Compiler Warning C0406

Message: The implicit check function '<name of check function>' is hidden by another variable or function. Checks will not be performed! Resolve the conflict and clean the application to use the check function.

Possible error cause: A method of a POU has the same name as an implicit check function.

Error correction: Rename the method or remove the implicit check function.

Example of the warning:

// Automatically generated code: Do not edit
FUNCTION CheckBounds: DINT
VAR_INPUT
      index, lower, upper:DINT;
END_VAR

FUNCTION_BLOCK TestFB
VAR
      a:ARRAY [0..1] OF INT;
      i : INT;
END_VAR
a[i] := i;

METHOD CheckBounds:DINT
VAR_INPUT
      index, lower, upper : DINT;
END_VAR

The array access in the TestFB function block produces the following warning.

Message:

C0406: The implicit check function 'CHECKBOUNDS' is hidden by another variable or function. Checks will not be performed! Resolve the conflict and clean the application to use the check function.