1 / 19

Status FEE and DAQ

Status FEE and DAQ. Walter F.J. Müller , GSI, Darmstadt 5 th CBM Collaboration Meeting GSI, March 9-12, 2005. CBM Trigger Requirements (reminder). assume archive rate: few GB/sec 20 kevents/sec. In-medium modifications of hadrons

benjy
Download Presentation

Status FEE and DAQ

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Status FEE and DAQ Walter F.J. Müller, GSI, Darmstadt 5th CBM Collaboration MeetingGSI, March 9-12, 2005

  2. CBM Trigger Requirements (reminder) assume archive rate: few GB/sec 20 kevents/sec • In-medium modifications of hadrons onset of chiral symmetry restoration at high ρBmeasure: , ,   e+e- open charm (D0, D±) • Strangeness in matter enhanced strangeness productionmeasure: K, , , ,  • Indications for deconfinement at high ρB anomalous charmonium suppression ?measure: D0, D±- J/  e+e • Critical point event-by-event fluctuations measure: π, K offline trigger trigger ondisplaced vertex offline drives FEE/DAQarchitecture trigger trigger trigger on high pte+ - e- pair offline 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  3. CBM DAQ Requirements Profile • D and J/Ψ signal drives the rate capability requirements • D signal drives FEE and DAQ/Trigger requirements • Adopted approach: displaced vertex 'trigger' in first level • Additional Problem: DC beam → interactions at random times → time stamps with ns precision needed → explicit event association needed • Current design for FEE and DAQ/Trigger: • Self-triggered FEE • Data-push architecture 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  4. L1 Select L2 Select Self-triggered FEE – Data Push DAQ Detector Self-triggered front-end Autonomous hit detection fclock FEE No dedicated trigger connectivity All detectors can contribute to L1 Cave Shack DAQ Large buffer depth available System is throughput-limited and not latency-limited High bandwidth Modular design: Few multi-purpose rather many special-purpose modules Special hardware Use term: Event Selection Archive 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  5. Front-End for Data Push Architecture • Each channel detects autonomously all hits • hit finding and sparsification needed in FEE • An absolute time stamp, precise to a fraction of the sampling period, is associated with each hit • time distribution system needed (replaces trigger distribution) • All hits are shipped to the next layer (usually concentrators) • de-randomization buffers needed • large output bandwidth • Association of hits with events done later using time correlation • Typical Parameters: • with 1% occupancy and 107 interaction rate: • some 100 kHz channel hit rate • few MByte/sec per channel • whole CBM detector: 1 Tbyte/sec 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  6. FEE – DAQ Interface FEE FEE FEE FEE FEE Diversityinevitavble Concentrator orread-out controller Cave 3 logical interfaces Shack Clock and Time(in only) Control(bidirectional) Commoninterfacesindispensible Hit Data(out only) First Drafts readyfor fall 2005CBM TB Meeting Time DAQ DCS 3 Specs: 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  7. FEE Working Group Session Check for last minutechanges in WG programs Friday 9:00 – 13:00 – Theory Seminar Room RPCFront-end Timemeasurement Time distribution TRD/RICHrequirements straw TRD FEE solution Si Strip FEE Building blocksfor amulti-purposeFEE ASICarchitecture 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  8. FEE Summary • Several FEE developments have started • define interfaces (Time, DAQ, DCS) • FAIR FEE workshop this summer • communicate with PANDA, NuSTAR, ... • Concrete R&D on FEE buildings blocks has started • MPWs planned in 2005 covering essential blocks for RICH, TRD, RPC (,ECAL) • Some Subsystems still in beginning of conceptual stage: • Hybrid Pixel FEE • Strip Detector FEE • Some requirements not yet finalized • RICH: PMT or MWPC • RICH(PMT) and ECAL: desired or required timing resolution 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  9. CBM DAQ and Online Event Selection • More than 50% of total data volume relevant for first level event selection • Aim for simplicity • Simple two layer approach: 1. event building 2. event processing neededfor D neededfor J/μ usefullfor J/μ STS, TRD, and ECAL data usedin first level event selection 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  10. Logical Data Flow Concentrators:multiplex channelsto high-speed links Time distribution Buffers Build Network Processing resources forfirst level event selectionstructured in small farms Connection to'high level' selection processing 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  11. Bandwidth Requirements Data flow: ~ 1 TB/sec Gilder helps Moore helps 1st level selection: ~ 1014-15 operation/sec Data flow: few 10 GB/sec to archive: few 1 GB/sec→ ~ 20 PByte/year → 100 Gevt/year 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  12. Event Building – Alternatives • Straight event-by-event approach: • data arrives on ~1000 links • ~100 byte per event and link • 1010 packets/sec to handle... • Handle time intervals or event intervals • 10 μs or 100 events seems reasonable • event slices allow to suppress background • time slices work also to p-p and p-A • Very regular and fully controlled traffic pattern: • data traffic can be scheduled to avoid network congestion • a large fraction of the switch bandwidth can be used • aim at COTS solution for BNet (→ Ethernet) • discrete event simulations under way 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  13. Network Characteristics Data PushDatagram'serrors markedbut not recovered Request/Responseand Data PushTransactionserrors recovered 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  14. L1 Event Selection Farm Layout • Current working hypothesis: CPU + FPGA hybrid system • Use programmable logic for cores of algorithms • Use CPU for the non-parallelizable parts • Use serial connection fabric (links and switches) • Modular design (only few board types) 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  15. Algorithms • Performance of L1 feature extraction algorithms is essential • critical in CBM: STS tracking + vertex reconstruction TRD tracking and Pid • Look for algorithms which allow massive parallel implementation • Hough Transform Trackerneeds lots of bit level operations, well suited for FPGA • Cellular Automaton Tracker • Co-develop tracking detectors and tracking algorithms • L1 tracking is necessarily speed optimized (>109 tracks/sec)→ possibly more detector granularity and redundancy needed • Aim for CBM:Validate final hardware design with at least 2 trackers suitable for L1 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  16. Design Iterations DetectorDesign TriggerPerformance Rejection ratio SignalPerformance S/N ratio Process has now successfullystarted Still somepieces missingin CVS PhysicsPerformance Many parameter studies neededGeneric, parametrizableHitProducers required 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  17. Computing and DAQ Session Check for last minutechanges in WG programs Thursday 14:00 – 17:00 – Theory Seminar Room Handle 20PB a year CBM Gridfirst steps Controls, not anafter sought this time Network & processing p-p, p-A – >108 int/sec 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  18. DAQ Summary • Event definition has changed: • now based on time stamps and time correlation • cope with >100 MHz interaction rate in p-p and p-A • Role of DAQ has changed: • DAQ is simply responsible to transport data from producers to consumers • Role of 'Trigger' has changed: • filter events delivered by DAQ • 'Online Event Selection' is better term • Online Event Selection Algorithms: • design iteration process now started (detector needs to change....) • System aspects: • 'online' – 'offline' boundary blurs • next: work on data model and compute model 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

  19. The End Thanks for your attention dinner time .. finally 5th CBM Collaboration Meeting, GSI, March 9-12, 2005

More Related