def get_ilo_version(ilo_fw_str):
    """Gets the float value of the firmware version

    Converts a string with major and minor numbers to a float value.

    :param ilo_fw_tup: String containing the major and minor versions
                       of the form <major>.<minor>
    :returns: float value constructed from major and minor numbers.
    """
    if not ilo_fw_str:
        return None
    try:
        major_minor_val = float(ilo_fw_str)
    except Exception:
        return None
    return major_minor_val
