HEIDENHAIN 548431-05, User Manual, Page: 54 / 722

Introduction and fundamentals | Fundamentals
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HEIDENHAIN | MANUALplus 620 | User's Manual | 12/2017
Incremental coordinates
Incremental coordinates are always given with respect to the last
programmed position. They specify the distance from the last
active position to the subsequent position. Each position on a
workpiece is clearly defined by its incremental coordinates.
Polar coordinates
Positions located on the face or lateral surface can either be
entered in Cartesian coordinates or polar coordinates.
When programming with polar coordinates, a position on the
workpiece is clearly defined by the entries for diameter and angle.
Machine datum
The point of intersection of the X and Z axes is called the machine
datum . On a lathe, the machine datum is usually the point of
intersection of the spindle axis and the spindle surface. The
machine datum is designated with the letter
M .