def parse_response_adu(resp_adu, req_adu=None):
    """ Parse response ADU and return response data. Some functions require
    request ADU to fully understand request ADU.

    :param resp_adu: Resonse ADU.
    :param req_adu: Request ADU, default None.
    :return: Response data.
    """
    resp_pdu = resp_adu[1:-2]
    validate_crc(resp_adu)

    req_pdu = None

    if req_adu is not None:
        req_pdu = req_adu[1:-2]

    function = create_function_from_response_pdu(resp_pdu, req_pdu)

    return function.data
Parse response ADU and return response data. Some functions require
    request ADU to fully understand request ADU.

    :param resp_adu: Resonse ADU.
    :param req_adu: Request ADU, default None.
    :return: Response data.