pip 安装 opcua
pip install opcua
opcua 客户端
from opcua import Client
if __name__ == "__main__":
client = Client("opc.tcp://localhost:4840/freeopcua/server/")
# client = Client("opc.tcp://admin@localhost:4840/freeopcua/server/") #connect using a user
try:
client.connect()
# Client has a few methods to get proxy to UA nodes that should always be in address space such as Root or Objects
root = client.get_root_node()
print("Objects node is: ", root)
# Node objects have methods to read and write node attributes as well as browse or populate address space
print("Children of root are: ", root.get_children())
# get a specific node knowing its node id
#var = client.get_node(ua.NodeId(1002, 2))
#var = client.get_node("ns=3;i=2002")
#print(var)
#var.get_data_value() # get value of node as a DataValue object
#var.get_value() # get value of node as a python builtin
#var.set_value(ua.Variant([23], ua.VariantType.Int64)) #set node value using explicit data type
#var.set_value(3.9) # set node value using implicit data type
# Now getting a variable node using its browse path
myvar = root.get_child(["0:Objects", "2:MyObject", "2:MyVariable"])
obj = root.get_child(["0:Objects", "2:MyObject"])
print("myvar is: ", myvar)
print("myobj is: ", obj)
# Stacked myvar access
# print("myvar is: ", root.get_children()[0].get_children()[1].get_variables()[0].get_value())
finally:
client.disconnect()
opcua 服务端
import sys
sys.path.insert(0, "..")
import time
from opcua import ua, Server
if __name__ == "__main__":
# setup our server
server = Server()
server.set_endpoint("opc.tcp://0.0.0.0:4840/freeopcua/server/")
# setup our own namespace, not really necessary but should as spec
uri = "http://examples.freeopcua.github.io"
idx = server.register_namespace(uri)
# get Objects node, this is where we should put our nodes
objects = server.get_objects_node()
print(objects)
# populating our address space
myobj = objects.add_object(idx, "MyObject")
myvar = myobj.add_variable(idx, "MyVariable", 6.7)
myvar.set_writable() # Set MyVariable to be writable by clients
# starting!
server.start()
try:
count = 0
while True:
time.sleep(1)
count += 0.1
myvar.set_value(count)
finally:
#close connection, remove subcsriptions, etc
server.stop()