Operation of the upgraded ATLAS Central Trigger Processor during the LHC Run 2

The ATLAS Central Trigger Processor (CTP) is responsible for forming the Level-1 trigger decision based on the information from the calorimeter and muon trigger processors. In order to cope with the increase of luminosity and physics cross-sections in Run 2, several components of this system have been upgraded. In particular, the number of usable trigger inputs and trigger items have been increased from 160 to 512 and from 256 to 512, respectively. The upgraded CTP also provides extended monitoring capabilities and allows to operate simultaneously up to three independent combinations of sub-detectors with full trigger functionality, which is particularly useful for commissioning, calibration and test runs. The software has also undergone a major upgrade to take advantage of all these new functionalities. An overview of the commissioning and the operation of the upgraded CTP during the LHC Run 2 is given.