HEIDENHAIN TNC 320 User Manual page 178

7.4 CONTOUR DATA (Cycle 20,
DIN/ISO: G120)
Please note while programming:
Machining data for the subprograms describing the subcontours are
entered in Cycle 20.
Cycle 20 is DEF active, which means that it becomes
effective as soon as it is defined in the part program.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program
DEPTH=0, the TNC performs the cycle at the depth 0.
The machining data entered in Cycle 20 are valid for
Cycles 21 to 24.
If you are using the SL cycles in Q parameter programs,
the cycle parameters Q1 to Q20 cannot be used as
program parameters.
178 Fixed Cycles: Contour Pocket