The Configuration System of the ATLAS Trigger

The ATLAS detector at CERN's LHC will be exposed to proton-proton collisions at a rate of 40 MHz. To reduce the data rate to a manageable level, only potentially interesting events are selected by a three-level trigger system. A system has been designed and implemented that enables the configuration of all three trigger levels from a centrally maintained relational database, for the purpose of both online data taking and offline trigger simulation. We present the current status of this trigger configuration system configuration system, covering the database design, client software and user interface tools, and putting emphasis on its multiple uses for data-taking, Monte-Carlo simulation, and trigger validation on express-stream data.