Feedforward control (G135/G136/G137)

G135 Selection of feedforward control (modal)
G136 Specification of weighting (modal)
G137 Deselection of feedforward control (modal)

By using a velocity- and acceleration-feedforward control, the path distortions can be reduced.

The axis group specific activation is programmed with G135. Axis-specific, percentage weighting of the calculated feedforward control variables is done with G136. It is limited to 100% for all the axes.

G137 deactivates, axis group-specifically, the feedforward control. After a global selection with G135, for those axes who don’t have a feedforward control, G136 has to be programmed with a weighting of 0%. It is also possible to enter the selection and weighting of the feedforward control into a single block.

During every program start the feedforward control is explicitly switched off in the interpolator and the weighting factors are set to 100%.

If the feedforward control is switched on or off during the NC-program, the weighting factors remain on the values set through G136, or if no G136 is programmed on 100%.

Programming example

G135 (Selection of feedforward control: weighting for all axes 100%)
G136 X80 Y95 Z0 (Weighting; here Z-axis receives no feedforward control)