HEIDENHAIN TNC 640 (34059x-02) ISO programming - Manual (Page 425)

Basis Functions (Software Option 50) 14.2
14
TNC 640 | User's Manual for DIN/ISO Programming | 5/2013
425
Recessing and undercutting
Some cycles machine contours that you have written in a
subprogram. You program these contours with plain-language path
functions or FK functions. Further special contour elements are
available to you for writing turning contours. In this way you can
program complete recessing and undercutting as complete contour
elements with a single NC block.
Recessing and undercutting always reference a
previously defined linear contour element.
Recessing elements GRV and undercut elements
UDC can only be used in contour subprograms that
are called by a turning cycle (see User's Manual,
Cycles, Turning).
You have various input possibilities when defining recessing and
undercutting. Some of these inputs are mandatory, and others
you can leave out (optional). The mandatory inputs are symbolized
as such in the help graphics. In some elements you can select
between two different definitions. The TNC has soft keys with the
corresponding selection possibilities.
Programming recessing and undercutting:
Show the soft-key row with special functions
Select the menu for TURNING PROGRAM
FUNCTIONS
Select RECESS/UNDERCUT
Select GRV (recess) or UDC (undercut)