The FBD editor enables the drawing of LD rungs. A particular object, the "OR" rail can be inserted on a rung in order to connect parallel contacts togetherPress the following button in the FBD toolbar for inserting a new "OR" rail:
rail: In this mode, the mouse is
used for inserting a rail that collects several Boolean data flows
for an OR operation, in order to insert parallel contacts such as
done in Ladder Diagrams.
The "OR" rail has exactly the same meaning as an "OR" block regarding the execution of the diagram.