The INI operator can be used to initialize retain variables which are provided by a function block instance used in the POU.
The operator must be assigned to a boolean variable.
Syntax: <bool-Variable> := INI(<FB-instance, TRUE|FALSE)
If the second parameter of the operator is set to TRUE, all retain variables defined in the function block FB will be initialized.
Example in ST:
fbinst is the instance of function block fb, in which a retain variable retvar is defined.
Declaration in POU:
fbinst:fb; b:bool;
Implementation part:
b := INI(fbinst, TRUE); ivar:=fbinst.retvar (* => retvar gets initialized *)
Example of operator call in FUP:
