Development of a DAQ system for Phase 2 recommissioning of ECAL supermodules.

The barrel region (EB) of the electromagnetic calorimeter (ECAL) of the CMS experiment is made of 61200 lead tungstate scintillating crystals. In view of the high-luminosity phase of the LHC, the ECAL electronics must be upgraded to cope with the more stringent requirements in terms of trigger latency and rate. The current crystals and APD detectors will remain, while the upgrade will affect the front end (trigger towers) and off-detector read-out electronics of EB. The new electronics will have to follow the requirements of the upgraded L1 trigger system (the increasing rate and latency) and is needed to preserve detector energy resolution despite the increased instantaneous luminosity. Moreover, an important characteristic of the new design will be the capability to provide precision timing measurements, of the order of $30 {ps}$, for photons and electrons. The excellent time resolution will be a key ingredient to efficiently suppress contributions from pileup events, which are expected to be 200 per bunch crossing. The new very front end and front end cards which will compose new trigger towers will be shown, as well as the first test of the new data acquisition chain.