National Instruments NI-9501 C Series Motor Drive Module

The NI-9501 (Part Number: 779767-01, 196083B-01L) can be utilized with 2-phase hybrid stepper motors in bipolar or unipolar winding configuration. The NI 9501 utilizes an advanced PWM algorithm that minimizes torque ripple, reduces emissions, lowers power loss, and generates a smoother motion throughout microstepping. NI has NEMA 17 and NEMA 23 stepper motors, which are compatible with the NI-9501 C Series Motor Drive Module. This single-axis module is designed for the CompactRIO platform, adding integrated stepper motion capabilities to a CompactRIO system without requiring an external power drive or connector block.

This C Series Motor Drive Module supports software-programmable full step, half step, and microstepping rates to 256 maximum. While full-stepping, a resonance takes place at low speeds, which is classified as speeds between 50 and 150 RPM. The low-speed resonance can result in vibration and minimizes the motor torque. For speeds greater than 150 RPM, the advantages of microstepping are reduced and can ultimately negatively effect performance by delivering lower motor torque when compared to full-stepping.

The NI-9501 can additionally deliver for phase current reduction after the motor has ceased moving for a specified quantity of time by utilizing the Enable Current Reduction property in software. Dissimilar to servo motors, the stepper motor coil will stay completely energized when the motor is not moving. The outcome is strong holding torque, but it creates a great amount of heat in the motor. Numerous applications do not entail the greatest amount of holding torque when the motor is at rest, so the motor is wasting power. The quantity of current reduction and delay prior to current reduction becoming active is software-programmable.