Connection Refused

Hi,I meet some problem that my pc can't connect with Kasli(V2.0 ). When I used artiq_coremgmt -D 192.168.50.182 log to get the log, the ConnectionRefusedError error occurred. And, when I used artiq_run to run a program, the error also occurred.

Traceback (most recent call last):
  File "/nix/store/2nl0z2rx7ca21w177fb92iw5scdr427j-python3.8-artiq-7.7639.9dee8bb9.beta/bin/.artiq_coremgmt-wrapped", line 9, in <module>
    sys.exit(main())
  File "/nix/store/plhrkjfx84wai17hjy1122ivv3c04i1a-python3-3.8.8-env/lib/python3.8/site-packages/artiq/frontend/artiq_coremgmt.py", line 159, in main
    print(mgmt.get_log(), end="")
  File "/nix/store/plhrkjfx84wai17hjy1122ivv3c04i1a-python3-3.8.8-env/lib/python3.8/site-packages/artiq/coredevice/comm_mgmt.py", line 138, in get_log
    self._write_header(Request.GetLog)
  File "/nix/store/plhrkjfx84wai17hjy1122ivv3c04i1a-python3-3.8.8-env/lib/python3.8/site-packages/artiq/coredevice/comm_mgmt.py", line 87, in _write_header
    self.open()
  File "/nix/store/plhrkjfx84wai17hjy1122ivv3c04i1a-python3-3.8.8-env/lib/python3.8/site-packages/artiq/coredevice/comm_mgmt.py", line 64, in open
    self.socket = initialize_connection(self.host, self.port)
  File "/nix/store/plhrkjfx84wai17hjy1122ivv3c04i1a-python3-3.8.8-env/lib/python3.8/site-packages/artiq/coredevice/comm.py", line 25, in initialize_connection
    sock = socket.create_connection((host, port))
  File "/nix/store/qy5z9gcld7dljm4i5hj3z8a9l6p37y81-python3-3.8.8/lib/python3.8/socket.py", line 808, in create_connection
    raise err
  File "/nix/store/qy5z9gcld7dljm4i5hj3z8a9l6p37y81-python3-3.8.8/lib/python3.8/socket.py", line 796, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [Errno 111] Connection refused

The IP address is right and I can ping the address.