The monitoring system of the ARGO-YBJ data acquisition

The ARGO-YBJ detector has been completely installed at the YangBaJing High Altitude Cosmic Ray Observatory (Tibet, China), at 4300 m a.s.l., and is taking data with a trigger rate of about 4 kHz and a dead time of about 4%. The ARGO-YBJ Data Acquisition System is based on a two-layer readout architecture implementing an event-driven data collection. In order to sustain a high data throughput and have a good readout efficiency or keep the dead time as low as possible, the decoupling FIFOs have been housed on the data packet processing modules. In this paper, the hardware solution to monitor the DAQ system and to track in real-time anomalous data transfers is presented.