January 2012 6.15 Reference Marks 789
6.15 Reference Marks
6.15.1 Definition
The position value (the coordinates) of an axis position is defined with respect
to a freely chosen datum. When the axes are moved, the ACTUAL position is
calculated incrementally. An interruption in power causes the reference
between the axis position and the position value to be lost.
HEIDENHAIN linear encoders are designed with one or more reference marks.
The reference marks identify an axis position at a known distance from the
machine datum. The position of the freely selectable datum is defined with
respect to the machine datum.
The datum and the actual position can be reproduced as soon as the reference
marks are traversed.
HEIDENHAIN recommends position encoders with distance-coded reference
marks. With distance-coded reference marks, the position value can be
reestablished after traverse of a short distance over any two reference marks.
Position encoder
Machine table
REF value
0
10 20 30 40
Machine datum
+Z
+X
0
Workpiece
datum
Workpiece
Reference mark
REF value
–44.985
To Next Page
Loading...
