Mitsubishi Electric MELSEC Q Series Programming Manual page 400

6 POSITIONING CONTROL
(3) Home position return execution
Home position return by the proximity dog method 2 is executed using the servo
program in Section 6.23.19.
(4) Cautions
(a) A system in which the servo motor can rotate one time or more is required.
(b) When a servo motor stops with the specified condition enabled and rotates
to reverse direction one time after proximity dog ON, make a system which
does not turn OFF the external upper/lower stroke limit.
(c) Keep the proximity dog ON during deceleration from the home position
return speed to the creep speed.
If the proximity dog turns OFF before deceleration to the creep speed, a
deceleration stop is made and the next zero point is set as the home position.
(d) If home position return is executed in the proximity dog ON, it starts with the
creep speed.
(e) When home position return retry function is not set, if home position return is
executed again after home position return completion, a minor error (error
code: 115) will occur, the home position return is not executed.
(f) When "1 : Not need to pass motor Z phase after the power supply is
switched on" is selected in the "function selection C-4 (PC17)" of servo
parameter (expansion setting parameter), even if it does not pass zero point
at the servo amplifier power ON, the zero pass signal (M2406+20n) turns
ON. This operation is the same as proximity dog method 1.
(g) If in-position signal (M2402+20n) does not turn ON, home position return is
not ended.
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