CN202906911U

CN202906911U - EPON-based electric energy meter optical fiber communication module

Info

Publication number: CN202906911U
Application number: CN 201220637991
Authority: CN
Inventors: 何昭晖; 李先怀; 童嵘
Original assignee: Wasion Group Co Ltd
Current assignee: Wasion Group Co Ltd
Priority date: 2012-11-28
Filing date: 2012-11-28
Publication date: 2013-04-24
Anticipated expiration: 2022-11-28

Abstract

Disclosed is an EPON-based electric energy meter optical fiber communication module, comprising a photoelectric conversion and control module, a storage module, a power supply module, an MCU master controller, a power supply monitoring module, a clock module, a DBG module, an I2C-to-UART module, and a level conversion module, wherein the power supply monitoring module is used for MCU resetting and low voltage alarm; the clock module is used for providing clock signals for a master control chip; the DBG debugging module is used for providing a debugging interface via a serial port; the I2C-to-UART module is used for the expansion of the serial port; and the level conversion module is used for level conversion via the serial port. The EPON-based electric energy meter optical fiber communication module of the utility model employs the EPON technology to replace wireless communication or power carrier communication, thereby substantially improving the stability, reliability, and real-time performance. As the transmission medium is the passive optical fiber, the channel capacity is greater; the device maintenance cost is lower; and the networking is simpler. Therefore, the EPON-based electric energy meter optical fiber communication module can better meet the requirements of the intelligent electrical network development.

Description

Electric energy meter optical fiber communication module based on EPON

Technical field

The utility model relates to a kind of optical fiber communication module, particularly a kind of electric energy meter optical fiber communication module based on EPON.

Background technology

At present, existing electric energy meter optical fiber communication module based on EPON comprises EPON protocol controller module (built-in MCU controller and clock module), photoelectric isolation module, signal conversion module, memory cell, power module, level switch module.Level switch module links to each other with EPON protocol controller module by serial ports, link to each other with intelligent electric meter by serial ports simultaneously, this control module links to each other with photoelectric isolation module by the UART mouth, this photoelectric isolation module links to each other with signal conversion module by serial ports again, signal conversion module links to each other with EPON protocol controller module by the GPIO mouth, simultaneously the 12V power supply signal is reached power module, power module is the main control chip power supply.This scheme only has one road UART to link to each other with electric energy meter, and communication mode is single, in case break down, whole photoelectric communication network is caused very big impact.

The utility model content

The purpose of this utility model provides a kind of electric energy meter optical fiber communication module based on EPON of high reliability.

This electric energy meter optical fiber communication module based on EPON that the utility model provides, comprise the MCU master controller, opto-electronic conversion and control module, memory cell, power module, clock module, the power supply monitoring module, the DBG module, I2C turns UART module and level switch module, the power supply monitoring module is used for MCU and resets and the low-voltage warning, the DBG debugging module links to each other with the MCU master controller by serial ports, be used for providing debugging interface, I2C turns the UART module and links to each other with the MCU master controller by the I2C bus, be used for serial ports expansion, level switch module turns the UART module by serial ports with I2C and links to each other, be used for level conversion, described memory cell comprises Flash module and PSRAM module.

Described MCU master controller adopts the second generation high-performance Ethernet passive optical network exchange chip of Cortina company, and its model is CS8016E.The UART module that turns described I2C adopts the I2C/SPI of company to turn the UART chip, and its model is XR20M1172.

Adopt the networking of EPON technology between the utility model and the main website, and in ethernet frame encapsulation 376.1 agreements, upstream and downstream bandwidth is 1.25Gbps, longer transmission distance 20km; And and adopt the networking of RS485 bus between the electric energy meter, and encapsulate 645 agreements, and improved the reliability of transfer of data, prolonged the effective propagation path of data, improve the link utilization of its up link.The utility model adopts the EPON technology to substitute radio communication or power line carrier, PLC mode, and its stability, reliability, real-time all have significantly raising.Because transmission medium is passive fiber, its channel capacity is larger, and cost of equipment maintenance is lower, and networking is simpler, more meets the demand of intelligent grid development.

Description of drawings

Fig. 1 is structured flowchart of the present utility model.

Fig. 2 is opto-electronic conversion of the present utility model and control module circuit diagram.

Fig. 3 is that I2C of the present utility model turns the UART module circuit diagram.

Fig. 4 is level switch module circuit diagram of the present utility model.

Fig. 5 is power supply monitoring module circuit diagram of the present utility model.

Fig. 6 is a kind of embodiment figure of the present utility model.

Embodiment

As shown in Figure 1, the utility model comprises opto-electronic conversion and control module, memory cell, power module, the MCU master controller, the power supply monitoring module, clock module, the DBG module, I2C turns UART module and level switch module, the power supply monitoring module is used for MCU and resets and the low-voltage warning, clock module is used to main control chip that clock signal is provided, the DBG debugging module links to each other with the MCU master controller by serial ports, be used for providing debugging interface, I2C turns the UART module and links to each other with the MCU master controller by the I2C bus, be used for serial ports expansion, level switch module turns the UART module by serial ports with I2C and links to each other, be used for level conversion, described memory cell comprises Flash module and PSRAM module.

The MCU controller module is system core control assembly, is the key that realizes systemic-function.That native system adopts is second generation high-performance Ethernet passive optical network (EPON) the exchange chip CS8016E of Cortina company.

The used MCU master controller of the utility model is a highdensity ONU solution, complete compatible IEEE802.3ah stipulations, be provided with that frame buffer is used for storing packet on the sheet, adopt priority query to report mechanism to support dynamic bandwidth allocation algorithm, adopt forward error correction to increase the optical power budget of laser at up link and down link, increase the transmission range of light.CS8016E is a feature richness and the very high terminal part of cost performance, adopt the BGA encapsulation of 256 pin, it is an integrated Gigabit Ethernet interface, GEPON mouth, Fast Ethernet management mouthful and a built-in ARM9 kernel, hang with a plurality of peripheral hardwares on the kernel bus in order to Function Extension, EPON interface, FLASH/SRAM interface, UART interface, I2C interface, SPI excuse, LED interface, GPIO interface etc. are arranged.This device can be competent at the functions such as packet classification, exchange, traffic policing, queue management and scheduling fully.

The MCU controller module is kernel control module of the present utility model, and its function mainly contains two broad aspect: one, finish the Network Management Function of the ONU of EPON system end, the transmitting-receiving control of optical module, these two functions must be based upon on the IEEE802.3ah standard.Two, move embedded real-time operating system eCOS thereon, to satisfy the requirement of the numerous functional requirement of ONU module and real-time, finish the conversion of state's net 376.1 agreements and 645 agreements, to realize communicating by letter between main website and the intelligent electric energy meter.

As shown in Figure 2, opto-electronic conversion and control module major function are to realize the conversion of photoelectricity/electro-optical signal, comprise luminous power control, modulation transmission, acquisition of signal, IV conversion and limited range enlargement judgement regeneration function, also have in addition the functions such as anti-counterfeiting information inquiry, TX-disable.This module and main control chip adopt the SerDes interface communication.Its two pairs of differential signal lines, constant transmissions speed is 1.25Gbps, possesses long-distance transmissions function (the 1000BASE-PX10 specification can be transmitted 10km, and the 1000BASE-PX20 specification can be transmitted 20km); Adopt single fiber bi-directional, up-downlink direction uses the light source of different wave length (1 310 nm/1,490 nm), realizes the working method of full duplex.

As shown in Figure 3, I2C of the present utility model turns the UART module for serial ports expansion and level conversion.The design has adopted the I2C/SPI of Exar Corporation company to turn the UART chip, and its model is XR20M1172.This is a high performance Dual-Channel UART conversion chip, and the sending and receiving FIFO buffer memory of built-in 64 bytes can select I2C or SPI from interface.Its supply power voltage is 1.62 ~ 3.63V, and sending and receiving FIFO is cached with 16 selectable activation threshold values, and hardware handshaking also has complete modem interface automatically.4 times or 8 sampling rates able to programme, when chip power supply was 3.3V, baud rate reached as high as 16Mbps, can satisfy the communication requirement of this module fully.This chip also needs external passive crystal oscillator, in order to the baud rate generation module of system clock to UART to be provided.When using typical 14.7456Mhz crystal oscillator, by software configuration, the highest baud rate that obtains 3.68Mbps.

Be illustrated in figure 4 as level switch module, its level that is used for communication module and intelligent electric energy meter is compatible.The level that the utility model adopts all is the 3.3V level, and the intelligent electric energy meter employing is the 5V level.Therefore, for make the utility model can with the intelligent electric energy meter proper communication, must carry out 3.3V to the conversion of 5V level at its link.The utility model adopts the PNP triode of MMBT2907ALT1 model that the TXA/TXB signal is carried out boost operations.When the TX signal is 1(3.3V) time, PNP manages cut-off, and output signal is 1(5V), vice versa.For the RX signal, input signal is 5V, only needs a bleeder circuit, the output that can produce 3.3V.

Be illustrated in figure 5 as the power supply monitoring module.The utility model adopts special-purpose power supply of microprocessor monitoring chip, and improving the reliability of system, it is that processor reset, low-voltage are reported to the police and voltage function such as reset chip again when recovering normal that power monitoring chip need to be finished when powering on.The utility model has adopted the professional power monitoring chip of Pericom company, and its model is PT7A7514WEX.Be that microprocessor system is exported the approximately reset signal of 200ms when this chip powers in system, when system power supply voltage is lower than 9.2V, will cause that a processor interrupts, software is identified as the low-voltage early warning with this interruption in the processor, and processes accordingly.

As shown in Figure 6, the Optical fiber electricity meter communication module provides two-way UART mouth to be connected with base table, and wherein one road UART mouth directly is connected with the microcontroller of base table, can be directly and the microcontroller of base table communicate; Another road UART mouth is directly connected to that the UART on another road turns the RS485 circuit on the base table, then communicates by RS485 bus and base table and lower pocket watch.Wherein RS485_RE/DE is self-defined pin, links to each other with the GPIO mouth, is 485 transmitting-receiving control signals.High level is 485 accepting states, and low level is 485 transmission states.

The utility model meets the IEEE802.3ah-2004 standard fully, can interconnect with any OLT with this protocol-compliant.The utility model has two-way UART mouth to intelligent electric energy meter, and the RS485 change-over circuit of utilization table end is realized the networking of local ammeter.

Claims

1. electric energy meter optical fiber communication module based on EPON, comprise the MCU master controller, opto-electronic conversion and control module, memory cell, power module, clock module, it is characterized in that, also comprise the power supply monitoring module, the DBG module, I2C turns UART module and level switch module, the power supply monitoring module is used for MCU and resets and the low-voltage warning, the DBG debugging module links to each other with the MCU master controller by serial ports, be used for providing debugging interface, I2C turns the UART module and links to each other with the MCU master controller by the I2C bus, be used for serial ports expansion, level switch module turns the UART module by serial ports with I2C and links to each other, be used for level conversion, described memory cell comprises Flash module and PSRAM module.

2. the electric energy meter optical fiber communication module based on EPON according to claim 1 is characterized in that, described MCU master controller adopts the second generation high-performance Ethernet passive optical network exchange chip of Cortina company, and its model is CS8016E.

3. the electric energy meter optical fiber communication module based on EPON according to claim 1 is characterized in that, described I2C turns the UART module and adopts the I2C/SPI of company to turn the UART chip, and its model is XR20M1172.