The Argo YBJ Daq System and the GRID Based Data Transfer

The Argo-YBJ experiment has now reached its final design configuration. The detector system consists of a full coverage array (about 5800 square meters) of resistive plate chambers (RPCs). The throughput depends on the trigger rate and threshold. The DAQ system must be able to sustain a maximum transfer rate of the order of 15 MB/s and a high peak data flow. Data are read out using a typical front-end acquisition chain built around a custom bus. Specialized electronics have been designed and dedicated software has been written to perform this task. Data are sent to the online farm through a switch exploiting a gigabit ethernet protocol. A solution to transfer data from the YBJ laboratory to the laboratories belonging to the Argo-YBJ collaboration exploiting the GRID middleware has also been implemented. In this paper we describe the daq and the data mover main characteristics and performance.