The complete range of ac/dc drives are offered by siemens. This ac/dc drives are used for a variety of industrial applications. Following are some technical features of these drives which include:drive technology is flexible, modular and is optimally designed for cost- effectiveness;wide range of ac/dc motors with state-of-the-art fully digital ac master drives and simoreg dc converters supplies solutions for different industrial needs. These solutions can be tailored to meet specific application requirements. Siemens drives guarantee stable operation in the manufacturing process, holding the process parameters within extremely tight limits whichensure optimum product quality and maximum production. These drives have some beneficial features which include: are energy conserving, adaptable to all voltage levels used world-wide and can be simply integrated into automation environment via communication bus systems.