"SET_POINT" mode

"SET_POINT" mode (P-AXIS-00753) is based on the same principle as "INDIRECT" mode.

The filer cascade is identical to the “DIRECT” mode.

As the above diagram of the control loop shows, mechanical vibration is simulated in "SET_POINT" mode in the same way as in "INDIRECT" mode.

The difference between this mode and "INDIRECT" mode lies in the input values on which the simulation is based.

"SET_POINT" mode uses the command speeds of the position controller directly. This avoids the dead time caused by the measurement and transfer of the actual speed.

Advantage of "SET_POINT" mode

The output additive speed values are therefore somewhat faster in “SET_POINT” mode than in "INDIRECT" mode. As a result, the phase shift has significantly less effect, and even higher frequencies can be effectively damped.

Another advantage is that the drive is not excited to vibrate due to feedback of the actual values since only command values are used in this mode.

On the downside, however, information that "INDIRECT" mode provides by using the actual motor values is lost.

Notice

At high frequencies, a phase shift of the output additive speed may occur due to the dead time of the simulation.

Consequence: Vibrations may be intensified instead of being damped.

Notice

Low damping ratios may cause the output of high additive speeds.

Consequence: The drive may be excited to vibrate.