1. L0DU software interface L0 workshop – LHCb 12 May 2005 Rémi Cornat, Emmanuel Delage, Olivier Deschamps, Julien Laubser, Pascal Perret LPC-Clermont

2. The user interface for the L0DU algorithm setup is more advanced, so far. Open discussion about the other items in this workshop L0DU Software Interface  Functionnalities  Configure & parametrize the L0DU algorithm  Test & debug the L0DU board  Control & monitor during data taking : counters, histograms, statistics,... ➛ preliminary version developped by Emmanuel Delage

3. Configure & parametrize the L0DU algorithm  L0DU algorithm : remind the flexible architecture 17 words : 7 from Calo + 8 from Muon + 2 from PUVeto Fields : value (E t /P t /Content/Multiplicity) / address / status / BCID /... e.g : Electron(Et), Photon(adress), Muon1(Pt) + Muon2(Pt), Pi0(Et) - Photon(Et),... So far, only +/-/Id operators are foreseen More sophisticated operators could be implemented in L0DU board : i.e. LUT(adress) defining a sub-detector region or neighbourhood of an object,... threshold is a pair : (upscale,downscale) value So far, only >/</= comparators are defined eg Electron(Et) > 2.4 GeV, SPD(multiplicity)<280, Pi0(Address)-Photon(Address) = 0, 1 - L0 Processor Data : 32 bits words sent by L0-processors to L0DU 2 - L0DU Elementary Data : L0PU field or result of an operation on L0PU fields 3 – Elementary Condition : Comparison of L0DU data with a threshold value

4. Configure & parametrize the L0DU algorithm e.g: electron channel is currently defined as: [Electron(Et)>2.4 GeV] & [SPD(mult) 5GeV] Dimuon channel is: [Muon1(Pt)+ Muon2(Pt)> >1.5 GeV] & [Total(Et)>5GeV] Some Elementary Conditions are common to several L0DU channels ➛ Global Condition i.e. : Total(Et)>5 GeV / SPD(mult)<280 / PU(mult)<112 Electron OR Photon OR Hadron OR... 4 – L0DU channels : One or several (AND’ed) elementary conditions 6 – L0DU decision : L0DU Channels OR’ed 5 – Downscale : Apply the low threshold in Elem. Cond. at a given rate A downscaling rate is associated to each L0DU channel. All Elementary Conditions linked to the L0DU channel are downscaled with this rate except Global Conditions (otherwise they are not Global !!) Rate is modified along the FILL in order to keep 1MHz constant when luminosity drops. Rate is modified manually. A new RUN is defined at each rate modification.

5. Architecture of the current L0DU algorithm L0 Processor Units (17 PU Data) L0DU Elementary Data (10 used) Elementary Conditions (10) e-E T h-E T μ 2 -p T pu-mult π° G -E T γ-E T μ 1 -p T π° L -E T TOTAL E T spd-mult IdIdIdIdIdIdIdId + Id eγπ°Lπ°L π°Gπ°G hμμμ < & & & &&&&&& >>><>>>>> CALOMuonPU L0DU Trigger Channels (7) downscale Picture not user friendly !!!

6. Elementary Conditions eγhπ°Lπ°L π°Gπ°G μμμ Downscaling 0 1 &&&&&&& Counter 250 kHz100kHz400 kHz120kHz180kHz300kHz140 kHz Add a new condition Add a new global criteriaAdd a new channel Setup name RUN number Algorithm architecture Rate division Decision pattern L0 rate L0DUchannels #spd #PU ΣEt Global criteria G1 G3 &&&&&& - &&&&&& - G2 Architecture of the current L0DU algorithm eγhπ°Lπ°L π°Gπ°G μ1μ1 Name :Dimuon (comment) Elementary Condition μ2μ2 μ3μ3 Peak1Peak2 L0-CaloL0-MuonL0-PU ----- Pt --- threshold Downscaled threshold Valid > Add an operator + A possible display could be : L0DU Data Field Operator (+/-/Id) Comparator ( /=)

7. A single channel (electron) Elementary condition Electron(Et) > Threshold Elementary condition SumMuon(Et) > Threshold  Preliminary version developped by E. Delage Configure & parametrize the L0DU algorithm  C++ software  Graphical User Interface : QT toolkit (cross-platform library : Unix, Windows, OS)  Developments under Windows so far

8. photonhadronglobal pi0local pi0muondimuon The current L0DU algorithm Elementary Conditions Downscaling L0DUchannels Global criteria Configure & parametrize the L0DU algorithm

9. Diphoton 2 & Flexible architecture  « Exotic » L0DU channels : e.g. « diphoton » (as proposed in LHCb note 2001-022) LocalPi0(Et) - Photon(Et) > threshold when Pi0(address) = Photon(address)  Also easy to implement the « di-electron » trigger proposed by Eduardo (LHCb 2004-002)

10. Configure & parametrize the L0DU algorithm Next steps  Develop the software-hardware interface Hope to have soon a working version we can use to configure the L0DU prototype USB library implemented. Interfacing Glue-card/CCPC under developpment  Developp the monitoring of the board in test mode Monitor the various tests for internal and external test benches Diagnostic Basic user (shift crew) : allowed to change the downscale rates Advanced user: allowed to change thresholds Expert: allowed to reconfigure the algorithm  Finalize the software-user interface Possibility to save/reload a configuration Implement limitations in algorithm configuration (hardware ressources) Define several levels of user

11. Configure & parametrize the L0DU algorithm  Connection with offline L0DU simulation code The offline code “DecisionUnit.cpp” (L0DU Gaudi package) is being rewritten with a structure close to hardware architecture, including Downscaling, Rate Division, … new classes of object : Processor Unit Data  L0PUData.h Elementary Data  L0DUData.h Elementary Condition  L0DUElementaryCondition.h L0DU Channel  L0DUChannel.h The monitoring software could produce the option files corresponding to a given configuration of the L0DU board. ➛ Possibility to easily run a L0DU simulation on MC with the same configuration than a given RUN of data taking (no need to adapt the cpp code). The gaudi algorithm is possibly entirely configurable & parametrizable via options file

12. Control & monitoring  L0DU board internal counters : How/when the counters are readed-out by the software ? Which frequency ? Synchronisation with holes in the bunch structure ?  size of counters  Ressource needed  Statistics (software) Trigger-rate versus time for all L0DU channels Trigger-rates distribution for all L0DU channels Run summary Trigger-rate for all L0DU channels Trigger-rate for all Elementary Conditions independantly ? Histograming the elementary data ?? To be evaluated : Refresh frequency ? Which/how many CPU ?

13. First version of L0DU control software in developpment ➛ user interface more advanced, so far Next step : developp the interface with hardware ➛ expect to have soon a working version to monitor the L0DU prototype ➛ will boost the developpments of both software & hardware Need to developp/define other functionnalities of the software A proposition is to be written in a formal way (EDMS) OPEN DISCUSSION Feed-back / Ideas ? ➛ user interface ➛ monitoring ➛ control/ test ➛ other features Summary