Skip to main content

SA0160: Recursive calls

Detects recursive calls in actions, methods, and properties of function blocks. Also detects possible recursions from virtual function calls and interface calls.

Justification: Recursions lead to non-deterministic behavior and are therefore a source of errors.

Importance: Medium

PLCopen rule: CP13

Example 118. Example

The following method Call is assigned to the function block FB_Test:

FUNCTION_BLOCK FB_Test
VAR
    bParameter: BOOL;
END_VAR

METHOD Call : BOOL
VAR_INPUT
END_VAR

Call := THIS^.Call();    //SA0160

The program PLC_PRG calls FB_Test:

PROGRAM PLC_PRG
VAR
    fbTest : FB_Test;
    bValue : BOOL;
END_VAR

bValue := fbTest.bParameter;
fbTest.Call();

Output in the Messages view:

  • sa_icon_message.png SA0160: Recursive call detected: 'PLC_PRG' -> 'FB_Test.Call' -> 'FB_Test.Call'



: