Safety Semantic Error: The defined FB instance '...' is never used.
An FB instance is declared in the variables table of a safety-related POU but not called in the code. Any declared FB instance must be inserted into a safety-related code network.
Remedy:- Double-click the error in the Error List to jump to the suspected variables table (where the declaration is marked).
- Insert the FB instance into a safety-related code network or delete the instance declaration in the variables table.