West Control Solutions Pro-4 - Manual (Page 20)

3.5.7 Optimization at the set-point for 3-point stepping controller
With 3-point stepping controllers, the pulse attempt can be made with or without
position feedback. Unless feedback is provided, the controller calculates the mo-
tor actuator position internally by varying an integrator with the adjusted actuator
travel time. For this reason, precise entry of the actuator travel time (tt), as time
between stops is highly important. Due to position simulation, the controller
knows whether an increased or reduced pulse must be output. After supply volta-
ge switch-on, position simulation is at 50%. When the motor actuator was varied
by the adjusted travel time in one go, internal calculation occurs, i.e. the position
corresponds to the simulation:
Simulation actual position
Internal calculation
tt
Internal calculation always occurs, when the actuator was varied by travel time
tt in one go , independent of manual or automatic mode. When interrupting the
variation, internal calculation is cancelled. Unless internal calculation occurred
already after self-tuning start, it will occur automatically by closing the actuator
once.
Unless the positioning limits were reached within 10 hours, a significant deviati-
on between simulation and actual position may have occurred. In this case, the
controller would realize minor internal calculation, i.e. the actuator would be clo-
sed by 20 %, and re-opened by 20 % subsequently. As a result, the controller
knows that there is a 20% reserve for the attempt.
Operation
Self-tuning 20 KS 90-1 / KS 92-1