
B-63944EN/02 PROGRAMMING 6.REFERENCE POSITION
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Limitation
- Status the machine lock being turned on
The lamp for indicating the completion of reference position return
does not go on when the machine lock is turned on, even when the
tool has automatically returned to the reference position. In this case,
it is not checked whether the tool has returned to the reference
position even when a reference position return check command is
specified.
- When automatic reference position return (G28) is executed if no reference
position is established
When automatic reference position return (G28) is executed if no
reference position is established, movement from the intermediate
position in a reference position direction is the same as that in manual
reference position return.
(This movement is referred to as a low-speed type of automatic
reference position return (G28).)
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.
NOTE
When automatic reference position return (G28) is
executed after a reference position is established,
positioning is performed from the intermediate
position to the reference position. This movement is
referred to as a high-speed type of automatic
reference position return (G28).
- Reference position return check in an offset mode
In an offset mode, the position to be reached by the reference position
return check is the position obtained by adding the offset value.
Therefore, if the position with the offset value added is not the
reference position, the lamp for indicating the completion of reference
position return does not light up, but an alarm is displayed instead.
Usually, cancel offsets before G27 is commanded.
- Lighting the lamp when the programmed position does not coincide with the
reference position
When the machine tool system is an inch system with metric input, the
lamp for indicating the completion of reference position return may
also light up even if the programmed position is shifted from the
reference position by the least setting increment. This is because the
least setting increment of the machine tool system is smaller than its
least command increment.