Clock Distributionfor IceCube

June 8, 2004

Lawerence Berkeley National Laboratory

Gerald Przybylski

GTPrzybylski LBNL 10/13/2003

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

2

Big Picture

ExacTime ET6000GPS Clock(s)

ExacTime ET6000GPS Clock(s)

DOM HubDOM HubDOM Hub

FanOut

1pps

10 MHz

Equal Length Twisted Pairs;10 Mhz, 1pps, RS-232;Cat5E with RJ-45s

SlavedRubidiumOscillatorInside, < 1x10-11

Allan Var.

US Naval Observatory(~1E-15 Allan Var. ) UTC

BalancedDrivers

Master Clock Unit

GTPrzybylski LBNL 6/8/2004

Serial

DOM HubDOM Hub~90 DOM Hubs

(With Oven Crystal option)

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

3

Rubidium Oscillator Allan Variance

Figure from http://www.srsys.com/products/PRS10.htm

GTPrzybylski LBNL 10/13/2003

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

4

Rubidium Clock Phase Noise

Figure from http://www.srsys.com/products/PRS10.htm

GTPrzybylski LBNL 10/13/2003

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

5

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

GTPrzybylski LBNL 10/13/2003

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

6

Inside the DOM Hub

DO

R c

ard

DO

R c

ard

DO

R c

ard

DO

R c

ard

DO

R c

ard

DO

R c

ard

DO

R c

ard

DO

R c

ard

Clk

Fan

-Out

CP

U

Cable FromMaster ClockUnit 20 MHz (Orange Twisted Pair)

1 Pulse per Second (Green Twisted Pair)RS-232 Time String (Brown Twisted Pair)

Internal, equal length fanout cables

Power SuppliesFans

Monitors(PossiblyDiskless)

GTPrzybylski LBNL 10/13/2003

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

7

DSB:1-to-8SlaveClockFan-out(PCI

Card)

20 MHz Aux. Osc.

AlteraPLD

EPM7064

The DOR Card

Data Buffer

SRAM2 x 256Kx16

Cable Interface #0

Cable Interface #1

Cable Interface #2

Cable Interface #3

PCI-Core

FLASH1M x 8

Config JTAG

Altera FPGA

EP20K200E

JTAG

PCIBus

DOM 1..4

JTAG

96 V

DOM 5..8

10 MHz

1 pulse/second

(Serial) Time StringMasterClock

KHS 10-2003

GTPrzybylski LBNL 10/13/2003

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

8

Communications

ControllerAltera EP1C20F400C8

DOR_Rev1, Block Diagram

Data Buffer

SRAM2 x

256Kx16

Cable Interface #0

FLASH2M x 8

Config. PLDAltera

EPM7128BFC100-10

Config JTAG

JTAG

PCIBus

DOM 1..4

JTAG

Clock

+/-48 V

DOM 5..8

PCI Bus-Ctrl Altera

EP1K50FC256-1JTAG ConfigMemory Bus

Local Bus

PLLQS5LV9

19

local

Osc.

Power-sw. #1..4wired

OR Power-filter #1..4

nPON_1..4 nPON_1..4

Clock_sel

PCICore

DSB:1-to-8SlaveClockFan-out(PCI

Card)

20 MHz Aux. Osc.

MasterClock

1PPSSerial

Cable Interface #1

Cable Interface #2

Cable Interface #3

K-H Sulanke 6/8/.04

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

9

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

GTPrzybylski LBNL 6/8/04

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

10

Master Clock to DSB

Like 802.3

RS-485

GTPrzybylski LBNL 6/8/04

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

11

DSB to DOR

LVDS

GTPrzybylski LBNL 6/8/04

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

12

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)

GTPrzybylski LBNL 6/8/04

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

13

PY03 Deployment

GPS Clock (Hot)

DOM Hub, String 0

DOM Hub, String 1

DOM Hub, String 2

DOM Hub, String 3

Temporary Counting House

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

10 MHz

1 PPS

Serial Port cable

GTPrzybylski LBNL 6/8/04

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

14

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

GTPrzybylski LBNL 6/8/04

June 8, 2004 IceCube DOMHub Hardware Review and Workshop

15

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.

GTPrzybylski LBNL 6/8/04