Computing Architecture of the ALICE Detector Control System

The ALICE Detector Control System (DCS) is based on a commercial SCADA product, running on a large Windows computer cluster. It communicates with about 1200 network attached devices to assure safe and stable operation of the experiment. In the presentation we focus on the design of the ALICE DCS computer systems. We describe the management of data flow, mechanisms for handling the large data amounts and information exchange with external systems. One of the key operational requirements is an intuitive, error proof and robust user interface allowing for simple operation of the experiment. At the same time the typical operator task, like trending or routine checks of the devices, must be decoupled from the automated operation in order to prevent overload of critical parts of the system. All these requirements must be implemented in an environment with strict security requirements. In the presentation we explain how these demands affected the architecture of the ALICE DCS.