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Clock Distribution for IceCube. June 8, 2004 Lawerence Berkeley National Laboratory Gerald Przybylski. GTPrzybylski LBNL 10/13/2003. Big Picture. ExacTime ET6000 GPS Clock(s). US Naval Observatory (~1E-15 Allan Var. ) UTC. Slaved Rubidium Oscillator Inside, < 1x10 -11 Allan Var.
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Clock Distributionfor IceCube June 8, 2004 Lawerence Berkeley National Laboratory Gerald Przybylski GTPrzybylski LBNL 10/13/2003
Big Picture ExacTime ET6000 GPS Clock(s) US Naval Observatory(~1E-15 Allan Var. ) UTC Slaved Rubidium Oscillator Inside, < 1x10-11 Allan Var. Master Clock Unit Serial Fan Out Balanced Drivers 1pps 10 MHz (With Oven Crystal option) DOM Hub Equal Length Twisted Pairs; 10 Mhz, 1pps, RS-232; Cat5E with RJ-45s DOM Hub DOM Hub DOM Hub DOM Hub ~90 DOM Hubs IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/2004
Rubidium Oscillator Allan Variance Figure from http://www.srsys.com/products/PRS10.htm IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 10/13/2003
Rubidium Clock Phase Noise Figure from http://www.srsys.com/products/PRS10.htm IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 10/13/2003
Accuracy and Precision The US Naval Observatory20 Atomic Clock array keeps time to < 2x10-15. GPS SatellitesSynchronized to USNO clock. DOMs more stable than XL GPS clocks40ns RMS; 150ns Peak Error; 3E-10 10 sec Allan variance Radio Propagation Path variationsGPS Receiver Local Oscillator jitter. In House Cable Delays; Fixed Phase ShiftsGPS Clock -to- Master Clock UnitMaster Clock -to- DOM Hub Fan-OutFan-out -to- DOR FPGA FPGA -to- Wire IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 10/13/2003
Inside the DOM Hub Internal, equal length fanout cables Power Supplies Fans Monitors (Possibly Diskless) CPU Clk Fan-Out DOR card DOR card DOR card DOR card DOR card DOR card DOR card DOR card Cable From Master Clock Unit 20 MHz (Orange Twisted Pair) 1 Pulse per Second (Green Twisted Pair) RS-232 Time String (Brown Twisted Pair) IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 10/13/2003
Data Buffer SRAM 2 x 256Kx16 The DOR Card Cable Interface #0 PCI - Core Cable Interface #1 DOM 1..4 Cable Interface #2 Cable Interface #3 DOM 5..8 PCI Bus Altera FPGAEP20K200E 10 MHz DSB: 1-to-8 Slave Clock Fan-out (PCI Card) 20 MHz Aux. Osc. 1 pulse/second Config JTAG Master Clock (Serial) Time String JTAG JTAG Altera PLD EPM7064 FLASH 1M x 8 96 V IceCube DOMHub Hardware Review and Workshop KHS 10-2003 GTPrzybylski LBNL 10/13/2003
Power-filter #1..4 DOR_Rev1, Block Diagram +/-48 V wiredOR Power-sw. #1..4 DOM 1..4 nPON_1..4 nPON_1..4 CommunicationsControllerAlteraEP1C20F400C8 Cable Interface #0 PCI Core Local Bus Cable Interface #1 DOM 5..8 Cable Interface #2 PCI Bus Cable Interface #3 PCI Bus-Ctrl AlteraEP1K50FC256-1 Memory Bus Config JTAG Config JTAG Clock_sel DSB: 1-to-8 Slave Clock Fan-out (PCI Card) 20 MHz Aux. Osc. JTAG 1PPS Serial Master Clock JTAG Config. PLD Altera EPM7128BFC100-10 Data Buffer SRAM 2 x 256Kx16 local Osc. FLASH 2M x 8 PLL QS5LV919 Clock IceCube DOMHub Hardware Review and Workshop K-H Sulanke 6/8/.04
Signaling Issues: • Maximize Noise Immunity in Counting House- Avoid Winter Noise Storms- Avoid Motor Noise, Welder Noise, etc… • Minimize EMI and RFI- Computers and Instruments • Proven Technology- Price- Component Availability- Track Record IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/04
Master Clock to DSB Like 802.3 RS-485 IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/04
DSB to DOR LVDS IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/04
Master Clock Features[PY03, this year] • Single ET6000 (Xtal, or Rubidium?)- OCXO: 10 Sec Allan Variance 2E-11, -120 dBc/Hz Phase Noise - Rubidium: 10 Sec Allan Variance 1E-11, -91 dBc/Hz Phase Noise • 10 MHz from Half the Optional Outputs- Drive LEMO Inputs through coax • 1 Hz from Half the Optional Outputs- Drive LEMO Inputs through coax • RS-232 from (DTR) DB-9- Daisy-Chain cable • Cold Spare in Rack • Heated “Radome” on TCH Roof (>-40°C) IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/04
PY03 Deployment Temporary Counting House GPS Clock (Hot) BOM: GPS Clock 4 identical BNC to LEMO cables (10 MHz) 4 identical BNC to LEMO cables (1 PPS) 1 Serial daisy-chain cable (Time String) Antenna Heater Serial Port cable DOM Hub, String 0 DOM Hub, String 1 DOM Hub, String 2 DOM Hub, String 3 10 MHz 1 PPS IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/04
Master Clock Features[Post PY03] • Multiple GPS clock inputs (?)- Fail-over (?); Voting (?) • Status display (?)- Local Time display- Fault indicator- Fault Reporting- Selected Clock • Clock Relay Port feeding back to MAPO (?)- Supply AMANDA with the IceCube Ref Clock • CPU Monitoring Functions via POE, or CAN (?)- Voltages, Temperatures, Fans- CPU Reset; Power on/off IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/04
Summary • DSB to DOR card Functionality Demonstrated • GPS clock Drive to DSB demonstrated • Firmware under development (Sulanke) possible involvement by LBNL too… • DSB usable, as is, at the Pole for first deployment • Oven Crystal GPS Clock in hand (ExacTime ET6000) • Simplified Deployment Plan Exists for this year. IceCube DOMHub Hardware Review and Workshop GTPrzybylski LBNL 6/8/04
