The First Running Period of the CMS Detector Controls System - A Success Story

The Detector Control System (DCS) of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN has been running since the first detector test in summer 2006. It has proven to be robust, efficient and easy to maintain. The efficiency of the system is close to 100% and thus maximizes the time for physics data taking. The challenges in the design of that system, however, were unprecedented due to the large size (millions of parameters to monitor) and its diversity. The CMS detector has been taking data from the autumn of 2009 until the beginning of 2013. During this period the CMS DCS had to show if it would meet the expectations and allow for an efficient running of the CMS detector. In the following we will discuss the solutions applied to cope with those challenges, which also allowed for the good performance the CMS detector is showing since its start of data taking. The shortness required by this document, however, does not allow for an exhaustive presentation of the different mechanisms and thus they will only be sketched.