Optical links for CMS ECAL clock and control system

1
Optical links for CMS ECAL clock and control
system
A.Singovski University of Minnesota

• Outline.
• CMS detector Clock and Control system
  architecture
• ECAL-specific parts
• Cost and schedule

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Digital Control Link
ECAL will use the TRACKER design of the Clock and
Control system with the minimal modifications
Token Ring with off-detector Front-End Controller
as the primary node and on-detector Communication
and Control Units as the secondary ones
US group responsibility
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Digital Control Link reliability
The choice of the ring architecture for the
system designed to run for 10 years without
maintenance with zero failures in radiation hard
conditions is not evident. Bonus Low
cost Minus The ring brake leads to the loss of
several hundreds of the detector
units Solution All chain elements should be
radiation tolerant and redundant
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Custom designed Communication and Control Unit
Double Token Ring controller

• Radiation-tolerant design
• rad-tolerant technology
• three identical copy of the same logic and voting
  logic used for the node controller
• all data paths are protected by parity

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Architecture for redundancy
A redundancy scheme based on doubling signal path
and bypassing of interconnection lines between
CCUs and between CCU and FEC
Ring B
Ring A
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Tracker System implementation
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ECAL System implementation
Token Ring Board
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Token Ring Board I
LV connectors
Token Ring connectors
Dummy CCU
Cooling bar
DOH
LV regulators
Single fiber 12 fibers ribbon adapter
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Token Ring Board II
Token Ring connectors
Token Ring Board PCB layout
LV regulators
DOH
CCU
LVDS MUX
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Token Ring Integration to ECAL Barrel
Up to 8x
Module
Natural structure one control ring per Module
four per Super Module ? 400-500 calorimeter
channels per ring. Maximum allowed by
off-detector electronics design two rings per
Module eight per Super Module ? 200-250
channels/ring.
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Cost estimate
Barrel 33332 rings 1058500 CHF EndCup
909 rings 287100 CHF Preshower 525 rings
165300 CHF
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Status
1
2
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Digital Opto Hybrid designed, tested, final
specification is ready, Producer is specified
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Tracker components, ECAL orders will follow
Optical cables and connectors specified, tested,
delivery for TRK is started
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4 way transiver commercial product, tested,
specification is ready
3
ECAL-specific item
Token Ring Board all components are specified,
board design is ready, first 3 prototypes are in
production
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Summary

• The ECAL Control system design is well advanced
  thanks to the excellent information transfer from
  the Tracker project.
• The optical components of the tracker control
  link are defined, characterized and partially
  ordered. ECAL will join these orders soon.
• The first prototype of the Token Ring board is
  designed. 3 prototypes are produced for the
  system and beam tests in June-August 2003.
• The mass production of all ECAL Control Link
  components (US part, FE and CCS excluded) can be
  started in October-November 2003.