The NEMO trigger and data acquisition system

The second phase of the NEMO project represents a valuable occasion to test a new Trigger and Data Acquisition System (TriDAS), designed to scale up to the km3km3. Because of the deep sea optical background, the NEMO “all data to shore” approach requires to handle a large continuous data-stream from off-shore to on-shore. The TriDAS consists of four computing layers: hit managing into time-coherent aggregates, data selection according to possible concurrent trigger algorithms, composition of the selected events into post-trigger files and finally persistent data storage. The finalized design of TriDAS adapted for NEMO Phase 2 is reviewed together with the dedicated on-line monitoring tool and networking architecture.