SA0042: Usage of different access paths

Function	Determines the usage of different access paths for the same variable.
Reason	Different access to the same element reduces the readability and maintainability of a program. We recommend consistent use of {attribute 'qualified-only'} for libraries, global variable lists and enumerations. This forces fully qualified access.
Importance	Low

Samples:

In the following sample SA0042 is output as error/warning, because the global variable nGlobal is accessed directly and via the GVL namespace, and because the function CONCAT is accessed directly and via the library namespace.

Global variables:

VAR_GLOBAL
    nGlobal   : INT; 
END_VAR

MAIN program:

PROGRAM MAIN
VAR
    sVar      : STRING; 
END_VAR

nGlobal      := INT#2;                              // => SA0042
GVL.nGlobal  := INT#3;                              // => SA0042
 
sVar := CONCAT('ab', 'cd');                         // => SA0042
sVar := Tc2_Standard.CONCAT('ab', 'cd');            // => SA0042