Well, most depends on the motor driver: usually the stepper comes with a driver that can accept une or both of the following signals:
- two separate train pulses for CW and CCW rotation
- one train pulse for rotation and one signal (high/low) for direction
Once you have discovered / decided which method to apply, you'll have to generate the proper signals with either pulse train generation or waveform generation: NI-DAQ comes with some example of these applications you could use as a starting point; you'll have to deal next with acceleration and deceleration when motor starts and stops and some other specialized items; since this matter is quite particular, I suggest you post this question on the
Motion forum, where someone with more experience can guide you through the process,