Siemens SINUMERIK 808D User Manual page 111

An gle ANG
If only one end point coordinate of the plane is known for a straight line or for contours across multiple blocks the cumulative
end point, an angle parameter can be used for uniquely defining the straight line path. The angle is always referred to the
abscissa of the current plane G17 to G19, e.g. for G17 on the X axis. Positive angles are aligned counter-clockwise.
See the following specification of an angle for determination of a straight line using the example of the G17 plane:
See the following illustration for multiple block contours using the example of the G17 plane:
Programming and Operating Manual (Milling)
111
6FC5398-4DP10-0BA6, 09/2017