Mitsubishi Electric MELSEC Q Series Programming Manual page 405

6 POSITIONING CONTROL
6.23.6 Home position return by the count method 3
V
Home position
return speed
1 revolution
Proximity dog
Fig. 6.37 Home position return operation by the count method 3 (zero point no passing)
(1) Count method 3
After the proximity dog ON, the zero point after the specified distance (travel
value after proximity dog ON) is home position in this method.
When the zero point is passed (zero pass signal: M2406+20n ON) during travel
of specified distance set in the "travel value after proximity dog ON" from the
home position return start, home position return operation is the same as "count
method 1". (Refer to Section 6.23.4)
When a zero point is not passed (zero pass signal: M2406+20n OFF) during
travel of specified distance set in the "travel value after proximity dog ON" from
the home position return start, it rotates one time to reverse direction and passes
the zero point, re-travels to home position return direction, and then the first zero
point after the specified distance (travel value after proximity dog ON) after
proximity dog ON is set as home position.
The travel value after proximity dog ON is set in the home position return data
(Refer to Section 6.23.1).
(2) Home position return by the count method 3
Operation of home position return by count method 3 for not passing the zero
point during travel of specified distance set in the "travel value after proximity dog
ON" from the home position return start is shown below.
Home position
return direction
1)
2)
3)
Home position
return start
4)
Home position
return speed
Zero point no passing
5)
Creep speed
Home position
Zero point
The travel value in this range is stored in the monitor
register "travel value after proximity dog ON".
The travel value in this range is stored in the monitor
register "home position return re-travel value".
6 - 218
1) It travels to preset direction of home
position return with the home position
return speed.
2) A deceleration is made to the creep speed
by the proximity dog ON, after that, it
travels with the creep speed.
3) A deceleration stop is made in the position
which traveled the travel value set as travel
value after proximity dog ON.
4) After a deceleration stop, it travels for one
revolution of servo motor to reverse
direction of home position return with the
home position return speed.
5) It travels to direction of home position
return with the home position return speed,
the home position return with first zero
point after traveling the travel value set as
travel value after proximity dog ON from
after the proximity dog ON.
(At this time, a deceleration to the creep
speed is not made with the proximity dog
OFF to ON. And if the zero point is not
passed because of droop pulses for
processing of 4) and 5), a minor error "ZCT
not set" (error code: 120) will occur, a
deceleration stop is made and home
position return does not end normally. In
this case, adjust a position of proximity dog
ON.)