Use of ST expressions in graphic language
Expression must be written in ST language. An expression is anything you can imagine between parentheses in a ST program. Obviously the ST expression must fit the data type required by the diagram (e.g. an expression put on a contact must be Boolean).
FBD language:
A complex ST expression can be entered in any "variable box" of a FBD diagram, if the box is not connected on its input. Below is an example:
FFLD language:
A complex ST expression can be entered on any kind of contact, and on any input of a function or function block. Below is an example: