HEIDENHAIN TNC 640 (34059x-05) ISO programming - Manual (Page 359)

Miscellaneous functions for path behavior 10.4
10
TNC 640 | User's ManualDIN/ISO Programming | 1/2015
359
Feed rate factor for plunging movements: M103
Standard behavior
The TNC moves the tool at the last programmed feed rate,
regardless of the direction of traverse.
Behavior with M103
The TNC reduces the feed rate when the tool moves in the
negative direction of the tool axis. The feed rate for plunging
FZMAX is calculated from the last programmed feed rate FPROG
and a factor F%:
FZMAX = FPROG x F%
Programming M103
If you enter M103 in a positioning block, the TNC continues the
dialog by asking you the factor F.
Effect
M103 becomes effective at the start of block.
To cancel M103, program M103 once again without a factor.
M103 is also effective in an active tilted working
plane. The feed rate reduction is then effective during
traverse in the negative direction of the
tilted
tool
axis.
Example NC blocks
The feed rate for plunging is to be 20% of the feed rate in the plane.
... Actual contouring feed rate (mm/min):
N170 G01 G41 X+20 Y+20 F500 M103 F20 * 500
N180 Y+50 * 500
N190 G91 Z-2.5 * 100
N200 Y+5 Z-5 * 141
N210 X+50 * 500
N220 G90 Z+5 * 500