Mitsubishi Electric MELSEC Q Series Programming Manual page 420

6 POSITIONING CONTROL
(4) Cautions
(a) When home position is in the proximity dog, if home position return is
executed again after home position return end, a minor error (error code:
123) will occur, the home position return is not executed.
(b) Set "0: Need to pass motor Z phase after the power supply is switched on"
in the "function selection C-4 (PC17)" of servo parameter (expansion
setting parameter). When "1: Not need to pass motor Z phase after the
power supply is switched on" is set, a minor error (error code: 124) will
occur at home position return by the scale home position signal detection
method starting, the home position return is not executed.
(c) When zero pass signal (M2406+20n) turns on by passing zero point at home
position return start, this signal turns off once at the reverse direction of
home position return start and turns on again at the next zero point
passage.
(d) Home position return is executed in the proximity dog, it travels to reverse
direction of home position return. If home position signal (zero point) is
detected, a deceleration stop is made, it travels to direction of home position
return again with the creep speed and the detecting position of home
position signal (zero point) is home position.
Home position
V
return direction
Creep speed
3)
2)
Home position
return start
Home
position
1)
Proximity
dog
Zero point
6 - 233
1) It travels to preset reverse direction
of home position return with the
home position return speed.
2) Home position signal (zero point) is
detected, and a deceleration stop is
made.
3) After a deceleration stop, it travels
to preset direction of home position
return with the creep speed, and
the home position return ends with
the position of home position signal
(zero point).
External limit switch