Rockwell Automation 20G PowerFlex 750-Series AC Drives - Manual (Page 338)

338 Rockwell Automation Publication 750-RM002B-EN-P - September 2013
Chapter 6 Integrated Motion on the EtherNet/IP Network Applications for PowerFlex 755 AC Drives
Motor Brake Control When a PowerFlex 755 drive is configured for Integrated Motion on the
EtherNet/IP Network none of the I/O option modules are supported. Normal
means of having the drive control the brake and utilizing drive’s I/O are not
supported. Motor brake control must be user-configured in the Logix controller.
The basic functionality involved is to enable the drive using an MSO instruction,
verify that the drive is enabled, and then apply power to disengage the motor
brake. The specific motor used and the application often dictates a time delay
between when the drive is enabled and the brake is disengaged. A very similar
sequence is followed with disabling the drive using an MSF instruction. In this
case the brake is engaged, and after a user-configured amount of time, the drive is
disabled.
Figure 35 depicts this operation.
Figure 35 - Timing Diagram
The sample ladder logic code in Figure 36 on page 339 depicts a possible solution
for performing brake control (the code is an example only and is not the only
solution for performing brake control). Each individual application determines
the requirements for the necessary brake control.
Enable
Brake
MSO MSF
Time