The ATLAS liquid argon calorimeters Read Out Driver (ROD) system

The electronic Readout chain for the Liquid Argon calorimeters of the ATLAS detector is briefly presented. Special attention is given to the Read Out Drivers (ROD) which will receive the triggered data from approximately 200,000 calorimeter cells at a 100 kHz event rate. In the ROD boards the energy will be computed for each cell from discrete samples of the waveform using optimal filtering algorithms running in fast digital signal processors. The monitoring of the calorimeter data will also be performed at the ROD level. Performances expected in ATLAS which have been evaluated from simulation studies are presented. A demonstrator system currently under construction is described and performances of the Processing Units (DSP daughter boards) are presented. 4 Refs.