Newport PMC-200, Manual, Page: 31 / 42

21
Motion Control
Using a digital servo circuit, the motion control ICs (HCTL-1000) perform all
of the position and velocity control for each axis. The system software
directs all position and velocity control by writing to its registers.
Positional feedback comes to the motion control ICs from an incremental
encoder in the actuator assembly. The encoder outputs are TTL compat-
ible signals on two feedback channels. The two channels are 90
°
out of
phase.
The behavior of the digital servo circuit is controlled by a digital filter in
each motion controller IC. The actuator dynamics dictate the selection of
the digital filter parameters.
3.3