HEIDENHAIN TNC 640 User Manual page 621

Multiple-Axis Machining | Miscellaneous functions for rotary axes
M128 on tilting tables
If you program a tilting table movement while M128 is active, the
control rotates the coordinate system accordingly. For example,
if you rotate the C axis by 90 (through a positioning command
or datum shift) and then program a movement in the X axis, the
control executes the movement in the machine Y axis.
The control also transforms the preset, which has been shifted by
the movement of the rotary table.
M128 with 3-D tool compensation
If you carry out a three-dimensional tool compensation while M128
and an RL/RR/ radius compensation are active, the control will
position the rotary axes automatically with particular machine
geometries (Peripheral Milling).
Further information: "Three-dimensional tool compensation
(option 9)", page 631
Effect
M128 becomes effective at the start of the block, M129 at the end
of the block. M128 is also effective in the manual operating modes
and remains active even after a change of mode. The feed rate for
the compensation movement will be effective until you program a
new feed rate or until you cancel M128 with M129.
Enter M129 to cancel M128. The control will also cancel M128 if
you select a new program in a program run operating mode.
Example: Feed rate of 1000 mm/min for compensation
movements
L X+0 Y+38.5 IB-15 RL F125 M128 F1000
HEIDENHAIN | TNC 640 | Conversational Programming User's Manual | 10/2017
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