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MELSEC-A
12 CONTROL AUXILIARY FUNCTIONS
(b) Zero point return retry operation when the workpiece is outside the range
between the upper and lower limits.
1) When the direction from the workpiece to the zero point is the same as the "
Pr.46 Zero point
return direction", a normal machine zero point return is carried out.
Zero point return direction
Near-point dog
Lower limit Upper limit
Zero point
Movement range
Machine zero point return start
Zero point
Pr.46
2) When the direction from the workpiece to the zero point is the opposite direction from the
"
Pr.46 Zero point return direction", the operation carries out a deceleration stop when the near-
point dog turns OFF, and then carries out a machine zero point return in the direction set in
"
Pr.46 Zero point return direction".
Zero point return direction
Near-point dog
Lower limit Upper limit
Zero point
Movement range
Machine zero point return start
Zero point
Pr.46
Fig. 12.2 Zero point return retry operation from on limit (limit signal OFF)