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MELSEC-Q
4 SEQUENCE PROGRAM CONFIGURATION AND EXECUTION
CONDITIONS
(2) Response lag
An output module lags max.2 scans behind an input module. (See Fig.4.8)
Ladder examples
Ladder that turns the Y5E output
ON when an X5 input turns ON.
Y5E
X5
55
When Y5E turns ON fastest
OFF
OFF
ON
ON
0
External contact
X5
OFF
ON
Y5E
OFF
ON
External load
END
0 56
END
0
Input refresh
Input refresh
Output refresh
QCPU
devices
Lag time
(Minimum 1 scan)
Y5E output turns on fastest if the external contact is turned ON immediately before
the refresh operation. Then X5 turns ON at the input refresh, Y5E turns ON at step
56, and the external load turns ON at the output refresh following execution of the
END instruction. In this case, the time lag between the external contact ON and the
external load ON is 1 scan.
When Y5E turns ON slowest
OFF
OFF
ON
ON
0
External contact
X5
OFF
ON
Y5E
OFF
ON
External load
END
0 56
END
0
Input refresh
Input refresh
Output refresh
QCPU
devices
Lag time
(Maximum 2 scan)
Y5E turns on slowest if the external contact is turned ON immediately after the
refresh operation. Then X5 turns ON at the input refresh, Y5E turns ON at step 56,
and the external load turns ON at the output refresh following execution of the END
instruction. In this case, the time lag between the external contact ON and the
external load ON is 2 scan.
Fig.4.8 Timing chart showing response of Output "Y" when Input "X" turns ON
