CN218771301U - Protection circuit and intelligent gateway of RS485 chip - Google Patents
Protection circuit and intelligent gateway of RS485 chip Download PDFInfo
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- CN218771301U CN218771301U CN202222693255.3U CN202222693255U CN218771301U CN 218771301 U CN218771301 U CN 218771301U CN 202222693255 U CN202222693255 U CN 202222693255U CN 218771301 U CN218771301 U CN 218771301U
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Abstract
The utility model provides a protection circuit and intelligent gateway of RS485 chip, include: the RS485 chip is provided with a receiver output end, a driver input end, a forward receiving input end and a reverse receiving input end; the output end of the receiver and the input end of the driver are respectively connected with the micro control unit through the optical isolation protection module; the forward receiving input end and the reverse receiving input end of the surge suppression module are respectively connected with the surge suppression module; the pulse discharge module comprises a discharge tube, wherein the discharge tube is provided with a first electrode end, a second electrode end and a grounding end, the first electrode end is connected with a first external end, the second electrode end is connected with a second external end, and the grounding end is grounded; the current limiting module comprises a first fuse and a second fuse, the forward receiving input end is connected with the first peripheral end through the first fuse, the reverse receiving input end is connected with the second peripheral end through the second fuse, various interference signals can be effectively isolated, and effectiveness and accuracy of communication are guaranteed.
Description
Technical Field
The utility model relates to the field of communication technology, concretely relates to protection circuit and intelligent gateway of RS485 chip.
Background
The RS485 communication mode is a wired longer-distance communication mode, is simple to realize and convenient to install, and is widely applied to communication of various devices.
At present, between an RS485 chip and a micro control unit and between the RS485 chip and external equipment, anti-interference and protection are carried out by arranging a single isolation circuit, but the single isolation circuit has poor anti-interference capability, and effectiveness and accuracy of communication can be influenced by an isolated interference signal.
SUMMERY OF THE UTILITY MODEL
The following is a summary of the subject matter described in detail herein and is not intended to limit the scope of the claims.
The utility model provides a protection circuit and intelligent gateway of RS485 chip can effectively keep apart multiple interference signal, guarantees the validity and the rate of accuracy of communication to having played holistic guard action to the RS485 chip, can avoiding the RS485 chip to damage, thereby reduce the maintenance cost.
In a first aspect, the utility model provides a protection circuit of RS485 chip, include:
the RS485 chip is provided with a receiver output end, a driver input end, a forward receiving input end and a reverse receiving input end;
the receiver output end and the driver input end are respectively connected with the micro control unit through the optical isolation protection module;
the forward receiving input end and the reverse receiving input end are respectively connected with the surge suppression module;
the pulse discharge module comprises a discharge tube, wherein the discharge tube is provided with a first electrode end, a second electrode end and a grounding end, the first electrode end is connected with a first external end, the second electrode end is connected with a second external end, and the grounding end is grounded;
the current limiting module comprises a first fuse and a second fuse, the forward direction receiving input end is connected with the first peripheral end through the first fuse, and the reverse direction receiving input end is connected with the second peripheral end through the second fuse.
In some embodiments, the mobile terminal further includes a lifting loading module, the lifting loading module includes a pull-up resistor and a pull-down resistor, one end of the pull-up resistor is connected to a power supply voltage, the other end of the pull-up resistor is connected to the forward receiving input terminal, one end of the pull-down resistor is grounded, and the other end of the pull-down resistor is connected to the reverse receiving input terminal.
In some embodiments, the optical isolation protection module comprises a first isolation optocoupler and a second isolation optocoupler, the receiver output is connected to the input of the micro control unit via the first isolation optocoupler, and the driver input is connected to the output of the micro control unit via the second isolation optocoupler.
In some embodiments, the surge suppression module includes a first bidirectional clamping diode, a second bidirectional clamping diode, and a third bidirectional clamping diode, one end of the first bidirectional clamping diode is connected to the forward receiving input terminal, the other end of the first bidirectional clamping diode is connected to the reverse receiving input terminal, one end of the second bidirectional clamping diode is connected to the forward receiving input terminal, the other end of the second bidirectional clamping diode is connected to one end of the third bidirectional clamping diode, the other end of the third bidirectional clamping diode is connected to the reverse receiving input terminal, and the other end of the second bidirectional clamping diode is grounded.
In some embodiments, the power supply circuit further comprises a filter circuit, the filter circuit comprises a first capacitor and a second capacitor, one end of the first capacitor is connected with a power supply voltage, the other end of the first capacitor is grounded, the second capacitor is connected with the first capacitor in parallel, the RS485 chip is further provided with a power connection end, and one end of the first capacitor is connected with the power connection end.
In some embodiments, the device further comprises an enabling circuit, the enabling circuit comprises a triode, a first resistor and a second resistor, a collector of the triode is connected with one end of the first resistor, the other end of the first resistor is connected with a power supply voltage, a base of the triode is connected with one end of the second resistor, the other end of the second resistor is connected with the second isolating optocoupler, and an emitter of the triode is grounded; the RS485 chip is further provided with a receiver output enable end and a driver output enable end, wherein the receiver output enable end and the driver output enable end are respectively connected with the collector electrode of the triode.
In some embodiments, the apparatus further comprises a matching circuit, wherein the matching circuit comprises a third resistor, one end of the third resistor is connected to the first peripheral terminal, and the other end of the third resistor is connected to the second peripheral terminal.
In some embodiments, the discharge tube is a ceramic gas discharge tube, which is model number 3SPC090F.
In some embodiments, the first fuse and the second fuse are both self-healing fuses.
In a second aspect, the present invention further provides an intelligent gateway, which includes the protection circuit of the RS485 chip as described in the first aspect.
The embodiment of the utility model provides an include: a protection circuit of an RS485 chip and an intelligent gateway; the utility model discloses a protection circuit of RS485 chip includes: the RS485 chip is provided with a receiver output end, a driver input end, a forward receiving input end and a reverse receiving input end; the output end of the receiver and the input end of the driver are respectively connected with the micro control unit through the optical isolation protection module; the forward receiving input end and the reverse receiving input end of the surge suppression module are respectively connected with the surge suppression module; the pulse discharge module comprises a discharge tube, the discharge tube is provided with a first electrode end, a second electrode end and a grounding end, the first electrode end is connected with the first external end, the second electrode end is connected with the second external end, and the grounding end is grounded; and the current limiting module comprises a first fuse and a second fuse, the forward receiving input end is connected with the first peripheral end through the first fuse, and the reverse receiving input end is connected with the second peripheral end through the second fuse.
According to the scheme provided by the embodiment of the utility model, firstly, the receiver output end and the driver input end of the RS485 chip are respectively connected with the micro control unit through the optical isolation protection module, and the optical isolation protection module can respectively isolate the input signal and the output signal of the micro control unit from the RS485 chip, thereby effectively isolating the signal interference from the RS485 chip; then, a forward receiving input end and a reverse receiving input end of the RS485 chip are respectively connected with a surge suppression module, and the surge suppression module can filter surge voltage higher than the RS485 chip, so that the interference of the surge voltage is effectively isolated; secondly, the pulse discharge module comprises a discharge tube, a first electrode end of the discharge tube is connected with a first external end, a second electrode end of the discharge tube is connected with a second external end, a grounding end of the discharge tube is grounded, and the discharge tube can absorb high-voltage pulse interference signals from the first external end and the second external end and discharge the high-voltage pulse to the grounding end, so that the high-voltage pulse interference signals are effectively isolated; finally, a forward receiving input end of the RS485 chip is connected with a first peripheral end through a first fuse, a reverse receiving input end of the RS485 chip is connected with a second peripheral end through a second fuse, when a strong current enters the RS485 chip from the first peripheral end and the second peripheral end, the first fuse and the second fuse are instantly fused, the damage of the RS485 chip caused by the entering of the strong current is prevented, and therefore a strong current interference signal is effectively isolated; therefore, the protection circuit of the RS485 chip can effectively isolate various interference signals, the effectiveness and the accuracy of communication are guaranteed, the RS485 chip is protected integrally, the RS485 chip can be prevented from being damaged, and the maintenance cost is reduced.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The accompanying drawings are included to provide a further understanding of the technical aspects of the present invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention, and together with the description, serve to explain the technical aspects of the present invention.
Fig. 1 is a schematic circuit diagram of a protection circuit of an RS485 chip according to an embodiment of the present invention;
FIG. 2 is a first system block diagram of an RS485 chip in the protection circuit shown in FIG. 1;
FIG. 3 is a second system block diagram of an RS485 chip in the protection circuit shown in FIG. 1;
fig. 4 is a third system block diagram of an RS485 chip in the protection circuit shown in fig. 1;
fig. 5 is a fourth system block diagram of an RS485 chip in the protection circuit shown in fig. 1.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present invention, and should not be construed as limiting the present invention.
In the description of the present invention, it should be understood that the orientation or positional relationship referred to, for example, the upper, lower, front, rear, left, right, etc., is the orientation or positional relationship shown on the drawings, and is only for convenience of description and simplification of the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number. If there is a description of first and second for the purpose of distinguishing technical features only, this is not to be understood as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.
In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.
In the related art, the RS485 communication mode is a wired longer-distance communication mode, which is simple to implement and convenient to install, and is widely applied to communication of various devices.
At present, between an RS485 chip and a micro control unit and between the RS485 chip and external equipment, anti-interference and protection are carried out by arranging a single isolation circuit, but the single isolation circuit has poor anti-interference capability, and effectiveness and accuracy of communication can be influenced by an isolated interference signal.
Based on the above situation, the embodiment of the utility model provides a protection circuit and an intelligent gateway of an RS485 chip; the utility model discloses a protection circuit of RS485 chip includes:
the RS485 chip is provided with a receiver output end, a driver input end, a forward receiving input end and a reverse receiving input end;
the output end of the receiver and the input end of the driver are respectively connected with the micro control unit through the optical isolation protection module;
the forward receiving input end and the reverse receiving input end of the surge suppression module are respectively connected with the surge suppression module;
the pulse discharge module comprises a discharge tube, the discharge tube is provided with a first electrode end, a second electrode end and a grounding end, the first electrode end is connected with the first external end, the second electrode end is connected with the second external end, and the grounding end is grounded;
and the current limiting module comprises a first fuse and a second fuse, the forward receiving input end is connected with the first peripheral end through the first fuse, and the reverse receiving input end is connected with the second peripheral end through the second fuse.
According to the scheme provided by the embodiment of the utility model, firstly, the receiver output end and the driver input end of the RS485 chip are respectively connected with the micro control unit through the optical isolation protection module, and the optical isolation protection module can respectively isolate the input signal and the output signal of the micro control unit from the RS485 chip, thereby effectively isolating the signal interference from the RS485 chip; then, a forward receiving input end and a reverse receiving input end of the RS485 chip are respectively connected with a surge suppression module, and the surge suppression module can filter surge voltage higher than the RS485 chip, so that the interference of the surge voltage is effectively isolated; secondly, the pulse discharge module comprises a discharge tube, a first electrode end of the discharge tube is connected with a first external end, a second electrode end of the discharge tube is connected with a second external end, a grounding end of the discharge tube is grounded, and the discharge tube can absorb high-voltage pulse interference signals from the first external end and the second external end and discharge the high-voltage pulse to the grounding end, so that the high-voltage pulse interference signals are effectively isolated; and finally, the forward receiving input end of the RS485 chip is connected with the first peripheral end through a first fuse, the reverse receiving input end of the RS485 chip is connected with the second peripheral end through a second fuse, and when a strong current enters the RS485 chip from the first peripheral end and the second peripheral end, the first fuse and the second fuse are instantly fused, so that the damage of the RS485 chip caused by the entering of the strong current is prevented, and a strong current interference signal is effectively isolated. Therefore, the protection circuit of the RS485 chip can effectively isolate various interference signals, the effectiveness and the accuracy of communication are guaranteed, the whole protection effect is achieved on the RS485 chip, the damage of the RS485 chip can be avoided, and the maintenance cost is reduced.
The embodiments of the present invention will be further explained with reference to the drawings.
As shown in fig. 1 to fig. 5, the protection circuit of the RS485 chip according to the embodiment of the present invention includes but is not limited to:
the RS485 chip 120 is provided with a receiver output end R, a driver input end D, a forward receiving input end A and a reverse receiving input end B;
the receiver output end R and the driver input end D are respectively connected with the micro-control unit 100 through the optical isolation protection module 110 by the optical isolation protection module 110;
the surge suppression module 130, the forward receiving input end a and the reverse receiving input end B are respectively connected with the surge suppression module 130;
the pulse discharge module 150 comprises a discharge tube D4, the discharge tube D4 is provided with a first electrode end, a second electrode end and a grounding end, the first electrode end is connected with the first external end A1, the second electrode end is connected with the second external end B1, and the grounding end is grounded;
the current limiting module 140 includes a first fuse F2 and a second fuse F1, the forward receiving input end a is connected to the first peripheral end A1 through the first fuse F2, and the reverse receiving input end B is connected to the second peripheral end B1 through the second fuse F1.
Specifically, to the technical solution of the embodiment of the present invention, first, the receiver output end R and the driver input end D of the RS485 chip 120 are respectively connected to the micro control unit 100 through the optical isolation protection module 110, and the optical isolation protection module 110 can isolate the input signal and the output signal of the micro control unit 100 from the RS485 chip 120, so as to effectively isolate the signal interference from the RS485 chip 120; then, a forward receiving input end a and a reverse receiving input end B of the RS485 chip 120 are respectively connected to the surge suppression module 130, and the surge suppression module 130 can filter out a surge voltage higher than the RS485 chip 120, thereby effectively isolating interference of the surge voltage; secondly, the pulse discharge module 150 includes a discharge tube D4, a first electrode end of the discharge tube D4 is connected with the first external end A1, a second electrode end of the discharge tube D4 is connected with the second external end B1, a ground terminal of the discharge tube D4 is grounded, the discharge tube D4 can absorb high-voltage pulse interference signals from the first external end A1 and the second external end B1, and discharge the high-voltage pulse to the ground terminal, thereby effectively isolating the high-voltage pulse interference signals; finally, the forward direction receiving input end A of the RS485 chip 120 is connected with a first peripheral end A1 through a first fuse F2, the reverse direction receiving input end B of the RS485 chip 120 is connected with a second peripheral end B1 through a second fuse F1, when strong current enters the RS485 chip 120 from the first peripheral end A1 and the second peripheral end B1, the first fuse F2 and the second fuse F1 are instantly fused, the strong current is prevented from entering and the RS485 chip 120 is damaged, and therefore strong current interference signals are effectively isolated. Therefore, the protection circuit of the RS485 chip can effectively isolate various interference signals, the effectiveness and accuracy of communication are guaranteed, the whole protection effect is achieved on the RS485 chip 120, the RS485 chip 120 can be prevented from being damaged, and the maintenance cost is reduced.
It should be noted that the embodiment of the present invention further includes the lifting belt loading module 210, the lifting belt loading module 210 includes a pull-up resistor R9 and a pull-down resistor R8, in this embodiment, the resistance values of the pull-up resistor R9 and the pull-down resistor R8 are 1000 ohms, one end of the pull-up resistor R9 is connected to the power supply voltage, the other end of the pull-up resistor R9 is connected to the forward receiving input end a, one end of the pull-down resistor R8 is grounded, and the other end of the pull-down resistor R8 is connected to the reverse receiving input end B; through pull-up resistor R9 and pull-down resistor R8, provide output current to the forward receiving input A and the reverse receiving input B of RS485 chip 120 to guarantee that little the control unit 100 can receive the information that a plurality of external equipment transmitted through RS485 chip 120, perhaps guarantee that little the control unit 100 can send information to a plurality of external equipment through RS485 chip 120, thereby improved RS485 chip 120's loading ability.
Specifically, the optical isolation protection module 110 includes a first isolation optocoupler U1 and a second isolation optocoupler U2, in this embodiment, the models of the first isolation optocoupler U1 and the second isolation optocoupler U2 are both KPS2801_ SOP4, the receiver output end R is connected to the input end of the micro control unit 100 through the first isolation optocoupler U1, the anode of the first isolation optocoupler U1 is connected to one end of a resistor R3, the other end of the resistor R3 is connected to the supply voltage, the cathode of the first isolation optocoupler U1 is connected to the receiver output end R, the collector of the first isolation optocoupler U1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the supply voltage, the collector of the first isolation optocoupler U1 is connected to the input end of the micro control unit 100, a capacitor C1 is connected between the collector and the emitter of the first isolation optocoupler U1, and the emitter of the first isolation optocoupler U1 is grounded; the input end D of the driver is connected with the output end of the micro control unit 100 through a second isolation optocoupler U2, the anode of the second isolation optocoupler U2 is connected with one end of a resistor R2, the other end of the resistor R2 is connected with a power supply voltage, the cathode of the second isolation optocoupler U2 is connected with the output end of the micro control unit 100, the collector of the second isolation optocoupler U2 is connected with one end of a resistor R4, the other end of the resistor R4 is connected with the power supply voltage, the collector of the second isolation optocoupler U2 is connected with one end of a resistor R6, the other end of the resistor R6 is connected with the input end D of the driver, a capacitor C2 is connected between the collector and the emitter of the second isolation optocoupler U2, and the emitter of the second isolation optocoupler U2 is grounded; through setting up two isolation opto-couplers, can keep apart the input signal and the output signal of little the control unit 100 with RS485 chip 120 respectively, first isolation opto-coupler U1 keeps apart the input of little the control unit 100 and the receiver output R of RS485 chip 120, and second isolation opto-coupler U2 keeps apart the output of little the control unit 100 and the driver input D of RS485 chip 120.
Specifically, the surge suppression module 130 includes a first bidirectional clamping diode D1, a second bidirectional clamping diode D2, and a third bidirectional clamping diode D3, one end of the first bidirectional clamping diode D1 is connected to the forward receiving input terminal a, the other end of the first bidirectional clamping diode D1 is connected to the reverse receiving input terminal B, one end of the second bidirectional clamping diode D2 is connected to the forward receiving input terminal a, the other end of the second bidirectional clamping diode D2 is connected to one end of the third bidirectional clamping diode D3, the other end of the third bidirectional clamping diode D3 is connected to the reverse receiving input terminal B, the other end of the second bidirectional clamping diode D2 is grounded, and by providing the first bidirectional clamping diode D1, the second bidirectional clamping diode D2, and the third bidirectional clamping diode D3, a surge voltage higher than the RS485 chip 120 can be filtered, so that interference of the surge voltage is effectively isolated, and the RS485 is prevented from being damaged by being impacted by the surge voltage.
It should be noted that the embodiment of the utility model provides a still include filter circuit 170, filter circuit 170 includes first electric capacity C3 and second electric capacity C4, supply voltage is connected to first electric capacity C3's one end, first electric capacity C3's other end ground connection, second electric capacity C4 is parallelly connected with first electric capacity C3, RS485 chip 120 still is provided with the end of connecting, first electric capacity C3's one end is connected with the end of connecting, through setting up first electric capacity C3 and second electric capacity C4, keep apart the power of little the control unit 100 and the power of RS485 chip 120, prevent to produce the interference because of RS485 chip 120's power, thereby influence little the control unit 100.
It should be noted that the embodiment of the present invention further includes an enabling circuit 180, where the enabling circuit 180 includes a triode Q1, a first resistor R7 and a second resistor R5, a collector of the triode Q1 is connected with one end of the first resistor R7, the other end of the first resistor R7 is connected with a power supply voltage, a base of the triode Q1 is connected with one end of the second resistor R5, the other end of the second resistor R5 is connected with a collector of the second isolation optocoupler U2, and an emitter of the triode Q1 is grounded; the RS485 chip 120 is further provided with a receiver output enable terminal
And a driver output enable terminal DE, a receiver output enable terminal>
And the driver output enable end DE is respectively connected with the collector electrode of the triode Q1; when the triode Q1 is in a conducting state, the receiver output enable end->
And the driver output enable terminal DE are both in a low level state, and the RS485 chip 120 operates in a receiving state; when the triode Q1 is in a cut-off state, the output enabling end of the receiver is combined with the device>
And the driver output enable terminal DEIn a high state, the RS485 chip 120 operates in a transmitting state.
It should be noted that, the embodiment of the present invention further includes matching circuit 200, matching circuit 200 includes third resistor R10, in this embodiment, the resistance of third resistor R10 is 120 ohms, one end of third resistor R10 is connected with first peripheral end A1, the other end of third resistor R10 is connected with second peripheral end B1, be connected with external device 160 through first peripheral end A1 and second peripheral end A2, in practical application, the communication carrier is a twisted pair, its characteristic impedance is about 120 ohms, so when the circuit is designed, connect a 120 ohms resistance between first peripheral end A1 and second peripheral end B1, in order to reduce the reflection of the transmission signal on the circuit.
Specifically, the discharge tube D4 is a ceramic gas discharge tube, in this embodiment, the ceramic gas discharge tube is 3SPC090F, and when the first electrode end and the second electrode end of the ceramic gas discharge tube are impacted by the transient high voltage, the high impedance between the first electrode end and the second electrode end of the ceramic gas discharge tube changes to the low impedance, so that the voltage between the first electrode end and the second electrode end of the ceramic gas discharge tube is lower than the safety voltage of the RS485 chip 120, and the RS485 chip 120 is effectively protected from the damage of the surge voltage.
Specifically, the first fuse F2 and the second fuse F1 are self-recovery fuses, the self-recovery fuses can suppress a strong current, when the strong current of the external device 160 enters the RS485 chip 120 from the first external end A1 and the second external end B1, the first fuse F2 and the second fuse F1 are instantly fused, so that the RS485 chip 120 is prevented from being damaged due to the entering of the strong current, and a strong current interference signal is effectively isolated.
The protection circuit of the RS485 chip based on the embodiment has the following beneficial effects:
firstly, a receiver output end R and a driver input end D of the RS485 chip 120 are respectively connected with the micro control unit 100 through the optical isolation protection module 110, and the optical isolation protection module 110 can respectively isolate an input signal and an output signal of the micro control unit 100 from the RS485 chip 120, so that signal interference from the RS485 chip 120 is effectively isolated; then, a forward receiving input end a and a reverse receiving input end B of the RS485 chip 120 are respectively connected to the surge suppression module 130, and the surge suppression module 130 can filter out a surge voltage higher than the RS485 chip 120, thereby effectively isolating interference of the surge voltage; secondly, the pulse discharge module 150 includes a discharge tube D4, a first electrode end of the discharge tube D4 is connected with the first external end A1, a second electrode end of the discharge tube D4 is connected with the second external end B1, a ground terminal of the discharge tube D4 is grounded, the discharge tube D4 can absorb high-voltage pulse interference signals from the first external end A1 and the second external end B1, and discharge high-voltage pulses to the ground terminal, thereby effectively isolating the high-voltage pulse interference signals; finally, the forward direction receiving input end a of the RS485 chip 120 is connected with the first peripheral end A1 through the first fuse F2, the reverse direction receiving input end B of the RS485 chip 120 is connected with the second peripheral end B1 through the second fuse F1, a strong current of the external device 160 enters the RS485 chip 120 from the first peripheral end A1 and the second peripheral end B1, the first fuse F2 and the second fuse F1 are instantly fused, the strong current is prevented from entering and causing the RS485 chip 120 to be damaged, and thus a strong current interference signal is effectively isolated. Therefore, the protection circuit of the RS485 chip can effectively isolate various interference signals, the effectiveness and accuracy of communication are guaranteed, the whole protection effect is achieved on the RS485 chip 120, the RS485 chip 120 can be prevented from being damaged, and the maintenance cost is reduced.
In addition, based on the protection circuit of the RS485 chip shown in fig. 1 to fig. 5, the embodiment of the present invention further provides an intelligent gateway, specifically, the present invention provides an intelligent gateway including but not limited to the protection circuit of the RS485 chip in any of the above embodiments.
It should be noted that, because the utility model discloses intelligent gateway is including the protection circuit of the RS485 chip in above-mentioned arbitrary embodiment, consequently, the utility model discloses intelligent gateway's concrete implementation and technological effect can refer to the concrete implementation and the technological effect of the protection circuit of the RS485 chip in above-mentioned arbitrary embodiment.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.
Claims (10)
1. The protection circuit of the RS485 chip is characterized by comprising:
the RS485 chip is provided with a receiver output end, a driver input end, a forward receiving input end and a reverse receiving input end;
the receiver output end and the driver input end are respectively connected with the micro control unit through the optical isolation protection module;
the forward receiving input end and the reverse receiving input end are respectively connected with the surge suppression module;
the pulse discharge module comprises a discharge tube, wherein the discharge tube is provided with a first electrode end, a second electrode end and a grounding end, the first electrode end is connected with a first external end, the second electrode end is connected with a second external end, and the grounding end is grounded;
the current limiting module comprises a first fuse and a second fuse, the forward direction receiving input end is connected with the first peripheral end through the first fuse, and the reverse direction receiving input end is connected with the second peripheral end through the second fuse.
2. The protection circuit of claim 1, further comprising a lifting loading module, wherein the lifting loading module comprises a pull-up resistor and a pull-down resistor, one end of the pull-up resistor is connected to a supply voltage, the other end of the pull-up resistor is connected to the forward receiving input terminal, one end of the pull-down resistor is grounded, and the other end of the pull-down resistor is connected to the reverse receiving input terminal.
3. The protection circuit of claim 1, wherein the optical isolation protection module comprises a first isolation optocoupler and a second isolation optocoupler, wherein the receiver output is coupled to the input of the micro control unit via the first isolation optocoupler, and wherein the driver input is coupled to the output of the micro control unit via the second isolation optocoupler.
4. The protection circuit of an RS485 chip according to claim 1, wherein the surge suppressing module comprises a first bidirectional clamping diode, a second bidirectional clamping diode and a third bidirectional clamping diode, one end of the first bidirectional clamping diode is connected to the forward receiving input terminal, the other end of the first bidirectional clamping diode is connected to the reverse receiving input terminal, one end of the second bidirectional clamping diode is connected to the forward receiving input terminal, the other end of the second bidirectional clamping diode is connected to one end of the third bidirectional clamping diode, the other end of the third bidirectional clamping diode is connected to the reverse receiving input terminal, and the other end of the second bidirectional clamping diode is grounded.
5. The protection circuit of the RS485 chip as claimed in claim 1, further comprising a filter circuit, wherein the filter circuit comprises a first capacitor and a second capacitor, one end of the first capacitor is connected to a supply voltage, the other end of the first capacitor is grounded, the second capacitor is connected in parallel with the first capacitor, the RS485 chip is further provided with a power connection terminal, and one end of the first capacitor is connected with the power connection terminal.
6. The protection circuit of claim 3, further comprising an enabling circuit, wherein the enabling circuit comprises a triode, a first resistor and a second resistor, a collector of the triode is connected with one end of the first resistor, the other end of the first resistor is connected with a power supply voltage, a base of the triode is connected with one end of the second resistor, the other end of the second resistor is connected with the second isolating optocoupler, and an emitter of the triode is grounded; the RS485 chip is further provided with a receiver output enable end and a driver output enable end, and the receiver output enable end and the driver output enable end are respectively connected with the collector electrode of the triode.
7. The protection circuit of claim 1, further comprising a matching circuit, wherein the matching circuit comprises a third resistor, one end of the third resistor is connected to the first peripheral end, and the other end of the third resistor is connected to the second peripheral end.
8. The protection circuit of claim 1, wherein the discharge tube is a ceramic gas discharge tube, and the ceramic gas discharge tube is 3SPC090F.
9. The protection circuit of claim 1, wherein the first fuse and the second fuse are self-recovery fuses.
10. An intelligent gateway, characterized in that it comprises the protection circuit of an RS485 chip of any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222693255.3U CN218771301U (en) | 2022-10-12 | 2022-10-12 | Protection circuit and intelligent gateway of RS485 chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222693255.3U CN218771301U (en) | 2022-10-12 | 2022-10-12 | Protection circuit and intelligent gateway of RS485 chip |
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| Publication Number | Publication Date |
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| CN218771301U true CN218771301U (en) | 2023-03-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222693255.3U Active CN218771301U (en) | 2022-10-12 | 2022-10-12 | Protection circuit and intelligent gateway of RS485 chip |
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| Country | Link |
|---|---|
| CN (1) | CN218771301U (en) |
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2022
- 2022-10-12 CN CN202222693255.3U patent/CN218771301U/en active Active
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