CN206224464U - A kind of communicator with antijamming capability - Google Patents
A kind of communicator with antijamming capability Download PDFInfo
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- CN206224464U CN206224464U CN201621291540.0U CN201621291540U CN206224464U CN 206224464 U CN206224464 U CN 206224464U CN 201621291540 U CN201621291540 U CN 201621291540U CN 206224464 U CN206224464 U CN 206224464U
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Abstract
The utility model discloses a kind of communicator with antijamming capability, including interface chip, isolation circuit and isolating chip, the receiver output end of interface chip, receiver exports Enable Pin, driver exports Enable Pin and driver input end is connected through isolation circuit with single-chip microcomputer, the receiver in-phase input end of interface chip connects the first output control line through first resistor, the receiver in-phase input end of interface chip is connected every positive source through second resistance, the receiver in-phase input end of interface chip is also grounded through the first voltage-regulator diode, the receiver inverting input for receiving chip connects the second output control line through 3rd resistor, the receiver inverting input of chip is received through the 4th resistance eutral grounding, 4th resistance two ends are parallel with the second voltage-regulator diode.The utility model simple structure, can not only effectively filter electromagnetic interference signal, and can absorb lightning surge electric current, and the effective work safety for ensureing late-class circuit and single-chip microcomputer, reliability is high.
Description
Technical field
The utility model is related to art communication systems field, more particularly to a kind of communicator with antijamming capability.
Background technology
With the requirement of the increasingly mature and IT application in enterprises of singlechip technology, smart machine gradually grows up, and looks forward to
A necessary condition of the industry in lectotype selection is sought to connected network communication interface.Initial communicator is digital simulation letter
Number output simple procedure amount, was later that using RS232 interfaces, RS232 interfaces can realize point-to-point communication mode, but this
Mode can not realize network savvy, and subsequent occurrences of RS485 communication modules solve this problem.
The host tape multiple slave of master-slave communication mode, i.e., one is generally adopted by RS485 communication modules.Many feelings
Simply simply " A " of each interface is held to be held with " B " with a pair of twisted-pair feeders under condition, during connection RS485 communication links and connected
Come, and have ignored the connection of signal ground, this connection method many occasions be can normal work, but buried very big
Hidden danger.
Traditional RS485 telecommunication circuits are as shown in figure 1, operationally, the reception I/O port of microcontroller serial port is connected to
On 1 pin (RO ends) of MAX487 chips, the transmission I/O port of single-chip microcomputer is connected on 4 pins of MAX487 (DI ends), single-chip microcomputer
Transmitting-receiving control IO is connected to 2 pins of MAX487 chipsOn 3 pins (DE), 8 pins (VCC) of MAX487 and 5 draw
Pin (GND) connects the signal of working power VCC and digitally GND, 6 pins (A) and 7 pins (B) difference RS485 order wires respectively
A and signal B.But this circuit drawback is a lot, due to being done using the industrial occasions in bad environments, electromagnetism more than RS485 buses
Disturb serious, when communication module is operated in the environment with strong electromagnetic, the electromagnetic interference signal of working site is from signal A
MAX487 chip internals are directly entered with signal B, and are spread out of by 1,2,3 and 4 pins, entered into late-class circuit, disturb it
The normal work of his electronic component and single-chip microcomputer, can cause whole system to be collapsed.Further, since RS485 buses are through conventional
In telecommunication occasion, so the communications cable is often laid on the cable testing bridge of outdoor, rainy day is readily incorporated thunderbolt,
If the RS485 order wires of outdoor are struck by lightning, instantaneous high pressure can be applied directly to MAX487 chips by signal A and signal B
6 pins and 7 pins on, so as to the chip be burnt.
The Chinese patent of Application No. 2016205490069 discloses a kind of 485 Magnetic isolations with automatic transceiving function
Circuit, including DC-DC circuit, Magnetic isolation chip, automatic transceiving circuit, ESD anti-jamming circuits and bus resistance to shorting circuit, pass through
ESD anti-jamming circuits realize anti-lightning strike and electrostatic, and Bus isolation is realized by bus resistance to shorting circuit, increase the reliability of module
Property.But this isolation circuit is merely capable of isolating electrostatic and thunderbolt, and when electromagnetic interference occurs in surrounding environment, this circuit is still
Subsequent conditioning circuit failure can be caused, reliability is not high.
Utility model content
The purpose of this utility model is to provide a kind of communicator with antijamming capability, can not only effectively be filtered
Except the electromagnetic interference signal in industrial environment, and lightning surge electric current is absorbed, it is effective to ensure late-class circuit and monolithic
The work safety of machine, so as to lift product service behaviour under complex environment.
To achieve the above object, the utility model is adopted the following technical scheme that：
A kind of communicator with antijamming capability, including interface chip, first resistor, second resistance, 3rd resistor,
4th resistance, the first voltage-regulator diode, the second voltage-regulator diode, the first electric capacity, isolation circuit and isolating chip, the interface core
The receiver output end of piece, receiver output Enable Pin, driver export Enable Pin and driver input end through isolation circuit
It is connected with single-chip microcomputer, the receiver in-phase input end of interface chip connects the first output control line, interface chip through first resistor
Receiver in-phase input end the output positive voltage terminal of isolating chip is connected through second resistance, the receiver of interface chip is with mutually defeated
Enter the output ground terminal that end also connects isolating chip through the first voltage-regulator diode, receive the receiver inverting input of chip through the 3rd
Resistance connects the second output control line, and the receiver inverting input for receiving chip connects the output of isolating chip through the 4th resistance
Ground terminal, the 4th resistance two ends are parallel with the second voltage-regulator diode, receive the output of the power end connection connection isolating chip of chip
Positive voltage terminal, receives the power end of chip also through the output ground terminal of the first capacitance connection isolating chip, and the ground terminal for receiving chip connects
Connect the output ground terminal of isolating chip.
The isolation circuit includes the first isolation circuit, the second isolation circuit and the 3rd isolation circuit, first isolation
Circuit uses the LED positive poles of the first photoelectrical coupler, the first photoelectrical coupler to connect positive source, the first photoelectrical coupler
LED negative poles connect the serial data transmitting terminal of single-chip microcomputer, the colelctor electrode connecting interface core of the first photoelectrical coupler through the 5th resistance
The driver input end of piece, the colelctor electrode of the first photoelectrical coupler also connects the output positive voltage of isolating chip through the 6th resistance
End, the emitter stage of the first photoelectrical coupler connects the output ground terminal of isolating chip；
Second isolation circuit uses the second photoelectrical coupler, and the LED positive poles of the second photoelectrical coupler are through the 7th resistance
The output positive voltage terminal of connection isolating chip, the receiver output end of the LED negative pole connecting interface chips of the second photoelectrical coupler,
The colelctor electrode of the second photoelectrical coupler connects the serial data output terminal of single-chip microcomputer, and the colelctor electrode of the second photoelectrical coupler is also through the
Eight resistance connect positive source, the grounded emitter of the second photoelectrical coupler；
3rd isolation circuit uses the 3rd photoelectrical coupler, and the LED positive poles of the 3rd photoelectrical coupler are through the 9th
Resistance connects positive source, and the LED negative poles of the 3rd photoelectrical coupler connect the 3rd output control line, the collection of the 3rd photoelectrical coupler
Electrode connects the output positive voltage terminal of isolating chip, the receiver output of the emitter stage connecting interface chip of the 3rd photoelectrical coupler
Enable Pin, the emitter stage of the 3rd photoelectrical coupler also connects the output ground terminal of isolating chip through the tenth resistance.
The first resistor and 3rd resistor are using the thermistor of positive temperature coefficient.
First voltage-regulator diode and the second voltage-regulator diode use transient voltage suppressor.
The interface chip uses MAX487 chips, the isolating chip to use B0505S-1 chips.
The utility model has the advantages that：
(1) the utility model sets first steady by the first output control line 485A and the second output control line 485B
Diode VT1 and the second voltage-regulator diode VT2 is pressed to isolate thunderbolt, when order wire is struck by lightning, instantaneous high pressure passes through first
Output control line 485A and the second output control line 485B are transferred to the first voltage-regulator diode VT1 and the second voltage-regulator diode VT2
Place, because voltage is higher, the first voltage-regulator diode VT1 and the second voltage-regulator diode VT2 are reversed and puncture, and cause holding wire and connect
Earth short, instantaneous high pressure directly discharges over the ground, prevents instantaneous high pressure from entering single-chip microcomputer and subsequent conditioning circuit through interface chip U1, protects
Protection circuit is not burned out；
(2) the utility model isolates electromagnetic interference by setting photoelectrical coupler, is done when strong electromagnetic occurs in site environment
When disturbing, electromagnetic interference signal is transmitted to optocoupler through order wire, because photoelectrical coupler transmits level using optical signal, is not had
There is electrical connection, therefore interference signal can be blocked at photoelectrical coupler, it is impossible to enter in subsequent conditioning circuit, so that effectively
Protect the normal work of single-chip microcomputer and subsequent conditioning circuit；
(3) the utility model is by the setting pull-up resistor R2 on the first output control line 485A, in the second output control
It is normal to ensure the communication for receiving chip U1 that pull down resistor R4 is set on line 485B.Due to the characteristic of RS487 chips, receiver
Detection sensitivity be ± 200mV, i.e., as the output voltage difference VA-VB >=+200mV of differential input end, output logic 1, when
During the output voltage difference VA-VB≤- 200mV of differential input end, logical zero is exported；First output control line 485A and second defeated
When the absolute value for going out the potential difference of control line 485B is less than 200mV, it is output as not knowing, if all transmitters are banned in bus
When only, i.e., when all 485 chips are all in state is received, receiver output state is indefinite, if receiver is output as 1,
Then communicate normal, if receiver is output as 0, receiver can be made to be considered the beginning of a new envelope message, so as to cause to lead to
News are abnormal；Therefore, in the utility model, the first output control line 485A connects positive source, the second output through pull-up resistor R2
Control line 485B is grounded through pull down resistor R4 so that and bus level VA-VB when receiving the pressure bus free of chip U1 >=+
200mV, it is ensured that receive chip U1 and be output as 1, it is ensured that communication is normal；
(4) the utility model respectively concatenates a temperature-sensitive on the first output control line 485A and the second output control line 485B
Resistance carries out Bus isolation, and when MAX487 wafer damages cause short circuit, due to the presence of thermistor, bus " will not be drawn
Extremely ", the reliability of communication is improved；First resistor R1 and 3rd resistor R3 are the thermistor of positive temperature coefficient, when in bus
When electric current is excessive, resistance can be raised rapidly, and when electric current recovers normal value, resistance reduction recovers normal communication, prevents
MAX487 chips are burned out.
The utility model simple structure, only by two chips and its peripheral circuit, can be achieved with isolation effect, cost
It is cheap, the electromagnetic interference signal in industrial environment can not only be effectively filtered, and lightning surge electric current is absorbed, effectively
The work safety for ensureing late-class circuit and single-chip microcomputer, effectively protect the safety of late-class circuit, reliability is high.
Brief description of the drawings
Fig. 1 is the circuit theory diagrams of existing RS485 communication modules；
Fig. 2 is circuit theory diagrams of the present utility model.
Specific embodiment
The technical solution of the utility model is clearly and completely described below in conjunction with accompanying drawing, it is clear that described reality
It is only section Example of the present utility model to apply example, rather than whole embodiments.Based on the embodiment in the utility model,
Other all embodiments that those of ordinary skill in the art are obtained on the premise of creative work is not made, belong to this
The protection domain of utility model.
As shown in Fig. 2 the utility model includes interface chip U1, isolation circuit and isolating chip U2, interface chip U1 warps
Isolation circuit is connected with single-chip microcomputer, and isolation circuit includes the first isolation circuit, the second isolation circuit and the 3rd isolation circuit, first
Isolation circuit using the first photoelectrical coupler OC1, the first photoelectrical coupler OC1 LED positive poles connection positive source VCC, first
The LED negative poles of photoelectrical coupler OC1 connect the serial data transmitting terminal TX1 of single-chip microcomputer, the first photoelectric coupling through the 5th resistance R5
The driver input end DI of the colelctor electrode connecting interface chip U1 of device OC1, the colelctor electrode of the first photoelectrical coupler OC1 is also through the 6th
The emitter stage connection isolating chip of output the positive voltage terminal VCOM, the first photoelectrical coupler OC1 of resistance R6 connection isolating chips U2
The output ground terminal GCOM of U2；
Second isolation circuit is using the LED positive poles of the second photoelectrical coupler OC2, the second photoelectrical coupler OC2 through the 7th electricity
The LED negative pole connecting interface chips U1 of output the positive voltage terminal VCOM, the second photoelectrical coupler OC2 of resistance R7 connection isolating chips U2
Receiver output end RO, the second photoelectrical coupler OC2 colelctor electrode connection single-chip microcomputer serial data output terminal RX1, second
The colelctor electrode of photoelectrical coupler OC2 also connects positive source VCC, the emitter stage of the second photoelectrical coupler OC2 through the 8th resistance R8
Ground connection；
3rd isolation circuit uses the 3rd photoelectrical coupler OC3, and the LED positive poles of the 3rd photoelectrical coupler OC3 are through the 9th electricity
The LED negative poles of resistance R9 connection positive sources VCC, the 3rd photoelectrical coupler OC3 connect the 3rd output control line 485C, the 3rd photoelectricity
The emitter stage of output the positive voltage terminal VCOM, the 3rd photoelectrical coupler OC3 of the colelctor electrode connection isolating chip U2 of coupler OC3 connects
The receiver output Enable Pin of connection interface chip U1The emitter stage of the 3rd photoelectrical coupler OC3 also connects through the tenth resistance R10
Meet the output ground terminal GCOM of isolating chip U2.
The driver input end DI of interface chip U1 is connected with the first isolation circuit, the receiver output end of interface chip U1
RO is connected with the second isolation circuit, the receiver output Enable Pin of interface chip U1It is connected with driver output Enable Pin DE,
And the driver output Enable Pin of interface chip U1It is connected with the 3rd isolation circuit, the receiver of interface chip U1 is with mutually defeated
Enter to hold A to connect the first output control line 485A through first resistor R1, the receiver in-phase input end A of interface chip U1 is through the second electricity
The receiver in-phase input end A of output the positive voltage terminal VCOM, interface chip U1 of resistance R2 connection isolating chips U2 is also steady through first
The output ground terminal GCOM of pressure diode VT1 connection isolating chips U2, receives the receiver inverting input B of chip U1 through the 3rd electricity
Resistance R3 connects the second output control line 485B, and the receiver inverting input B for receiving chip also connects through the second voltage-regulator diode VT2
The output ground terminal GCOM of isolating chip U2 is met, the second voltage-regulator diode VT2 two ends are also parallel with the 4th resistance R4, receive chip U1
Power end VCC connections isolating chip U2 output positive voltage terminal VCOM, receive the power end VCC of chip U1 also through the first electric capacity
The output ground terminal GCOM of C1 connection isolating chips U2, receives the output ground terminal of the ground terminal GND connection isolating chips U2 of chip U1
GCOM。
In the present embodiment, first resistor R1 and second resistance R2 are using the thermistor of positive temperature coefficient, and first is steady
Pressure diode VT1 and the second voltage-regulator diode VT2 uses transient voltage suppressor, and interface chip U1 uses MAX487 cores
Piece, isolating chip U2 uses B0505S-1 chips, and for communicating, isolating chip U2 is used for isolating interface chip U1 to interface chip U1
With subsequent conditioning circuit, other can realize that the chip of this function can also do equivalent, will not be repeated here.
The course of work of the present utility model is identical with existing RS485 communication modules, when order wire is struck by lightning, instantaneously
High pressure is transferred to the first voltage-regulator diode VT1 and second steady by the first output control line 485A and the second output control line 485B
At pressure diode VT2, because voltage is higher, the first voltage-regulator diode VT1 and the second voltage-regulator diode VT2 are reversed and puncture, and lead
Holding wire and ground wire short circuit are caused, instantaneous high pressure directly discharges over the ground, prevents instantaneous high pressure from entering single-chip microcomputer through interface chip U1
And rear virtual circuit, protection circuit is not burned out.
When strong electromagnetic occurs in site environment, electromagnetic interference signal is transmitted to optocoupler through order wire, due to photoelectricity
Coupler transmits level using optical signal, and without electrical connection, therefore interference signal can be blocked in photoelectrical coupler
Place, it is impossible to enter in subsequent conditioning circuit, so as to be effectively protected the normal work of single-chip microcomputer and subsequent conditioning circuit.
Due to the characteristic of RS487 chips, the detection sensitivity of receiver is ± 200mV, i.e., when the output of differential input end
During voltage difference VA-VB >=+200mV, logic 1 is exported, it is defeated as the output voltage difference VA-VB≤- 200mV of differential input end
Go out logical zero；It is defeated when the absolute value of the potential difference of the first output control line 485A and the second output control line 485B is less than 200mV
It is uncertain to go out, if all transmitters are prohibited in bus, i.e., when all 485 chips are all in state is received, receiver is defeated
It is indefinite to do well, and if receiver is output as 1, then communicates normally, if receiver is output as 0, can make receiver
The beginning of a new envelope message is considered, so as to cause communication abnormality；Therefore, in the utility model, the first output control line
485A connects positive source through pull-up resistor R2, and the second output control line 485B is grounded through pull down resistor R4 so that receive chip
Bus level VA-VB >=+200mV during the pressure bus free of U1, it is ensured that receive chip U1 and be output as 1, it is ensured that communication is normal.
On first output control line 485A and the second output control line 485B one thermistor of each concatenation enter row bus every
From when MAX487 wafer damages cause short circuit, due to the presence of thermistor, bus " will not be drawn dead ", improve communication
Reliability；First resistor R1 and 3rd resistor R3 are the thermistor of positive temperature coefficient, when electric current is excessive in bus,
Resistance can be raised rapidly, and when electric current recovers normal value, resistance reduction recovers normal communication, prevents MAX487 chips to be burned out.
The utility model simple structure, only by two chips and its peripheral circuit, can be achieved with isolation effect, cost
It is cheap, the electromagnetic interference signal in industrial environment can not only be effectively filtered, and lightning surge electric current can be absorbed,
The effective work safety for ensureing late-class circuit and single-chip microcomputer, reliability is high.
Claims (5)
1. a kind of communicator with antijamming capability, it is characterised in that：Including interface chip, first resistor, second resistance,
3rd resistor, the 4th resistance, the first voltage-regulator diode, the second voltage-regulator diode, the first electric capacity, isolation circuit and isolating chip,
It is equal that the receiver output end of the interface chip, receiver export Enable Pin, driver output Enable Pin and driver input end
It is connected with single-chip microcomputer through isolation circuit, the receiver in-phase input end of interface chip connects the first output control through first resistor
Line, the receiver in-phase input end of interface chip connects the output positive voltage terminal of isolating chip through second resistance, interface chip
Receiver in-phase input end also connects the output ground terminal of isolating chip through the first voltage-regulator diode, and the receiver for receiving chip is anti-phase
Input through 3rd resistor connect the second output control line, receive chip receiver inverting input through the 4th resistance connect every
The output ground terminal of off-chip piece, the 4th resistance two ends are parallel with the second voltage-regulator diode, receive the power end connection connection of chip every
The output positive voltage terminal of off-chip piece, receives the power end of chip also through the output ground terminal of the first capacitance connection isolating chip, receives
The ground terminal of chip connects the output ground terminal of isolating chip.
2. a kind of communicator with antijamming capability as claimed in claim 1, it is characterised in that：The isolation circuit bag
The first isolation circuit, the second isolation circuit and the 3rd isolation circuit are included, first isolation circuit uses the first photoelectrical coupler,
The LED positive poles connection positive source of the first photoelectrical coupler, the LED negative poles of the first photoelectrical coupler connect monolithic through the 5th resistance
The serial data transmitting terminal of machine, the driver input end of the colelctor electrode connecting interface chip of the first photoelectrical coupler, the first photoelectricity
The colelctor electrode of coupler also connects the output positive voltage terminal of isolating chip through the 6th resistance, and the emitter stage of the first photoelectrical coupler connects
Connect the output ground terminal of isolating chip；
Second isolation circuit uses the second photoelectrical coupler, the LED positive poles of the second photoelectrical coupler to be connected through the 7th resistance
The output positive voltage terminal of isolating chip, the receiver output end of the LED negative pole connecting interface chips of the second photoelectrical coupler, second
The colelctor electrode of photoelectrical coupler connects the serial data output terminal of single-chip microcomputer, and the colelctor electrode of the second photoelectrical coupler is also through the 8th electricity
Resistance connection positive source, the grounded emitter of the second photoelectrical coupler；
3rd isolation circuit uses the 3rd photoelectrical coupler, and the LED positive poles of the 3rd photoelectrical coupler are through the 9th resistance
Connection positive source, the LED negative poles of the 3rd photoelectrical coupler connect the 3rd output control line, the colelctor electrode of the 3rd photoelectrical coupler
The output positive voltage terminal of isolating chip is connected, the receiver output of the emitter stage connecting interface chip of the 3rd photoelectrical coupler is enabled
End, the emitter stage of the 3rd photoelectrical coupler also connects the output ground terminal of isolating chip through the tenth resistance.
3. a kind of communicator with antijamming capability as claimed in claim 2, it is characterised in that：The first resistor and
3rd resistor is using the thermistor of positive temperature coefficient.
4. a kind of communicator with antijamming capability as claimed in claim 3, it is characterised in that：First voltage stabilizing two
Pole pipe and the second voltage-regulator diode use transient voltage suppressor.
5. a kind of communicator with antijamming capability as claimed in claim 4, it is characterised in that：The interface chip is adopted
MAX487 chips, the isolating chip is used to use B0505S-1 chips.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621291540.0U CN206224464U (en) | 2016-11-29 | 2016-11-29 | A kind of communicator with antijamming capability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621291540.0U CN206224464U (en) | 2016-11-29 | 2016-11-29 | A kind of communicator with antijamming capability |
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| Publication Number | Publication Date |
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| CN206224464U true CN206224464U (en) | 2017-06-06 |
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ID=58786401
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| Application Number | Title | Priority Date | Filing Date |
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| CN201621291540.0U Active CN206224464U (en) | 2016-11-29 | 2016-11-29 | A kind of communicator with antijamming capability |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109167594A (en) * | 2017-10-30 | 2019-01-08 | 武汉奇致激光技术股份有限公司 | A kind of photoelectric coupling structures and methods of micro controller and one-wire bus device |
| CN112987618A (en) * | 2021-03-25 | 2021-06-18 | 镇江中煤电子有限公司 | 485 communication circuit of sensor of coal mine safety monitoring system |
-
2016
- 2016-11-29 CN CN201621291540.0U patent/CN206224464U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109167594A (en) * | 2017-10-30 | 2019-01-08 | 武汉奇致激光技术股份有限公司 | A kind of photoelectric coupling structures and methods of micro controller and one-wire bus device |
| CN112987618A (en) * | 2021-03-25 | 2021-06-18 | 镇江中煤电子有限公司 | 485 communication circuit of sensor of coal mine safety monitoring system |
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