The Online System of the ARGO Experiment

The ARGO experiment has been designed to detect shower events at an energy threshold as low as a few hundreds of GeV. To achieve this goal, the data acquisition system has been implemented to handle a high data flow up to 7Mbytes/s for a single chain. In such conditions the software architecture plays an important role. We report on the software structure and on the algorithms implemented to control the data flow to the event builder and storage system.