HEIDENHAIN ITNC 530 - Circular path CTP with tangential connection

HEIDENHAIN iTNC 530 249
6.5 Path contours—Polar coordinates
Circular path CTP with tangential connection
The tool moves on a circular path, starting tangentially from a
preceding contour element.
 Polar coordinate radius PR: Distance from the arc
end point to the pole CC
 Polar coordinates angle PA: Angular position of the
arc end point
Example NC blocks
X
Y
40
35
CC
30°
120°
R30
R25
12 CC X+40 Y+35
13 L X+0 Y+35 RL F250 M3
14 LP PR+25 PA+120
15 CTP PR+30 PA+30
16 L Y+0
The pole is not the center of the contour arc!!