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
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(); --> SA0160: Recursive call detected: 'PLC_PRG -> FB_Test.Call -> FB_Test.Call