[Lazarus] SdpoSerial port open problems

[Bo Berglund]

I have used SdpoSerial as the RS232 handler in a class which is used
in a test application.
In this I create the SdpoSerial component in code in the constructor
of my class like this:

  FComm := TSdpoSerial.Create(NIL);
  case Baud of
    1200: FComm.BaudRate := br__1200;
    2400: FComm.BaudRate := br__2400;
    4800: FComm.BaudRate := br__4800;
    9600: FComm.BaudRate := br__9600;
    19200: FComm.BaudRate := br_19200;
    38400: FComm.BaudRate := br_38400;
    else
      FComm.BaudRate := br_38400;
  end;
  FComm.DataBits := db8bits;
  FComm.Parity := pNone;
  FComm.StopBits := sbOne;
  FComm.FlowControl := fcNone;
  {$IFDEF LINUX}
  FComm.Device:= '/dev/ttyS' + IntToStr(Port-1);
  {$ELSE}
  FComm.Device:= 'COM' + IntToStr(Port);
  {$ENDIF}
  FComm.OnRxData := @OnRxComm;
  FComm.SynSer.Purge;
  FCommTimeout := COMTIMEOUT;

Then I open the port like this:

function TSSComm.Connect: boolean;
begin
  if not FComm.Active then
    FComm.Open;
  if FComm.Active then <== Always true even for bogus port!
    FCommState := csOpen
  else
  begin
    FCommState := csClosed;
    Result := false;
    exit;
  end;
  Result := FCommState = csOpen;
end;

I keep track of various communication states in the FCommState
variable (it is indicating the state in a state machine).

The problem I have is that even though I open a non-existing port the
SdpoSerial does not indicate this. Following the Open method Active is
true even though a completely bogus port number has been given!

Why is this and how can I fix it?
I need to know if the port is actually working or not....



-- 
Bo Berglund
Developer in Sweden