CN104090511A - Circuit and method for achieving non-polar 485 communication - Google Patents
Circuit and method for achieving non-polar 485 communication Download PDFInfo
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- CN104090511A CN104090511A CN201410307611.0A CN201410307611A CN104090511A CN 104090511 A CN104090511 A CN 104090511A CN 201410307611 A CN201410307611 A CN 201410307611A CN 104090511 A CN104090511 A CN 104090511A
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Abstract
The invention provides a circuit for achieving non-polar 485 communication. The circuit comprises a polar 485 chip and further comprises an MCU having the serial port polarity setting function. The transmitting end of the polar 485 chip is connected to the first master control receiving end and the second master control receiving end of the MCU, wherein the first master control receiving end is set to have serial port positive polarity, and the second master control receiving end is set to have serial port negative polarity. The receiving end of the polar 485 chip is connected to the master control transmitting end of the MCU. According to the circuit for achieving non-polar 485 communication, non-polar 485 communication is achieved through the polar 485 chip and the MCU having the serial port transceiving inversion function or in the mode that an inverter is connected into the MCU, the cost is not increased, reliability of communication is ensured, and large-scale application and population are facilitated.
Description
Technical field
The present invention relates to the design of 485 telecommunication circuits of electric energy meter, particularly a kind of circuit and method that realizes nonpolarity 485 communications.
Background technology
Existing electric energy meter generally adopts 485 group-net communications, and in the communication line of unipolarity 485 chips of common use, exist A, B polarity point, thereby in networking construction, easily there is A, B end reversal connection and the unsuccessful problem of communication that causes, have a strong impact on on-the-spot operating efficiency.Therefore need to realize the method for nonpolarity 485 communications.
The method that realizes at present nonpolarity 485 communications has following several:
1) realize with 485 chips of 2 pieces of independent outputs that work alone.In the time that outer lines order be can not determine, 2 piece of 485 chip received and dispatched simultaneously, but the signal that only has 1 piece of chip to receive is correct, MCU determines that wherein correct piece, then turn-off that piece of garble, how to access no matter can realize outer lines order, object that all can proper communication.
The shortcoming of this scheme is, must use 2 piece of 485 chip, and every piece 485 all will have holding circuit, increased fabric swatch area, increased cost.
2) realize with 1 piece of non-polar 485 chip.The principle of non-polar 485 chip is to detect identification communication pin polarity by the differential voltage of chip internal, then realizes the communication pin forward of chip or oppositely by being serially connected with the identifying poles switch of communication pin.
The shortcoming of this scheme is, in large-area use, if being close to, the quantity of forward and oppositely chip equates, and while sharing one group of (2) 485 order wire, chip internal cannot judge the polarity of pin, and in large-scale application, and one group of (2) 485 order wire is in the situation that giving no thought to line order, the probability of the positive and negative reciprocity of wiring is exactly equal again, and therefore this chip is in large-scale application, and effect is unsatisfactory.
Summary of the invention
For the method for nonpolarity 485 communications of realizing of a kind of low cost and high reliability is provided, the invention discloses a kind of circuit of realizing nonpolarity 485 communications, include polarity 485 chips, also comprise the MCU that there is serial ports polarity and arrange function, wherein, described in, there is the transmitting terminal of polarity 485 chips to be connected respectively to the first master control receiving end that is set to serial ports positive polarity and the second master control receiving end that is set to serial ports negative polarity of described MCU; The described master control transmitting terminal that has the receiving end of polarity 485 chips to be connected to described MCU.
Preferably, described transmitting terminal is connected to described the first and second master control receiving ends by coupling mechanism respectively, and described receiving end is connected to described master control transmitting terminal by coupling mechanism.
The invention also discloses a kind of circuit of realizing nonpolarity 485 communications, include polarity 485 chips, also comprise MCU, wherein, described the first master control receiving end that has the transmitting terminal of polarity 485 chips to be connected to described MCU, and be connected to the second master control receiving end of described MCU by the first reverser; Second reverser of the described receiving end that has polarity 485 chips by parallel connection and switch are connected to the master control transmitting terminal of described MCU.
Preferably, described transmitting terminal is connected to described the first master control receiving end and described the first reverser by coupling mechanism respectively, and described receiving end is connected to described the second reverser by coupling mechanism.
Further, described in, there is the transmitting-receiving control end of polarity 485 chips to be connected to the master control control end of described MCU.
The invention also discloses a kind of method that realizes nonpolarity 485 communications, comprise: when described 485 chips are during to described MCU transmitted signal, described MCU receives respectively the first and second data messages by described the first and second master control receiving ends, and judges that whether the described first and/or second data message is correct; When determining, described the first data message is correct, stops the reception of described the second master control receiving end, and when determining, described the second data message is correct, stops the reception of described the first master control receiving end.
Further, also comprise: when described MCU is during to described 485 chip transmitted signal, the described master control transmitting terminal of described MCU is set to serial ports positive polarity, and by described master control transmitting terminal to described 485 chip transmitted signals; If described the first master control receiving end receives wrong answer signal, described the second master control receiving end receives correct answer signal, and the described master control transmitting terminal of described MCU is set to serial ports negative polarity continuation transmitted signal.
The invention also discloses a kind of method that realizes nonpolarity 485 communications, comprise: when described 485 chips are during to described MCU transmitted signal, described MCU receives respectively the first and second data messages by described the first and second master control receiving ends, and judges that whether the described first and/or second data message is correct; When determining, described the first data message is correct, stops the reception of described the second master control receiving end, and when determining, described the second data message is correct, stops the reception of described the first master control receiving end.
Further, also comprise: when described MCU is during to described 485 chip transmitted signal, the described switch of described MCU is set to closure state, and by described master control transmitting terminal to described 485 chip transmitted signals; If described the first master control receiving end receives wrong answer signal, described the second master control receiving end receives correct answer signal, and the described switch of described MCU is set to open-circuit condition and continues transmitted signal.
Preferably, also comprise: if described the first and second master control receiving ends all receive correct answer signal, be judged as communication abnormality.
Circuit and the method that realizes nonpolarity 485 communications of the present invention, in circuit design, utilizes and has polarity 485 chips and possess the MCU of serial ports transmitting-receiving negative function or be connected to MCU by reverser, realizes nonpolarity 485 communications.This circuit and method neither increase cost, also can ensure the reliability of communication, are convenient to large-scale promotion application.
Brief description of the drawings
Fig. 1 is the electrical block diagram of circuit the first embodiment of realizing nonpolarity 485 communications of the present invention;
Fig. 2 is the electrical block diagram of circuit the second embodiment of realizing nonpolarity 485 communications of the present invention.
Embodiment
Below in conjunction with the drawings and specific embodiments, circuit and the method that realizes nonpolarity 485 communications of the present invention is described in further detail, but not as a limitation of the invention.
With reference to figure 1, it is the electrical block diagram of circuit the first embodiment of realizing nonpolarity 485 communications of the present invention.In this first embodiment, circuit includes polarity 485 chips and has serial ports polarity the MCU that function is set.Having the MCU that serial ports polarity arranges function, is also the MCU with serial ports transmitting-receiving negative function.There are polarity 485 chips to be connected to acquisition terminal by 485 order wires.
Having the MCU of serial ports negative function, can be BL6531, the BL6536 chip of company of Belling, or the chip of part model in PIC24 series and the PIC18 series of MICROCHIP company etc.Having polarity RS485 chip, can be BL3085 family chip or the BL1585 family chip of company of Belling, or the MAX13085 chip of MAXIM company, or the chip of other models such as the 75LBC184 chip of TI company.
There is the transmitting terminal R pin of polarity 485 chips to be connected to the first master control receiving end RXD0 and the second master control receiving end RXD1 of MCU by optocoupler Q1, wherein, the first master control receiving end RXD0 does not open serial ports negative function, and the second master control receiving end RXD1 opens serial ports negative function.There is the transmitting-receiving control end RE/DE of polarity 485 chips to be connected to the master control control end 485EN of MCU by optocoupler Q2.Meanwhile, there is the receiving end D of polarity 485 chips to be connected to the master control transmitting terminal TXD1 of MCU by optocoupler Q3.
Method based on nonpolarity 485 communications of realizing of foregoing circuit is:
When 485 chips are during to MCU transmitted signal, MCU receives respectively the first data message and the second data message by the first master control receiving end RXD0 and the second master control receiving end RXD1 respectively, and judges that whether data message is correct.If it is correct to determine the first data message, the data that the first master control receiving end RXD0 receives are correct, conclude that 485 line order is correct, give up the second data message of mistake, and stop the reception of the second master control receiving end RXD1, then MCU completes DRP data reception process.If it is correct to determine the second data message, the data that the second master control receiving end RXD1 receives are correct, conclude that 485 line order is abnormal, give up the first data message of mistake, and stop the reception of described the second master control receiving end, then MCU completes DRP data reception process.
When MCU is during to 485 chip transmitted signal, MCU master control transmitting terminal TXD1 is set to serial ports positive polarity, does not open the serial ports negative function of master control transmitting terminal TXD1, and by master control transmitting terminal TXD1 to 485 chip transmitted signals.If the first master control receiving end RXD0 receives correct answer signal, the second master control receiving end RXD1 receives wrong answer signal, illustrate that line order is correct, while transmission without MCU, carry out oppositely signal inside, still do not open the serial ports negative function of master control transmitting terminal TXD1, MCU continues transmitted signal until be sent.If the first master control receiving end RXD0 receives wrong answer signal, the second master control receiving end RXD1 receives correct answer signal, line order mistake is described, while needing MCU transmitted signal, carrying out inner counter is set to serial ports negative polarity to, MCU master control transmitting terminal TXD1 and continues transmitted signal until be sent.If the first master control receiving end RXD0 and the second master control receiving end RXD1 all receive correct answer signal, illustrate that communication occurs abnormal, need to carry out circuit investigation.
With reference to Fig. 2, it is the electrical block diagram of circuit the second embodiment of realizing nonpolarity 485 communications of the present invention.If do not use the MCU with serial ports negative function, can also realize nonpolarity 485 communications by the method for external phase inverter.There is the transmitting terminal R of polarity 485 chips to be connected to the first master control receiving end RXD0 of MCU by optocoupler Q1, and be further connected to the second master control receiving end RXD1 of MCU by the first reverser N1.There is the transmitting-receiving control end RE/DE of polarity 485 chips to be connected to the master control control end 485EN of MCU by optocoupler Q2.Meanwhile, by optocoupler Q3, further the second reverser N2 by parallel connection and K switch are connected to the master control transmitting terminal TXD1 of MCU to the receiving end D that has polarity 485 chips.
Method based on nonpolarity 485 communications of realizing of foregoing circuit is:
When 485 chips are during to MCU transmitted signal, it is consistent that its communication means is described with the first embodiment, repeats no more herein.
When MCU is during to 485 chip transmitted signal, MCU K switch is set to closure state, makes the second reverser N2 being connected with master control transmitting terminal TXD1 inoperative, and by master control transmitting terminal TXD1 to 485 chip transmitted signals.If the first master control receiving end RXD0 receives correct answer signal, the second master control receiving end RXD1 receives wrong answer signal, illustrate that line order is correct, carry out oppositely without the signal that MCU is sent, still K switch is set to closure state, and MCU continues transmitted signal until be sent.If the first master control receiving end RXD0 receives wrong answer signal, the second master control receiving end RXD1 receives correct answer signal, line order mistake is described, need the signal that MCU is sent to carry out oppositely, MCU K switch is set to open-circuit condition to make the second phase inverter N2 carry out oppositely, then continuing transmitted signal until be sent to the transmitted signal of MCU.If the first master control receiving end RXD0 and the second master control receiving end RXD1 all receive correct answer signal, illustrate that communication occurs abnormal, need to carry out circuit investigation.
Be understandable that, in the situation that not departing from purport of the present invention, the signal that can also use other method that MCU is received and sent carries out oppositely, thereby realizes object of the present invention.Such as, can realize serial ports negative function with simulative serial port.
Circuit and the method that realizes nonpolarity 485 communications of the present invention, in circuit design, utilizes and has polarity 485 chips and possess the MCU of serial ports transmitting-receiving negative function or be connected to MCU by reverser, realizes nonpolarity 485 communications.This circuit and method neither increase cost, also can ensure the reliability of communication, are convenient to large-scale promotion application.
Above embodiment is only illustrative embodiments of the present invention, can not be used for limiting the present invention, and protection scope of the present invention is defined by the claims.Those skilled in the art can, in essence of the present invention and protection domain, make various amendments or be equal to replacement the present invention, these amendments or be equal to replacement and also should be considered as dropping in protection scope of the present invention.
Claims (10)
1. circuit of realizing nonpolarity 485 communications, include polarity 485 chips, it is characterized in that, also comprise the MCU that has serial ports polarity and arrange function, wherein,
Described the first master control receiving end that is set to serial ports positive polarity and the second master control receiving end that is set to serial ports negative polarity that has the transmitting terminal of polarity 485 chips to be connected respectively to described MCU;
The described master control transmitting terminal that has the receiving end of polarity 485 chips to be connected to described MCU.
2. the circuit of realizing nonpolarity 485 communications according to claim 1, is characterized in that, described transmitting terminal is connected to described the first and second master control receiving ends by coupling mechanism respectively, and described receiving end is connected to described master control transmitting terminal by coupling mechanism.
3. a circuit of realizing nonpolarity 485 communications, includes polarity 485 chips, it is characterized in that, also comprises MCU, wherein,
Described the first master control receiving end that has the transmitting terminal of polarity 485 chips to be connected to described MCU, and be connected to the second master control receiving end of described MCU by the first reverser;
Second reverser of the described receiving end that has polarity 485 chips by parallel connection and switch are connected to the master control transmitting terminal of described MCU.
4. the circuit of realizing nonpolarity 485 communications according to claim 3, it is characterized in that, described transmitting terminal is connected to described the first master control receiving end and described the first reverser by coupling mechanism respectively, and described receiving end is connected to described the second reverser by coupling mechanism.
5. according to the circuit of nonpolarity 485 communications of realizing described in claim 1 or 3, it is characterized in that, described in have the transmitting-receiving control end of polarity 485 chips to be connected to the master control control end of described MCU.
6. the method based on nonpolarity 485 communications of realizing of circuit claimed in claim 1, comprising:
When described 485 chips are during to described MCU transmitted signal, described MCU receives respectively the first and second data messages by described the first and second master control receiving ends, and judges that whether the described first and/or second data message is correct;
When determining, described the first data message is correct, stops the reception of described the second master control receiving end, and when determining, described the second data message is correct, stops the reception of described the first master control receiving end.
7. the methods that realize nonpolarity 485 communications according to claim 6, is characterized in that, also comprise: when described MCU is during to described 485 chip transmitted signal,
The described master control transmitting terminal of described MCU is set to serial ports positive polarity, and by described master control transmitting terminal to described 485 chip transmitted signals;
If described the first master control receiving end receives wrong answer signal, described the second master control receiving end receives correct answer signal, and the described master control transmitting terminal of described MCU is set to serial ports negative polarity continuation transmitted signal.
8. the method based on nonpolarity 485 communications of realizing of circuit claimed in claim 3, comprising:
When described 485 chips are during to described MCU transmitted signal, described MCU receives respectively the first and second data messages by described the first and second master control receiving ends, and judges that whether the described first and/or second data message is correct;
When determining, described the first data message is correct, stops the reception of described the second master control receiving end, and when determining, described the second data message is correct, stops the reception of described the first master control receiving end.
9. the methods that realize nonpolarity 485 communications according to claim 8, is characterized in that, also comprise: when described MCU is during to described 485 chip transmitted signal,
The described switch of described MCU is set to closure state, and by described master control transmitting terminal to described 485 chip transmitted signals;
If described the first master control receiving end receives wrong answer signal, described the second master control receiving end receives correct answer signal, and the described switch of described MCU is set to open-circuit condition and continues transmitted signal.
10. according to the method that realizes nonpolarity 485 communications described in claim 7 or 8, it is characterized in that, also comprise: if described the first and second master control receiving ends all receive correct answer signal, be judged as communication abnormality.
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| CN201410307611.0A CN104090511B (en) | 2014-06-30 | 2014-06-30 | Circuit and method for achieving non-polar 485 communication |
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| CN201410307611.0A CN104090511B (en) | 2014-06-30 | 2014-06-30 | Circuit and method for achieving non-polar 485 communication |
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| CN104090511B CN104090511B (en) | 2017-01-18 |
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| CN105429907A (en) * | 2015-11-04 | 2016-03-23 | 上海斐讯数据通信技术有限公司 | Automatic serial port identification device and method |
| CN105719468A (en) * | 2014-12-04 | 2016-06-29 | 天津市品通电力科技有限公司 | Power dynamic simulation screen controller based on ethernet network |
| CN108988845A (en) * | 2017-05-31 | 2018-12-11 | 无锡华润矽科微电子有限公司 | Nonpolarity RS485 realizes the circuit of polarity upset |
| CN109101362A (en) * | 2018-06-28 | 2018-12-28 | 广州视源电子科技股份有限公司 | Communicate bearing calibration, device, readable storage medium storing program for executing and slave |
| CN113064849A (en) * | 2021-03-10 | 2021-07-02 | 深圳拓邦股份有限公司 | Communication method, device and communication circuit |
| CN114064533A (en) * | 2020-07-29 | 2022-02-18 | 鸣志电器(太仓)有限公司 | RS-485 signal polarity identification method |
| CN114064533B (en) * | 2020-07-29 | 2024-04-12 | 鸣志电器(太仓)有限公司 | RS-485 signal polarity identification method |
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