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  • 基于python使用opcua通信

    官方文档


     例子:

      Server: https://github.com/FreeOpcUa/python-opcua/blob/master/examples/server-minimal.py

     1 import sys
     2 sys.path.insert(0, "..")
     3 import time
     4 
     5 
     6 from opcua import ua, Server
     7 
     8 
     9 if __name__ == "__main__":
    10 
    11     # setup our server
    12     server = Server()
    13     server.set_endpoint("opc.tcp://0.0.0.0:4840/freeopcua/server/")
    14 
    15     # setup our own namespace, not really necessary but should as spec
    16     uri = "http://examples.freeopcua.github.io"
    17     idx = server.register_namespace(uri)
    18 
    19     # get Objects node, this is where we should put our nodes
    20     objects = server.get_objects_node()
    21 
    22     # populating our address space
    23     myobj = objects.add_object(idx, "MyObject")
    24     myvar = myobj.add_variable(idx, "MyVariable", 6.7)
    25     myvar.set_writable()    # Set MyVariable to be writable by clients
    26 
    27     # starting!
    28     server.start()
    29     
    30     try:
    31         count = 0
    32         while True:
    33             time.sleep(1)
    34             count += 0.1
    35             myvar.set_value(count)
    36     finally:
    37         #close connection, remove subcsriptions, etc
    38         server.stop()

      Client: https://github.com/FreeOpcUa/python-opcua/blob/master/examples/client-minimal.py

     1 import sys
     2 sys.path.insert(0, "..")
     3 
     4 
     5 from opcua import Client
     6 
     7 
     8 if __name__ == "__main__":
     9 
    10     client = Client("opc.tcp://localhost:4840/freeopcua/server/")
    11     # client = Client("opc.tcp://admin@localhost:4840/freeopcua/server/") #connect using a user
    12     try:
    13         client.connect()
    14 
    15         # Client has a few methods to get proxy to UA nodes that should always be in address space such as Root or Objects
    16         root = client.get_root_node()
    17         print("Objects node is: ", root)
    18 
    19         # Node objects have methods to read and write node attributes as well as browse or populate address space
    20         print("Children of root are: ", root.get_children())
    21 
    22         # get a specific node knowing its node id
    23         #var = client.get_node(ua.NodeId(1002, 2))
    24         #var = client.get_node("ns=3;i=2002")
    25         #print(var)
    26         #var.get_data_value() # get value of node as a DataValue object
    27         #var.get_value() # get value of node as a python builtin
    28         #var.set_value(ua.Variant([23], ua.VariantType.Int64)) #set node value using explicit data type
    29         #var.set_value(3.9) # set node value using implicit data type
    30 
    31         # Now getting a variable node using its browse path
    32         myvar = root.get_child(["0:Objects", "2:MyObject", "2:MyVariable"])
    33         obj = root.get_child(["0:Objects", "2:MyObject"])
    34         print("myvar is: ", myvar)
    35         print("myobj is: ", obj)
    36 
    37         # Stacked myvar access
    38         # print("myvar is: ", root.get_children()[0].get_children()[1].get_variables()[0].get_value())
    39 
    40     finally:
    41         client.disconnect()
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  • 原文地址:https://www.cnblogs.com/Pio-GD/p/14319555.html
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