Mitsubishi Electric MELSEC iQ-F Series FX5 User Manual page 91

Restrictions
Since an error of approximately 1 ms occurs in taking in the ON state of the near-point dog, the stop position (OP) varies
compared to other OPR methods.
Precautions during the operation
• If the distance set in "[Pr.50] Setting for the movement amount after near-point dog ON" is shorter than the deceleration
distance from "[Pr.46] OPR speed" to deceleration stop, a Count method movement amount fault (Error code: 1944H)
occurs and the operation does not start. Depending on the set value of "[Pr.50] Set travel amount after near-point dog turns
ON", when the travel amount set after the near-point dog turns ON is reached, a warning "Insufficient travel amount
(Warning code: H0998)" occurs, and the machine OPR stops suddenly. Further, if the travel amount set in "[Pr.50] Set travel
amount after near-point dog turns ON" is reached before the creep speed is reached, a "Count method movement amount
fault (Error code: H1944)" occurs.
• If the speed is changed to a speed faster than the speed set in [Pr.46] OPR speed using the speed change function
(Page 241 Speed change function) during a machine OPR operation, the distance required for deceleration stop may
not be assured depending on the setting of "[Pr.50] Setting for the movement amount after near-point dog ON". In this case,
a Count method movement amount fault (Error code: 1944H) occurs and the machine OPR is stopped.
• The following shows the operation performed when the machine OPR is started while the near-point dog is on.
(4)
(3)
ON
Near-point dog
OFF
• The near-point dog must be turned off at a sufficient distance from the OP. There is no harm in operation even if the near-
point dog is turned off during a machine OPR. However, ensuring a sufficient distance from the OP is recommended for the
following reasons when the near-point dog is turned off.
(1) If the workpiece is at a point where the near-point dog is still ON when the machine OPR is completed, another machine OPR can be implemented from that
point even though the OPR complete flag ([Md.31] Status: b4) is ON.
(2) If the workpiece is at a point where the near-point dog is OFF when the machine OPR is completed and another OPR is implemented, the workpiece travels
at the OPR speed until it reaches a limit switch. This causes Hardware stroke limit (+)/Hardware stroke limit (-) (Error code: 1905H/1907H). If a sufficient
distance cannot be ensured for Near-point dog signal to be turned on, use the OPR retry function. When the OPR retry function is used, a retry operation
can be performed using limit switches.
• When the machine OPR has been stopped by a stop signal, perform the machine OPR again. If the restart command is
turned ON after the stop by a stop signal, OPR restart not possible (Error code: 1946H) occurs.
[Pr.50] Setting for the movement amount
after near-point dog ON
(1) (5)
(2)
[Operation when the machine OPR is started from a point where the near-point
dog is on]
(1) A machine OPR is started.
(2) The machine moves at the OPR speed in the direction reverse to the
specified OPR direction.
(3) The deceleration processing is performed according to the setting of [Pr.39]
Stop group 3 sudden stop selection when the OFF state of the near-point
dog is detected.
(4) After the machine stops, the machine OPR is performed in the specified
OPR direction.
(5) When the machine moves for the movement amount set in [Pr.50] Setting
for the movement amount after near-point dog ON from the point where the
on state of the near-point dog is detected, the machine OPR will be
completed.
8 OPR CONTROL
89
8.2 Machine OPR
8