CMS Electromagnetic Trigger commissioning and performance towards the start of operation

The CMS electromagnetic calorimeter (ECAL) is a high-resolution calorimeter made of 75848 lead tungstate (PbWO4) crystals and optimized for the discovery of the Higgs boson in its two photons decay mode. In view of the high raw event rate at the Large Hadron Collider (LHC), the ECAL Trigger will play a major role. This poster will present a review of the strategy and the tests completed to ensure that the ECAL Trigger reaches the required specifications. The results from the commissioning will be presented as well as the first analysis of cosmic ray data used in the assessment of its efficiency.