socket.error: [Errno 111] Connection refused [closed]

edit

i am the noob with the socket command ,i don't know where the problem happen. The forum just said that there are some different problem with the errno 111. but i don't know which problem cause this happen. Thank you first if anyone met this problem before. i use the nmea_navsat_driver package, because i want to use GPS cotroll my robot moving.

$ rosrun nmea_navsat_driver nmea_topic_serial_reader _port:=/dev/ttyACM0 _baud:=9600 
Traceback (most recent call last):
  File "/home/gordonlin/robot/src/nmea_navsat_driver-master/scripts/nmea_topic_serial_reader", line 38, in <module>
    libnmea_navsat_driver.nodes.nmea_topic_serial_reader.main()
  File "/home/gordonlin/robot/src/nmea_navsat_driver-master/src/libnmea_navsat_driver/nodes/nmea_topic_serial_reader.py", line 59, in main
    rospy.init_node('nmea_topic_serial_reader')
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/client.py", line 326, in init_node
    _init_node_params(argv, name)
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/client.py", line 186, in _init_node_params
    set_param(rosgraph.names.PRIV_NAME + param_name, param_value)
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/client.py", line 539, in set_param
    _param_server[param_name] = param_value #MasterProxy does all the magic for us
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/msproxy.py", line 136, in __setitem__
    self.target.setParam(rospy.names.get_caller_id(), resolved_key, val)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1243, in __call__
    return self.__send(self.__name, args)
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/core.py", line 670, in _ServerProxy__request
    self, methodname, params)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1602, in __request
    verbose=self.__verbose
  File "/usr/lib/python2.7/xmlrpclib.py", line 1283, in request
    return self.single_request(host, handler, request_body, verbose)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1311, in single_request
    self.send_content(h, request_body)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1459, in send_content
    connection.endheaders(request_body)
  File "/usr/lib/python2.7/httplib.py", line 1095, in endheaders
    self._send_output(message_body)
  File "/usr/lib/python2.7/httplib.py", line 898, in _send_output
    self.send(msg)
  File "/usr/lib/python2.7/httplib.py", line 860, in send
    self.connect()
  File "/usr/lib/python2.7/httplib.py", line 837, in connect
    self.timeout, self.source_address)
  File "/usr/lib/python2.7/socket.py", line 575, in create_connection
    raise err
socket.error: [Errno 111] Connection refused