P4026¶

Code: P4026
Message: Function call argument type does not match parameter type

This error occurs when a function call passes an argument whose type does not match the declared parameter type. IronPLC allows implicit widening between integer types (for example, INT to DINT), but rejects other type mismatches such as integer to real or narrowing conversions.

For the full set of allowed implicit conversions, see Type Conversions.

Example¶

The following code will generate error P4026:

FUNCTION DOUBLE_REAL : REAL
VAR_INPUT
    A : REAL;
END_VAR
    DOUBLE_REAL := A + A;
END_FUNCTION

PROGRAM main
VAR
    result : REAL;
    x : INT;
END_VAR
    result := DOUBLE_REAL(x);  (* Error: INT argument for REAL parameter *)
END_PROGRAM

The variable x is INT, but parameter A expects REAL.

To fix this error, use an explicit type conversion:

result := DOUBLE_REAL(INT_TO_REAL(x));