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 km 3 . 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.