Mitsubishi Electric MELSEC-L LD75D, User Manual

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(2) Restrictions
When this method is used, a deviation will occur in the stop position (OP) compared to other OPR methods
because an error of about 1ms occurs in taking in the near-point dog ON.
(3) Precautions during operation
• 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".
• If the speed is changed to a speed faster than "[Pr.46] OPR speed" by the speed change function (refer to

Page 543, Section 12.5.1.) during a machine OPR, the distance to decelerate to "[Pr.47] Creep speed"
may not be ensured, depending on the setting value of "[Pr.50] Setting for the movement amount after near-
point dog ON". In this case, the error "Count method movement amount fault" (error code: 206) occurs and
the Machine OPR is stopped.
• The following shows the operation when a machine OPR is started while the near-point dog is 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 moving the movement amount set in the "[Pr.50] Setting for
the movement amount after near-point dog ON".
• 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. If
a sufficient distance cannot be kept, consider the use of the OPR retry function.
• 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.
1. 5.
4.
3.
2.
ON
OFF
Pr.50
Near-point dog OFF
Setting for the movement amount after
near-point dog ON