Position Control Mode

In Position Control application mode, either the application control program (command execution function) or the motion planner (move trajectory control function) provide a setpoint value to the CIP Motion device using the cyclic data connection. The Position Control method can be either open loop or closed loop.

Open Loop Position Control Method

A device configured for open loop position control applies to a class of drive devices called stepper drives.

A feedback device for this configuration is optional. In the absence of a feedback device, the drive estimates the actual position and returns it 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 the 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 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.

Axis Test Mode

Axes with the Test Mode Enable attribute set to Enabled and that are configured for Controller Loop Back simulate the drive in Position Loop control mode.