12 - 6
MELSEC-Q
12 CONTROL SUB FUNCTIONS
(3) Setting the dwell time during an OPR retry
The OPR retry function can perform such function as the dwell time using
"Pr.57 Dwell time at OPR retry" when the reverse run oper ation is carried
out due to detection by the limit signal for upper and lower li mit s and wh en
the machine OPR is executed after the near poi nt dog is turned OFF to stop
the operation.
"Pr.57 Dwell time during OPR" is validated when the operation stops at
the "A" and "B" positions in the following dra wing. (The dwell time is the
same value at both positions "A" and "B".)
Machine OPR
executed again
Stop by near-point
dog OFF
Stop by limit
signal detection
Reverse run operation
after limit signal detection
BOP
Pr. 44 OPR direction
Machine OPR start
A
Limit signal OFF
Near-point dog
Zero signal
Fig. 12.3 Setting the dwell time during an OPR retry