Ladder Branches And Compilation Results - Mitsubishi Electric MELSEC Q Series Structured Programming Manual

5.2.4

Ladder branches and compilation results

When the ladder is branched, different compilation results are produced for the program after the
branch depending on the program up to the branch.
The following explains the precautions on compilation results depending on ladder branches.
(1) When one contact is used up to the branch, the instruction of the contact is used multiple
times in the compilation result.
< Example >
< Precautions >
When the device in which the value changes during one scan (such as SM412) is used, only
a part of the sequence program after the branch is executed, and the rest of the sequence
program may not be executed.
< Example >
When executing multiple instructions against one contact, connect the instructions in series.
Since the sequence program uses the LD instruction only once in the compilation result, all
sequence programs are executed.
< Example >
< Compile Result >
< Compilation result >
< Compilation result >
5.2 Structured Ladder/FBD
5.2.4 Ladder branches and compilation results
The LD instructions are
created using the contact.
If the value of SM412
changes during one scan,
a part of the program may
not be executed.
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