HEIDENHAIN TNC 620 (81760x-02) ISO programming - Manual (Page 236)

Programming: Programming contours
6.6 Path contours – FK free contour programming (option 19)
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TNC 620 | User's ManualDIN/ISO Programming | 2/2015
The following prerequisites for FK programming
must be observed:
The FK free contour programming feature can only
be used for programming contour elements that lie in
the working plane.
The working plane for FK programming is defined
according to the following hierarchy:
1. By the plane defined in a FPOL block
2. By the working plane pre-defined in the T block
(e.g. G17 = X/Y plane)
3. The standard X/Y plane is active if none of
these applies
The display of the FK soft keys depends on the
spindle axis in the workpiece blank definition. If for
example you enter spindle axis
G17 in the workpiece
blank definition, the TNC only shows FK soft keys for
the X/Y plane.
You must enter all available data for every contour
element. Even the data that does not change must
be entered in every block—otherwise it will not be
recognized.
Q parameters are permissible in all FK elements,
except in elements with relative references (e.g.
RX
or RAN), i.e. elements that are referenced to other
NC blocks.
If both FK blocks and conventional blocks are entered
in a program, the FK contour must be fully defined
before you can return to conventional programming.
The TNC needs a fixed point from which it can
calculate the contour elements. Use the gray path
function keys to program a position that contains
both coordinates of the working plane immediately
before programming the FK contour. Do not enter
any Q parameters in this block.
If the first block of an FK contour is an
FCT or FLT
block, you must program at least two NC blocks
with the gray path function keys to fully define the
direction of contour approach.
Do not program an FK contour immediately after an
L
command.