HEIDENHAIN POSITIP 880 User Manual page 20

ENABLE REF function
The purpose of the ENABLE REF function, is to give the operator the
opportunity to either ignore the reference marks as they are crossed
over by disabling it, or finding reference marks when necessary by
enabling it. When the ENABLE REF soft key is pressed, the POSITIP 880
is ready to identify a reference mark. When the ENABLE REF soft key is
not depressed, POSITIP 880 will ignore all reference marks. When all
reference marks have been found, the ENABLE REF soft key will
disappear.
If an encoder is setup without reference marks, then the
REF indicator will not be displayed.
Once reference marks for all desired axes are established, press NO
REF soft key to cancel out of routine. You do not have to cross over the
reference marks of all the encoders, only those that you need.
If you do not cross over the reference marks, POSITIP 880
does not store the datum points. This means that it is not
possible to re-establish the relationship between axis slide
positions and display values after a power interruption
(switch-off).
Turn on power and press any key.
Cross over the reference marks (in any order).
Do not cross over the reference marks. Note: In this
case the relationship between axis slide position and
display value will be lost after a power interruption.
Press the NO REF soft key.
20 I Operating Instructions