HEIDENHAIN ITNC 530 - CONVERSATIONAL PROGRAMMING User Manual page 370

Restrictions
After an external or internal stop, you can only re-enter the contour
with the function RESTORE POS. AT N. Before you start the block
scan, you must cancel M120, otherwise the TNC will output an error
message.
When using the path functions RND and CHF, the blocks before and
after RND or CHF must contain only coordinates in the working plane.
If you want to approach the contour on a tangential path, you must
use the function APPR LCT. The block with APPR LCT must contain
only coordinates of the working plane.
If you want to depart the contour on a tangential path, use the
function DEP LCT. The block with DEP LCT must contain only
coordinates of the working plane.
Before using the functions listed below, you have to cancel M120
and the radius compensation:
Cycle 32 Tolerance
Cycle 19 Working plane
PLANE function
M114
M128
M138
M144
TCPM FUNCTION
WRITE TO KINEMATIC
370 Programming: Miscellaneous Functions