The ATLAS DAQ and event filter prototype “−1” project

Abstract A project has been approved by the ATLAS Collaboration for the design and implementation of a Data Acquisition and Event Filter prototype, based on the functional architecture described in the ATLAS Technical Proposal. The prototype consists of a full “vertical” slice of the ATLAS Data Acquisition and Event Filter architecture, including all the hardware and software elements of the data flow, its control and monitoring as well as all the elements of a complete on-line system. This paper outlines the project, its goals, structure, schedule and current status and describes details of the system architecture and its components.