Triggers, Data Flow and the Synchronization Between the Auger Surface Detector and the AMIGA Underground Muon Counters

The aim of the AMIGA project (Auger Muons and Infill for the Ground Array) is an investigation of Extensive Air Showers at energies lower than those accesible with the standard Auger array, where the transition from galactic to extragalactic sources is expected. The paper describes the working principle of the Master/Slave (standard Auger surface detector/the underground muon counters) synchronous data acquisition and general triggering applied in two prototypes: with 12.5 ns resolution built from 4 segments (2 FPGAs and 2 standard micro-controllers) and 3.125 ns resolution built from two segments only (2 FPGAs with implemented NIOS^® processors).