HEIDENHAIN TNC 320 User Manual page 98

Please note while programming:
Machine and TNC must be specially prepared by the
machine tool builder for use of this cycle.
This cycle is effective only for machines with servo-
controlled spindle.
Program a positioning block for the starting point (hole
center) in the working plane with radius compensation R0.
The algebraic sign for the total hole depth parameter
determines the working direction.
The TNC calculates the feed rate from the spindle speed.
If the feed-rate override is used during tapping, the TNC
automatically adjusts the feed rate.
The feed-rate override knob is disabled.
At the end of the cycle the spindle comes to a stop. Before
the next operation, restart the spindle with M3 (or M4).
Danger of collision!
Use the machine parameter displayDepthErr to define
whether, if a positive depth is entered, the TNC should
output an error message (on) or not (off).
Keep in mind that the TNC reverses the calculation for pre-
positioning when a positive depth is entered. This
means that the tool moves at rapid traverse in the tool axis
to set-up clearance below the workpiece surface!
98 Fixed Cycles: Tapping / Thread Milling