参考链接Question about Python OPCUA session timeout and client.import asyncio, json from asyncua import Client, ua, Node from asyncua.common.events import Event from datetime import datetime #################################################################################### # Globals: #################################################################################### # OPC UA Client server_url opc.tcp://192.168.10.1:4840 nodes_to_subscribe [ #node-id ns4;i1000, ns0;i2267, ns0;i2259, ] events_to_subscribe [ #(eventtype-node-id, event-node-id) ] #################################################################################### # OpcUaClient: #################################################################################### class SubscriptionHandler: The SubscriptionHandler is used to handle the data that is received for the subscription. def datachange_notification(self, node: Node, val, data): Callback for asyncua Subscription. This method will be called when the Client received a data change message from the Server. print(node, val, data) def event_notification(self, event: Event): called for every event notification from server print(event) def status_change_notification(self, status): called for every status change notification from server print(status) async def opcua_client(): -handles connect/disconnect/reconnect/subscribe/unsubscribe -connection-monitoring with cyclic read of the service-level client Client(urlserver_url) handler SubscriptionHandler() subscription None case 0 subscription_handle_list [] while 1: if case 1: #connect print(connecting...) try: await client.connect() await client.load_type_definitions() print(connected!) case 2 except: print(connection error!) case 1 await asyncio.sleep(5) elif case 2: #subscribe all nodes and events print(subscribing nodes and events...) try: subscription await client.create_subscription(50, handler) subscription_handle_list [] if nodes_to_subscribe: for node in nodes_to_subscribe: handle await subscription.subscribe_data_change(client.get_node(node)) subscription_handle_list.append(handle) if events_to_subscribe: for event in events_to_subscribe: handle await subscription.subscribe_events(event[0], event[1]) subscription_handle_list.append(handle) print(subscribed!) case 3 except: print(subscription error) case 4 await asyncio.sleep(0) elif case 3: #running read cyclic the service level if it fails disconnect and unsubscribe wait 5s connect try: service_level await client.get_node(ns0;i2267).get_value() if service_level 200: case 3 else: case 4 await asyncio.sleep(5) except: case 4 elif case 4: #disconnect clean unsubscribe, delete subscription then disconnect print(unsubscribing...) try: if subscription_handle_list: for handle in subscription_handle_list: await subscription.unsubscribe(handle) await subscription.delete() print(unsubscribed!) except: print(unsubscribing error!) subscription None subscription_handle_list [] await asyncio.sleep(0) print(disconnecting...) try: await client.disconnect() except: print(disconnection error!) case 0 else: #wait case 1 await asyncio.sleep(5) #################################################################################### # Run: #################################################################################### if __name__ __main__: asyncio.ensure_future(opcua_client()) asyncio.get_event_loop().run_forever()
