Overview of the second level trigger system for the FAST detector

The second level trigger (LV2) system of the FAST detector is described in this paper. The fiber active scintillator target (FAST) is an imaging particle detector intended for muon lifetime measurement with a precision of 1 ppm. The aim of the trigger system is to reduce the data throughput that the data acquisition (DAQ) chain must handle to make the experiment able to run with a first level trigger rate of 1 MHz. The electronic system is being designed at CIEMAT (Madrid, Spain). A first prototype was developed and satisfactory results have been obtained under beam operation conditions.