Zero Point Return Method (1): Near-Point Dog Method - Mitsubishi Electric AJ65BT-D75P2-S3 User Manual

8 ZERO POINT RETURN CONTROL

8.2.3 Zero point return method (1): Near-point dog method

The machine starts a machine zero point return.
(The machine starts acceleration specified in " Pr.53 Zero point return acceleration time selection" in the
1)
direction set in " Pr.46 Zero point return direction", and moves at " Pr.48 Zero point return speed".)
2) The machine detects near-point dog ON and starts deceleration.
The machine decelerates to " Pr.49 Creep speed" and then moves at the creep speed.
3)
At the first zero point signal after near-point dog OFF, pulse output from the D75P2 stops and "deviation
4)
counter clear output" is output to the drive unit.
After the completion of "deviation counter clear output", the zero point return complete flag (RX(n+2)0,
5) RX(n+5)0) turns from OFF
ON OFF.
Machine zero point return start
(Positioning start signal)
Zero point return request flag
[RX(n+1)F, RX(n+4)F]
Zero point return complete flag
[RX(n+2)0, RX(n+5)0]
Deviation counter clear output
Axis operation status
[RWrn+7, RWrn+15]
Md.44 Movement amount
after near-point dog ON
Current feed value
[RWrn+ 0 to 1, RWrn+8 to 9]
Md.30 Machine feed value
The following shows an operation outline of the "near-point dog method" zero point
return method.
Operation chart
ON and the zero point return request flag (RX(n+1)F, RX(n+4)F) turns from
V
1)
Near-point dog
Zero point signal
ON
OFF
ON
OFF
OFF
Standing by
In zero point return
Inconsistent 0
Inconsistent
Value the machine moved is stored
Fig. 8.2 Near-point dog method machine zero point return
Pr. 48 Zero point return speed
Deceleration at the near-point dog ON
Pr. 49 Creep speed
2) 3) 4) 5)
Md.44 Movement amount after near-point dog ON
ON
OFF
One servomotor rotation
ON
Standing by
Value of *1.
Zero point address
8 - 6
MELSEC-A
t
Adjust so the near-point dog OFF position is
as close as possible to the center of the zero
point signal HIGH level.
If the near-point dog OFF position overlaps
with the zero point signal, the zero point return
stop position may deviate by one servomotor
rotation.
*
1