Opr Method (1): Near-Point Dog Method - Mitsubishi Electric MELSEC-L LD75P User Manual

8.2.3

OPR method (1): Near-point dog method

The following shows an operation outline of the "near-point dog method" OPR method.
(1) Operation chart
1.
The machine OPR is started. (The machine begins the acceleration designated in "[Pr.51] OPR
acceleration time selection", in the direction designated in "[Pr.44] OPR direction". It then moves
at the "[Pr.46] OPR 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 pulse output from the LD75 will stop at the first zero signal,
outputting a "deviation counter clear signal" to the drive unit. (A "deviation counter clear signal
output time" is set in [Pr.55].)
5.
After a "deviation counter clear signal" is output to the drive unit, the OPR complete flag ([Md.31]
Status: b4) turns from OFF to ON and the OPR request flag ([Md.31] Status: b3) turns from ON to
OFF.
Machine OPR start
(Positioning start signal)
[Y10,Y11,Y12,Y13]
OPR request flag
Md.31 Status: b3
OPR complete flag
Md.31 Status: b4
Deviation counter clear output
Axis operation status
Md.26
Md.34 Movement amount after
near-point dog ON
Md.20 Current feed value
Md.21 Machine feed value
V
Pr.46 OPR speed
1 2
ON
OFF
Near-point dog
Zero signal
ON
OFF
ON
OFF
OFF
OPR
Standby
0
Inconsistent
Value of the machine moved is stored.
Inconsistent
Deceleration at the near-point dog ON
Creep speed
Pr.47
t
3 4 5
Movement amount after
Md.34
near-point dog ON * 1
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 stop position may
deviate by one servomotor rotation.
One servomotor rotation
ON
Deviation counter clear
Pr.55 signal output time
Standby
Value of *1
OP address
CHAPTER 8 OPR CONTROL
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