User guide

Xenus Plus User Guide Operational Theory
Copley Controls 17
2.3: Commutation Modes
The drive supports three commutation modes to drive brush and brushless motors: AC brushless
sinusoidal, AC brushless trapezoidal, and DC brush.
In most applications, sinusoidal commutation is preferred over trapezoidal, because it reduces
torque ripple and offers the smoothest motion at any velocity or torque. In the sinusoidal
commutation mode, an encoder or a resolver are required for all modes of operation.
In AC brushless trapezoidal commutation mode, the drive provides traditional six-step
commutation.
When driving a DC brush motor, the drive operates as a traditional H-Bridge drive.
2.4: Feedback
2.4.1: Encoder and Resolver Support
The standard versions of the Xenus Plus drives support digital quadrature encoders, analog
sin/cos encoders, and a variety of serial and absolute encoder formats. These versions normally
require the use of Hall switches for the commutation of brushless motors.
The resolver versions, designated by “–R” in the model number, support standard, single speed,
transmit-type resolvers.
2.4.2: Multi-Mode Port
All versions support a multi-mode port. This interface can be configured to:
Provide a buffered digital encoder output based on the digital quadrature encoder input.
Provide an emulated digital encoder output based on the analog encoder or resolver input.
Provide an emulated serial encoder output.
Provide a second digital encoder input to be used in the dual encoder position mode. In this
mode, an encoder attached to the load provides position loop feedback, and the motor
encoder or resolver provides velocity loop feedback.