National Instruments NI-Motion - Manual (Page 147)

Chapter 11 Acquiring Time-Sampled Position and Velocity Data
© National Instruments Corporation 11-3 NI-Motion User Manual
The data must be read one sample at a time. A four-axis sample uses the
following pattern for returning the data.
If you request 1,024 samples, you must read each of the 1,024 samples
individually.
Axis 1 position
Axis 1 velocity
Axis 2 position
Axis 2 velocity
Axis 3 position
Axis 3 velocity
Axis 4 position
Axis 4 velocity