SA0013: Declarations with the same variable name

Detects variables with names which are already used by other variables (for example, global and local variables with the same name). Variables are also detected whose names of functions, actions, methods, or properties are used in the same access range. Variables are also detected which are declared in a GVL in the Devices view or in the POUs pool. For this, however, the GVL of the POUs view have to be used in the application program.

Justification: The same names can be confusing when reading the code, and they can cause errors if the wrong object is accessed unintentionally. We recommend that you use naming conventions to avoid these situations.

PLCopen rule: N5 / N9

Importance: Medium

Example 25. Example

VAR_GLOBAL
    xVar1 : BOOL;
    iVar3 : INT;
END_VAR

PROGRAM PLC_PRG
VAR
    xVar1 : BOOL;  // SA0013
    iVar3 : INT;   // SA0013
END_VAR

xVar1 := NOT GVL.xVar1;
iVar3 := iVar3 + INT#2;
iVar3 := GVL.iVar3;

Output in the Messages view:

SA0013: Declaration of 'iVar1' hides symbol 'GVL.iVar1'
SA0013: Declaration of 'xVar3' hides symbol 'GVL.xVar3'

Example 26. Example

The FB_Pou function block has the ACT action, the METH method, and local variables with the same names.

FUNCTION_BLOCK FB_Pou
VAR
    ACT : UINT;  // SA0013
    METH : BYTE; // SA0013
END_VAR

PROGRAM PLC_PRG
VAR
    fbPou : FB_Pou;
END_VAR

fbPou();

Output in the Messages view:

SA0013: Declaration of 'ACT' hides symbol 'FB_Pou.ACT'
SA0013: Declaration of 'METH' hides symbol 'FB_Pou.METH'