HEIDENHAIN TNC 320 User Manual page 139

Please note while programming:
With an inactive tool table you must always plunge
vertically (Q366=0) because you cannot define a plunging
angle.
Pre-position the tool in the machining plane to the starting
position with radius compensation R0. Note parameter
Q367 (slot position).
The TNC automatically pre-positions the tool in the tool
axis. Note parameter Q204 (2nd set-up clearance).
At the end of the cycle the TNC returns the tool to the
starting point (slot center) in the working plane. Exception:
if you define a slot position not equal to 0, then the TNC
only positions the tool in the tool axis to the 2nd set-up
clearance. In these cases, always program absolute
traverse movements after the cycle call.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program
DEPTH=0, the cycle will not be executed.
If the slot width is greater than twice the tool diameter, the
TNC roughs the slot correspondingly from the inside out.
You can therefore mill any slots with small tools, too.
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!
If you call the cycle with machining operation 2 (only
finishing), then the TNC positions the tool to the first
plunging depth at rapid traverse!
HEIDENHAIN TNC 320 139