MCA_SetOperatingMode¶
Function Block MCA_SetOperatingMode
This Function Block changes the axis mode from positioning to velocity mode and vice versa.
By default, an axis is always a positioning axis which has to follow either the drives or the PLCs position control loop. In some applications, the movement is limited (e.g. by torque restrictions) so the position can´t be reached.
A position controlled axis would first speed up, and then create a following error, both caused by the increasing position lag.
The Function Block MCA_SetOperatingMode can be used to prevent this behavior and will switch between velocity- and position controlled behavior “on the fly”.
Note
To use the Function Block MCA_SetOperatingMode, the drive has to be used in CSV (ContinuousSyncronuousVelocity), or an analog drive has to be used, which means it has to move controlled by SPEED_REFERENCE (Kernel).
If the Function Block is called in StandStill, ErrorStop or Disabled, it will be effective immediately.
In any other mode, it will be effective with the next “Execute” rising edge on a Function Block which activates a movement. It can be called while the axis is moving and will create a bumpless transition between the velocity- and position controlled mode.
In velocity mode:
- The SPEED_REFERENCE is created by feed-forward, in an open loop. (It is not required to set FF_PERCENTAGE parameter) REFERENCE_POSITION will follow the DRIVE_ACTUAL_POSITION Position following error is not supervised.
- REFERENCE_POSITION will follow the DRIVE_ACTUAL_POSITION.
- Position following error is not supervised.
See the following chapter to check if this Function Block is supported by the used axis implementation: Overview
For this Function Block there is a visualization in the Library MC_Blocks_AC500_V11.
See the following chapter for a list of available data types: Overview