The ATLAS LAr calorimeter Level 1 trigger signal pre-processing system: Installation, commissioning and calibration results

We describe the ATLAS Liquid Argon calorimeter (LAr) electronics used to prepare signals for the L1 trigger, together with the system used in the commissioning of the LAr-L1 output. This includes calibration data used to extract gains of all LAr calorimeters and timing shifts for different layers of the electromagnetic (EM) calorimeter. Analysis tools have been developed to study the pulse shape, time and amplitude for both the main readout and the L1 signals. Performance studies using beam data is also shown.