Near-Point Dog Method - Mitsubishi Electric RD77MS2 User Manual

Near-point dog method

The following shows an operation outline of the home position return method "near-point dog method".
Operation chart
[POINT]
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.
Machine home position return start
(Positioning start signal)
Home position return request flag
([Md.31] Status: b3)
Home position return complete flag
([Md.31] Status: b4)
[Md.26] Axis operation status Standby
[Md.34] Movement amount after Inconsistent
near-point dog ON
[Md.20] Current feed value
Inconsistent
[Md.21] Machine feed value
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.
V
[Pr.46] Home position
return speed
1. 2.
ON
Near-point dog OFF
Zero signal
ON
OFF
ON
OFF
OFF
Home position return
0
Value of the machine moved is stored
Deceleration at the near-point dog ON
[Pr.47] Creep speed
t
3. A 4. 5.
[Md.34] Movement amount after near-point dog ON
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.
One servo motor rotation
ON
Standby
Value of *1
Home position address
2 HOME POSITION RETURN CONTROL
*1
2.2 Machine Home Position Return
2
35