User guide

Stepper Controls CME 2 User Guide
140 Copley Controls
12.1: Stepper Motor Support
CME 2 supports Copley’s stepper amplifier family. Stepper amplifiers can run in stepper
mode or servo mode.
This chapter describes controls that can be used to fine-tune a stepper amplifier in
stepper mode: Encoder Correction (p. 142) and Detent Compensation Gain (p. 142). It
also describes the screen used in stepper mode to set Position Limits (p. 140).
When a stepper amplifier is used in servo mode, it operates as a true, closed loop, servo
amplifier controlling a stepper motor. After putting the stepper amplifier into servo mode,
set it up and tune it just as you would a servo amplifier.
12.2: Position Limits (Stepper Amplifier)
Perform the following steps to set position limits for a stepper amplifier connected to an
encoder with Encoder Correction enabled (not operating in Servo mode).
Set Position Limits in Stepper Mode
1
Click to open the stepper Position Limits screen. Click the Trajectory Values
tab.
2
Change/verify the values as needed:
Max Velocity
Maximum trajectory velocity. Max value may depend upon the back EMF and the Max
feedback count. Min:0. Default: 0.25 x motor velocity limit.
Max Accel
Maximum trajectory acceleration. Max value may depend upon the load inertia and
peak current. Min:0. Default: 0.5 x velocity loop Accel. Limit value.
Max Decel
Maximum trajectory deceleration. Max value may depend upon the load inertia and
peak current. Min:0 (disables limit). Default: 0.5 x velocity loop Accel. Limit value.
Abort Decel
Deceleration rate used by the trajectory generator when motion is aborted. Min:0.
Default: 0.5 x velocity loop Accel. Limit value.
Note that setting limits to zero disables the trajectory generator so that the command
input is not limited by the generator. Velocity is only limited by the Velocity Limit set in
the Velocity Loop.