Mitsubishi Electric QD77MS User Manual page 451

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 1 ms occurs in taking
in the near-point dog ON.
Precautions during operation
(1) The 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".
(2) If the speed is changed to a speed faster than "[Pr.46] OPR speed" by the
speed change function (refer to "13.5.1 Speed change function".) 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.
(3) The following shows the operation when a machine OPR is started while the
near-point dog is ON.
4)
3)
ON
Near-point dog OFF
Fig. 8.9 Count method 2) machine OPR on the near-point dog ON position
(4) Turn OFF the near-point dog at a sufficient distance from the OP.
(5) When the stop signal stops the machine OPR, carry out the machine OPR
again. When restart command is turned ON after the stop signal stops the
OPR, the error "OPR restart not possible" (error code: 209) will occur.
Pr. 50 Setting for the movement amount
after near-point dog ON
1) 5)
2)
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.
8 - 13
[Operation when an 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 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".
Chapter 8 OPR Control