update

hash_sender.py

@@ -38,7 +38,6 @@ async def create_node_hierarchy(client, node_objects):
 async def get_send_hash(ENDPOINT,NAMESPACE,server_hash_udp_ip,server_hash_udp_port):
     global nm_no
     serverAddressPort = (server_hash_udp_ip, server_hash_udp_port)
-    bufferSize = 1024
     UDPClientSocket = socket.socket(family=socket.AF_INET, type=socket.SOCK_DGRAM)
     async with Client(url=ENDPOINT) as client:
         nm_no=await client.get_namespace_index(NAMESPACE)

opcua-transmitter.py

@@ -60,19 +60,22 @@ async def get_nodes(client,node_objects):
 
 async def main() -> None:
     global nm_no
-    async with Client(url=ENDPOINT) as client:
-        nm_no = str(await client.get_namespace_index(NAMESPACE))
-        object_root_node = client.get_objects_node()
-        objects = await object_root_node.get_children()
-        node = await get_nodes(client,objects)
-        t1=threading.Thread(target=hash_sender.send_hash,args=(ENDPOINT,NAMESPACE,server_hash_udp_ip,server_hash_udp_port,))
-        t1.start()
-        handler = MyHandler()
-        subscription = await client.create_subscription(period=0, handler=handler)
-        await subscription.subscribe_data_change(node)
-        while True:
-            await handler.process()
-            await asyncio.sleep(0.01)
+    try:
+        async with Client(url=ENDPOINT) as client:
+            nm_no = str(await client.get_namespace_index(NAMESPACE))
+            object_root_node = client.get_objects_node()
+            objects = await object_root_node.get_children()
+            node = await get_nodes(client,objects)
+            t1=threading.Thread(target=hash_sender.send_hash,args=(ENDPOINT,NAMESPACE,server_hash_udp_ip,server_hash_udp_port,))
+            t1.start()
+            handler = MyHandler()
+            subscription = await client.create_subscription(period=0, handler=handler)
+            await subscription.subscribe_data_change(node)
+            while True:
+                await handler.process()
+                await asyncio.sleep(0.01)
+    except:
+        print("No connection found for opcua server, check if the server is active")
 
 if __name__ == '__main__':
     asyncio.run(main())