Compiler Warning C0441

Message: Access to uninitialized VAR_IN_OUT variable

Possible error cause: A VAR_IN_OUT variable is used as the initial value of another variable declaration.

Error correction: Remove the initial value and assign the value to the variable in the implementation part.

Example of the warning:

FUNCTION_BLOCK POU
VAR_INPUT
      i:INT;
END_VAR
VAR_OUTPUT
      b:BOOL := a[i];
END_VAR
VAR_IN_OUT
      a:ARRAY [1..5] OF BOOL;
END_VAR

The initial value of the variable b produces the following warning.

Message:

C0441: Access to uninitialized VAR_IN_OUT variable