Front End Driver (FED) Crates and Racks +Tracker PSU racks Matthew Pearson RAL m.pearson@rl.ac.uk Electronics Week November 2002 Matthew Pearson 21/02/2019

Considerations How many FEDs per crate? How shall we arrange the FEDs? Don’t mix FEDs from different partitions In crates? In racks? Separate into +/-? Do we need to reserve space in case we need to use more FEDs than we expect? (if data rate per FRL is >200Mbytes/s) Can we keep the S-LINK64 short enough? (Has to be less than 15m) Matthew Pearson 21/02/2019

How many FEDs per partition? 440 FEDs in total 4 Partitions: TEC+, TEC-, TIB+TID, TOB Partition Layer #FEDs TEC+ (1-3,4-6,7-8,9) (40,32,16,8) = 96 TEC- (1-3,4-6,7-8,9) (40,32,16,8) = 96 TIB+TID 2*(1,2,3,4)+2*(1,2,3) 2*(12,16,6,8) + 2*(5,5,5) = 114 TOB 2*(1,2,3,4,5,6) 2*(11,12,7,8,14,15) = 134 What’s the best way to arrange these? Note: Data rate per FED is highest for TIB1 and TEC7,8,9 Matthew Pearson 21/02/2019

How many FEDs per crate? VME64 crates have 21 9U slots (see reference 1) 17-19 FEDs per crate ---- Depending on other modules used. Other modules: Spare slots (eg. Tester board) 1 or 2 less slots in each crate FMM (Fast Merging Module) Or something similar, which may be a transition card on the back-plane. 1 less slot in each crate (?) Crate or rack controllers? 1 less slot in each crate Matthew Pearson 21/02/2019

Crate/Rack Controllers Remote PC based crate controllers are favoured. Need VME interface module in each crate Interface module has to be 6U A 6U module needs 6U-9U adapter. (only takes up one slot) 6U 9U Frame 400mm 160mm VME Backplane Matthew Pearson 21/02/2019

Number of crates Partition #Crates TEC+ 6 TEC- 6 TIB+TID 7 TOB 8 Assume a given crate contains FEDs from only 1 partition. If 17 or 18 FEDs per crate: Partition #Crates TEC+ 6 TEC- 6 TIB+TID 7 TOB 8 For 19 FEDs per crate: Partition #Crates TEC+ 6 TEC- 6 TIB+TID 6 TOB 8 Matthew Pearson 21/02/2019

How many racks? Don’t mix partitions in a rack. Partition #Racks * 07/16/96 How many racks? Don’t mix partitions in a rack. Partition #Racks TEC+ 2 TEC- 2 TIB+TID 3 TOB 3 TOTAL: 10 racks true for both 17 or 18 FEDs per crate. for 19 FEDs per crate we save one rack. …also, dedicated DAQ racks for each partition (64 FRLs per DAQ rack). 3 crates per rack * Matthew Pearson 21/02/2019

Suggested FED rack layout * 07/16/96 Suggested FED rack layout 1.0m 1.5m A B C Need PC racks for FEDs and DAQ FED racks are grouped to assist in cabling (Francois) Each DAQ is close to FEDs from same partition 1 DAQ DAQ 2 TIB+TID TOB 3 TIB+TID TOB 4 TIB+TID TOB 5 DAQ DAQ 6 FED PCs DAQ 7 DAQ DAQ 8 TEC- TEC+ 9 TEC- TEC+ 10 TEC- TEC+ 11 12 13 . * S-LINK length minimised (<10m) Matthew Pearson 21/02/2019

TIB+TID Crates Assuming 17 FEDs per crate FRLs TIB4 (16) TID3 (10) (The number of FEDs in each crate is shown in brackets) FRLs TIB4 (16) TID3 (10) TID1 FRLs TIB2+ (16) TID2+ (5) TIB1+ (12) TID2- (5) TIB2- (16) TIB3 (12) TIB1- (12) B1 B2 B3 B4 B5 Matthew Pearson 21/02/2019

TOB Crates FRLs TOB1 (17) TOB1 (5) TOB2- (12) TOB5+ (14) TOB3 (14) (15) TOB6+ TOB4 (16) FRLs TOB2+ (12) C1 C2 C3 C4 C5 Matthew Pearson 21/02/2019

TEC+/- Crates FRLs TEC1-3 (15) TEC1-3 (10) TEC4-6 (16) TEC7-8 (16) C7/B7 C8/B8 C9/B9 C10/B10 Matthew Pearson 21/02/2019

S-LINK64 cable length the S-LINK cable lengths between FEDs and The S-LINK64 standard will be used for the FED-FRL connection. If using S-LINK PCI source card on VME transition card, the link runs at 66MHz. This has been shown to be OK for cable length of 15m. Therefore: the S-LINK cable lengths between FEDs and FRLs of <10m are OK. Matthew Pearson 21/02/2019

Some other S-LINK points We would like to run FED at 40 or 80MHz (320 or 640Mbytes/s). For convenience To run as fast as possible (to cope with unexpected high data rates) If FED runs at 80MHz, we will get back-pressure signals from the S-LINK source card. An alternative is to drive the S-LINK directly from the FED FPGA. We could then run at any speed up to 100MHz (the S-LINK standard limit) – but would prefer to run at 80MHz This would place tighter restrictions on the S-LINK cable length. How much tighter????? Matthew Pearson 21/02/2019

Tracker PSU racks Current base-line plan is to place TK PSUs in the Experimental Hall (UXC55). 20 racks for SST 2 racks for Pixel 4 racks for 48V DC PSUs (estimates from Horst) Allocate space: 2*9 racks on Upper Balcony in central position 2*4 racks on Middle Balcony in central position Still things to consider (accessibility, maintenance, cost, radiation and magnetic field issues ...) Matthew Pearson 21/02/2019

Summary A scheme has been presented detailing the FED layout within the crates and racks, and the placement of the racks in USC55. Note: If the scheme is approved, and once the cables are cut by Francois, nothing can be changed. Matthew Pearson 21/02/2019

References Technical specification for subracks for LHC experiments http://atlas.web.cern.ch/Atlas/GROUPS/FRONTEND/rackscrates.html 2. The S-LINK 64 bit extension specification: S-LINK64 http://his.web.cern.ch/HIS/s-link/spec/ 3. CMS DAQ: Technical Design Report 4. Rack layout in USC55 http://cmsdoc.cern.ch/~wsmith/USC55_racks_v36.html Matthew Pearson 21/02/2019