New STAC6-Si stepper drives are programmable for standalone operation via Windows-based Si Programmer software with integrated tuning. A graphical point-and-click format combines motion, I/O, and operator interface functionality for simple machine sequencing. As a result, STAC6-Si drives integrate with other devices, such as sensors and PLCs, on a machine. STAC6-Si drives offer current output from 0.5 to 6.0 A with 90 to 135 VAC input and 50/60 Hz. The drives provide software-selectable resolutions from 200 to 51,200 steps/rev at speeds up to 133 rps. Features include self-test and auto-setup functions that measure and configure motor parameters automatically and anti-resonance technology that eliminates midrange instability for higher motor speeds and full use of available torque. Demand signal smoothing is designed to reduce extraneous system resonances for smooth motor performance and reduced wear on mechanical components. Torque ripple smoothing adjusts the current waveform to reduce low speed torque ripple for smooth motion at low motor speeds. Microstep emulation ensures smooth motion in systems that require low step resolutions. These include retrofit systems with a controller resolution that is fixed at a low value and cannot easily be changed.