HEIDENHAIN ND 287 User Manual - Manual (Page 16)

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I Working with the ND 287 position display unit
I – 2 F
undamentals of positioning
I – 2 Fundamentals of positioning
Datums
The workpiece drawing identifies a certain point on the workpiece
(usually a corner) as the absolute datum and perhaps one or more
other points as relative datums.
The datum setting procedure establishes these points as the origin of
the absolute or relative coordinate systems. The workpiece, which is
aligned with the machine axes, is moved to a certain position relative
to the length gauge and the display is set either to zero or to another
appropriate value.
Fig. I.2 Length gauge without datum setting:
Unknown assignment of measured values
to positions
Fig. I.3 Length gauge with datum setting: Known
assignment of measured values to positions
?
Z
?
?
?
?
0
Z
10
20
30
40