Compiler Warning C0516

Message: Should not access internal variable <POU name> of library <library name>

Possible error cause: A library contains a POU with a variable. The visibility of the POU is restricted to this library with the INTERNAL keyword. The variable is accessed from outside of this library.

Error correction: Change the visibility of the POU (for example, remove the INTERNAL keyword) or change the declaration of the variable.

PROGRAM PLC_PRG
VAR
    somevar1 : INT := MyLib.GVL.p.varIn;
END_VAR