Sequence Program Operation - Mitsubishi MELSEC QS Series User Manual

3
SEQUENCE PROGRAM EXECUTION

3.1.2 Sequence program operation

The CPU module calculates in order from the left to the right side vertical bus and
from top to bottom.
Diagram 3.4 Comparison between ladder mode and list mode
(1) Execution operation of sequence program
Sequence
program
[Ladder mode]
From left to right
1) 2) 7) 8)
X100 X101 X105 X106 X107
0
3) 4)
From top
X102 X103
5)
to bottom
6)
X104
10
1) to 11) indicate operation order of
sequence program.
The sequence program is executed from Step 0 to the END instruction, where
END processing is performed.
After the END processing, the program restarts operation from Step 0.
END
Diagram 3.5 Sequence program
9)
10)
Y110
11)
END
Step 0
Indicates execution of program.
END
END
processing
3.1 Sequence Program
3.1.2 Sequence program operation
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