A problem with calling a method in another method

So here it is:

A method that works well, when i click manually on the button(It opens the door):

procedure TForm1.Button3Click(Sender: TObject);
begin
  try
    Screen.Cursor := crHourGlass;
    try
      intf.ExecuteControllerCommand(162, 1); //<--- THIS IS THE METHOD IM TALKING ABOUT
    finally
      Beep();
      Screen.Cursor := crDefault;
    end;
  except
    on e: Exception do
      HandleException(e);
  end;
end;

However, when I want to call the above mentioned method in some procedure event a exception is thrown(its about the possibility of door opening - it doesn't open the door):

procedure TForm1.HandlerOnMonitoringEvent(ASender: TObject;
                                date: TDateTime; time: TDateTime; networkID: Integer;
                                readerID: Integer; userID: Integer; groupID: Integer;
                                eventCode: Integer; zoneID: Integer; TandAID: Integer;
                                const strEvent: WideString; const strAccessPoint: WideString;
                                const strUserSource: WideString; const strGroup: WideString;
                                const strNetwork: WideString; const strZone: WideString;
                 开发者_StackOverflow中文版               const strTandAMode: WideString);
begin
  ListBox1.Items.Add(DateToStr(date) + ' ' + TimeToStr(time) + '; ' + strEvent +
    '; ' + strAccessPoint + '; ' + strUserSource + '; ' + strGroup + '; ' + strNetwork +
    '; ' + strZone + '; ' + strTandAMode);
  try
    Screen.Cursor := crHourGlass;
    try
      intf.ExecuteControllerCommand(162, 1); //<--- THIS IS THE METHOD
    finally
      Beep();
      Screen.Cursor := crDefault;
    end;
  except
    on e: Exception do
      HandleException(e);
  end;
end;

Moreover, when I try to call the button click from procedure event(in this procedure above):

Form1.Button3Click(Button3);

it throws the same exception! I repeat: with manually clicked button everything is alright. What is the problem?!

intf is an instance of IPRMasterAutomation class. Its initialized ALWAYS(100% sure) in another procedure as follows: intf := CoPRMasterAutomation.Create().

I have found something that might be a tip: intf is connected to prma. prma is an instance of TPRMasterAutomation. The procedure event(after prma initialization is declared like this: prma.OnMonitoringEvent := HandlerOnMonitoringEvent(event from the first post);

then connnection: prma.ConnectTo(intf);