Siemens sinumerik 808d Programming And Operating Manual page 179

If the parameter has a value other than A ... D, the cycle aborts and creates alarm 61609
"Form defined incorrectly".
Internally in the cycle, the tool radius compensation is selected automatically.
The cycle only uses the tool point directions 1 ... 4. If the cycle detects a tool point direction 5
... 9 or if the form of the undercut cannot be machined with the selected tool point direction,
alarm 61608 "Wrong tool point direction programmed" is issued, and the cycle is canceled.
VARI (undercut position)
The position of the undercut can be either specified directly or derived from the tool point
direction with the VARI parameter. See also the topic "Undercut (forms E and F to DIN) -
CYCLE94 (Page 157)".
The cycle will find the starting point determined by the tool point direction of the active tool
and the thread diameter automatically. The position of this starting point referred to the
programmed coordinate values is determined by the tool point direction of the active tool.
Turning Part 2: Programming (Siemens instructions)
Programming and Operating Manual, 05/2012, 6FC5398-5DP10-0BA0
Cycles
2.5 Turning cycles
179