Plcc Modem

Power Line Carrier CommunicationEmbedded Module

User Guide

Version 0.1

TOC 1 Prodigy Labs Pvt Ltd

Table of Contents1 Introduction............................................................................................................................................3

1-1 Kit Components.............................................................................................................................. 41-2 Minimum Requirements ................................................................................................................ 4

2 PLCC Board Overview.......................................................................................................................... 42-1 PLCC Board Key Features..............................................................................................................52-2 PLCC Board Components...............................................................................................................62-4 PLCC Board Dimensions................................................................................................................72-5 Block Diagram................................................................................................................................ 7

3 PLCC Board Module............................................................................................................................. 83-1 Communication Interface................................................................................................................83-2 Automatic Meter Reading (AMR) Demo Interface........................................................................ 83-3 Street Light Application Demo Interface (Optional).................................................................... 10

4 About PLCC Transceivers................................................................................................................... 114-2 Reliable Data Communication...................................................................................................... 124-4 Summary....................................................................................................................................... 12

5 Automatic Meter Reading (AMR) Demo............................................................................................ 135-1 Determining the Concentrator-Node devices................................................................................135-2 Setting Up the User Interface........................................................................................................135-3 Running the AMR Demo.............................................................................................................. 14

6 Street Light Application Demo............................................................................................................ 156-1 Determining the Master-Slave devices......................................................................................... 156-2 Setting Up the Demo Interface......................................................................................................156-3 Running the Street Light Application Demo................................................................................ 17

7 Revision History.................................................................................................................................. 188 About Prodigy Labs Pvt. Ltd. -Bangalore............................................................................................189 Change Notice Information..................................................................................................................18


1 Introduction

PLCC is a technology which uses power lines as physical media for data transmission. PLCC can offer a“no new wires” solution because the infrastructure has already been established. PLCCs are used for transmitting data at a rapid speed through a power line in a house, an office, a building, and a factory, etc. Here, the existing alternating current (AC) power wires serve as a transmission medium by which information is relayed from a transmitter or control station to one or more receivers or loads connected downstream from an AC source.Typical applications of PLCC are Street light control, Automatic Meter Reading,HVAC control, Low Speed Data Networks, Signs and Information Display, Fire and Security Alarm etc.The PLCC board developed by Prodigy Labs Pvt. Ltd. robust, low-cost way to communicate over power lines.

Figure 1: PLCC board

The Embedded PLCC modem is based on the Differential Code Shift Keying (DCSK)Technology. This technology in Power Line Carrier (PLCC) communication is well known for its high immunity to electrical noise persistent in the power line.The PLCC Modem is in the form of a ready-to-go circuit module, which is capable of transferring data over the power cable at the low voltage end of the power transformer of a 3-phase/ 4-wire distribution network. A pair of Embedded PLCC Modems connected on the power line can provide low speed bi-directional data communication at a baud rate of 9600 bps.


1-1 Kit Components

The following table lists the components of the Embedded PLCC modem developed by Prodigy Labs Pvt. Ltd. Bangalore.

Hardware Component Qty Description

Embedded PLCC modem 1 The Versatile board with highly integrated SoC power line modem which incorporates a high performance DLL and extremely robust PHY layer. This PLCC board is designed for host of applications like Automatic Meter Reading (AMR), Street light control, HVAC control etc.

RS-232 cable 1 Required for applications that use the COM port of the PC.

Table1: Kit Components

1-2 Minimum Requirements

● PC with OS installed like Microsoft® XP® OS or Linux® based OS.● At least one free COM port.● Hyperterminal like serial communication program.

2 PLCC Board Overview

The Embedded PLCC modem developed by Prodigy Labs Pvt. Ltd. provides communication over power lines using CENELEC frequency band (outdoor: 20 kHz to 80 kHz , indoor:95-125 kHz ) and achieves data transfer rates of up to 2.5 kbps (Robust Mode).

Figure 2: MCU on PLCC board


2-1 PLCC Board Key Features

The following are some key technical features of the Embedded PLCC modem : Data Rate

○ 2.5Kbps (RM : Robust Mode)○ 0.625Kbps(ERM : Extremely Robust Mode)

Modulation○ Differential Code Shift Keying- DCSK

Frequency Band○ CENELEC : 20-80 kHz outdoor), 95-125 kHz(indoor)

Bi-directional half-duplex data communication over the mains.

Simple serial interface to user's data devices.

Built-in on board AC coupling circuit with direct connection to mains.

High in-phase and cross-phase reliability.

CSMA / CA Channel Access Protocol.

Forward short-block soft decoding error correction mechanism and CRC-16 .

Selectable TTL and RS232C level serial interface to user's data devices.

Built-in carrier generation and detection.

Current consumption is as low as 60 mA @Idle, 90 mA @ Rx and 300 mA @ Tx mode.

Protocol independent, data transfer transparent to user's data terminals.

High noise immunity and reliable data communication.


2-2 PLCC Board Components

The following figure highlights some of the key components of the PLCC Board.

2-3 Power Supply

The Embedded PLCC modem operates at 5 V. A power supply of 5 V, 1A rating is required and output should be connected to pin 2 (VCC ) of serial interface connector ( CON J2 on PLCC board). For details refer Figure 11 and Table 3.


2-4 PLCC Board Dimensions

The following figure shows the dimensions of the Embedded PLCC Board :

Figure 4: Embedded PLCC Board Dimensions

2-5 Block Diagram

A block diagram of the Embedded PLCC Board is provided below.

Figure 5: Embedded PLCC module Block Diagram


Maincontroller

TTL

RS232

Programming Con

XformerSMD

AC

Line Driv er

100 mm

50 mm

Main Controller

3 PLCC Board Module

3-1 Communication Interface

The Communication Interface provides serial communication between the Embedded PLCC Board and a PC. The board uses a standard RS-232/UART port for communication with a COM port on a PC. In Case on board RS-232 level translator is not needed a TTL interface is also provided. It can be used with, for example, a PC running a terminal program such as Hyperterminal® (for use under Windows®) or Minicom® (for use under Linux®). General communication interafce is as shown in figure 6 below. For details refer Figure 11 and Table 3.

Figure 6: Communication Interface

3-2 Automatic Meter Reading (AMR) Demo Interface

Automatic meter reading (AMR), is the technology used for automatic collection of energy consumption, diagnostic, and status data for billing and analysis purposes. AMR system gathers this data and transfer it to central database through networking topology. Embedded PLCC module is a key component of AMR system employed for energy meter data collection.

The modules provides bi-directional half-duplex data communication over the mains of any voltage up to 250 V A.C. and for frequency of 50 or 60 Hz. Data communication of the modules is transparent to user's data terminals and is protocol independent; as a result, multiple units can be connected to the mains without affecting the operation of the others. The use of DCSK modulation technique ensures high noise immunity and reliable data communication. There is no hassle of building interface circuits. Interface to user's data devices is a simple data-in and data-out serial link. It has a built-in on board AC coupling circuit, which allows direct and simple connection to the mains.

In the demo application AMR network is a Tree network structure controlled by a main device (Master device ) located at level 0 of the network.Network depth can be upto 7 levels and at each level upto 255 nodes ( Slave devices ) can be connected.Master can send both unicast as well as broadcast commands in the network.


These nodes are already available throughout the network ( household / Industrial), which makes PLCC to a low-cost solution, by offering this number of possible gateways. Any device requiring power is already attached to the power line network making PLCC convenient and accessible for every user.

Figure 7: AMR network

Master device can be connected to a AMR database server through a serial RS232 port and nodes ( slave devices) to energy meters.Commands sent from master device will be received by nodes over power lines and will send data in response to commands received.


3-3 Street Light Application Demo Interface (Optional)

Streetlights can be managed much easily and can be made more efficient by using Streetlight monitoring solution developed by Prodigy Labs Pvt Ltd.

Prodigy Labs has developed an architecture for Street Light Control application.In this architecture there are two modes, one is Base support mode and the other is autonomous mode.

In Base Support mode, the control is through the central server station. Street light controlcan be done through this server. In Autonomous mode, the nodes at each of the street lighthas its own intelligence to control itself. However, data about its operation will be relayed over to the central control station.

Figure 8: Streetlight control architecture

Control StationControl station is core intelligence of the whole system. This block is responsible for the street light switching control when operating in base-support mode. This stationhas an user interface through which the control is possible. This control station can beaccessed by the power line concentrator module through GSM/GPRS interface.

Power Line ConcentratorEach Power line Concentrator can handle a minimum of 255 nodes upto a maximum definedby the application network layer. However, in typical lighting application as regulated by theconcerned authorities, each phase of the power line will have up to 30 lights. This number can be easily controlled by one concentrator.


Power line NodeThe nodes are the modules which are fixed in the street lights. The central station essentiallyspeaks to this node, via the concentrator, for its application. The system has the followingarchitecture.

Figure 9: Streetlight control schematic

The above schematic is a typical dual street light controller node. Each such node canmonitor and control two street lights at a time.

● The IO control can turn ON/OFF each light independently.

● The sensor and IO control unit can detect ON/OFF status of each streetlight and can also detect burn out condition of each light as well.

● This has an ambiance light sensor for autonomous operation. With this feature, the street light can be automatically turned ON if the surrounding light intensity goes below a preset threshold. Similarly, the light can be turned OFF, if ambiance light detected is higher than a preset threshold.

● This can measure the amount of energy consumed by each of the lights so as to report to the central station its energy usage.

4 About PLCC Transceivers

The quality and range of a PLCC is dependent on a number of key factors. Theseinclude, but are not limited to, the physical environment/media in which the transmissions take place.The maximum communication distance depends on various factors like noise and impedance on the power line at the sender and at the receiver side.


4-1 Reliability of PLCC LinksPLCCs are well-adapted to a range of automation tasks. Power transmission lines are ideal for communication as they extend from the power generation site to the remote sites without intervening obstacles. Line driver performance is also related to the network impedance.The following table shows the peak to peak voltage levels over a range of resistive loads. These values are only to be used as a guide. These figures are for the CENELEC A band Analogue Front End.

Resistive Load ( Ohm) 1.0 5.0 10.0 50.0

Output Swing ( Vss ) 0.72 2.68 4.48 6.44

Table2: Line driver performance

4-2 Reliable Data Communication

The Embedded PLCC modem is based on the Differential Code Shift Keying (DCSK)Technology. This technology in Power Line Carrier (PLCC) communication is well known for its high immunity to electrical noise persistent in the power line.Other suppliers use narrow band modulation, which are sensitive against single tone noise sources.The external Analogue front end (AFE) ensures high line drivability even at low impedances.

The Embedded PLCC modem has many mechanisms to make the communication more robust. Theseare built-in hardware features such as:

• CRC (Cyclic Redundancy Checksum)• FEC (Forward Error Correction)• CSMA/CA (Carrier Sense Multiple Access / Carrier Avoidance)• LQI (Line Quality Indication)• 3 different communication modes (Standard Mode, Robust Mode, Extremely

Robust Mode)

4-3 Obtainable Range

The maximum communication distance depends on various factors like noise and impedance on the power line at the sender and at the receiver side.Line attenuation factor is negligible (approx 1dB/100m) as compared to the other factors mentioned above.With relatively low noise level and high line impedance a distance of more than 1000m is easy to achieve.This can be even expanded when routing technologies of the network layer are utilized.

4-4 Summary

In summary PLCCs are well adapted and robust systems for a range of automation tasks.The Embedded PLCC module developed by Prodigy Labs Pvt Ltd is well suited for reliable data communication.


5 Automatic Meter Reading (AMR) Demo

For demo application Prodigy Labs Pvt. Ltd. provides an energy meter emulation software for Master device as well as nodes.This demo requires a minimum two PCs with Microsoft® XP® OS.

5-1 Determining the Concentrator-Node devices

Same Embedded PLCC modem hardware is used for both PLCC Master device and nodes (Slave device).A 3 pin jumper setting is provided on the board, connecting the jumper to pin 1 and pin 2 configure the device as Master ( Concentrator ) while connecting it to pin 2 and 3 configure the device as node.

5-2 Setting Up the User Interface

The demo requires a minimum two PCs with Microsoft® XP® OS. On one PC, PLCC Master emulation code runs and sends data to Embedded PLCC modem (Master device) via RS232 interface which in turn sends data over power lines to node device connected to another PC via RS232 interface running node emulation code.

Figure 10: AMR Demo Setup

Figure 10 shows the minimal hardware setup required for AMR demo, of course user can add more than one slave nodes. The requirement for additional PC at slave end can be completely knocked off by configuring slave nodes to send data in response to pre defined master commands.


5-3 Running the AMR Demo

The following assumes that the Embedded PLCC board hardware has been fully assembled and powered on and that all the required software has been installed on the PC.For AMR demo simply run the Master and slave emulation software exe files on the respective PCs connected to the Master and slave devices.

In another minimal demo application user can comprehend the functionality simply by running PC communication program such as Hyperterminal without the need of any emulation software. Just run the Hyperterminal application at 9600 bps baud rate and send data from the terminal.The data sent will be received by another PLCC device over power line and can be seen on the respective PC's Hyperterminal.The following figure and table below shows the connection and signal name for each connector pin

Figure 11: PLCC Board Pin conneection


J2

1 GND

2 VCC 5V

3 TXD

4 RXD

5 CTS

6 RTS

Table3: Power Supply and Serial Interface connection

J10 1-2 MASTER

2-3 SLAVE

Table4: Master / Slave Jumper setting

6 Street Light Application Demo

As described in section 3.4 Prodigy Labs has developed an architecture for Street Light Control application.For demo application Prodigy Labs Pvt Ltd provides an Embedded PLCC module with on board Streetlight switching circuitry.

6-1 Determining the Master-Slave devices

Same Embedded PLCC modem hardware is used for both PLCC Master device and Slave device. A 3 pin jumper setting is provided on the board, connecting the jumper to pin 1 and pin 2 configure the device as Master while connecting it to pin 2 and 3 configure the device as slave.

6-2 Setting Up the Demo Interface

For streetlight application demo a master device is connected to a PC with OS and communication program such as Microsoft® XP® with Hyperterminal or Linux® with minicom terminal emulation program.Two or more nodes (slave devices ) are connected to load ( lighting devices ) and can be switched on and off by sending commands from the Master device.Following diagram illustrate the streetlight application demo.


Figure 12: Streetlight Demo Setup

Streetlight Application Demo Block Diagrams :

Figure 13: Block diagram for master connection

Figure 14: Block diagram for Node connection

Figure 15: Block diagram for Node connection


Test Application

PC withHyperterminal Master Mains

Serial Port 2 Pincable

Connect Load Node 1 MainsSerial Port 2 Pincable

Connect Load Node 2 MainsSerial Port 2 Pincable

6-3 Running the Street Light Application Demo

Getting Started :

Connect the Master unit Plug to mains and perform the following steps :

1. Connect the Master Unit serial port connector to the PC with a serial cable ( 1:1 connection ) with a running terminal program as e.g Hyper Terminal.

2. Select the following setting for the terminal application○ 9600 baud○ Data bits 8○ Parity none○ Stop bits 1○ Flow control : none

3. Switch ON the master unit.4. Some information should appear on your PC terminal screen.5. Similarly connect the two nodes as shown in Fig13 and Fig14 and connect the load like

light,fan etc as load ( load must be less than 6 mA ) , after that switch ON the two nodes.

Following Information will appear on Hyperterminal

Serial Port 1 – Hyper Terminal

Enter the Destination Node ID ( 3 or 4 ) >

6. Enter the node id that you want to switch ON/OFF the load, after that next command will appear on the terminal screen

Serial Port 1 – Hyper Terminal

Enter Relay Command ( 0 : Off 1 : ON ) >

7. If you enter a 1 the load will ON , if you enter a 0 the load will OFF .


7 Revision History

Version Date Description/Changes

0.1 September 25th

2009-

8 About Prodigy Labs Pvt. Ltd. -Bangalore

Prodigy Labs is a fast growing technology firm operating from Bangalore, India. Prodigy labs was incorporated in June 2002 with a focus to establish as a premier technology service provider offering best of breed solutions in the Embedded Technology space. We continuously focus on critical organizational attributes

● People ● Technology ● Knowledge

and their applicability in providing optimal solutions. We regard these as a catalyst to establish a viable and mutually beneficial business relationship with our clients.

Further Information:For more information about this product and other products from Prodigy Labs Pvt Ltd, contact a sales representative at the following address:

Prodigylabs Pvt Ltd #1403, 13th Main, 12th 'B' Cross ,WOC Road 2nd Stage,Mahalakshmipuram,Bangalore-560086,India.

Phone :- 91-80-23598938, 91-80-57600470. Fax :- 91-80-23490373.

Email:[email protected] Website: www.prodigylabs.com

9 Change Notice Information

Prodigy Labs reserves the right to make corrections, modifications, enhancements, improvements and other changes to its products and services at any time, and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders, and should verify that such information is current and complete. All products are sold subject to Prodigy Labs's terms and conditions of sale, supplied at the time of order acknowledgment. Information relating to device applications, and the like, is intended as suggestion only and may be superseded by updates. It is the customer’s responsibility to ensure that their application meets their own specifications. Prodigy Labs makes no representation and gives no warranty relating to advice, support or customer product design.


http://www.prodigylabs.com/




mailto:[email protected]

Prodigy Labs assumes no responsibility or liability for the use of any of its products, conveys no license or title under any patent, copyright or mask work rights to these products, and makes no representations or warranties that these products are free from patent, copyright or mask work infringement, unless otherwise specified.Prodigy Labs's products are not intended for use in life support systems/appliances or any systems where product malfunction can reasonably be expected to result in personal injury, death, severe property damage or environmental damage. Prodigy Labs's customers using or selling Prodigy Labs products for use in such applications do so at their own risk and agree to fully indemnify Prodigy Labs for any damages resulting from such use.


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Plcc Modem