The Bosch Rexroth MPN R911271217 (RAC 2.3-250-460-D00-W1) is an AC main spindle drive controller designed for precise speed and position control in industrial applications. It features both digital (16 bit parallel) and analog 10V speed set-point interfaces, supporting diverse controller integrations. The unit provides a SERCOS interface for real-time communication and a synchronised encoder input to coordinate servo drive functions. Core specifications include a 3 x AC 400 V, 50 Hz, ±15% or 3 x AC 460 V rated connection voltage, 250 A rated current, and internal blower cooling. The controller supports automatic adaptation to spindle motors via the AS programming module, with microprocessor-based operation eliminating manual initial adjustment. Interface terminal X4 is provided with 25 poles.