8 OPR CONTROL

Restrictions

MELSEC-Q

When this method is used, a deviation will occur in the stop position (OP) compared to other OPR methods because an error of about 1 ms occurs in taking in the near-point dog ON.

Precautions during operation

(1) An error "Count method movement amount fault (error code: 206)" will occur

and the operation will not start if the "

Pr.50

Setting for the movement

amount after near-point dog ON" is smaller than the deceleration distance

from the "

Pr.46

OPR speed" to "

Pr.47

Creep speed".

A deceleration stop will be carried out if the speed is changed during the operation and an error occurs.

(2)The following shows the operation when a machine OPR is started while the near-point dog is ON.

Pr.50 Setting for the movement amount after near-point dog ON

4)

1) 5)

3)

2)

ON

Near-point dog OFF

[Operation when a machine OPR is started at the near-point dog ON position]

1)A machine OPR is started.

2)The machine moves at the OPR speed in the opposite direction of an OPR.

3)Deceleration processing is carried out by " Pr.39 Stop group 3 sudden stop

selection" when the near-point dog OFF is detected.

4)After the machine stops, a machine OPR is carried out in the OPR direction.

5)The machine OPR is completed after moving the movement amount set in the " Pr.50

Setting for the movement amount after near- point dog ON".

Fig. 8.15 Count method 2) machine OPR on the near-point dog ON position

(3)Turn OFF the near-point dog at a sufficient distance from the OP. Although there is no harm in operation if the near-point dog is turned OFF during a machine OPR, it is recommended to leave a sufficient distance from the OP when the near-point dog is turned OFF for the following reason.

If machine OPRs are performed consecutively after the near-point dog is turned OFF at the time of machine OPR completion, operation will be performed at the OPR speed until the hardware stroke limit (upper/lower limit)

is reached.

(4)When a machine OPR is stopped with the stop signal, perform a machine OPR again.

If the restart command is turned ON after a stop with the stop signal, an error "OPR restart not possible" (error code: 209) occurs.

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Mitsubishi Electronics QD75D, QD75P user manual Setting for the movement amount after near- point dog on