Attention

IronPLC supports IEC 61131-3 Structured Text excluding I/O mapping.

Branches

Branches create parallel and series connections in ladder diagrams, allowing multiple logic paths within a single rung.

IEC 61131-3	Section 3.2
Support	Not yet supported

Description

Parallel branches (OR logic) connect contacts side by side. Power flows if any branch is TRUE:

|    input_a                         |
|---| |---+---( output )---|
|         |                          |
|    input_b                         |
|---| |---+
|                                    |

This is equivalent to output := input_a OR input_b in Structured Text.

Series connections (AND logic) place contacts end to end. Power flows only if all contacts are TRUE:

|    input_a     input_b     output  |
|---| |-------| |---( )---|
|                                    |

This is equivalent to output := input_a AND input_b in Structured Text.

See Also

• Rungs — logic lines

• Contacts — input elements

• Coils — output elements