If you are controlling the wheel via LV DAQ, you should be able to translate the AO voltage to a RPM value. Then, based on this RPM value, take data for a time period equal to one revolution.
If you don't know the translation from V to RPM or are not controlling the wheel through LV, you may need to find the relationship. Make a target wheel with one small target. Vary the voltage to the motor and take waveform data. From this data, you can come up with the equation to convert V to RPM. Hope this helps. Dave.