor, one end of which is connected with the cathode of the first diode, and the other end of which is grounded; an inductor, one end of which is connected with the one end of the first capacitor and the switch module respectively, and the other end of which is connected with the signal isolation module; a second capacitor, one end of which is connected with the other end of the inductor, and the other end of which is connected with the other end of the first capacitor.

7. The input recognition circuit according to claim 6, characterized by The protection module further comprises: a second diode, an anode of which is connected with the other end of the first capacitor, and a cathode of which is connected with the anode of the first diode.

8. Industrial plant, characterized in that, The input recognition circuit comprises: the input recognition circuit according to any one of claims 1 to 7; a control system, configured to be connected with the recognition module, and configured to perform a corresponding operation according to the logical value.

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