Power Line Communication Module for Home/Building Smart Light(IoT)
About this Solution:
This document documents PLC(Power Line Communication) module. PLC module is designed to send/receive serial data over the power line network. PLC module is designed to transparently move serial data over the power line network, and achieves the target of replacing cables by the ubiquitous power line network.
PLC module has the built-in packet-level repeater function. This feature can greatly extend the coverage of the power line communication. PLC module has both physical and logic addresses. In a network, both physical and logic addresses can be used to address different nodes in the network.
The specific idea of power line carrier bidirectional transmission module design is: PLC module consists of modulation, oscillation, power amplifier, T/R switch, coupled circuit and demodulator etc. And the oscillation can provide carrier signal for the modulator. When data transmission, the signal sends out from TXD, and modulates the signal through the modulator, then the signal will be sent to power amplifier, and then through the T/R changeover switch and coupled circuit to load the modulated signal on the power line. Similarly, when data is received, the transmitter module sends out the modulated signal through the coupled circuit and T/R switch into the demodulator, demodulated by a demodulator to extract the original signal, and the original signal sent from the RXD terminal to the next level of digital processing devices.
PLC module basic principle is when sending the signal, the user data will be modulated by modulation techniques, and loading the high-frequency signal containing information on the electric current, then make the transmission on the power line. At the receive port, take out the modulated signal through the filter first, and then demodulated, the original communication signal can be obtained and sent to the back-end device, to do information transmission.
PLC equipment can be divided into two parts, the first part of the Central Office Application Interface (Host machine is asynchronous communications interface, auxiliary machine can be GPIO or PWM or ADC) and the other part is the modulator (=PLC Module), CO communication interface is responsible for the communication with PLC modulator and the connection with external application control devices. During the communication, the data from the user enters modems and been modulated, through the user's distribution line (power line) and being transmitted to another central office application interface, the central office will have the demodulated information corresponding to the real application control signals, for example: pulse width modulation signal or switch data signals, and then go to the external application control devices, such as lighting control devices. If the central office application interface is a SENSOR, the signal path is the opposite path.
PLC Module can be divided into sub-machine host control terminal and controlled end, the host is used to send control signals or collect data, the sub-machine is used to control applications devices, such as: LED lamps, SENSOR or METER, a host can control 128 sub-machine, the slave address uses the switch for setting, the switch address setting can refer to Switch define.
To have more than 128 sets of sub-machine control applications, you can use WIFI or Internet to expand the number of hosts in order to achieve a large network control applications, you can refer to the sequence Application Illustration.
- AC power line Communications
- Opto-electronic coupling on the UART interface to provide protection of the host machine or board.
- No ceramic filter and therefore non-fragile.
- Fully transparent mode, plug and play coming out of the box without the need to do any programming.
- Built-in error correction codes.
- Built-in repeater function to extend the coverage.
- Physical and logic address
- 3.3V TTL UART interfaces
- BPSKï¼ˆBinary Phase Shift Keyingï¼‰modulation used in physical layer
- Average Power consumption < 0.1W
- UART Over Power line Communication Transceiver Module
- Small module size (50mm X 440mm including the on-board power switch regular keep out area), and easy to be implemented into existing products.
- Industry manufacture and control
- Safeguard, fire alarm, smoke alarm
- Collect and transmit instrument data
- Safeguard and monitor
- Home automation
- Solar/Wind electricity generation system
4. Command & Interface
- UART Interface
- UART Baud of 57600
- Format: 8, 1, N (LSB first)
- 8 Data bits, 1 stop bit, No parity bit.
- Sending: 1st byte Command (receive echo), 2st byte LEDID (receive echo), 3st byte SliderLowByte (receive echo), 4st byte SliderHightByte (receive echo)
- Command: 0x03 slider command
- LEDID: LED ID Address 0x00 ~ 0x7F
- SliderHightByte, SliderLowByte: 0 ~ 1638 (0x00: 0x00 ~ 0x06: 0x66)
- Waiting time is 4msec, after send one byte.
5. Application Illustration
5.1 Intelligent lighting control system
Using PLC module to control the Lighting system, the infrastructure as below:
5.2 Power-meter automatic meter reading systems
Using PLC module, one can use the existed power lines to directly complete data transmission.
This Solution is most applicable for the following stages and categories: