The CERN CMS tracker control system

Due to the high integration level of the experiments planned for the Large Hadron Collider (LHC) of the European Organization for Nuclear Research (CERN), the data acquisition and the control systems need complex developments both in hardware and software. The purpose of this paper is to describe the control system of a sub-detector of one of the CERN experiments, the tracker of the compact muon solenoid (CMS). The CMS tracker control system is based on dedicated hardware and software. The hardware is based on the front end controller (FEC), an interface board that hosts token rings for the communication with the control and communication unit (CCU) modules. These in turn contain dedicated I/O channels for the front end readout and control chips. The software is built in layers: one device driver, a C++ dedicated application program interface (API) plus a database for the storage of all the information needed for the front end electronics. This system will also be adopted in some other CMS sub-detectors.