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8 ZERO POINT RETURN CONTROL
8.2.5 Zero point return method (3): Stopper stop method 2)
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".)
The machine detects near-point dog ON and starts deceleration.
2)
(At this time, torque limit is required. If torque limit is not applied, the servomotor may fail at 4).)
3)
The machine decelerates to " Pr.49 Creep speed" and then moves at the creep speed.
4)
The machine comes into contact with the stopper at the creep speed, and stops.
At the zero point signal after the stop, pulse output from the D75P2 stops and "deviation counter clear
5)
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,
6)
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 "stopper stop method 2)" zero point
return method.
Operation chart
ON and the zero point return request flag (RX(n+1)F, RX(n+4)F) turns from
OFF
OFF
OFF
Standing by
Inconsistent
Inconsistent
Fig. 8.6 Stopper stop method 2) machine zero point return
V
Pr. 48 Zero point return speed
2)
1)
Zero point signal
Valid torque limit range
Torque limit
ON
Near-point dog OFF
ON
ON
In zero point return
0
Value the machine moved is stored
8 - 11
MELSEC-A
Pr. 49 Creep speed
Stops at stopper
t
3) 4)
5)
6)
ON
Standing by
Zero point address
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