Development of Communication and Control (C2) Subsystems

AIF Research Forum, Fredericton, New Brunswick, May, 19, 2006

Julian Meng and Shane Barnes

Task Description

• Development of cost-effective communication and supervisory control technologies for DPG.

• Concentrate on internet access and low-cost point-to-point (multipoint) wireless solutions.

• Simple but effective link between Energy Control Center (ECC) and desired DPG device.

DPG Network

DPG C2 Requirements

• Requirements: Modular, Reliable, Flexible

• Bandwidth: Low, kbps (based on anticipated control requirements)

• Distance: Variable

• Control protocol: MODBUS compliant

Deliverables

• Solutions for short and long distance communication links to form a DPG network.

• Hardware and software for communication links.

• Control interface: ECC-DPG.

• Demonstration of reliable field operation.

DPG Communication System

• System components: WAN (Internet), LAN (unlicensed serial radio), Gateway (cellular radio)

DPG Communication System

Scalable Point-to-point Solution

• Low-cost unlicensed (900 MHz ISM band) radios for Gateway to DPG link

• Maxstream, Microhard, others

• Cost: $200 US (low end) to $1500 US (high end)

• Can radios achieve performance of stated specifications?

Gateway Solution

• Cellular Modems: Airlink Redwing ($500 US)

• Low cost wireless access to the Internet

Low-cost Radio Specifications

Test Bench

• Performance expectations of low-cost radio solutions must be managed.

• Field deployment testing is difficult.

• RF test bench was developed to test and validate performance of radios under varying conditions.

• Components include: various RF components, spectrum analyser, signal generator and FPGA channel simulator

Test Bench

• Performance expectations of low-cost radio solutions must be managed.

• Field deployment testing is difficult.

• RF test bench was developed to test and validate performance of radios under varying conditions.

• Components include: various RF components, spectrum analyser, signal generator and FPGA channel simulator

Test Bench

FPGA-based Channel Simulator

Characteristics: Low-cost Quick data collection & analysis Real-time simulation of real-world channel

conditions Critical performance comparison Problem identification before costly market failure Re-configurable FPGA for broad range of

scenarios

FPGA-based Channel Simulator

• Free space loss• Propagation delay and multipath reflections• Additive white Gaussian noise• Multi-access interference• Narrowband interference

PER Sensitivity Performance 9600 kbps

-116 -115 -114 -113 -112 -111 -110 -109 -10810

-3

10-2

10-1

100

Free-Space Path LossInput Power: 20 dBm ; RF Data Rate: 9600 bps

Pac

ket-

Err

or-R

ate

Received Power, dBm

Microhard Spectra 910

MaxStream XStream-PKG

PER External Interference Performance 9600 kbps

-120 -115 -110 -105 -100 -95 -90 -85 -8010

-3

10-2

10-1

100

Multiple Access Interference

Input Power: 20 dBm ; RF Data Rate: 9600 bps ; Interferer Code: x7 + x1 + 1

Pac

ket-

Err

or-R

ate

Received Power, dBm

Microhard Spectra 910

MaxStream XStream-PKG

MODBUS Protocol

Control layer: Internet based Open standard Scaleable Universal recognition

MODBUS Protocol

Gateway

PLC

HMI

Drive

I/O

I/O

Gateway Gateway

PLC

I/O

I/O

DeviceDevice

MODBUS on TCP/IP

Drive PLC HMIM

OD

BU

S o

n M

B+

MO

DB

US

on

RS

232

MO

DB

US

on

RS

485

PLCI/O I/O

MODBUS Communication

Where we are …

• Two low-cost P-to-P radios have been bench tested.

• Simple Gateway/P-to-P solution was shown to be successful. Meaning: From anywhere in the world where we can access the internet, we can observe/control the DPG conditions.

• The selected (as are most) telemetry radios are MODBUS capable to allow for flexibility, interoperability and industry compliance.

Where we need to be …

• Communication layer utilization by the application layer i.e. ECC to DPG.

• Bench level mockup.

• Field testing and validation.