1. Sector Collector Electronics
Consolidation of DT
Sector Collector Electronics
C. Fernández Bedoya on behalf of DT Upgrade group
CMS Upgrade Week
October 26th, 2010

2. DT Electronics Sector Collector
Second level of DT read-out and trigger
C. Fernández Bedoya October 26th, 2010 2
DTTF

3. DDU ROS ROB DT CHAMBERS DT Read-Out System UXC55 USC55 DDU (FED)
40 m copper
240 Mbps
~16 Mbps throughput
60 m optical
800 Mbps
~80 Mbps throughput
S-LINK64
320 MB/s
~ 200 MB/s throughput
DDU (FED)
10 DDU => half a wheel
12 ch/DDU (only half needed)
Data merging
Data quality monitoring
TTS interface
~ 0.7 kB muon event size/DDU
Chambers
5 wheels
60 sectors
250 chambers
660 super-layers
1640 layers
~ channels
Minicrates
1500 ROB
128 ch/ROB
Time digitalization (0.7 ns resolution)
1 µs time window
Sector Collector
60 ROS
25 ch/ROS => sector
Data merging
Data quality monitoring
~ 260 bytes muon event size/ROS
C. Fernández Bedoya October 26th, 2010 3

4. DT Trigger System TSC 40 m copper 480 Mbps 60 m fiber 1.6 Gbps OptoRX
C. Fernández Bedoya October 26th, 2010 4

5. DT Sector Collector - 2 SC crates per wheel
- Located in tower racks in UXC level 2 Near
- 60 ROS and 60 TSC boards in the system (1 per sector)
- Complex electronic system
- Main elements:
LINCO, TIM, ROS, TSC
LINCO
C. Fernández Bedoya October 26th, 2010 5

6. DT SC Consolidation: Motivation
Proposed upgrade is not motivated by the physics performance but by the fact that aging and other risks may jeopardize detector operation and contribute to an accelerated degradation
Magnetic fields (40 mT) => tangential turbines
SC crate power consumption (aprox 1 kW) is already marginal for CMS cooling system in the cavern. Temperature of some boards reach 45ºC.
Turbines aging will lead to accelerated aging of the system and increased failure rate.
Radiation doses 0.2 Gy per year (charged particle fluxes 20 cm-2 s-1)
SC boards include large amount of logic, sensitive to SEU. Higher L => higher SEU rate.
Important constrain for future upgrades.
Limited access tighten to LHC technical stops and radiation protection issues
In case of failure, it can take easily one week until access to the cavern is granted.
Impact of failures in the detector can be VERY LARGE:
Part failing
Affected region
%DT affected
LINCO
Half a wheel in trigger and read-out
10%
TIM
ROS
1 Sector in the readout
1.7%
TSC
1 Sector in the trigger
C. Fernández Bedoya October 26th, 2010 6

7. Proposed Upgrade
-Relocation of DT SC electronics in the USC counting room
-Make a “simple” copper to OF conversion at SC level
-Modify input mezzanines of ROS and TSC
Low impact modifications: compatible with present system and with possible future upgrades
Present system
Proposed upgrade
C. Fernández Bedoya October 26th, 2010 7

8. Cu to OF conversion Present proposal is to make a 1 to 1 channel Cu-OF
(Present links are copper based which length cannot be increased without compromising its reliability)
Optical fiber
240Mbps
240 Mbps
480 Mbps
480Mbps
Copper
In the tower racks (substituting present SC)
Plus few components for bias setting (DAC) and monitoring.
OF could be extracted from the back of the SC crate
VME interface at tower rack may not be needed
Power can be extracted from present power supplies
C. Fernández Bedoya October 26th, 2010 8

9. Installation of fibers
Number of links between Minicrates and SC electronics
Per Sector
Per Wheel
Total
ROB to ROS 25
300
1500
SB to TSC
32/40*
400
2000
57/65
700
3500
*(S4 and S10 have 5 DT chambers each instead of 4)
Large number of fibers
4 of these cables per SC crate
(40 cables in total, large number of spare fibers)
Total cross section needed around 100 cm2
144 fibers cable
C. Fernández Bedoya October 26th, 2010 9

10. Routing of the fibers should be done through present “trigger” tunnels

13. -CERN EN/EL/EF section can provide and manage optical fiber installation.
-We are in contact with them. -

14. OF input stage
In principle, there is enough space below the false floor in S1 USC to recover extra cable lengths (though it depends on the exact racks to be used).
Main problem is to allocate the SC crates in S1:
-10 SC crates 11U each
-To minimize L1A latency, they should be close to DTTF racks (S1D01 and S2D02)
-In DT racks at present there is only space to allocate 6 SC crates (and not very close to DTTF)
(Relocation can be done in batches of half a wheel)
C. Fernández Bedoya October 26th, 2010 14

15. OF to Cu conversion
-TSC and ROS input stages are mounted on mezzanines.
-Modification to receive optical signals instead of copper can be made reusing most of the present modules
-Interface with DDU and DTTF can remain unchanged
C. Fernández Bedoya October 26th, 2010 15

16. First tests
-Two prototype boards to perform Cu-to-OF and OF-to-Cu conversion have been developed at Ciemat.
-With these boards we intend to qualify different devices at the market.
-First tests are positive both in standalone and in the integrated chain with ROB and ROS
-More studies are ongoing mainly in the reliability of the link
Cu -> OF
Cu -> OF
ROB
ROS
C. Fernández Bedoya October 26th, 2010 16

17. DT SC Consolidation: Motivation
Additional issues that may make the effort worth:
ROS:
-very big noise events that sporadically fill up the buffers
Present FIFOs are external, cannot be easily enlarged
Faster processing time requires higher performance FPGAs
(Very expensive solution in radiation environment)
OptoRX:
-Problems with JTAG interface for configuration and monitoring
-Upgrade connected with possible DTTF redesign
Plus, we are talking of running CMS until 2030 (20 years from now), system will evolve (at some point by force), OF from the cavern to USC is very likely what we may want at some point (it is not a wasted effort).
Any increase in performance cannot be accompanied by an increase of power consumption if present location remains
Any improvement in the present location has a higher cost and longer design time (due to radiation constrains)
C. Fernández Bedoya October 26th, 2010 17

18. Compatibility with future upgrades
Step 1
Future upgrades?
Present
Cu-OF
(trg)
Minicrate
Minicrate
Minicrate
Cu-OF
(RO)
OF Patch panel
ROS
TSC
Cu-OF
(RO)
Cu-OF
(trg)
UXC
UXC
UXC
USC
USC
USC
OptoRx
ROS
TSC
ROS
TSC +
OptoRx
DDU
DTTF
OptoRx
DTTF
DTTF
DDU
DDU
C. Fernández Bedoya October 26th, 2010 18

19. DT SC consolidation: Plan
PRESENT PLAN
1. Fibers installation (2012):
-Requires long access time
-Needs to be done simultaneously for all the fibers
2. Scaled installation at any time (winter shutdowns). Minimal unit is half a wheel.
-Modification of TSC and ROS input mezzanines
-Relocation of SC electronics in USC
Estimated cost 800 k€ (+600k€ if ROS and TSC are totally redesigned)
C. Fernández Bedoya October 26th, 2010 19

20. Back up

21. DTTF
BPTX
33 U
16 U
10 U*
DTTF
bottom
10 U
13 U
13 U empty
13*+13 U empty
15 U
0 U
16 U
10 U*
16 U
10 U*
14 U*
33 U
0 U
15 U
Since 26 U
Since 26 U
0 U
In row D we could put more racks to the left, in the corridor, there is space
0 U

25. SC to USC
-Move SC crates to USC (VME access in UXC may not be needed, compatible with future RS485 board)
-Modify input ROS and TSC mezzanines for OF reception
Fully compatible with present system
Drawbacks:
-trigger latency may be slightly increased
-Find space in USC for 10 SC crates
-Route large number of fibers (with present 48 fibers => 73 cables)

26. DT Chambers YB+2 YB+1 YB0 YB-1 YB-2 250 chambers 5 wheels26
May 29th, 2009
C. F. Bedoya
DT Chambers
Sector 4
YB+2
YB+1
YB0
YB-1
YB-2
Sector 5
Sector 3
Sector 6
Sector 2
Sector 7
Sector 1
MB2
MB1
MB3
MB4
Sector 8
Sector 12
Sector 9
Sector 11
Sector 10
250 chambers
5 wheels
12 sectors/wheel
4 layers/sector:
MB1, MB2, MB3, MB4
172,200 drift cells
Covers 0<η<1.2.
Provide muon identification
Precise momentum measurement. Good pT resolution at high
transverse momenta: σ(pT)/pT~ 1TeV/c
Reliable and robust trigger:
pT standalone Level-1 and High Level Trigger
and precise Bunch Crossing (BX) assignment.

27. DT Chamber DT Cell  DT Chambers 27 May 29th, 2009 C. F. Bedoya
Tmax < 400 ns
Efficiency ~ 99%
Drift velocity ~ 55 μm/ns 
DT Cell
Anode wire
3 Superlayers per chamber, 2 for Ф coordinate and 1 for  coordinate.
Almost linear space-time relationship.
Single wire resolution ~ 250 µm
Local reconstruction (rФ) ~ 100 µm
Gas: Ar/CO2 (85/15)%
High Voltage: wires kV
strips kV
cathods -1.2 kV

28. 28
May 29th, 2009
C. F. Bedoya
Minicrate
Attached to the DT Chambers it contains the first level read-out, trigger and full chamber control electronics.
CCB: Full chamber control and monitoring: configures, sets thresholds, reads temperatures, etc.
CCBlink: Connects the CCB to the external DT DCS system.
TRB: Searches track segments and performs bunch identification.
SB: Performs track selection and transmits to TSC.
ROB: Time digitalization of signals coming from the chambers.
ROLINK: Collects outputs from ROBs and sends it to the ROS.
New Minicrate firmware means new CCB firmware.

29. MC secondary link upgrade for 2012 shutdown From Franco G.
Replacement of 485 boards (10) housed in SC crates
Improvements in secondary link system done 2 years ago
have solved the many RS485 IC ruptures on MC linkboard
But:
Improvements were realized with many ‘handmade’ patches added to boards
The UXC-USC link for half wheel is slow, 38.4Kbps
Often 485 boards lost communication with DCS (last week 2 of 10, sometimes more)
Recovering requires cycling on/off the SC crate
Enhancement of MC communications reliability
Integration of all patches on PCB
new
485
board
Maximization of USC-UXC link speed
Boards remain compatible with present hardware
Required the modification of part of DCS server software
Cost: about 15Keuro. Man power by INFN PD

30. present system after 2008 improvements
MC SECONDARY LINK
present system after 2008 improvements
From Franco G.
Primary serial link -> optical fiber MC
communication
Secondary serial link -> RS485 copper chain
Half wheel
RS485 board
38.4Kbps
Sector 1/7
driver485
Sector 2/8
driver485
38.4Kbps
UXC
Upper/bottom
SC 9U crate
Sector 3/9
controller
Sector 4/10
driver485
38.4Kbps
Sector 5/11
driver485
38.4Kbps
Sector 6/12
UXC-USC optical link
38.4Kbps
485 chain termination
& overvoltage protection

31. From Franco G.
Proposed new 485 BOARD
485 chain termination
& overvoltage protection
RS485
38.4Kbps
RS422 link to ADLINK PMC8681
(PMC board already mounted on VME SC crate controller)
230.4Kbits full duplex
S1/S7
S2/S8
485 link
controllers
1/sector
S3/S9
USC Interface controllers
S4/S10
S5/S11
S6/S12
Backup optical link
38.4Kbps for present system compatibility
(upgradable to full duplex)
Power from LV caen module

32. Consequences of LHC plan for DT:
Reassess the robustness of our stock of spares, in particular for on detector electronics (with only 2 openings of CMS, the number of hot spares needs to be larger than planned):
Meticulous failure rate measurements during 2010
On detector electronics:
Not sensible redoing the Minicrates before 2020, however we are for sure short of BTIM.
Present approach is remaking the theta trigger boards and use old boards to retrieve spare BTIMs
UXC racks electronics:
CAEN Low Voltage connectors: weak point in particular for A3100.
Plan is to move to A3100B (bolts) this year.
For A3050 the plan is to test lubricant in 10% of the detector this year and see how it behaves.
Sector Collector electronics:
Currently we need to wait until LHC stops to get UXC access in order to fix a SC problem. A SC problem may handicap a large fraction of the detector (min a sector in trigger or readout).
Present approach under study is to make a “simple” copper to OF conversion at SC level and move SC electronics to USC
Expectations: 3 ROBus/year , 5 TRB/year, 1 CCB Link/year
Failure rate= 46 in 2009, 4 in 2010
Failure rate low at present (~1/year)

33. Equalizer
Laser driver
25/ROS
32/TSC …
Equalizer