CN209267569U - A kind of improved 485 automatic transceiving circuit - Google Patents
A kind of improved 485 automatic transceiving circuit Download PDFInfo
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- CN209267569U CN209267569U CN201920229165.4U CN201920229165U CN209267569U CN 209267569 U CN209267569 U CN 209267569U CN 201920229165 U CN201920229165 U CN 201920229165U CN 209267569 U CN209267569 U CN 209267569U
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Abstract
The utility model discloses a kind of improved 485 automatic transceiving circuits, including chip, diode TX, diode RX, triode, regulator tube group Z1, capacitor C1, R1, R2, R3, R4, R5, R6, R7, R8 and R9, the left end of the R1 and the cathode of diode TX are electrically connected, the right end of the R1 is electrically connected with the base stage of the left end of R2 and triode respectively, the end D of the emitter of the triode and the right end of R2 and chip is electrically connected, and the utility model relates to RS485 field of circuit technology.The improved 485 automatic transceiving circuit, the automatic transceiving of data is realized by sending the low and high level of data, with data transmit-receive state instruction class, transmitting-receiving conversion process is realized by circuit itself completely, MCU does not have to be concerned about RD pin status, the software processing flow of data transmit-receive is enormously simplified, circuit stability is reliable, is easy to use.
Description
Technical field
The utility model relates to RS485 field of circuit technology, specially a kind of improved 485 automatic transceiving circuit.
Background technique
Intelligence instrument grows up with the maturation of singlechip technology, and present world's instrument market is substantially by intelligence instrument
It is monopolized, this is attributed to the needs of IT application in enterprises, and enterprise's one of necessary condition in instrument selection seeks to have
There is connected network communication interface.It is initially data analog signal output simple process quantity, later instrumentation tap is RS232 interface, this
Point-to-point communication mode may be implemented in interface, but this mode can not achieve network savvy, and subsequent occurrences of RS485 is solved
This problem.RS485 is the standard of the electrical characteristic of the driver and receiver in a definition balance digital multi-drop system, should
Standard is defined by Telecommunications Industries Association and electronic industries alliance.It can be under the conditions of remote using the digital communications network of the standard
And effectively transmitted signal under the big environment of electronic noise.RS-485 makes cheap local network and multiple branch circuit communication link
It is configured as possibility.
The sending and receiving data that TTL turns 485 control chips is controlled by the RD pin of chip, is normally applied in circuit, is needed by MCU
This pin is dragged down or drawn high to realize the transmitting-receiving of data, therefore in corresponding data receiver and transmission process, needs especially
Pay attention to the state of RD pin, otherwise easily causes the transmitting-receiving mistake of data.
Utility model content
In view of the deficiencies of the prior art, the utility model provides a kind of improved 485 automatic transceiving circuit, solves existing
485 automatic transceiving circuits having, be easy to cause the problem of data transmit-receive mistake.
In order to achieve the above object, the utility model is achieved by the following technical programs: a kind of improved 485 automatic receipts
Power Generation Road, including chip, diode TX, diode RX, triode, regulator tube group Z1, capacitor C1, R1, R2, R3, R4, R5, R6,
The cathode of R7, R8 and R9, the left end of the R1 and diode TX are electrically connected, the right end of the R1 respectively with the left end of R2 and three
The base stage of pole pipe is electrically connected, the end the D electric connection of the emitter of the triode and the right end of R2 and chip, the triode
Collector be electrically connected respectively with the end DE of chip and R3, R10, R4, R5, capacitor is electrically connected in the other end of the R3
The end VCC of C1 and chip, the other end of the R10 and the anode of diode TX are electrically connected, the end R of the chip and diode
The cathode of RX is electrically connected, and the anode of the diode RX and one end of R4 are electrically connected, the other end of the R4 and chip
The end VCC is electrically connected, and the end VCC of one end of the R5 and chip is electrically connected, the other end of the R5 respectively with one end of R6
It is electrically connected with the end A of chip.
Preferably, the end B of the chip is electrically connected with R7 and R8 respectively.
Preferably, the other end of the R6 is electrically connected with R9 and regulator tube group Z1 respectively.
Preferably, the other end of the R9 is electrically connected with the other end of R7 and regulator tube group Z1 respectively.
Preferably, one end of the R5 is electrically connected with capacitor C1 and power supply VCC respectively.
Preferably, one end of the R8 and capacitor C1 and ground terminal are electrically connected.
Beneficial effect
The utility model provides a kind of improved 485 automatic transceiving circuit.Have compared with prior art following beneficial
Effect:
(1), the improved 485 automatic transceiving circuit is arranged by diode TX and pull-up resistor R10, by sending number
According to low and high level realize the automatic transceivings of data, have data transmit-receive state instruction class, transmitting-receiving conversion process is completely by this
Body circuit realizes that MCU does not have to be concerned about RD pin status, enormously simplifies the software processing flow of data transmit-receive, circuit stability can
It leans on, is easy to use.
(2), the improved 485 automatic transceiving circuit, by the setting of R6 and R7, above-mentioned resistance rise in circuit current limliting and
The effect for improving voltage regulation result is easy to burn out voltage-stabiliser tube, voltage regulation result also can be very poor, the resistance of current-limiting resistance if the resistance is not added
Value is bigger, and circuit voltage regulation performance is better.
Detailed description of the invention
Fig. 1 is the utility model electrical block diagram.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work
Every other embodiment obtained, fall within the protection scope of the utility model.
Referring to Fig. 1, the utility model provides a kind of technical solution: a kind of improved 485 automatic transceiving circuit, including core
Piece, diode TX, diode RX, triode, regulator tube group Z1, capacitor C1, R1, R2, R3, R4, R5, R6, R7, R8 and R9, core
The cathode of the left end of piece model MAX485, the R1 and diode TX are electrically connected, the right end of the R1 respectively with a left side of R2
The base stage of end and triode is electrically connected, and the end the D electric connection of the emitter of the triode and the right end of R2 and chip passes through
The low and high level of data is sent to realize the automatic transceiving of data, has data transmit-receive state instruction class, transmitting-receiving conversion process is complete
It is realized entirely by circuit itself, MCU does not have to be concerned about RD pin status, enormously simplifies the software processing flow of data transmit-receive, circuit
It is reliable and stable, it is easy to use, the collector of the triode is electrically connected with the end DE of chip and R3 respectively, and the R3's is another
The end VCC of R10, R4, R5, capacitor C1 and chip, the other end of the R10 and the anode electricity of diode TX is electrically connected in end
Property connection, the cathode of the end R of the chip and diode RX is electrically connected, and the anode of the diode RX and one end of R4 are electrical
Connection, the other end of the R4 and the end VCC of chip are electrically connected, and one end of the R5 and the end VCC of chip are electrically connected, institute
The other end for stating R5 is electrically connected with one end of R6 and the end A of chip respectively, and the end B of chip is electrically connected with R7 and R8 respectively,
The other end of R6 is electrically connected with R9 and regulator tube group Z1 respectively, the other end of R9 respectively with the other end of R7 and regulator tube group Z1
It is electrically connected, one end of R5 is electrically connected with capacitor C1 and power supply VCC respectively, and one end and the capacitor C1 and ground terminal of R8 electrically connects
It connects.
When work, when reception, when default does not have data, TX is high level, and triode Q1 conducting, RE is enabled for low level, R
It is effective to receive data, chip MAX485 is to receive state, when transmission, when sending data 1, when TX is high level, triode Q1 conducting, DE
For low level, transceiver is in reception state at this time, and driver has reformed into high-impedance state, that is, transmitting terminal is disconnected with A, B,
The voltage between A, B is dependent on the upper pull down resistor of A, B at this time, and A is high level, B is low level, that is, logic 1, hair
When sending data 0, TX is low level, and triode Q1 cut-off, DE is high level, and driver is enabled, and just D is ground connection at this time,
It is exactly low level, it is 1, A 0, that is, logical zero that driver, which will also drive output B,.
It should be noted that, in this document, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any actual relationship or order or sequence.Moreover, the terms "include", "comprise" or its any other variant are intended to
Non-exclusive inclusion, so that the process, method, article or equipment including a series of elements is not only wanted including those
Element, but also including other elements that are not explicitly listed, or further include for this process, method, article or equipment
Intrinsic element.
While there has been shown and described that the embodiments of the present invention, for the ordinary skill in the art,
It is understood that these embodiments can be carried out with a variety of variations in the case where not departing from the principles of the present invention and spirit, repaired
Change, replacement and variant, the scope of the utility model is defined by the appended claims and the equivalents thereof.
Claims (6)
1. a kind of improved 485 automatic transceiving circuit, including chip, diode TX, diode RX, triode, regulator tube group Z1,
Capacitor C1, R1, R2, R3, R4, R5, R6, R7, R8 and R9, it is characterised in that: the left end of the R1 and the cathode electricity of diode TX
Property connection, the right end of the R1 respectively with the base stage of the left end of R2 and triode be electrically connected, the emitter of the triode with
The right end of R2 and the end D of chip are electrically connected, and the collector of the triode is electrically connected with the end DE of chip and R3 respectively, institute
The end VCC of R10, R4, R5, capacitor C1 and chip, the other end and diode of the R10 is electrically connected in the other end for stating R3
The anode of TX is electrically connected, and the end R of the chip and the cathode of diode RX are electrically connected, the anode and R4 of the diode RX
One end be electrically connected, the end VCC of the other end of the R4 and chip is electrically connected, one end of the R5 and the end VCC of chip
It is electrically connected, the other end of the R5 is electrically connected with one end of R6 and the end A of chip respectively.
2. the improved 485 automatic transceiving circuit of one kind according to claim 1, it is characterised in that: the end B of the chip point
It is not electrically connected with R7 and R8.
3. the improved 485 automatic transceiving circuit of one kind according to claim 1, it is characterised in that: the other end of the R6
It is electrically connected respectively with R9 and regulator tube group Z1.
4. the improved 485 automatic transceiving circuit of one kind according to claim 1, it is characterised in that: the other end of the R9
It is electrically connected respectively with the other end of R7 and regulator tube group Z1.
5. the improved 485 automatic transceiving circuit of one kind according to claim 1, it is characterised in that: one end of the R5 point
It is not electrically connected with capacitor C1 and power supply VCC.
6. the improved 485 automatic transceiving circuit of one kind according to claim 1, it is characterised in that: one end of the R8 with
Capacitor C1 and ground terminal are electrically connected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920229165.4U CN209267569U (en) | 2019-02-22 | 2019-02-22 | A kind of improved 485 automatic transceiving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920229165.4U CN209267569U (en) | 2019-02-22 | 2019-02-22 | A kind of improved 485 automatic transceiving circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209267569U true CN209267569U (en) | 2019-08-16 |
Family
ID=67585269
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920229165.4U Active CN209267569U (en) | 2019-02-22 | 2019-02-22 | A kind of improved 485 automatic transceiving circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209267569U (en) |
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2019
- 2019-02-22 CN CN201920229165.4U patent/CN209267569U/en active Active
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