Based on power line communications home network intelligent control technology (1)

This article primarily describes PIC technology in intelligent home system, PLC of networked control systems structure. Description of the smart home systems control terminal equipment and the design of Central Office equipment to Xiamen device. electromagnetic compatibility.

The system enables appliances intelligent control, security control and Internet capabilities.

At present, China's intelligent home system with intelligent security, are gradually to home appliances networking control extension.

How to more effectively address the security, home appliances, such as intelligent control, Internet access, becoming the focus of the study. PLC (Power Line Communication, PLC), refers to the use of medium and low-voltage power line as a communication medium for data, voice, image and other integrated business transfer of communication technology. With PLC intelligent home networked control without stringing, does not undermine the residential structure, convenient, fast connection, is a smart home network control. This system uses Intcllon company INT5200 chip chip as a power line carrier, network data from and home appliances that is connected to the transmission of power lines, and interact via HomePlug Protocol implementation, using OFDM (Orthogonal Frequency Division Multiplexing) orthogonal frequency division multiplexing technology modem for appliance control, PLC Internet and home security.

1 network control system structure

Figure l for PLC network control system structure diagram.

Modem for existing ADSL or cable Modem, coaxial cables PLC master terminal receiving Modem demodulation of network signal, converts it to a power line communication packets, and encryption, OFDM modulation, D/A conversion, magnification, and so on, and then through the coupling circuit will power line differential signal coupling to the family of 220V AC power line by line and transfer. In this way, any of the family one power socket that are coupled circuit for power line differential signal; then through PLC communication interfaces to the Central Office line signal filtering, A/D conversion, gain adjustment, OFDM demodulation, etc.; then restore the data to the standard network information sent to the PC card or directly according to the content of information received, through the Central Office of microprocessor control PLC and other home appliances and security control equipment. Likewise, PC, other household devices or security control equipment data and status information, or you can follow the reverse process to the PLC after the master terminal Modem online, sent to the Internet by remote users.

2 smart home systems PLC controlling terminal

PLC controlling terminal mainly by the master terminal interface and power line coupling of two parts.

PLC controlling terminal of the most important feature is the implementation of Ethernet packets and power packs are converted, OFDM modulation and demodulation, and signal and power line coupling. Where the master terminal interface by INT5200, Ethernet PHY chip RTL8201BL, network isolation transformer H1102, receive, filter and protection circuit, sending the drive circuit, E2PROM storage device, LED status indication, power line coupling circuits, etc. Its circuit structure as shown in Figure 2.

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