ATLAS TDAQ Integration and Commissioning

The ATLAS detector will be exposed to proton proton collision at the center of mass energy of 14 TeV with the bunch crossing rate of 40 MHz. In order to reduce this rate down to the level at which only interesting events will be fully reconstructed, a three-level trigger system has been designed. The level 1 trigger reduces the rate down to 75 kHz via the custom-built electronics. The Region of Interest Builder delivers the Region of Interest records to the level 2 trigger which runs the selection algorithms with the commodity processors and brings the rate further down to 3 KHz. Finally the Event Filter reduces the rate down to 200 Hz for permanent storage. The subsystems will be reviewed. The commissioning in situ using detectors, the full trigger system and the DAQ system will be discussed. Results on system functionality and performance based on the cosmic data will be presented. Some studies on system scalability and reliability will be shown with preselected simulated events running through the trigger and data ow system.