Special cases

Special case 1: Look Ahead range overflow

Large number of blocks between START – END

The Look Ahead range comprises a maximum of 20 NC blocks. Lifting is executed prematurely if the range of the motion path (Look Ahead range) considered during lifting is fully occupied due to a large number of blocks. In this case, the axis is first lifted to the specified maximum height and lowered shortly before END (see blue curve in the figure)..

Premature lifting can lead to a situation where less motion path is available for the lifting motion than the user actually assumes. As a result, path velocity may be reduced in order to execute the lifting motion and re-engagement.

Conclusion: A high number of blocks between lift start and end leads to premature lifting of the lift axis and to a possible deceleration of the path motion. For this reason Advanced Lifting is recommended.

Programming Example

Look Ahead range overflow

Special case 2: Lifting and explicit flushing of the channel

LIFT and flushing the channel (#FLUSH)

During lifting, the motion blocks are first stored to enable calculation of the optimum lifting motion from LIFT start to end. With various NC commands, however, immediate execution is necessary and this is achieved implicitly by "flushing the channel".

If channel output of the NC blocks is compelled during lifting (e.g. NC command #FLUSH), the LIFT motion is executed as if LIFT_END and again LIFT_START were programmed at this point.

Programming Example

Lifting and explicit flushing of the channel

Operating principle of #FLUSH with comparable programming