Fehler bei ReadLn(F,xx)

...
Import SysTick, WatchDog, ModBus, I2Cport, SerPort1, SerPort2;
Import TWInet,FAT16_32;
Import RTclock, FlashWrite;
Import BeepPort;

From System Import LongWord, Float, LongInt, Processes;
From ModBus import {MOD_Radio};


Define
      ProcClock      = 16000000;       {Hertz}
      SysTick        = 10,Timer2;                {msec}
      StackSize      = $0040, iData;
      FrameSize      = $0100, iData;
      WatchDog       = msec2000;                       {2048msec}
      Scheduler      = iData;

      FAT16           = MMC_SPI, IData;
      F16_MMCspeed    = standard;       // standard, slow, fast
      F16_FileHandles = 2;
      F16_DirLevels   = 2;
      F16_StrLen      = 80;
...
(*------------------------------------------------------------------*)
(*                                                                  *)
(*------------------------------------------------------------------*)
Function MMC_LoadSim:Boolean;
Var
   F : File Of Text;
   ASCII : String[32];
Begin
    Return(False);
    if F16_FileAssign(F, '', 'VBSim.csv') then
      If F16_FileReset (F) Then
        while not F16_EndOfFile (F) do
          ReadLn (F,ASCII);   // error: fuktion or string or Byte expected
        EndWhile;
        BeepSiren(0, 3);
//        WriteLn(SerOut1,ASCII);
        Return(F16_FileClose(F));
      Else
        Return(False);
      EndIf;
    Else
      Return(False);
    endif;
End;

   F : File Of Text;