User guide

Control Loops CME 2 User Guide
128 Copley Controls
…Manually Tune the Position Loop, continued:
6
and
Set up a trapezoidal profile by setting the trajectory limits and distance. See table:
Trajectory Limits Tab
Parameter
Description
Maximum Velocity
Set values typical of those expected to be used in the application.
Maximum
Acceleration
Maximum
Deceleration
Profile Tab
Distance
Set the move distance to produce a complete trajectory profile. Be sure
that this distance does not exceed mechanical limits of the system.
Move
Relative
Type
Trap
7
Adjust position proportional gain (Pp) to minimize following error:
 On the Gains tab, set velocity feed forward (Vff) and acceleration feed forward (Aff)
to zero.
 On the Profile tab, click Start. On the Gains tab, adjust position loop proportional
gain (Pp) until best result is obtained.
 Click Start after each adjustment to test on a new profile move.
NOTES:
1) Too much position loop proportional gain (Pp) might cause oscillation.
2) If a following error occurs, open the Control Panel and click Clear Faults.
8
Adjust velocity feed forward (Vff):
 Velocity feed forward (Vff) reduces following error in the constant velocity portion of
the profile. Often, a velocity feed forward (Vff) value of 16384 (100%) provides best
results.
 Click in the Vff field and adjust the value.
 Click Start after each adjustment to test on a new profile move.
Continued…