Design specifications and test of the HMPID's control system in the ALICE experiment

The HMPID (High Momentum Particle Identification Detector) is one of the ALICE subdetectors planned to take data at LHC, starting in 2006. Since ALICE will be located underground, the HMPID will be remotely controlled by a Detector Control System (DCS). In this paper we will present the DCS design, accomplished via GRAFCET (GRAphe Fonctionnel de Commande Etape/Transition), the algorithm to translate into code readable by the PLC (the control device) and the first results of a prototype of the Low Voltage Control System. The results achieved so far prove that this way of proceeding is effective and time saving, since every step of the work is autonomous, making the debugging and updating phases simpler.