CN203054078U

CN203054078U - Nonpolar 485 communication circuit suitable for electric energy meter

Info

Publication number: CN203054078U
Application number: CN 201220655741
Authority: CN
Inventors: 任智仁; 薛雷; 周宣; 吴海强
Original assignee: ZHUHAI ZHONGHUI MICROELECTRONICS CO Ltd
Current assignee: ZHUHAI ZHONGHUI MICROELECTRONICS CO Ltd
Priority date: 2012-11-30
Filing date: 2012-11-30
Publication date: 2013-07-10
Anticipated expiration: 2022-11-30

Abstract

The utility model discloses a nonpolar 485 communication circuit suitable for an electric energy meter. The nonpolarity 485 communication circuit comprises an external power supply V485, an external 485 bus, and two pieces of general polar 485 chips U1 and U2. Terminals A and B of the external 485 bus are respectively connected to terminals A and B of the 485 chip U1 and terminals A and B of the 485 chips U2. The external power supply V485 supplies power to the two pieces of general polar 485 chips U1 and U2 independently. The two pieces of general polar 485 chips U1 and U2 respectively have independent output. The nonpolar 485 communication circuit further comprises a main MCU of the electric energy meter and two independent paths of UART communication interfaces. The main MCU receives data signals on the external 485 bus through the two independent paths of UART communication interfaces and identifies the reversal connection of the 485 chip U1 or the 485 chip U2. The two 485 chips in the nonpolar 485 communication circuit work simultaneously and have the independent output and the two independent paths of UART communication interfaces of the MCU simultaneously receive the data signals of the 485 bus to abandon data of reversely connected loops, thereby realizing the nonpolar communication of the 485 circuit in the intelligent electric energy meter.

Description

Be applicable to nonpolarity 485 communicating circuits of electric energy meter

Technical field

The utility model relates to the electronic circuit technology field, is specifically related to a kind of nonpolarity 485 communicating circuits that are applicable to electric energy meter.

Background technology

Existing electric energy meter generally adopts 485 networking communications, and has the branch of A, B polarity in the 485 common communication lines, occurs A easily like this in networking construction, the B termination causes communication unsuccessful on the contrary, has a strong impact on site operation efficient.

No. 200620003503.5 utility model patents of China disclose a kind of nonpolarity 485 telecommunication circuits, it comprises the telecommunication circuit with 485U1 chip, at the two ends of 485U1 chip 485U2 chip in parallel, the wherein A of 485 buses of 485U2 chip and 485U1 chip, the mutual cross connection in B the two poles of the earth, power control circuit is selected one by triode and is provided working power for 485U1 or 485U2, when the two poles of the earth of 485 buses were just connecing, 485U1 work realized 485 communication letters between instrument and equipment; When the reversal connection of the two poles of the earth of 485 buses, judge communications codes by communication facilities, form 485 correct polarization state, control end KZ by power control circuit provides level, provide working power by triode for 485U2, cut off the working power of 485U1 simultaneously by triode, realize 485 communications between instrument and equipment.

Though above-mentioned patented technology provides a kind of effectively nonpolarity 485 telecommunication circuits, but it also is not suitable for the networking communication of electric energy meter, be mainly reflected in: its two 485 chips have only same output, and two 485 chips are to select one power supply, the work that replaces by power control circuit.So then need a process that detects and be judged as which piece 485 chip power supplies, in this process, have the possibility of obliterated data signal.

Summary of the invention

The utility model provides a kind of nonpolarity 485 communicating circuits, and can be applicable to the electric energy meter communication and guarantee can the obliterated data signal.

Above-mentioned purpose is realized by following technical scheme:

A kind of nonpolarity 485 communicating circuits that are applicable to electric energy meter, comprising that externally fed power supply V485, outside 485 buses and two are general has polarity 485 chip U1, a U2, and outside 485 bus A, B end is received A, the B end of 485 chip U1, B, the A end of U2 respectively; It is characterized in that: externally fed power supply V485 is two generally has polarity 485 chip U1, U2 independently-powered, and two general has polarity 485 chip U1, U2 to have independently output respectively; The main MCU and the two independent UART communication interface thereof that also comprise electric energy meter, main MCU receives the data-signal on outside 485 buses and identifies 485 chip U1 reversal connections or U2 reversal connection by two-way independence UART communication interface.

Two 485 chips in the utility model are to work simultaneously, independent output, MCU two the tunnel independently the UART communication interface receive the data-signal of 485 buses simultaneously, judged, handled receiving data by software, give up for the data in reversal connection loop simultaneously, in intelligent electric energy meter, realize the nonpolarity communication of 485 circuit with this.

Description of drawings

Fig. 1 is the circuit diagram of nonpolarity 485 communicating circuits that provide of embodiment.

The invention will be further described below in conjunction with accompanying drawing and example.

Embodiment

As shown in Figure 1, nonpolarity 485 communicating circuits that present embodiment provides comprise: two general polarity 485 chip U1, U2, externally fed power supply V485, the AB terminals of 485 communication buses, the main MCU of electric energy meter and two independent UART interface (not shown) thereof.

The annexation of above-mentioned each unit and the course of work of the present utility model are as follows: power supply V485 gives two 485 chips independently-powered; Outside 485 bus A, B end is received A, the B end of 485 chip U1, B, the A end of U2 respectively; The U1 of 485 chips, U2 receive the data-signal on outside 485 buses simultaneously; Main MCU handles by the data-signal that two-way independence UART communication interface receives on outside 485 buses respectively, is judged, handles receiving data by software, thereby identify 485 chip U1 reversal connections or U2 reversal connection automatically.Wherein, main MCU handles for the data of judging the 485 chip loops that just connecing, gives up for the data in reversal connection loop, thereby utilizes general nonpolarity 485 communications that have polarity 485 chips to realize ammeter.

Claims

1. nonpolarity 485 communicating circuits that are applicable to electric energy meter, comprising that externally fed power supply V485, outside 485 buses and two are general has polarity 485 chip U1, a U2, and outside 485 bus A, B end is received A, the B end of 485 chip U1, B, the A end of U2 respectively; It is characterized in that: externally fed power supply V485 is two generally has polarity 485 chip U1, U2 independently-powered, and two general has polarity 485 chip U1, U2 to have independently output respectively; The main MCU and the two independent UART communication interface thereof that also comprise electric energy meter, main MCU receives the data-signal on outside 485 buses and identifies 485 chip U1 reversal connections or U2 reversal connection by two-way independence UART communication interface.