Python访问OPCUA服务器,订阅一个变量标签方式

from opcua import Client
from opcua import ua
import time
#By Weloveut:Python访问OPCUA服务器，展示get变量的方法和注册逢变触发的回调函数
#自定义回调函数
class SubHandler(object):
	def data_change(self, handle, node, val, attr):
		print("Python: New data change event", handle, node, val, attr)
#创建UA的客户端，包含IP地址和端口号
client = Client("opc.tcp://172.32.1.82:4840/")
#建立到服务器连接
client.connect()
#获取object对象
objects = client.get_objects_node()
#获取根对象
root = client.get_root_node()
#依据变量地址创建变量对象
myvar = client.get_node('ns=3;s="clocl0.5hz"."tags"[0]')
#获取变量当前值
valuetmp=myvar.get_value()
print(valuetmp)
#注册到服务器的变量订阅，变量逢变触发
handler = SubHandler()
sub = client.create_subscription(500, handler)
sub.subscribe_data_change(myvar)
time.sleep(100000)
client.disconnect()

endpoint = "opc.tcp://{}:{}".format(url, port)
myserver.set_endpoint(endpoint)

myserver = opcua.Server()

objects = myserver.get_objects_node()

addspace = myserver.register_namespace(name)

root = myserver.get_root_node()

objects.add_method(1, "Conveyor", Start_Conveyor_prog)

myclient = Client(endpoint)

myclient.get_node("ns=2;i=3")

Start_Lathe_Prog1 = method[4] 

Workpiece = objects_node.call_method(Start_Conveyor_prog,[WorkpieceID.get_value()])

return_value_kuka_prog1 = objects_node.call_method(Start_Kuka_Prog1)

import opcua
from time import sleep
from random import randint
from datetime import datetime
 
# Assign endpoint URL
url = "localhost"
port = 5001
endpoint = "opc.tcp://{}:{}".format(url, port)
 
# create instance/object of type opcua.Server
myserver = opcua.Server()
 
# Assign endpoint url on the OPC UA server address space
myserver.set_endpoint(endpoint)
 
# Create a name for OPC UA namespace
name = "Temperature Sensor"
 
# Register the name on OPC UA namespace
addspace = myserver.register_namespace(name)
 
# Get reference to the Objects node of the OPC UA server
objects = myserver.get_objects_node()
 
# Create objects on the object node
param = objects.add_object(addspace, "parameters")
 
# Create variables
Sensor_name = param.add_variable(addspace, "Sensor Name", "Temperature_Sensor_SF12")
Temperature = param.add_variable(addspace, "Temperature Value", 'NA')
 
# Set variable as writable
Sensor_name.set_writable()
Temperature.set_writable()
 
#########################################################################################
# Present the data structure of the OPC UA server
root = myserver.get_root_node()
print("Root Node Id: %s" % root)
print("Children of root are: %s" % root.get_children())
print()
 
my_objects = myserver.get_objects_node()
print("Defined object Node Id: %s" % my_objects)
print("Children of the defined object are: %s" % my_objects.get_children())
print()
 
sensor_name_node = my_objects.get_children()[1].get_children()[0]
print("Sensor name node Id: %s" % sensor_name_node)
print("Sensor name node browse name: %s" % sensor_name_node.get_browse_name())
print("Sensor name default value: %s" % sensor_name_node.get_value())
print()
 
temperature_node = my_objects.get_children()[1].get_children()[1]
print("Temperature node Id: %s" % temperature_node)
print("Temperature node browse name: %s" % temperature_node.get_browse_name())
print("Temperature default value: %s" % temperature_node.get_value())
print()
########################################################################################
 
# starting! The server will continue running
myserver.start()
current_time = str(datetime.now().time())[:-7]
print("{} - Server is initialising...".format(current_time))
 
while True:
    sleep(5)
    current_time = str(datetime.now().time())[:-7]
    current_temp = randint(10, 25)
 
    Temperature.set_value(current_temp)  # publish temperature value
    print("{} - Current temperature: {} Celsius".format(current_time, current_temp))

from opcua import Client
from datetime import datetime
 
# Assign endpoint URL
url = "localhost"
port = 5001
endpoint = "opc.tcp://{}:{}".format(url, port)
 
# Assign endpoint url on the OPC UA client  address space
myclient = Client(endpoint)
 
# Connect to server
myclient.connect()
 
# Assign nodes
Temperature_node = myclient.get_node("ns=2;i=3")
 
# Subhandler Class from OPC UA
class SubHandler(object):
    """
    Subscription Handler. To receive events from server for a subscription
    """
 
    def datachange_notification(self, node, val, data):
        """
        called for every datachange notification from server
        """
        global DataChange  # Global variable
        current_time = str(datetime.now().time())[:-7]
        DataChange = val  # Assigning value to global variable
        print("{} - Received temperature: {} Celsius".format(current_time, val))
 
    # Initailise variable
 
 
nodes = myclient.get_objects_node()
DataChange = "null"
 
# Create Sub handler
handler = SubHandler()
 
# create subscription by passing period in milliseconds and handler
subscribe = myclient.create_subscription(0, handler)
 
# pass variable node to subscribe data change method
handler = subscribe.subscribe_data_change(Temperature_node)