1 FUNCTION_BLOCK DELAY    (* N-sample delay *)

     2   VAR_INPUT

     3     RUN : BOOL ;     (* 1 = run, 0 = reset *)

     4     XIN : REAL ;

     5     N   : INT        (* 0 <= N < 128 or manufacturer- *)

     6   END_VAR            (*      specified maximum value  *)

     7   VAR_OUTPUT XOUT : REAL; END_VAR   (* Delayed output *)

     8   VAR X : ARRAY [0..127]     (* N-Element queue *)

     9                OF REAL;      (* with FIFO discipline *)

    10       I, IXIN, IXOUT : INT := 0;

    11   END_VAR

    12   IF RUN THEN IXIN := MOD(IXIN + 1, 128) ; X[IXIN] := XIN ;

    13               IXOUT := MOD(IXOUT + 1, 128) ; XOUT := X[IXOUT];

    14   ELSE XOUT := XIN ; IXIN := N ; IXOUT := 0;

    15        FOR I := 0 TO N DO X[I] := XIN; END_FOR;

    16   END_IF ;

    17 END_FUNCTION_BLOCK

    18