Error in source code FILL Step 7

[Vince]

Hi,

I was unable to use FILL fonction the return string is always empty


in the source code there is the declaration sx and Sx in the code ia it a probleme ?


can anybody explain the code ?? please why 2 loop in this code ??

thanks


I post here the code which works for me with step 7 scl 5.3

FUNCTION FILL : STRING
TITLE = 'FILL'
//version 1.1 17. dec. 2008
//programmer  hugo
//tested by  
//
//the function fill creates a string at length L of characters C.
//
//uses: oscat/String/CHR_TO_STRING (FC227)
//      oscat/Constants/CONSTANTS (DB6)
//      S7/Standard Library/IEC Function Blocks/CONCAT (FC2)
//
VERSION : '1.1'
AUTHOR  : hugo
NAME    : FILL
FAMILY  : STRINGS

VAR_INPUT
    C : BYTE;
    L : INT;
END_VAR

VAR
    tFILL : STRING[254];   <--- 256 byte in L Stack !!!!!!!!!!!!!
    tL : WORD;
    _L AT tL : ARRAY[0..15] OF BOOL;
    i: INT;
    sx: STRING[1];
END_VAR

BEGIN

sx := CHR_TO_STRING(C);
tFILL:='';                                       <---- add this line
(* limit L to maximum 80 characters the length of a standard string *)
tL := INT_TO_WORD(LIMIT(MN:=0,IN:=L,MX:=Constants.STRING_LENGTH));
(* create a string of characters to be connected to str *)
FOR i := 1 TO 8 DO
    tFILL := CONCAT(IN1:=tFILL,IN2:=tFILL);
    IF _L[0] THEN tFILL := CONCAT(IN1:=tFILL,IN2:=sx); END_IF;
    tL := SHL(IN:=tL,N:=1);
END_FOR;

FILL := tFILL;




(* revision histroy
hm  29. mar. 2008   rev 1.0
    original release

hm  17. dec. 2008   rev 1.1
    changed function chr to chr_to_string

*)
END_FUNCTION



this code work on but use more than 256 byte in L stack which is dangerous for most of CPU by default there is 256 byte in L stack

any idea for an other method ??