CN204733160U - A kind of RS485 telecommunication circuit of hyper tape isolation - Google Patents
A kind of RS485 telecommunication circuit of hyper tape isolation Download PDFInfo
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Abstract
The RS485 telecommunication circuit that the utility model provides a kind of hyper tape to isolate, belongs to RS485 telecommunication circuit field.The utility model comprises RS485 bus interface, RS485 interface chip U1, and A, B pin of RS485 interface chip U1 is connected with RS485 bus interface respective data lines A, B respectively; The described RXD pin of RS485 interface chip U1 is connected with the RXD pin of single-chip microcomputer; The described TXD pin of RS485 interface chip U1 is connected with the TXD pin of single-chip microcomputer; RS485 interface chip U1 /RE, DE pin is connected with an I/O mouth of single-chip microcomputer, and described RS485 interface chip U1 is provided with DC/DC converting unit and Magnetic isolation unit.The utility model circuit is simple, and achieve real signal isolation and isolated from power, do not need independent isolating power circuit, communication speed is faster.
Description
Technical field
The utility model relates to RS485 telecommunication circuit, particularly relates to the RS485 telecommunication circuit of a kind of hyper tape isolation.
Background technology
RS485 telecommunication circuit generally speaking can be divided into isolated form and non-isolation type, and what isolated form circuit all will be good in anti-interference and stability than non-isolation type is many.A kind of RS485 telecommunication circuit with isolation realized by optocoupler as shown in Figure 1.In the circuit diagram of Fig. 1, MAX485 chip internal is made up of a receiver and a transmitter, and receiver receives by the level signal of RS485 bus transfer by A, B two ends, and RO is receiver output, is connect the RXD pin of single-chip microcomputer by optocoupler; Be sent in RS485 bus by A, B transmitter receives the data transmitted by single-chip microcomputer by DI pin after, DI is transmitter input, is connect the TXD pin of single-chip microcomputer by optocoupler; / RE, DE pin are the Enable Pin of receiver, transmitter respectively.Because MAX485 chip is half-duplex work, therefore/RE, DE are by an I/O mouth control of single-chip microcomputer.Hold pull-up resistor at A, hold pull down resistor at B, thus when ensureing A, B open circuit or floating, export to be in and determine state (output high level).
But this circuit realizes signal isolation by optocoupler, because optocoupler conversion speed, current-limiting resistance coupling and temperature are on the impact of optocoupler, the baud rate of communication is difficult to reach more than 1M, further, the working power of MAx485 is not the power supply of an isolation, needs design independent isolating power circuit for this reason.
Utility model content
For solving problems of the prior art, the RS485 telecommunication circuit that the utility model provides a kind of hyper tape to isolate.
The utility model comprises RS485 bus interface, RS485 interface chip U1, and A, B pin of described RS485 interface chip U1 is connected with described RS485 bus interface respective data lines A, B respectively; The RXD pin of described RS485 interface chip U1 is receiver output, is connected with the RXD pin of single-chip microcomputer by RXD order wire; The TXD pin of described RS485 interface chip U1 is transmitter input, is connected with the TXD pin of single-chip microcomputer by TXD order wire; Described RS485 interface chip U1 /RE, DE pin is respectively the Enable Pin of receiver, transmitter, be connected with an I/O mouth of single-chip microcomputer, it is characterized in that: described RS485 interface chip U1 is provided with DC/DC converting unit and Magnetic isolation unit, the VCC pin of described RS485 interface chip U1 connects power supply, the VISOIN pin of described RS485 interface chip U1 is insulating power supply input, and the VISOOUT pin of described RS485 interface chip U1 is that insulating power supply exports.
The utility model is further improved, described TXD order wire is connected to the first indicating circuit, described RXD order wire is connected to the second indicating circuit, is used to indicate transfer of data.
The utility model is further improved, described first indicating circuit comprises LED 1, resistance R2 and voltage stabilizing didoe ZD2, described resistance R2 mono-termination power, the other end is connected with described voltage stabilizing didoe ZD2 negative pole with described LED 1 positive pole, described LED 1 negative pole is connected with TXD order wire, described voltage stabilizing didoe ZD2 plus earth; Described second indicating circuit comprises LED 2, resistance R1 and voltage stabilizing didoe ZD1, described resistance R1 mono-termination power, the other end is connected with described voltage stabilizing didoe ZD1 negative pole with described LED 2 positive pole, described LED 2 negative pole is connected with RXD order wire, described voltage stabilizing didoe ZD1 plus earth.Two communication LED light should in the communications status of the current circuit of instruction, and the LED1 flicker when there being data to send, when there being data receiver, LED2 flicker, is convenient to search communication failure.
The utility model is further improved, and is provided with interface protective circuit between described RS485 interface chip U1 and described RS485 bus interface, for the protection of the safety of communication interface, damages circuit when preventing voltage or electric current from changing suddenly.
The utility model is further improved; described interface protective circuit comprises thermistor PTC1, thermistor PTC2 and transient suppressor D1; series thermal-sensitive resistance PTC1 on described data wire A; series thermal-sensitive resistance PTC2 on described data wire B, between described transient suppressor D1 parallel connection and described data wire A and data wire B.The circuit that thermistor and transient suppressor are formed, effectively can protect and cause damage because accidental destruction or human error import civil power to serial ports, also effectively can reduce the impact of lightning induction on this interface.
The utility model is further improved, and described transient suppressor D1 is integrated with two bipolarity Transient Suppression Diodes, and they are connected with data wire A and data wire B respectively, other end ground connection.
The utility model is further improved, the VISOIN pin of described RS485 interface chip U1 and VISOOUT pin short circuit, and and is connected to anti-signal reflex circuit between data wire A, data wire B.The signal reflex that effective minimizing causes because communication distance is longer.
The utility model is further improved, described anti-signal reflex circuit comprises resistance R3, bigoted resistance R4 and R6, terminal resistance R5, voltage stabilizing didoe ZD3 and toggle switch K1, VISOIN pin and the VISOOUT pin of described resistance R3 one end and described RS485 interface chip U1 are connected, the other end is connected with voltage stabilizing didoe ZD3 negative pole with bigoted resistance R4, described voltage stabilizing didoe ZD3 plus earth, described bigoted resistance R4, terminal resistance R5, resistance R6 connects, described resistance R6 ground connection, described toggle switch K1 mono-side joint terminal resistance R5 two ends, opposite side is connected with data wire A and data wire B respectively.Terminal resistance R5 can be selected whether to access by plucking number sign switch K1, facilitate field adjustable.In addition, selectivity accesses bigoted resistance R4, R6 and terminal resistance R5, in the network of RS485 communication composition, access terminal resistance R5 and bigoted resistance R4, R6 of initiating terminal equipment and end-equipment can reduce the signal reflex caused because communication distance is longer, improves system communication ability.
The utility model is further improved, and described RS485 interface chip U1 is ADM2587E chip.
The utility model is further improved, described ADM2587E chip Y pin and A pin short circuit, described ADM2587E chip Z pin and B pin short circuit, be connected to electric capacity C1 and electric capacity C2 between described ADM2587E chip second pin VCC and power supply, described ADM2587E chip the 8th pin VCC is also connected to electric capacity C3 and electric capacity C4, be connected to electric capacity C5 and electric capacity C6 between described ADM2587E chip the 12 pin VISOOUT and antireflection circuit, be connected to electric capacity C7 and electric capacity C8 between described ADM2587E chip the 19 pin VISOIN and antireflection circuit, described electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, electric capacity C5, electric capacity C6, electric capacity C7, electric capacity C8 other end ground connection.External capacitor effectively suppresses DC/DC converting unit noise.
Compared with prior art, the beneficial effects of the utility model are: circuit is simple, and achieve real signal isolation and isolated from power, do not need independent isolating power circuit, communication speed is especially up to 16Mbps.Whether terminal resistance can be selected to access by plucking number sign switch, facilitate field adjustable, two communication LED light should, in the communications status of the current circuit of instruction, be convenient to search communication failure.Effectively can protect, because accidental destruction or human error import civil power, damage be caused to serial ports, also effectively can reduce the impact of lightning induction on this interface.
Accompanying drawing explanation
Fig. 1 is prior art RS485 telecommunication circuit figure;
Fig. 2 is the RS485 telecommunication circuit figure of the utility model hyper tape isolation;
Fig. 3 and Fig. 4 is the part details enlarged drawing of Fig. 2.
Embodiment
Below in conjunction with drawings and Examples, the utility model is described in further details.
As shown in Figures 2 to 4, the RS485 telecommunication circuit of the utility model hyper tape isolation, comprise RS485 bus interface, RS485 interface chip U1, A, B pin of described RS485 interface chip U1 is connected with described RS485 bus interface respective data lines A, B respectively; The RXD pin of described RS485 interface chip U1 is receiver output, is connected with the RXD pin of single-chip microcomputer by RXD order wire; The TXD pin of described RS485 interface chip U1 is transmitter input, is connected with the TXD pin of single-chip microcomputer by TXD order wire; Described RS485 interface chip U1 /RE, DE pin is respectively the Enable Pin of receiver, transmitter, be connected with the I/O mouth of single-chip microcomputer, it is characterized in that: described RS485 interface chip U1 is provided with DC/DC converting unit and Magnetic isolation unit, the VCC pin of described RS485 interface chip U1 connects power supply, the VISOIN pin of described RS485 interface chip U1 is insulating power supply input, and the VISOOUT pin of described RS485 interface chip U1 is that insulating power supply exports.
In the present embodiment, described RS485 interface chip U1 is ADM2587E chip, it comprises a triple channel isolator, the differential driver of a band ternary output, a differential receiver and a DC/DC transducer being with tri-state to input, be the RS-485/RS-422 transceiver of a isolation, can be configured to half-or full-duplex pattern.
In Fig. 2, described ADM2587E chip Y pin and A pin short circuit, described ADM2587E chip Z pin and B pin short circuit, be configured to semiduplex mode.The frequency of internal DC/DC converting unit---DC-DC pulse transformer is 180MHZ, need abundant shunt capacitance by its noise suppressed to minimum, therefore, be connected to electric capacity C1 and electric capacity C2 between described ADM2587E chip second pin VCC and power supply, described ADM2587E chip the 8th pin VCC is also connected to electric capacity C3 and electric capacity C4, be connected to electric capacity C5 and electric capacity C6 between described ADM2587E chip the 12 pin VISOOUT and antireflection circuit, be connected to electric capacity C7 and electric capacity C8 between described ADM2587E chip the 19 pin VISOIN and anti-signal reflex circuit, described electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, electric capacity C5, electric capacity C6, electric capacity C7, electric capacity C8 other end ground connection.
Described ADM2587E chip first pin, the 3rd pin, the 9th pin, the tenth pin, the 11 pin, the 14 pin, the 16 pin, the 20 pin ground connection; 4th pin is RXD pin, and the 5th pin is /RE pin, and the 6th pin is DE pin, and the 7th pin is TXD pin, and the 13 pin is Y pin, and the 15 pin is Z pin, and the 17 pin is B pin, and the 18 pin is A pin.
The RS485 telecommunication circuit of the utility model hyper tape isolation also comprises indicating circuit, anti-signal reflex circuit and interface protective circuit.
Described TXD order wire is connected to the first indicating circuit, described RXD order wire is connected to the second indicating circuit, described first indicating circuit comprises LED 1, resistance R2 and voltage stabilizing didoe ZD2, described resistance R2 mono-termination power, the other end is connected with described voltage stabilizing didoe ZD2 negative pole with described LED 1 positive pole, described LED 1 negative pole is connected with TXD order wire, described voltage stabilizing didoe ZD2 plus earth; Described second indicating circuit comprises LED 2, resistance R1 and voltage stabilizing didoe ZD1, described resistance R1 mono-termination power, the other end is connected with described voltage stabilizing didoe ZD1 negative pole with described LED 2 positive pole, described LED 2 negative pole is connected with RXD order wire, described voltage stabilizing didoe ZD1 plus earth.Two communication LED light should in the communications status of the current circuit of instruction, and the LED1 flicker when there being data to send, when there being data receiver, LED2 flicker, is convenient to search communication failure.
Be provided with interface protective circuit between described RS485 interface chip U1 and described RS485 bus interface, for the protection of the safety of communication interface, when preventing voltage or electric current from changing suddenly, damage circuit.
Described interface protective circuit comprises thermistor PTC1, thermistor PTC2 and transient suppressor D1; series thermal-sensitive resistance PTC1 on described data wire A; series thermal-sensitive resistance PTC2 on described data wire B, between described transient suppressor D1 parallel connection and described data wire A and data wire B.The circuit that thermistor and transient suppressor are formed, effectively can protect and cause damage because accidental destruction or human error import civil power to serial ports, also effectively can reduce the impact of lightning induction on this interface.
PTC thermistor is sealed in the data wire A and data wire B of telecommunication circuit; and access transient suppressor D1 formation protective circuit; its operation principle is as follows: PTC thermistor is equivalent to the current-limiting resistance sealing in this circuit under normal circumstances; resistance does not change, and during electric voltage exception, transient suppressor D1 will be caused breakdown; communication interface is protected; now big current flows through PTC thermistor, makes its resistance become sudden transformation, thus reaches the object of protection.After overvoltage disappears, PTC thermistor resistance will return to initial condition, not have influence on communication function.
The VISOIN pin of described RS485 interface chip U1 and VISOOUT pin short circuit, and and be connected to anti-signal reflex circuit between data wire A, data wire B.The signal reflex that effective minimizing causes because communication distance is longer.
Described antireflection circuit comprises resistance R3, bigoted resistance R4 and R6, terminal resistance R5, voltage stabilizing didoe ZD3 and toggle switch K1, VISOIN pin and the VISOOUT pin of described resistance R3 one end and described RS485 interface chip U1 are connected, the other end is connected with voltage stabilizing didoe ZD3 negative pole with bigoted resistance R4, described voltage stabilizing didoe ZD3 plus earth, described bigoted resistance R4 and R6, terminal resistance R5 connect, described resistance R6 ground connection, described toggle switch K1 mono-side joint terminal resistance R5 two ends, opposite side is connected with data wire A and data wire B respectively.Terminal resistance R5 can be selected whether to access by plucking number sign switch K1, facilitate field adjustable.In addition, selectivity accesses bigoted resistance R4 and terminal resistance R5, in the network of RS485 communication composition, initiating terminal equipment and the end-equipment resistance R5 and bigoted resistance R4 that accesses terminal can reduce the signal reflex caused because communication distance is longer, improves system communication ability.
The embodiment of the above is better embodiment of the present utility model; not limit concrete practical range of the present utility model with this; scope of the present utility model comprises and is not limited to this embodiment, and all equivalence changes done according to the utility model are all in protection range of the present utility model.
Claims (10)
1. a RS485 telecommunication circuit for hyper tape isolation, comprise RS485 bus interface, RS485 interface chip U1, A, B pin of described RS485 interface chip U1 is connected with described RS485 bus interface respective data lines A, B respectively; The RXD pin of described RS485 interface chip U1 is receiver output, is connected with the RXD pin of single-chip microcomputer by RXD order wire; The TXD pin of described RS485 interface chip U1 is transmitter input, is connected with the TXD pin of single-chip microcomputer by TXD order wire; Described RS485 interface chip U1 /RE, DE pin is respectively the Enable Pin of receiver, transmitter, be connected with an I/O mouth of single-chip microcomputer, it is characterized in that: described RS485 interface chip U1 is provided with DC/DC converting unit and Magnetic isolation unit, the VCC pin of described RS485 interface chip U1 connects power supply, the VISOIN pin of described RS485 interface chip U1 is insulating power supply input, and the VISOOUT pin of described RS485 interface chip U1 is that insulating power supply exports.
2. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 1, is characterized in that: described TXD order wire is connected to the first indicating circuit, and described RXD order wire is connected to the second indicating circuit.
3. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 2, it is characterized in that: described first indicating circuit comprises LED 1, resistance R2 and voltage stabilizing didoe ZD2, described resistance R2 mono-termination power, the other end is connected with described voltage stabilizing didoe ZD2 negative pole with described LED 1 positive pole, described LED 1 negative pole is connected with TXD order wire, described voltage stabilizing didoe ZD2 plus earth; Described second indicating circuit comprises LED 2, resistance R1 and voltage stabilizing didoe ZD1, described resistance R1 mono-termination power, the other end is connected with described voltage stabilizing didoe ZD1 negative pole with described LED 2 positive pole, described LED 2 negative pole is connected with RXD order wire, described voltage stabilizing didoe ZD1 plus earth.
4. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 1, is characterized in that: be provided with interface protective circuit between described RS485 interface chip U1 and described RS485 bus interface.
5. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 4; it is characterized in that: described interface protective circuit comprises thermistor PTC1, thermistor PTC2 and transient suppressor D1; series thermal-sensitive resistance PTC1 on described data wire A; series thermal-sensitive resistance PTC2 on described data wire B, described transient suppressor D1 is parallel between described data wire A and data wire B.
6. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 5, is characterized in that: described transient suppressor D1 is integrated with two bipolarity Transient Suppression Diodes, and they are connected with data wire A and data wire B respectively, other end ground connection.
7. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 1, is characterized in that: the VISOIN pin of described RS485 interface chip U1 and VISOOUT pin short circuit, and and is connected to anti-signal reflex circuit between data wire A, data wire B.
8. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 7, it is characterized in that: described anti-signal reflex circuit comprises resistance R3, bigoted resistance R4 and R6, terminal resistance R5, voltage stabilizing didoe ZD3 and toggle switch K1, VISOIN pin and the VISOOUT pin of described resistance R3 one end and described RS485 interface chip U1 are connected, the other end is connected with voltage stabilizing didoe ZD3 negative pole with bigoted resistance R4, described voltage stabilizing didoe ZD3 plus earth, described resistance R4, terminal resistance R5, resistance R6 connects, described resistance R6 ground connection, described toggle switch K1 mono-side joint terminal resistance R5 two ends, opposite side is connected with data wire A and data wire B respectively.
9. the RS485 telecommunication circuit of a kind of hyper tape isolation according to any one of claim 1-8, is characterized in that: described RS485 interface chip U1 is ADM2587E chip.
10. the RS485 telecommunication circuit of a kind of hyper tape isolation according to claim 9, it is characterized in that: described ADM2587E chip Y pin and A pin short circuit, described ADM2587E chip Z pin and B pin short circuit, be connected to electric capacity C1 and electric capacity C2 between described ADM2587E chip second pin VCC and power supply, described ADM2587E chip the 8th pin VCC is also connected to electric capacity C3 and electric capacity C4, be connected to electric capacity C5 and electric capacity C6 between described ADM2587E chip the 12 pin VISOOUT and anti-signal reflex circuit, be connected to electric capacity C7 and electric capacity C8 between described ADM2587E chip the 19 pin VISOIN and anti-signal reflex circuit, described electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, electric capacity C5, electric capacity C6, electric capacity C7, electric capacity C8 other end ground connection.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105553504A (en) * | 2016-01-15 | 2016-05-04 | 广州致远电子股份有限公司 | Isolated transceiver module and manufacturing method thereof |
| CN106021166A (en) * | 2016-05-16 | 2016-10-12 | 从兴技术有限公司 | RS485 bus-based multi-host communication circuit |
| CN106941349A (en) * | 2016-01-05 | 2017-07-11 | 浙江盾安机械有限公司 | A kind of low delay optical coupling isolation circuit and RS485 isolate telecommunication circuit |
| CN109245751A (en) * | 2018-11-16 | 2019-01-18 | 上海沥马自动化设备有限公司 | A kind of PNP or NPN input signal independence switch type power amplification plate |
| CN109587020A (en) * | 2018-11-08 | 2019-04-05 | 中国电子科技集团公司第三十八研究所 | A kind of the double redundancy airborne radar communication means and device of band isolation |
| CN114400171A (en) * | 2022-01-06 | 2022-04-26 | 南京觅丹电子信息有限公司 | Electric operating mechanism with 485 interface |
| CN115826663A (en) * | 2023-02-15 | 2023-03-21 | 鲁欧智造(山东)高端装备科技有限公司 | High-precision bipolar numerical control constant current source control system |
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2015
- 2015-05-29 CN CN201520362595.5U patent/CN204733160U/en active Active
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106941349A (en) * | 2016-01-05 | 2017-07-11 | 浙江盾安机械有限公司 | A kind of low delay optical coupling isolation circuit and RS485 isolate telecommunication circuit |
| CN105553504A (en) * | 2016-01-15 | 2016-05-04 | 广州致远电子股份有限公司 | Isolated transceiver module and manufacturing method thereof |
| CN106021166A (en) * | 2016-05-16 | 2016-10-12 | 从兴技术有限公司 | RS485 bus-based multi-host communication circuit |
| CN106021166B (en) * | 2016-05-16 | 2019-02-26 | 从兴技术有限公司 | Multi-host communication circuit based on RS485 bus |
| CN109587020A (en) * | 2018-11-08 | 2019-04-05 | 中国电子科技集团公司第三十八研究所 | A kind of the double redundancy airborne radar communication means and device of band isolation |
| CN109587020B (en) * | 2018-11-08 | 2020-11-27 | 中国电子科技集团公司第三十八研究所 | Dual-redundancy airborne radar communication method and device with isolation |
| CN109245751A (en) * | 2018-11-16 | 2019-01-18 | 上海沥马自动化设备有限公司 | A kind of PNP or NPN input signal independence switch type power amplification plate |
| CN109245751B (en) * | 2018-11-16 | 2024-02-09 | 上海沥马自动化设备有限公司 | PNP or NPN input signal independent switching type power amplification plate |
| CN114400171A (en) * | 2022-01-06 | 2022-04-26 | 南京觅丹电子信息有限公司 | Electric operating mechanism with 485 interface |
| CN115826663A (en) * | 2023-02-15 | 2023-03-21 | 鲁欧智造(山东)高端装备科技有限公司 | High-precision bipolar numerical control constant current source control system |
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