WCBI Team InformationWCBI Team InformationTeam number:

Client:

Faculty Advisors:

Technical Advisors:

Team Members:

May02-11

Square D Company(Greg Wiese)

Glenn HilleslandJames Triska

Mani MinaSteve Russell

Fahad AzeemMatt HenslerNeil PetersonGreg Stamp

Presented on March 12, 2002

Presentation OutlinePresentation Outline

Problem Statement

Design Objectives

End Product Description

Assumptions

Limitations

Risks and Concerns

Technical Approach

Technical Design

Milestones

Accomplishments

Future Work

Human Effort and Financial Budgets

Lessons Learned

Summary

Questions

Problem StatementProblem Statement

Many industrial circuit breakers use trip

units and Breaker Communication Modules

(BCMs)

Communication requires direct connection

Interrogation cumbersome and inefficient

Problems with faulty wiring

Need for wireless approach in improving

communication with trip units

Design ObjectivesDesign Objectives

Wireless communication device for each BCM

Attaches to circuit breaker

Wireless communication device for the laptop

connected via serial port

Operates in an industrial environment

Used by Square D

End Product DescriptionEnd Product DescriptionWCBI will consist of:

Laptop coupled with wireless communication device

Circuit breaker with BCM, trip unit, wireless interface

WCBI will be able to:

Improve efficiency of obtaining breaker settings

Demonstrate interrogation of at least two devices

Operate in a range up to 30 feet

AssumptionsAssumptions

Wireless link will be immune to interference in an industrial environment

Transmitters/Receivers will not interfere with each other

WCBI will work at distance up to 30 feet

24-volt DC BCM power supply sufficient for wireless hardware

Limitations Limitations

Interrogation of only 247 BCMs under MODBUS protocol

24-volt power supply only available power

Device must attach conveniently to circuit breaker

Device attached to laptop should weigh less than 3 lbs.

Risks and ConcernsRisks and Concerns

Lack of input from client

Square D changing the design requirements

Hardware design not operating correctly

Not finishing on time

Technical ApproachTechnical Approach

Wireless modems - too expensive Infrared - line of sight Build our own wireless devices

– Frequency bands: 315 MHz, 900 MHz, 2.4 GHz– ASK vs. FSK

Initial Design

Technical DesignTechnical Design

Existing System

Technical Design Technical Design Cont’d.Cont’d.

Proposed WCBI

Wireless Transceiver

Wireless Transceiver

4 Wire, RS485 MODBUS

baud = 4800, 9600, 19.2K

4 Wire, RS485 MODBUS

baud = 4800, 9600, 19.2K

INFRARED

INFRARED

RS-485/RS-232 Converter

MODBUS DRIVER

Wireless Transceiver

Technical Design Technical Design Cont’d.Cont’d.

RF IC’s use FSK and operate in the 900 MHz ISM band (unlicensed)

Transmits at ~920 MHz, Receives at ~905 MHz

Easier to implement as full duplex although unnecessary

Just a wire replacement

Can use current software

No need to worry about error control and addressing for hardware design

Technical Design Technical Design Cont’d.Cont’d.

Wireless Transceiver

RX

TX1

RX1

TX

Logic/485

485/Logic

Logic/485

485/Logic

RS485/ RS232

TX2

RX2

Logic/485

485/Logic

905 MHZ

920 MHZ

Computer End Circuit Breaker End

MilestonesMilestones

Decide on wireless communication method

Design circuit

Order parts and equipment

Assemble circuits

Insure wireless system successfully interrogates two trip units

AccomplishmentsAccomplishments

Met class requirements

Trip to Square D

Completed design

Purchased circuit components

Future WorkFuture Work

Improve on current software

Increase range

Removal of RS 485/RS 232 conversion, or use USB

Use transceiver chips (half duplex) instead of a receiver and transmitter (full duplex)

Human EffortHuman Effort

Personnel Original Effort Estimate

Revised Effort Estimate

Actual Effort To Date

Greg Stamp 56 hrs. 110 hrs. 82 hrs.

Matt Hensler 57 hrs. 80 hrs. 69 hrs.

Fahad Azeem 52 hrs. 75 hrs. 61 hrs.

Neil Peterson 55 hrs. 90 hrs. 74 hrs.

Totals 220 hrs. 355 hrs. 286 hrs.

Financial BudgetFinancial Budget

ItemOriginal Budget

Estimate

Revised Budget

Estimate

Actual Expenses To Date

Equipment and Parts  $400 $300 $90

Telephone and Postage $5 $5 $0

Printing $50 $50 $40

Totals  $455 $355 $130

Lessons LearnedLessons Learned

Communication is critical

Assigning specific tasks improves efficiency

Working around conflicting schedules

Need to be flexible, have several design options

SummarySummary

Wire replacement– Eliminates physical connection between the laptop and the

circuit breakers

Operates in the 900 MHz ISM band

Makes interrogation convenient

Questions Anyone?Questions Anyone?