Mitsubishi Electronics QD75P, QD75D OPR method 1 Near-point dog method, Operation chart, Pr.51

8 OPR CONTROL

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

MELSEC-Q

The following shows an operation outline of the "near-point dog method" OPR method.

Operation chart

The machine OPR is started.
(The machine begins the acceleration designated in "
			Pr.51	OPR acceleration time selection", in the direction
1)		OPR direction". It then moves at the "			OPR speed" when the acceleration is
designated in "	Pr.44			Pr.46
completed.)

2)The machine begins decelerating when the near-point dog ON is detected.

The machine decelerates to the " Pr.47 Creep speed", and subsequently moves at that speed.

3)(At this time, the near-point dog must be ON. The workpiece will continue decelerating and stop if the near-point dog is OFF.)

After the near-point dog turns OFF, the pulse output from the QD75 will stop at the first zero signal,

4)outputting a "deviation counter clear signal" to the drive unit.

5)

(The "deviation counter clear signal output time" is set in Pr.55 .)

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.

V	Pr.46	OPR speed	Deceleration at the near-point dog ON
			Pr.47 Creep speed

1) 2) 3)

4) 5)	t
	1

Md.34 Movement amount after near-point dog ON

ON

Near-point dog OFF

Zero signal

	ON
Machine OPR start	OFF
(Positioning start signal)
	ON
OPR request flag	OFF
Md.31 Status: b3
OPR complete flag	OFF

Md.31 Status: b4

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 output
Md.26 Axis operation statusStanding by			In OPR
			0
Md.34 Movement amount afterInconsistent
	near-point dog ON
Md.20	Current feed value		Value of the machine moved is stored.
		Inconsistent
Md.21	Machine feed value

Deviation counter clear Pr.55 signal output time

Standing by

Value of 1

OP address

Fig. 8.2 Near-point dog method machine OPR

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