Problem processing multiple files with dll

Question

I'm using a function in a dll that turns a binary data file into a TSV file with actual numbers.  The function takes three inputs, a pointer to a string for the input file path, a pointer to a string for the file to write and an integer for "integrity check" which as far as I can tell does nothing.  I have the dll in a subvi, pass it a string corresponding to the input file path and let it convert the file.  This works but will only convert the first 254 files then errors out.   The only way I can get it to work again is to close labview completely and reopen it.  My experiment requires the conversion of literally thousands of files so closing and reopening labview gets old real quick.  I have tried creating a reference to the subvi and closing it for each file but this still does not work, I have also tried on windows xp and windows 7.  When the new files are created they have a size of 0 kB and are empty until I close labview then they assume a reasonable size (few kB) and have data in them.  Additionally if I try to delete one of the newly created files while labview is open I get an error saying the file is open in labview.  I can delete the files when labview is closed.  I have also tried opening each file and closing it after the conversion but that does not work either.
I believe this is some sort of file open limitation but I don't know how to get around it, I'm almost to the point of writing one of those mouse move/button click macros nerds use for games to convert the files because this is driving me insane.

Answer 1

I managed to get the c code for the dll (it was somewhere on the computer). I can only pass an integer to validity otherwise it errors, is there an unsighed char in labview?
_declspec (dllexport) int converting(char *filetoRead, char *filetoWrite, unsighed char validity)
FILE *fpin, *fpout;
int result;
int records=0;
int valid=0;
unsigned long MTOFL=0;
unsigned long MT;
struct {unsigned ADC:12;
unsigned INVALID
unsigned MTOV:1;
unsigned GAP:1;
unsigned ZERO:1;
unsigned MTHIGH:
unsigned R:8;
unsigned MTLOW:
} DataRecord;
fpin=fopen(filetoRead,"rb");
fpout=fopen(filetoWrite,"w");
while(1)
result = fread( &DataRecord,
if (result!= 6)
return(0);
records++;
if(DataRecord.MTOV)
MTOFL += (unsign
if(validity==1)
if(DataRecord.INVA
continue; // don't sav
valid++;
MT = (((unsigned long)Data
fprintf(fpout,"%11lu",MTOF
fprintf(fpout,"%5u",DataRec
fprintf(fpout,"%4u",DataRec
fprintf(fpout,"%6u",DataRec
fprintf(fpout,"\n");
fclose(fpin);
fclose(fpout);
return 0;