Re-integration and consolidation of the Detector Control System for the Compact Muon Solenoid Electromagnetic Calorimeter

The current shutdown of the Large Hadron Collider (LHC), following three successful years of physics data-taking, provides an opportunity for major upgrades to be performed on the Detector Control System (DCS) of the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment. The upgrades involve changes to both hardware and software, with particular emphasis on taking advantage of more powerful servers and updating third-party software to the latest supported versions. The considerable increase in available processing power enables a reduction from fifteen to three or four servers. To host the control system on fewer machines and to ensure that previously independent software components could run side-by-side without incompatibilities, significant changes in the software and databases were required. Additional work was undertaken to modernise and concentrate I/O interfaces. The challenges to prepare and validate the hardware and software upgrades are described along with details of the experience of migrating to this newly consolidated DCS.