User guide

Xenus Plus User Guide Operational Theory
Copley Controls 35
2.9: Brake Operation
2.9.1: Digital Output Controls Brake
Many control systems employ a brake to hold the axis when the drive is disabled. Xenus Plus
drives have digital outputs designed specifically for brake outputs. Other outputs can be used but
these are recommended. Unlike the other outputs, these brake specific outputs are optically
isolated from the control signals and have internal fly back diodes connected to the +24 Vdc input.
By eliminating the need to connect into the drive control connector, having the brake output on the
+24 Vdc power connector simplifies wiring when the brake wires are in the power cable of the
motor.
For more information, see Logic Supply / Brake (p. 89).
2.9.2: Brake/Stop Sequences
Disabling the drive by a hardware or software command starts the following sequence of
events.
The motor begins to decelerate (at Abort Deceleration rate in position mode or Fast Stop
Ramp rate in velocity mode). At the same time, the Brake/Stop Delay Time count begins.
This allows the drive to slow the motor before applying the brake.
When the motor slows to Brake/Stop Activation Velocity OR the Brake/Stop Delay Time
expires, the brake output activates and PWM Delay Brake/Stop Response Time count
begins.
When response time has passed, the drive’s output stages are disabled. This delay
ensures the brake has time to lock in before disabling the power section.
This sequence is not available in the current mode of operation. Instead, in current mode, the drive
output turns off and the brake output activates immediately when the disable command is
received.