Speaker
Sebastian Robert Bablok
(Department of Physics and Technology, University of Bergen, Norway)
Description
The HLT, integrating all major detectors of ALICE, is designed to analyse LHC events
online. A cluster of 400 to 500 dual SMP PCs will constitute the heart of the HLT
system. To synchronize the HLT with the other online systems of ALICE (Data
Acquisition (DAQ), Detector Control System (DCS), Trigger (TRG)) the Experiment
Control System (ECS) has to be interfaced. In order to do so, the implementation of
finite state machines, with the usage of SMI++, offers an easy way to coordinate the
running conditions of the HLT with the other online systems. The mapping of the HLT
states has to offer the possibility to run the HLT in stand alone mode (for
commissioning and calibration) as well as controlled by ECS during the operational
stage.
After a full reconstruction of an event, the HLT provides Trigger decisions,
regions-of-interest (ROI) and compressed data to the DAQ in order to reduce the data
rate to permanent storage. In addition, the result of the online event
reconstruction, organised as ESD (Event Summary Data), has to be classified and
indexed for later reference to the offline analysis.
This talk will cover HLT interfaces as well as the structure of the processed data.
Primary author
Sebastian Robert Bablok
(Department of Physics and Technology, University of Bergen, Norway)
Co-authors
Bernhard Skaali
(Department of Physics, University of Oslo, Norway)
Cvetan Cheshkov
(CERN, Geneva, Switzerland)
Dieter Röhrich
(Department of Physics and Technology, University of Bergen, Norway)
Harald Appelshäuser
(Institute for Nuclear Physics, University of Frankfurt, Germany)
Heinz Tilsner
(Kirchhoff Institute of Physics, University of Heidelberg, Germany)
Håvard Helstrup
(Faculty of Engineering, Bergen University College, Norway)
Kjetil Ullaland
(Department of Physics and Technology, University of Bergen, Norway)
Matthias Richter
(Department of Physics and Technology, University of Bergen, Norway)
Thomas Vik
(Department of Physics, University of Oslo, Norway)
Timm M. Steinbeck
(Kirchhoff Institute of Physics, University of Heidelberg, Germany)
Torsten Alt
(Kirchhoff Institute of Physics, University of Heidelberg, Germany)
Volker Lindenstruth
(Kirchhoff Institute of Physics, University of Heidelberg, Germany)
