ADLINK PCI-8158 - Manual (Page 60)

50 Operation Theory
4.2.6 One axis position mode
Position mode means the motion controller will output a specific
amount of pulses which is equal to the desired position or dis-
tance. The unit of distance or position is pulse internally on the
motion controller. The minimum length of distance is one pulse.
With the PCI-8158, we provide a floating point function for users to
transform a physical length to pulses. Inside our software library,
we will keep those distance less than one pulse in register and
apply them to the next motion function. Besides positioning via
pulse counts, our motion controller provides three types of speed
profile to accomplish positioning: first-order trapezoidal, second-
order S-curve, and mixed bell curve. Users can call respective
functions to perform that. The following diagram shows the rela-
tionship between distance and speed profiles.
The distance is the area of the V-t diagram of this profile.