Design and Performance of the Detector Control System of the ATLAS Resistive-Plate-Chamber Muon Spectrometer

Muon detection plays a key role at the Large Hadron Collider. Resistive Plate Chambers (RPC) provide the barrel region of the ATLAS detector with an independent muon trigger as well as a two-coordinate measurement. The chambers, arranged in three concentric layers, are operated in a strong magnetic toroidal field and cover a surface area of about 4000 m$^2$. The RPC Detector Control System (DCS) is required to monitor and safely operate tens of thousand of channels, distributed on several subsystems, including low and high voltage power supplies, trigger electronics, currents and thresholds monitoring, environmental sensors and gas and electronic infrastructure. The DCS is also required to provide a level of abstraction for ease of operation as well as specific tools allowing expert actions and detailed analysis of archived data. The hardware architecture and the software solutions adopted are shown in detail along with a few results from the commissioning and first running phases. The material presented here can be used in future test facilities and projects.