MITSUBISHI ELECTRIC Mitsubishi Programmable Logic Controller QD75D - Manual (Page 481)

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MELSEC-Q
12 CONTROL SUB FUNCTIONS
(2) OPR retry operation when the workpiece is outside the range between the
upper and lower limits.
1) When the direction from the workpiece to the OP is the same as the " Pr.44 OPR direction", a
normal machine OPR is carried out.
Pr. 44 OPR direction
Upper limit Lower limit
Movement range
Machine OPR start
OP
Zero signal
Near-point dog
2) When the direction from the workpiece to the OP is the opposite direction from the " Pr.44 OPR
direction", the operation carries out a deceleration stop when the near-point dog turns OFF, and
then carries out a machine OPR in the direction set in "
Pr.44 OPR direction".
Pr. 44 OPR direction
Near-point dog
Upper limit Lower limit
Movement range
Machine OPR start
OP
Zero signal
Note) The above figures (a) and (b) are examples where " Pr.44 OPR direction" is set to "0: Positive
direction". When "0: Positive direction" is set in Pr.44 , check that the limit switch placed in the
OPR direction acts as the upper limit. When "1: Negative direction" is set in Pr.44 , check that
the limit switch placed in the OPR direction acts as the lower limit. Incorrect wiring of these limit
switches may cause improper OPR retry operation. If any malfunction is identified, check and
correct "
Pr.6 Rotation direction setting" and the wiring.
Fig. 12.2 OPR retry operation from on limit (limit switch OFF)