The ATLAS B-Physics Trigger

This paper gives an overview of the ATLAS Trigger and Data Acquisition (T/DAQ) system with an emphasis on B-physics capabilities. It describes recent work on how to maintain the B-physics programme within some constraints that have arisen: a higher target start-up luminosity, an incomplete configuration of the detector at start up, and cost constraints for the T/DAQ system. It also shows how the High Level Trigger (HLT) software has advanced and gives some results of new performance measurements.