PROGRAMMING
B–63684EN/01
6. REFERENCE POSITION
67
Tools are automatically moved to the reference position. When reference
position return is completed, the lamp for indicating the completion of
return goes on.
A (Start position for reference position return)
R (Reference position)
Reference position return A→B→R
Return from the reference position R→B→C
Fig.6.1 (c) Reference position return
G28_ ;
Reference position return
Reference positions are performed at the rapid traverse rate of each axis.
Example N1 G28
The lamp for indicating the completion of return does not go on when the
machine lock is turned on, even when the tool has automatically returned
to the reference position.
When the G28 command is specified when manual return to the reference
position has not been performed after the power has been turned on, the
movement from the intermediate point is the same as in manual return to
the reference position.
In this case, the tool moves in the direction for reference position return
specified in parameter ZMIx (bit 5 of No. 1006). Therefore the specified
intermediate position must be a position to which reference position
return is possible.
When the machine tool system is an inch system with metric input, the
reference position return lamp may also light up even if the programmed
position is shifted from the reference position by 1
µ. This is because the
least input increment of the machine tool system is smaller than its least
command increment.
See III–3.1.
D Reference position
return and movement
from the reference
position
Format
D Reference position
return
Explanations
D Reference position
return (G28)
Limitations
D Status the machine lock
being turned on
D First return to the
reference position after
the power has been
turned on (without an
absolute position
detector)
D Lighting the lamp when
the programmed position
does not coincide with
the reference position
Reference
D Manual reference
position return