Chapter 1
Integrated Motion on the EtherNet/IP Network
18
Rockwell Automation Publication MOTION-RM003I-EN-P - February 2018
A feedback device for this configuration is optional. In the absence of a feedback
device, actual position can be estimated by the drive and returned to the
controller.
Closed Loop Position Control Method
A motor control device configured for closed loop position control is traditionally
referred to as position loop drive or position servo drive. A position servo drive
implies an inner velocity and torque control loop as shown in following diagram.
The presence of the torque/current control loop sometimes results in this kind of
drive being referred to as a vector drive.
A feedback device for this configuration is generally required to achieve good
positioning accuracy. The feedback device can also be used to return Actual
Velocity and Actual Acceleration data to the controller using the cyclic data
connection.
In addition to Command Position, the controller can pass Command Velocity
and Command Acceleration for the purposes of forward control.
See also
In Velocity Control application mode the application control program and
motion planner provide a setpoint value to the CIP Motion device using the cyclic
data connection. The velocity control method can be either open loop or closed
loop.
Open Loop Velocity Control Method
A motor control device configured for open loop velocity control is traditionally
referred to as Variable Frequency, or V/Hz, or VFD, drive. This type of drive is
illustrated below.
Velocity Control Mode