Mitsubishi MELSEC QS Series, User Manual

Page: 41 / 264

3
SEQUENCE PROGRAM EXECUTION
3.1 Sequence Program
3.1.2 Sequence program operation
3
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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.
(1) Execution operation 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.
Diagram 3.4 Comparison between ladder mode and list mode
Diagram 3.5 Sequence program
X100 X101 X105 X106 X107
X102 X103
X104
0
10
[Ladder mode]
From left to right
From top
to bottom
1) to 11) indicate operation order of
sequence program.
1) 2)
3)
6)
4)
5)
7) 8) 9)
10)
11)
END
Y110
END
END
Sequence
program
Step 0
END
processing
Indicates execution of program.