Attention

These docs are a bit ambitious. The steps described are accurate but IronPLC cannot yet run programs.

P0022¶

This error occurs when a type is referenced that has not been declared.

Example¶

The following code will generate error P0022:

FUNCTION_BLOCK Example
VAR
    MyVar : UndeclaredType;  (* Error: UndeclaredType is not declared *)
END_VAR
END_FUNCTION_BLOCK

The variable MyVar uses the type UndeclaredType which has not been declared anywhere in the program.

To fix this error, declare the type before using it:

TYPE
    MyType : INT;
END_TYPE

FUNCTION_BLOCK Example
VAR
    MyVar : MyType;  (* Correct: MyType is now declared *)
END_VAR
END_FUNCTION_BLOCK