Fuji Electric ALPHA7, User Manual

Page: 84 / 662

CHAPTER 2 WIRING
Description of I/O Signals
2-37
2
(5) The in-position signal is turned on with the stopping position being home position after homing
completion PA2_16. In addition, the homing completion signal is turned on.
To perform homing, use up positive over-travel [+OT] and negative over-travel [-OT] signals to assure
safety.

Detection of over-travel signal
If homing is started from position A in the figure above, the home position LS is detected and
stoppage is caused.
If homing is started from position B in the figure above, the +OT signal is detected. In this case,
the following motions follow.
(6) Upon detection of +OT, controlled stop is caused according to deceleration time at OT during
homing PA2_18.
(7) A reverse travel begins at the homing speed.
(8) Upon detection of the home position LS, controlled stop is caused. Then the procedure (1) to (5)
described above is executed.

Starting direction for homing (PA2_08)
If homing is executed from B in the figure above, the distance to +OT must be traveled in a round
trip and therefore much time is taken.
If homing is set to negative starting direction, the home position LS will be detected first.

Reverse traveling unit amount for homing (PA2_09)
If homing is executed from B in the figure above, the distance to +OT must be traveled in a round
trip and therefore much time is taken.
If the reverse traveling unit amount for homing is specified, the next action is performed at the
start of homing.
Homing direction -OT +OT LS
A B