HEIDENHAIN iTNC 530 (340 49x-03) - Manual (Page 230)

230 6 Programming: Programming Contours
6.3 Cont
our Appr
oac
h
and Depar
tur
e „ End point P
N
The position P
N
lies outside of the contour and results from your
input in the DEP block. If the DEP block also contains a Z axis
coordinate, the TNC will first move the tool to P
H
in the working
plane, and then move it to the entered depth in the tool axis.
Abbreviation Meaning
APPR Approach
DEP Departure
L Line
C Circle
T Tangential (smooth connection)
N Normal (perpendicular)
The TNC does not check whether the programmed
contour will be damaged when moving from the actual
position to the auxiliary point P
H
. Use the test graphics to
simulate approach and departure before executing the
part program.
With the APPR LT, APPR LN and APPR CT functions, the
TNC moves the tool from the actual position to the
auxiliary point P
H
at the feed rate that was last
programmed. With the APPR LCT function, the TNC
moves to the auxiliary point P
H
at the feed rate
programmed with the APPR block. If no feed rate is
programmed yet before the approach block, the TNC
generates an error message.