Attention

IronPLC can only run very simple programs. The steps described are accurate but many language features are not yet supported.

P4002

Code

P4002

Message

Function invocation assigns named (formal) input that is not defined

This error occurs when a function block invocation assigns a named (formal) input that is not defined in the function block.

Example

The following code will generate error P4002:

FUNCTION_BLOCK Callee
VAR_INPUT
    Input1: BOOL;
END_VAR
END_FUNCTION_BLOCK

FUNCTION_BLOCK Caller
VAR
    FbInstance : Callee;
END_VAR
FbInstance(InvalidInput := TRUE);  (* Error: InvalidInput not defined *)
END_FUNCTION_BLOCK

The function block invocation references InvalidInput which is not defined in the Callee function block.

To fix this error, use only the defined input names:

FUNCTION_BLOCK Callee
VAR_INPUT
    Input1: BOOL;
END_VAR
END_FUNCTION_BLOCK

FUNCTION_BLOCK Caller
VAR
    FbInstance : Callee;
END_VAR
FbInstance(Input1 := TRUE);  (* Correct: Input1 is defined *)
END_FUNCTION_BLOCK