Mitsubishi Electric MELSEC-Q Series User Manual page 100

7 FUNCTION
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(c) Sequence program processing is suspended during the waiting time from
END processing execution in a sequence program until the start of the next
scan.
However, if an interrupt factor occurs after END processing execution, the
corresponding interrupt program is run.
(d) Constant scan accuracy
The following explains the accuracy when the constant scan time has been
set.
1) Refer to Chapter 11 for errors produced when the constant scan time
has been set and the interrupt program is not executed.
2) The interrupt program is also executed during the constant scan
waiting time.
Interruption is disabled during interrupt program execution. Therefore,
if the constant scan time is reached during interrupt program
execution, the constant scan cannot be finished unless the interrupt
program ends.
When the interrupt program is used, the constant scan time may delay
by the interrupt program execution time.
REMARK
Refer to "QCPU (Q mode)/QnACPU Programming Manual (Common Instructions)"
for the command processing time.
MELSEC-Q
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