def is_io_control(controldesc):
    """ Check if the control description is attached to the pipeline
    inputs/outputs.

    A pbox input/output control is specified as '<pbox_control>' while a
    pbox inner box control is specified as '<box_name>.<box_control_name>'.

    Parameters
    ----------
    controldesc: string (mandatory)
        a control description.

    Returns
    -------
    is_pbox_control: bool
        True if a pbox input/output control is detected.
    """
    if '.' not in controldesc:
        return True
    else:
        return False
