The detector control system for BABAR

The hardware/software system for the control of the BABAR detector at PEP-II is described. The contributions of a large and diverse collaboration were channeled into a standard hardware selection (VME crate, embedded CPU, fieldbus, etc.) and a uniform software environment, EPICS (Experimental Physics and Industrial Control System). These choices, with a judicious naming convention in place, allowed a distributed and modular development of the control system, which was then integrated within the Online System in the Interaction Hall. The design of the software to complement the EPICS layer is presented. The coordination of controls activities with the rest of the Online is overseen by Run Control; the interface and functionality that controls supports is described. The archival storage, retrieval and analysis/display of the process control data is described, as well as the interface that allows access to this data with the same API as for our physics data. We also describe our modifications to the online-wide messaging system ("cmlog") and our interface to the accelerator, PEP-II. Finally, we present our operational experiences with the control system.