Siemens sinumerik 808d Programming And Operating Manual page 170

Cycles
2.5 Turning cycles
With relief cut elements, the cycle checks whether the machining is possible using the active
tool. If the cycle detects that this machining will result in a contour violation, it will be aborted
after alarm 61604 "Active tool violates programmed contour" has been output.
If the tool clearance angle is specified with zero in the tool compensation, this monitoring will
not be performed.
If too large arcs are found in the compensation, alarm 10931 "Incorrect machining contour"
appears.
Overhanging contours cannot be machined by CYCLE95. Contours of this type are not
monitored by the cycle and consequently there is no alarm.
Starting point
The cycle determines the starting point for the machining operation automatically. The
starting point is located in the axis in which the depth infeed is carried out, shifted from the
contour by the amount of the finishing allowance + lift-off distance (parameter _VRT). In the
other axis, it is by finishing allowance + _VRT ahead of the contour starting point.
When the starting point is approached, the cutter radius compensation is selected internally
in the cycle.
The last point before the cycle is called must therefore be selected such that this approach is
possible without collision and space enough is provided to carry out the appropriate
compensatory motion.
170
Turning Part 2: Programming (Siemens instructions)
Programming and Operating Manual, 05/2012, 6FC5398-5DP10-0BA0