char Command[] = "READ\r";
...
Overlap.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!WriteFile(hCom, Command,  5 , &NumberByte, &Overlap))
{	dWaitRes = WaitForSingleObject(Overlap.hEvent, TIMEOUT);
	switch (dWaitRes)
	{	case WAIT_OBJECT_0:	if(!GetOverlappedResult(hCom, &Overlap, &dWrite, FALSE))
						MessageBox(GetActiveWindow(), "Ошибка выполения операции записи.","Ошибка", MB_OK | MB_ICONERROR);
					else
						std::cout << "Write Ok!" << std::endl;
					break;
		case WAIT_TIMEOUT:	MessageBox(GetActiveWindow(), "Вылет по таймауту!", "Внимание", MB_OK | MB_ICONINFORMATION);
					goto lEnd;
					break;
		default: break;
	}
}
...