DrufelCNC manual

4.7.2. Soft limit

If you want the tool to stop when it reaches the minimum and maximum of your axis, use the appropriate constraints. These settings are designed to not damage your machine.
DrufelCNC manual
Min - when the minimum limit of your axis is reached, the tool movement will stop and prevent it from moving towards the minimum.

Max - when the maximum limit of your axis is reached, the tool will stop moving and prevent it from moving towards the maximum.

Safe - if the specified value remains before reaching the minimum or maximum, the tool speed is reduced to the minimum.