outline: current status active splitter plan chris neu, daniel whiteson, rick van berg l2 upgrade...

Outline:

•Current status•Active splitter•Plan

Chris Neu, Daniel Whiteson, Rick Van Berg

L2 Upgrade Meeting11 June 2004

XCES Input Path: Status

June 11, 2004 L2 Upgrade Meeting Christopher Neu Penn/CDF


Recall from last time:

•48 XCES input channels for L2•Tx downstairs use Taxi

Optical Tx strength varies component-to-componentWeak optical Tx strength rampant – half too weak to split; others marginal or sufficient

•16 split channels16 NetOptics splittersHoused near bottom of rack 2RR31C (near entrypoint for XCES fibers from CH)2U chassis, Siemon patch panels on front and rear (thanks to Dervin’s guys for fabrication)Inputs fed in through backHalf of outputs sent out the back, half out the front (particularly convenient)Inputs to splitters coupled directly to XCES fibers at original patch panels

(to avoid moving input fibers)Have each output marked with ID # and loss value to facilitate channel swapping



•Staged 16 new 20’ long fibers feed pulsar boardLeft 4 fibers from stage 0 in as spares

•Installed 16 splitters on 4/15•Chose 16 strongest Tx channels for splitting:

•Tested with L2 tortureTev studies time – my favorite timeScript from Masa: allows user to adjust by hand the XCES thresholds to tune occupancyDuring studies one can mimic real dataAll looked well with Run 2A system

•Beam tests

Pulsar channel XCES channelTaxi Tx loss (-

dBm)

0 0W 15.2

1 0E 15.91

2 12E 15.56

3 15W 16

4 14E 15.73

5 3W 14.67

6 15E 15.47

7 16W 15.12

8 5W 13.22

9 19W 15.69

10 7W 15.33

11 19E 15.68

12 20E 15.5

13 9W 15.08

14 21W 14.82

15 21E 14.97


Results of Beam Tests: Run 2A system

ADC counts and turn-on curve for high and low XCES thresholds.


Results of Beam Tests: Run 2A System

bitstotal

unexmiss

bitstotal

wrongE

#

##

#

#0

bitswrong

bitsmissEmiss #

#

wrongtotal

bitsunexEunex #

#

= split channel


Results of Beam Tests: Run 2A system

Same run, restricting attention to events away from threshold to remove turn-on effects


Results of Beam Tests: Run 2B system

Two references for Pulsar path, each with their own quirks

Compare Pulsar data to simulation of trigger threshold

Compare Pulsar data tothreshold trigger bits in alpha

Raredifferences

CESD simulation as reference TL2D as reference


Results of Beam Tests: Run 2B system

Using absolute reference:L2Torture test with patterns in the SMXR thresholds so that the bits were predictable.

In 1 million bits:Run 2B:TP2D: Zero errors!

Run 2A:TL2D: Rare errors

Plots like these to be available in PulsarMon!


Commissioning Plan: Timeline Made Before Tx Power Problems ID’d

3/15: Stage0 splitter box complete DONE3/16: Install Stage0 splitter box DONE3/15-3/22: Perform optical measurements on all 48 XCES signals coming from downstairs DONE3/22: CDF power back 3/22-4/1: L2 Torture testing: debug/use/refine monitoring code DONE3/23-4/10: Beam tests after understanding L2 Torture DONE4/10: Stage0 complete DONE4/10-5/1: Develop DAQ code for XCES readout DONE5/1: Stage1 splitter boxes completeDONE

5/7: FW for driving out over SLink complete DONE5/1-5/7: Install Stage1 splitter boxes in systemDONE5/7-6/1: L2 Torture and beam tests of split system; DONE L2T of Slink output … Progress Made – BR, SP, Frans et al.5/7-6/1: Install and test XCES Merger link Progress Made6/1: Stage1 complete6/2004: Build and install Stage2 splitter boxes …. complicated by active splitterEnd of 6/2004: Have N Taxi Rx boards in hand ready for system (N = 2 + #spares) READY – thanks to others

7/2004: Install 2 more Taxi Rx boards in system; test with L2 Torture, beam8/2004: Burn-in time in beam; readout by default; monitor for errors8/24/2004: Stage2 complete8/25/2004: 10-week shutdown begins


The Virtues of Splitting All 48 Channels

•Commissioning of system possible with only 16 split channels

But painful

•Turn-on of XCES path cannot be parasitic-gradual would need to be threshold moment this is not optimal

•Future: would like to have a “hot spare” Pulsar system ready

being fed parasitically with upgrade in place

•Will make things “clean”each channel treated equivalently


Design of Active Splitter

RVB and I came up with this design at Penn a couple weeks back:

-5V

-5V

-5V

Variable Resistor To set Comparison

Voltage

Taxi Rx HFBR 2416

Taxi Tx HFBR 1414

Taxi Tx HFBR 1414

AD96687

MC10H115

Prototype has been built at Penn; will be here at FNAL for testing next week.


Two Possible Paths and Timelines

•Delay getting prototype here from PennAtlas test beam work required significant attentionThings calmer now

•Once the hand-made prototype is here we can test it using Taxi Tx-Rx setup in teststand crate•Those tests will determine if basic circuit logic is working and whether we can proceed•Would like to solicit help getting testing off the ground and ultimately testing all boards once they arrive

•Need 48 channels split + spares: so let’s say we need 60 split channels•Choices to consider: 2 channels-per-board x30, or 1 channel-per-board x60

•Two possible paths:Use PCBMake all splitters by hand

•Timeline estimates are different…


Two Possible Paths and Timelines

PCB:

6/14-6/18: test prototype here at FNAL

work on layout (4 layer, at Penn)6/19-6/25: finalize layout and

determine mechanical issues 6/28: submit design for fabrication 7/12: delivery of boards7/12-7/18: stuffing of parts at Penn

boards start to arrive at FNAL on daily basis

en-masse testing begins7/14-8/1: testing in situ 8/1: all 48 channels split

Assemble by hand:6/14-6/18: test prototype here at FNAL

finalize circuit determine mechanical

issues6/19-7/1: assemble at Penn using vector boards (2 students x several per day)

boards start to arrive at FNAL

on daily basistesting as they arrive

7/1-7/18: assemble boxes, installtest in situ

7/18: all 48 channels splitSchedule complicated by honeymoon in Spain and Italy – leaving in 7 days.But I will have time to test the prototype and look into mechanical issues before leaving.


Logistical Issues Splitting 48 Channels

•Input fibers from CH come into the rear of the rack•Prefer to leave them in place – do not want to disturb these•So input to splitters should be at rear of rack•Output fibers (for convenience) should come out the back as well•Have ~18 inches vertical space for splitter chassis

•Thinking about 2 rear-facing chassis on shelves looking like this:

•Power comes from a 5V supply plugged into power strip; boards get power across a simple backplane or jumpered together…need to talk to Bob DeMaat.

~17in

~7in


Summary

•Stage 0 and Stage 1 splitting completed ahead of schedule•Stage 2 splitting complicated by need for active splitters

•Have an active splitter design and prototype built•Needs testing - will be done next week

•Decision on path needs to be discussed•Cost issues?

•Will need help testing boards•Lots of things need to be done.

outline: current status active splitter plan chris neu, daniel whiteson, rick van berg l2 upgrade...

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