1. Radio Antenna Turntable System (RATS) Rhonda Blair John Carroll Cameron McKay Pierce Ruggles

2. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20041 Project Background Table Mountain Turntable Facility (TMTF)

3. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20042 Turntable Pictures

4. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20043 Project Funding Sponsored by US Department of Commerce

5. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20044 Project Requirements Precise position/speed control Remote operation via Telnet Reliability in harsh environment Maintainability

6. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20045 Project Block Diagram Ethernet-to-Serial Interface Master Controller Optical Encoder (RS-422) RS-422 Translation 20x4 Character LCD (Parallel) DAC (SPI) and Buffer Motor Controller Turntable Motor Internet

7. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20046 Project Block Diagram Ethernet-to-Serial Interface Master Controller Optical Encoder (RS-422) RS-422 Translation 20x4 Character LCD (Parallel) DAC (SPI) and Buffer Motor Controller Turntable Motor Internet

8. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20047 Project Block Diagram Purchased components: –Ethernet-to-Serial Interface –20x4 Character LCD (Parallel) –Optical Encoder (RS-422) –DAC –Motor Controller –Turntable Motor

9. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20048 Project Block Diagram Built components: –Master Controller HC11E1 Microcontroller 32k Flash (program storage) 32k SRAM –Buffer, other supporting hardware for DAC –RS-422 Translation board –Power board (+15V,-15V,+5V)

10. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 20049 Testing Modular design for easy testing/construction –Power supply –Encoder –Master Controller –Motor/DAC/Buffers

11. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200410 Testing Turntable model –Allows testing in Capstone lab –If TMTF not operational, allows for a demonstration on expo day

12. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200411 Project Goals For Expo: –Functioning model –Wire-wrapped prototype –Possible implementation at TMTF End of Summer: –TMTF fully operational –PCBs made –Spare boards configured/populated

13. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200412 Economic Aspects/Sustainability Limited market (1 customer) Multiple PCBs built for sustainability and easy maintenance Remotely-upgradeable firmware Expensive, exotic components by necessity –For reliability, precision, and power reasons –Encoder, motor controller, motor

14. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200413 Environmental Impact Low impact because of low production volume Possible noise issues when operating turntable –Located on 4 square miles of restricted land –May anger nearby residents and llamas –However, not feasible to replace turntable

15. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200414 Manufacturability Wide temperature range components –Outdoor operation year-round High-accuracy components –DAC, Optical Encoder Tested on a scale model before TMTF

16. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200415 Safety Emergency stop feature No turntable motion without explicit user request Extensive power-on self test Fail-safe DAC (defaults to ‘stop’) Watchdog timer

17. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200416 Schedule

18. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200417 Risks and Contingencies Risks –Wire-wrap prototype –Software development/debugging –Turntable model Solutions –Schedule has extra time for risky tasks –Can resort to only doing basic functionality for expo, complete the rest over the summer

19. Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, 200418 Questions?