[Katze]

function OpenCOMPort: Boolean; 
var 
  DeviceName: array[0..80] of Char; 
  ComFile: THandle; 
begin 
  StrPCopy(DeviceName, 'COM1:'); 

  ComFile := CreateFile(DeviceName, 
    GENERIC_READ or GENERIC_WRITE, 
    0, 
    nil, 
    OPEN_EXISTING, 
    FILE_ATTRIBUTE_NORMAL, 
    0); 

  if ComFile = INVALID_HANDLE_VALUE then 
    Result := False 
  else 
    Result := True; 
end; 


function SetupCOMPort: Boolean; 
const 
  RxBufferSize = 256; 
  TxBufferSize = 256; 
var 
  DCB: TDCB; 
  Config: string; 
  CommTimeouts: TCommTimeouts; 
  ComFile: THandle;
begin 
  Result := True; 

  if not SetupComm(ComFile, RxBufferSize, TxBufferSize) then 
    Result := False; 

  if not GetCommState(ComFile, DCB) then 
    Result := False; 

  // hier die Baudrate, Parität usw. konfigurieren 
    
  Config := 'baud=9600 parity=n data=8 stop=1'; 

  if not BuildCommDCB(@Config[1], DCB) then 
    Result := False; 

  if not SetCommState(ComFile, DCB) then 
    Result := False; 

  with CommTimeouts do 
  begin 
    ReadIntervalTimeout         := 0; 
    ReadTotalTimeoutMultiplier  := 0; 
    ReadTotalTimeoutConstant    := 1000; 
    WriteTotalTimeoutMultiplier := 0; 
    WriteTotalTimeoutConstant   := 1000; 
  end; 

  if not SetCommTimeouts(ComFile, CommTimeouts) then 
    Result := False; 
end; 



procedure SendText(s: string); 
var 
  BytesWritten: DWORD; 
begin 
  s := s + #13 + #10; 
  WriteFile(ComFile, s[1], Length(s), BytesWritten, nil); 
end; 



procedure ReadText: string; 
var 
  d: array[1..80] of Char; 
  s: string; 
  BytesRead, i: Integer; 
begin 
  Result := ''; 
  if not ReadFile(ComFile, d, SizeOf(d), BytesRead, nil) then 
  begin 
    { Raise an exception } 
  end; 
  s := ''; 
  for i := 1 to BytesRead do s := s + d[i]; 
  Result := s; 
end; 


procedure CloseCOMPort; 
begin 
  CloseHandle(ComFile); 
end;

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- Die Katze