unit SerialPortInterface; interface uses // VCL Windows, // This SerialParams; type { ISerialPort } ISerialPort = interface ['{50958146-2F13-47BA-A3C9-B29FC7F59B9C}'] procedure Close; function Opened: Boolean; function GetRxData: string; function GetTxData: string; function GetParams: TSerialParams; procedure ShowProperties(ParentWnd: HWND); procedure Open(const Params: TSerialParams); function SendCommand(const Data: string): string; property RxData: string read GetRxData; property TxData: string read GetTxData; property Params: TSerialParams read GetParams; end; implementation end.