unit Unit6;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, IdBaseComponent, IdComponent, IdUDPBase, IdUDPClient;

type
  TForm1 = class(TForm)
    IdUDPClient1: TIdUDPClient;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  IdUDPClient1.Send('GO');
  ShowMessage(IdUDPClient1.ReceiveString(500));
end;

end.