CN206077379U - Repeat circuit and half duplex communication circuit for half duplex communication - Google Patents
Repeat circuit and half duplex communication circuit for half duplex communication Download PDFInfo
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- CN206077379U CN206077379U CN201621095307.5U CN201621095307U CN206077379U CN 206077379 U CN206077379 U CN 206077379U CN 201621095307 U CN201621095307 U CN 201621095307U CN 206077379 U CN206077379 U CN 206077379U
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Abstract
The utility model discloses a kind of repeat circuit for half duplex communication, including the first transmission circuit and the second transmission circuit；First transmission circuit includes the first communication chip and first switch device, second transmission circuit includes the second communication chip and second switch device, the outfan of first communication chip is coupled to the input of the second communication chip, and the outfan of second communication chip is coupled to the input of the first communication chip.A kind of repeat circuit for half duplex communication that this utility model is provided, can be used in long-distance transmissions bus, it is ensured that communication speed, can also increase the number of nodes in bus, reduce data signal distortion.The invention also discloses a kind of half duplex communication circuit, including the repeat circuit for half duplex communication described at least one.A kind of half duplex communication circuit that this utility model is provided, in the case where data signal transmission baud rate is certain, increased transmission range.
Description
Technical field
This utility model is related to half duplex communication technical field, more particularly to for the transmission circuit of half duplex communication, in
Relay road and half duplex communication circuit.
Background technology
In Industry Control occasion, RS485 buses are simple because of its interface, and networking is convenient, obtain the features such as long transmission distance
Extensively apply.RS485 interfaces and RS232 interfaces are all based on the communication interface of serial ports, to the operation of data transmit-receive be it is consistent,
So being equally the bsp driver using WinCE.But there is larger difference in both communication modes in actual applications,
RS232 interfaces are full-duplex data communication mode, and RS485 interfaces are half-duplex data communication mode, and the transmitting-receiving to data
Can not carry out simultaneously, be to ensure that data transmit-receive does not have conflict, need to be switched by the travel direction on hardware, correspondingly be required soft
Coordinated on part, strictly transmitting-receiving process is separated.
RS485 interfaces composition half-duplex network, usually two-wire system, are transmitted using Shielded Twisted Pair more.This wiring side
Formula is bus type topological structure, and 32 nodes can be at most mounted in a bus.It is general using master in RS485 communication networks
From the host tape of communication mode, i.e.,.In Industry Control occasion, RS485 buses are simple because of its interface, and networking is convenient, transmission distance
The features such as away from and be used widely.
When using RS485 interfaces, for specific transmission line, from RS485 interfaces to load data signal transmission institute
The maximum transmission distance that can be reached is inversely proportional to the baud rate of data signal transmission, and maximum transmission distance is mainly lost by data signal
The factors such as true and noise affect.Although in theory, being transmitted by RS485 when data communication rates are less than 100Kbps
Transmission range up to 1200 meters, but in some long-distance transmissions occasions, this can not still meet requirement.
Utility model content
First purpose of the present utility model is to provide a kind of repeat circuit for half duplex communication, be can be used for remote
On transfer bus, increase the number of nodes in bus, reduce data signal distortion.
Second purpose of the present utility model is to provide a kind of half duplex communication circuit, in data signal transmission baud rate one
In the case of fixed, transmission range is increased.
Above-mentioned purpose of the present utility model technical scheme is that.
This utility model provides a kind of repeat circuit for half duplex communication, including the first transmission circuit and second is received
Power Generation Road；
First transmission circuit includes the first communication chip and first switch device；
The first switch device includes the first control pole, the first driving stage and the second driving stage；First control
Pole is coupled to the input of first communication chip, and first driving stage is coupled to the reception of first communication chip and makes
Energy end and transmission Enable Pin, first driving stage are further coupled to VCC voltages；The second driving stage ground connection；
Second transmission circuit includes the second communication chip and second switch device；
The second switch device includes the second control pole, the 3rd driving stage and the 4th driving stage；Second control
Pole is coupled to the input of second communication chip, and the reception that the 3rd driving stage is coupled to second communication chip makes
Energy end and transmission Enable Pin, the 3rd driving stage are further coupled to VCC voltages；The 4th driving stage ground connection；
The outfan of first communication chip is coupled to the input of the second communication chip, second communication chip
Outfan is coupled to the input of the first communication chip.
Optionally：First communication chip and the second communication chip are 485 chips.
Optionally：The first switch device and second switch device are field effect transistor.
Optionally：The first switch device is coupled to the input of the first communication chip by first resistor, and described
Two switching devices are coupled to the input of the second communication chip by second resistance.
Optionally：The first switch device and second switch device are transistor.
Optionally：The outfan of first transmission circuit is coupled to the second transmission circuit by the first signal holding unit
Input, the outfan of second transmission circuit is coupled to the input of the first transmission circuit by secondary signal holding unit
End.
Correspondingly, this utility model additionally provides a kind of half duplex communication circuit, including above-mentioned for half duplex communication
Repeat circuit.
The beneficial effects of the utility model are：
This utility model provide the repeat circuit for half duplex communication, by the first transmission circuit, second transmitting-receiving
In circuit and the circuit configurations between the first transmission circuit and the second transmission circuit, following function is realized：If no data letter
Number it is input into from the data transmit-receive end of the first communication chip, the first communication chip is made in receiving data letter by first switch device
Number state；If there is data signal to be input into from the data transmit-receive end of the first communication chip, the second communication is made by first switch device
Data signal is exported from its data transmit-receive end by chip in condition data signal is sent.In the same manner, above-mentioned functions are applied to second
Communication chip.
Therefore, the repeat circuit is used for long-distance transmissions bus, can increase the number of nodes in bus, reduces data letter
Number distortion.
The half duplex communication circuit that this utility model is provided, including above-mentioned repeat circuit, thus increased communication line
Interior joint quantity, reduces data signal distortion, it is ensured that communication speed, increased transmission range.
Description of the drawings
Fig. 1 is the schematic diagram of the transmission circuit for half duplex communication that this utility model embodiment one is provided；
Fig. 2 is the schematic diagram of the repeat circuit for half duplex communication that this utility model embodiment two is provided；
Fig. 3 is the schematic diagram of the repeat circuit for half duplex communication that this utility model embodiment three is provided；
Fig. 4 is the schematic diagram of the half duplex communication circuit that this utility model example IV is provided.
Specific embodiment
The present invention is described in further detail below in conjunction with accompanying drawing.
In following examples by the first communication chip, the second communication chip, first switch device, second switch device,
One signal holding unit, secondary signal holding unit, communication chip U1, communication chip U2 are expressed as respectively, switching device Q1, are opened
Close device Q2, resistance R1, resistance R2, signal holding unit 1, signal holding unit 2.
Embodiment one：
With reference to Fig. 1, a kind of transmission circuit for half duplex communication is shown, which includes communication chip U1, switching device
Q1, resistance R1 and resistance R2.
In the transmission circuit, communication chip U1, communication chip U2 are 485 chips, and switching device Q1, switching device Q2 are field
Effect pipe, wherein communication chip can also be this kind of chips for half duplex communication of picture CC2520 zigbee chips, wherein
Switching device can also be as GTO, GTR or MOSFET this kind of controllable switching device.
In the transmission circuit, 485 chip U1 have two data sending and receiving ends A, B, reception Enable Pin DE, a transmission
Enable Pin RE, an outfan RO, an input DI, and constitute a VCC end and a GND end of power end；Wherein,
Data transmit-receive end A, B are used to receive or send data signal；Receiving Enable Pin DE is used to make data transmit-receive end be in receiving data
Signal condition, and 485 chip U1 are in receiving data signal condition when receiving Enable Pin DE and being high level；Send Enable Pin RE
For making data transmit-receive end in transmission condition data signal, and 485 chip U1 are in when sending Enable Pin RE and being low level
Send condition data signal；Outfan RO is used to send digital signal；Input DI is used to receive digital signal；Herein, pass through
Data transmit-receive end A, B is received or the signal that sends is data signal, exported by outfan RO or input DI inputs signal
Digital signal is, digital signal is converted to by 485 chip U1 of data signal Jing.
In the transmission circuit, field effect transistor Q1 has control pole, the first driving stage and the second driving stage（I.e. above-mentioned first
Control pole, the second driving stage and the 3rd driving stage, are referred to as control pole, the first driving stage and the second driving stage below）, wherein
Field effect transistor Q1 control pole is coupled to 485 chip U1 inputs by resistance R2, and the first driving stage of field effect transistor Q1 is coupled to 485
Chip U1 receives Enable Pin DE and sends Enable Pin RE and be coupled to VCC voltages by resistance R1, and field effect transistor Q1 second drives
Pole is grounded.
In the transmission circuit, if no data signal is input into from data transmit-receive end A, B, 485 chip U1 outfans RO are height
Level, makes field effect transistor Q1 in the conduction state, and the current potential of 485 chip U1 reception Enable Pins DE, transmission Enable Pin RE is dragged down,
485 chip U1 are made to be in receiving data signal condition；If having data signal to be input into from data transmit-receive end A, B, data signal Jing
485 chip U1 are converted into digital signal and export from outfan RO；If having digital signal to be input into from input DI, the digital signal
485 chip U1 of Jing are converted into data signal and export from data transmit-receive end A, B.
Embodiment two：
With reference to Fig. 2, a kind of repeat circuit for half duplex communication is shown, which includes 485 chip U1, field effect transistor
Q1, resistance R1, resistance R2,485 chip U2, field effect transistor Q2, resistance R3, resistance R4.
In the repeat circuit, 485 chip U1, field effect transistor Q1, resistance R1, resistance R2 constitute an above-mentioned transmitting-receiving electricity
Road, hereinafter referred to as the first transmission circuit 100；In the repeat circuit, 485 chip U2, field effect transistor Q2, resistance R3, resistance R4
Constitute another above-mentioned transmission circuit, hereinafter referred to as the second transmission circuit 200.
In first transmission circuit 100 of the repeat circuit, 485 chip U1 have two data sending and receiving ends A, B, a reception
Enable Pin DE, transmission Enable Pin RE, an outfan RO, an input DI, and constitute a VCC end of power end
With a GND end；Field effect transistor Q1 has control pole, the first driving stage and the second driving stage, wherein field effect transistor Q1 control pole
485 chip U1 inputs are coupled to by resistance R2, the first driving stage of field effect transistor Q1 is coupled to 485 chip U1 and receives Enable Pin
DE is coupled to VCC voltages, the second driving stage of field effect transistor Q1 ground connection with transmission Enable Pin RE and by resistance R1.
In second transmission circuit 200 of the repeat circuit, 485 chip U2 have two data sending and receiving ends A, B, a reception
Enable Pin DE, transmission Enable Pin RE, an outfan RO, an input DI, and constitute a VCC end of power end
With a GND end；Field effect transistor Q2 has control pole, the first driving stage and the second driving stage（I.e. above-mentioned the second control pole,
Three driving stages and the 4th driving stage, are referred to as control pole, the first driving stage and the second driving stage below）, wherein field effect transistor
Q2 control poles are coupled to 485 chip U2 inputs by resistance R4, and the first driving stage of field effect transistor Q2 is coupled to 485 chip U2 and connects
Receive Enable Pin DE and send Enable Pin RE and VCC voltages, the second driving stage of field effect transistor Q2 ground connection are coupled to by resistance R3.
In the repeat circuit, in the first transmission circuit 100,485 chip U1 outfan RO are coupled to the second transmission circuit 200
In 485 chip U2 input DI, in the second transmission circuit 200,485 chip U2 outfan RO are coupled in the first transmission circuit 100
485 chip U1 input DI.
In the repeat circuit, if no data signal is received from 485 chip U1 data transmit-receives end A, B or 485 chip U2 data
Originator A, B input, 485 chip U1 outfan RO, 485 chip U2 outfan RO are high level, make field effect transistor Q1, field respectively
Pipe Q2 is in the conduction state for effect, and 485 chip U1 reception Enable Pins DE and transmission Enable Pin RE, 485 chip U2 are received and made
The current potential of energy end DE and transmission Enable Pin RE is dragged down, and makes 485 chip U1,485 chip U2 be in receiving data signal condition；If
There is data signal from 485 chip U1 data transmit-receives end A, B inputs, that is, have data signal to send from RS485 buses 1, should
Data signal exports Transistor-Transistor Logic level, i.e. digital signal from its outfan RO Jing after 485 chip U1 conversions, and the signal is transferred into 485
Chip U2 input DI, field effect transistor Q2 are coupled with 485 chip U2 inputs DI due to control pole, thus from original conducting state
Switch to cut-off state, the current potential that 485 chip U2 receive Enable Pin DE and transmission Enable Pin RE is raised, is in 485 chip U2
Send condition data signal, 485 chip U2 Transistor-Transistor Logic level is changed after from its data transmit-receive end A, B outputting data signals, will count
It is believed that number sending out from RS485 buses 2；If having data signal from 485 chip U2 data transmit-receives end A, B inputs, that is, there is number
It is believed that number sending from RS485 buses 2, the data signal is electric from its outfan RO output TTL Jing after 485 chip U2 conversions
Put down, i.e. digital signal, the signal is transferred into 485 chip U1 input DI, and field effect transistor Q1 is due to control pole and 485 chip U1
Input DI is coupled, thus switchs to cut-off state from original conducting state, and 485 chip U1 are received Enable Pin DE and enable is sent
The current potential of end RE is raised, and 485 chip U1 is counted from which after Transistor-Transistor Logic level is changed in condition data signal, 485 chip U1 are sent
According to sending and receiving end A, B outputting data signals, will data signal send out from RS485 buses 1.
In the repeat circuit, no matter data signal is sent from RS485 buses 1, or from RS485 buses 2
Send, one of transmission circuit can be guaranteed in receiving data signal condition, other in which is in transmission data
Signal condition, it is ensured that signal transmission unipolarity；And the program is only realized by hardware annexation, does not rely on software.
Embodiment three：
With reference to Fig. 3, a kind of repeat circuit for half duplex communication is shown, which is the middle relay provided to embodiment two
A kind of improvement on road.Specifically, the outfan in the first transmission circuit 100 is coupled to the second receipts by a signal holding unit 1
The input of Power Generation Road 200, is coupled to first transmitting-receiving by a signal holding unit 1 in the outfan of the second transmission circuit 200
The input of circuit 100.
In the repeat circuit, signal holding unit 1 can be voltage follower, signal keeper etc. some can make signal
Keep stable device.In the repeat circuit, 485 chip U1 inputs DI or 485 chips can be made using signal holding unit 1
The digital signal of U2 inputs DI outputs keeps stable, improves anti-interference.
Example IV：
With reference to Fig. 4, a kind of half duplex communication circuit is shown, which includes that at least one is connected in the communication line
Relay road, the repeat circuit are the repeat circuit that embodiment two or embodiment three are provided.
The half duplex communication circuit, increased communication line interior joint quantity, reduce data signal distortion, it is ensured that communication
Speed, can increased transmission range.Data of such as traffic rate less than 100Kbps, the transmission distance being transmitted by RS485
From can only achieve 1200 meters；But in the case of not change data traffic rate, by increasing a section in communication line
Point quantity, that is, increase a repeat circuit, the transmission range that RS485 is transmitted can be made in theory to increase to 2400 meters again, passed through
Increase by two number of nodes in communication line, that is, increase by two repeat circuits, the transmission that RS485 can be transmitted in theory
Distance increases to 3600 meters again, by that analogy.Therefore the half duplex communication circuit is applied to some long-distance transmissions occasions.
This specific embodiment is only explanation of the invention, and which is not limitation of the present invention, people in the art
Member can make the modification for not having creative contribution after this specification is read as needed to the present embodiment, but as long as at this
All protected by Patent Law in the right of invention.
Claims (7)
1. a kind of repeat circuit for half duplex communication, it is characterised in that including the first transmission circuit and the second transmission circuit；
First transmission circuit includes the first communication chip and first switch device；
The first switch device includes the first control pole, the first driving stage and the second driving stage；The first control pole coupling
The input of first communication chip is connected to, first driving stage is coupled to the reception Enable Pin of first communication chip
With send Enable Pin, first driving stage is further coupled to VCC voltages；The second driving stage ground connection；
Second transmission circuit includes the second communication chip and second switch device；
The second switch device includes the second control pole, the 3rd driving stage and the 4th driving stage；The second control pole coupling
The input of second communication chip is connected to, the 3rd driving stage is coupled to the reception Enable Pin of second communication chip
With send Enable Pin, the 3rd driving stage is further coupled to VCC voltages；The 4th driving stage ground connection；
The outfan of first communication chip is coupled to the input of the second communication chip, the output of second communication chip
End is coupled to the input of the first communication chip.
2. the repeat circuit for half duplex communication according to claim 1, it is characterised in that first communication chip
485 chips are with the second communication chip.
3. the repeat circuit for half duplex communication according to claim 1, it is characterised in that the first switch device
Field effect transistor is with second switch device.
4. the repeat circuit for half duplex communication according to claim 3, it is characterised in that the first switch device
The input of the first communication chip is coupled to by first resistor, the second switch device is coupled to second by second resistance
The input of communication chip.
5. the repeat circuit for half duplex communication according to claim 1, it is characterised in that the first switch device
Transistor is with second switch device.
6. the repeat circuit for half duplex communication according to claim 1, it is characterised in that first transmission circuit
Outfan the input of the second transmission circuit, the output of second transmission circuit are coupled to by the first signal holding unit
End is coupled to the input of the first transmission circuit by secondary signal holding unit.
7. a kind of half duplex communication circuit, it is characterised in that including at least one as any one of claim 1 to 6
For the repeat circuit of half duplex communication.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621095307.5U CN206077379U (en) | 2016-09-30 | 2016-09-30 | Repeat circuit and half duplex communication circuit for half duplex communication |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621095307.5U CN206077379U (en) | 2016-09-30 | 2016-09-30 | Repeat circuit and half duplex communication circuit for half duplex communication |
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| Publication Number | Publication Date |
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| CN206077379U true CN206077379U (en) | 2017-04-05 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106301450A (en) * | 2016-09-30 | 2017-01-04 | 浙江方大智控科技有限公司 | Repeat circuit and half duplex communication circuit for half duplex communication |
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2016
- 2016-09-30 CN CN201621095307.5U patent/CN206077379U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106301450A (en) * | 2016-09-30 | 2017-01-04 | 浙江方大智控科技有限公司 | Repeat circuit and half duplex communication circuit for half duplex communication |
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