Rexroth 500 series Variable Frequency Drive (VFD) functions include speed and torque control in a package characterized by modular construction of hardware and software. This new VFD series offers output ratings from 2 to 850 hp, along with programmable I/O points. Its SERCOS interface expands connectivity options in addition to Profibus, Interbus, and CANopen choices. Several features help to simplify startup and operation, among which are automatic motor optimization, "guided commissioning" via the control panel, and the REFUwin software tool. Freely configurable function blocks, including PID controllers, math blocks, digital gates, timers, and application-specific blocks help reduce cost and control complexity of operating the drive.