User manual

UTILITY-BAND BPSK 6.0 kbps PLM

PICtail™ PLUS DAUGHTER BOARD

USER’S GUIDE

Chapter 1. Introduction

Thank you for purchasing Microchip Technology’s Utility-band BPSK 6.0 kbps PLM

PICtail™ Plus Daughter Board. This daughter board provides a low-cost solution for

implementing a Power Line Modem (PLM) using the Microchip Explorer 16

Development Board.

The daughter board is used with the Explorer 16 Development Board to demonstrate

a software-based PLM implementing the Binary Phase Shift Keying (BPSK) modulation

technique.

This chapter introduces the daughter board and provides an overview of its features.

Topics covered include:

• Overview

• Board Setup

1.1 OVERVIEW

A PLM, also referred to as a Power Line Communication (PLC) modem, uses the

existing power lines to provide a cost-effective communication medium. This

technology can be used for a wide range of applications including, but not limited to,

Automated Meter Reading (AMR), energy consumption monitoring of individual

appliances, and lighting, heating, and solar applications. Data rate and robustness of a

power line communication link are the main parameters that decide its application

spectrum.

The Utility-band BPSK 6.0 kbps PLM PICtail™ Plus Daughter Board incorporates Ana-

log Front End (AFE) circuitry, which is required to implement a software-based modem,

using the dsPIC33F Digital Signal Controller (DSC) device on the Explorer 16 Devel-

opment Board. The daughter board fits into the expansion slot on the Explorer 16

Development Board. A HV adapter cable (included in the package) interfaces the

daughter board to the power line. The HV adapter cable incorporates the circuitry

required to provide noise-filtering and isolation from the power line. The daughter board

and the HV adapter cable are designed to operate at a carrier frequency of 72 kHz

(CENELEC-A band).

The daughter board does not implement any particular modulation technique. Software

on the dsPIC33F DSC device generates 4-channel PWM output, which when

summed-up and filtered suitably by the daughter board circuitry, forms an approxi-

mated sine wave. This approximated sine wave is modulated in the software using the

BPSK modulation technique by controlling the PWM channels. On the receive path, the

modulated signal on the power line is filtered and amplified by the daughter board

before being fed to the ADC input of the dsPIC33F DSC device. The ADC module on

the dsPIC33F DSC device converts this received signal into the digital domain where

further filtering and demodulation is performed in software to recover the data.

WARNING

SHOCK HAZARD – Do not open the HV adapter cable enclosure.

Failure to heed this warning could result in bodily harm.