Mitsubishi Electric RD77MS2 - Near-Point Dog Method

2 HOME POSITION RETURN CONTROL
2.2 Machine Home Position Return
35
2
Near-point dog method
The following shows an operation outline of the home position return method "near-point dog method".
Operation chart
1. The machine home position return is started.
(The machine begins the acceleration designated in "[Pr.51] Home position return acceleration time selection", in the direction
designated in "[Pr.44] Home position return direction". It then moves at the "[Pr.46] Home position return speed" when the
acceleration is completed.)
2. The machine begins decelerating when the near-point dog ON is detected.
3. The machine decelerates to the "[Pr.47] Creep speed", and subsequently moves at that speed.
(At this time, the near-point dog must be ON. The workpiece will continue decelerating and stop if the near-point dog is OFF.)
4. After the near-point dog turns OFF, the machine stops. It then restarts and stops at the first zero point.
5. The home position return complete flag ([Md.31] Status: b4) turns from OFF to ON and the home position return request
flag ([Md.31] Status: b3) turns from ON to OFF.
[Pr.46] Home position
return speed
Home position return complete flag
([Md.31] Status: b4)
t
Machine home position return start
(Positioning start signal)
ON
OFF
Deceleration at the near-point dog ON
ON
OFF
OFF
ON
Standby Home position return Standby
Inconsistent
0
Inconsistent
Value of the machine moved is stored
Home position address
V
Zero signal
Value of *1
Near-point dog
ON
One servo motor rotation
Adjust so the near-point dog OFF
position is as close as possible to the
center of the zero signal HIGH level.
If the near-point dog OFF position
overlaps with the zero signal,
the machine home position return stop
position may deviate by one servomotor
rotation.
1. 2. 3. 4. 5.
[POINT]
A
After the home position return
has been started, the zero point
of the encoder must be passed at
least once before point A is reached.
[Pr.47] Creep speed
[Md.34] Movement amount after near-point dog ON
*1
Home position return request flag
([Md.31] Status: b3)
[Md.26] Axis operation status
[Md.34] Movement amount after
near-point dog ON
[Md.20] Current feed value
[Md.21] Machine feed value
OFF