Hi,
In a later post of myself I asked about getting / setting the RTS line by software control (http://lists.boost.org/boost-users/2010/06/59700.php)
I managed to get working as explained in Windows as replied in by Michael Caisse (http://lists.boost.org/boost-users/2010/06/59723.php) but in linux I'm not being able to get it working.
I can control it in linux by calling ioctl ( ioctl(fd, TIOCMSET, &status) ) but in the set-option I do not have the file descriptor but the termios that I don't completely understand.
Does someone provide me and example to make this 'option'

This is my RTSControl option class:

class RTSControl
{
public:
    explicit RTSControl(bool enable = false) : m_enable(enable) {};
    boost::system::error_code store(BOOST_ASIO_OPTION_STORAGE& storage, boost::system::error_code& ec) const 
    {
        #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
        if (m_enable) storage.fRtsControl = RTS_CONTROL_ENABLE;
        else storage.fRtsControl = RTS_CONTROL_DISABLE;
        #else
        #endif
        return ec;
    };

    boost::system::error_code load(const BOOST_ASIO_OPTION_STORAGE& storage, boost::system::error_code& ec)
    {
        #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
        if (storage.fRtsControl == RTS_CONTROL_ENABLE) m_enable = true;
        else m_enable = true;
        #else
        #endif
        return ec;
    };
private:
    bool m_enable;
};
BOOST_ASIO_OPTION_STORAGE is termios for Linux systems.