HEIDENHAIN TNC 640 (34059x-01) - Manual (Page 424)

424 Programming: Turning Operations
13.2 Basis F
unctions (Sof
tw
ar
e Option 50)
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.
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:
U Show the soft-key row with special functions
U Select the menu for TURNING PROGRAM FUNCTIONS
U Select RECESS/UNDERCUT
U Select GRV (recess) or UDC (undercut)
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).