WCBI Team Information Team number: Client: Faculty Advisors: Technical Advisors: Team Members: May02-11 Square D Company (Greg Wiese) Glenn Hillesland James Triska Mani Mina Steve Russell Fahad Azeem Matt Hensler Neil Peterson Greg Stamp Presented on March 12, 2002

Presentation 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 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 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 Description WCBI 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

Assumptions 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 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 Concerns Lack of input from client Square D changing the design requirements Hardware design not operating correctly Not finishing on time

Technical 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 Design Existing System

Technical Design Cont’d. Proposed WCBI Wireless Transceiver 4 Wire, RS485 MODBUS baud = 4800, 9600, 19.2K 4 Wire, RS485 MODBUS baud = 4800, 9600, 19.2K INFRARED RS-485/ RS-232 Converter MODBUS DRIVER Wireless Transceiver

Technical Design 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 Cont’d. Wireless Transceiver RX TX1 RX1 TX Logic/ /Logic Logic/ /Logic RS485/ RS232 TX2 RX2 Logic/ /Logic 905 MHZ 920 MHZ Computer EndCircuit Breaker End

Milestones Decide on wireless communication method Design circuit Order parts and equipment Assemble circuits Insure wireless system successfully interrogates two trip units

Accomplishments Met class requirements Trip to Square D Completed design Purchased circuit components

Future 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 Effort Personnel Original Effort Estimate Revised Effort Estimate Actual Effort To Date Greg Stamp56 hrs.110 hrs.82 hrs. Matt Hensler57 hrs.80 hrs.69 hrs. Fahad Azeem52 hrs.75 hrs.61 hrs. Neil Peterson55 hrs.90 hrs.74 hrs. Totals220 hrs.355 hrs.286 hrs.

Financial Budget Item Original Budget Estimate Revised Budget Estimate Actual Expenses To Date Equipment and Parts $400$300$90 Telephone and Postage$5 $0 Printing$50 $40 Totals $455$355$130

Lessons Learned Communication is critical Assigning specific tasks improves efficiency Working around conflicting schedules Need to be flexible, have several design options

Summary Wire replacement – Eliminates physical connection between the laptop and the circuit breakers Operates in the 900 MHz ISM band Makes interrogation convenient

Questions Anyone?