Opr Method (1): Near-Point Dog Method - Mitsubishi Electric MELSECQ Series User Manual

8 OPR CONTROL

8.2.3 OPR method (1): Near-point dog method

1)
2)
3)
4)
5)
Machine OPR control start
(Positioning start signal: Y8 to YF)
OPR request flag
OPR complete flag
Deviation counter clear output
Md.4
Md.2
Md.1
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The following shows an operation outline of the "near-point dog method" OPR method.
Operation chart
Machine OPR control is started.
(Acceleration starts in the direction set in " OPR. 2 OPR direction" at the time set in " OPR. 6 ACC/DEC time at OPR",
and the axis moves at " OPR. 4 OPR speed".)
Near-point dog ON is detected and deceleration starts at the time set in " OPR. 6 ACC/DEC time at OPR".
The machine decelerates to the " OPR. 5 Creep speed", and subsequently moves at that speed.
(At this time, the near-point dog must be ON.)
On detection of the first zero signal after near-point dog OFF, the pulse output from the QD70 stops immediately and the
"deviation counter clear output" is output to the drive unit.
(The "deviation counter clear signal output time" is set in Pr. 8 .)
After a "deviation counter clear signal" is output to the drive unit, the OPR complete flag ( Md. 7 Status: b1) turns from
OFF to ON and the OPR request flag ( Md. 7 status: b0) turns from ON to OFF.
V
OFF
OFF
Md.7 Status: b0
OFF
Md.7 Status: b1
Axis operation status Standby
Movement amount after Unfixed
near-point dog ON
Current feed value Unfixed
Fig. 8.2 Near-point dog method machine OPR control
search engine
OPR.4 OPR speed Deceleration at the near-point dog ON
Pr.6
Bias speed at start
1) 2) 3)
ON
Near-point dog OFF
Zero signal
ON
ON
During OPR
0
Traveled value is stored
OPR.5 Creep speed
t
4) 5)
Md.2 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 OPR control
stop position may deviate by one motor rotation.
One motor rotation
ON
Deviation counter clear signal output time
Pr.8
Standby
1
Value marked
OP address
MELSEC-Q
1
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