Object Oriented Programming¶
IEC 61131-3 Edition 3 (2013) added object-oriented programming to the standard. A function block type can be derived from another by extension, one or more interfaces can describe a shared set of method signatures, and a type can be declared abstract when it is meant to be extended rather than instantiated directly.
This section documents the keywords that introduce these features. For the concepts behind them — inheritance, interfaces, and abstract types — see Object Oriented Programming.
Note
These keywords are recognized only when object-oriented syntax is enabled; otherwise each word is an ordinary identifier. See Enabling Dialects and Features for the flag and dialects reference. IronPLC currently parses this syntax but does not yet perform semantic analysis or code generation for it — see P9999.
Keywords¶
Keyword |
Description |
|---|---|
Derive a function block type or interface from a base type |
|
Declare that a function block type provides one or more interfaces |
|
Mark a function block type as not directly instantiable |
|
Declare an interface — a named set of method signatures |