MITSUBISHI ELECTRIC Mitsubishi Programmable Logic Controller QD75D - Manual (Page 295)

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MELSEC-Q
8 OPR CONTROL
Restrictions
A pulse generator with a zero signal is required.
When using a pulse generator without a zero signal, generate a zero signal using
an external signal.
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.
ON
1) 5)
4)
3)
2)
Zero signal
Near-point dog OFF
Pr. 50 Setting for the movement
amount after near-point dog ON [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 the
deviation counter clear output is provided on
detection of the first zero signal after the
travel of the movement amount set to
" Pr.50 Setting for the movement amount
after near-point dog ON" on detection of the
near-point dog signal ON.
Fig. 8.13 Count method 1) 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.