PROGRAM STEROWANIE
VAR_EXTERNAL (*$AUTO*)
END_VAR
VAR
    DirUp: BOOL;                      (* Napełnianie / Opróżnianie            *)
END_VAR

(* Program sterowania zbiornikiem *)
IF AUTO THEN
   IF START AND NOT ALM THEN
      IF NOT H1 OR DirUp THEN
         Z1 := TRUE;
         Z3 := FALSE;
         DirUp := TRUE;
      END_IF
      IF H3 OR NOT DirUp THEN
         Z1 := FALSE;
         Z3 := TRUE;
         DirUp := FALSE;
      END_IF
   ELSE
       Z1 := FALSE;
       Z2 := FALSE;
       Z3 := FALSE;
       IF ALM THEN
          AUTO := FALSE;
       END_IF
   END_IF
END_IF

END_PROGRAM