As with all detector systems at the Large Hadron Collider (LHC), the assignment of data to the correct bunch crossing, where bunch crossings will be separated in time by 25 ns, is one of the challenges for the ATLAS pixel detector. This document explains how the detector system will accomplish this by describing the general strategy, its implementation, the optimisation of the parameters, and the results obtained during a combined testbeam of all ATLAS subdetectors
