add sample on instantiating objects from imported nodesets into a server

examples/server-woodworking.py

+# Sample on instantiating objects from imported nodesets into a server
+
+import os.path
+import asyncio
+import logging
+import random
+from asyncua import ua, Server
+from asyncua.common.instantiate_util import instantiate 
+
+
+class HelloServer:
+    def __init__(self, endpoint, name, model_filepath):
+        self.server = Server()
+
+        self.model_filepath = model_filepath
+        self.server.set_server_name(name)
+        self.server.set_endpoint(endpoint)
+
+    async def init(self):
+        await self.server.init()
+
+        #  This need to be imported at the start or else it will overwrite the data
+        await self.server.import_xml(os.path.join(self.model_filepath, "../nodeset/DI/Opc.Ua.Di.NodeSet2.xml"))
+        await self.server.import_xml(os.path.join(self.model_filepath, "../nodeset/Machinery/Opc.Ua.Machinery.NodeSet2.xml"))
+        await self.server.import_xml(os.path.join(self.model_filepath, "../nodeset/Woodworking/Opc.Ua.Woodworking.NodeSet2.xml"))
+
+        # instantiate mandatory objects in server
+        self.device = await instantiate(await self.server.nodes.objects.get_child('3:Machines'),
+                                        await self.server.nodes.base_object_type.get_child('4:WwMachineType'),
+                                        bname = 'test_Server_OPC_UA',
+                                        dname = ua.LocalizedText('Planing Machine'),
+                                        idx = 4, instantiate_optional = False)
+
+
+        # write values to mandatory nodes
+        await self.server.get_node('ns=4;i=7821').write_value('ProfilingMachine') #DeviceClass
+        await self.server.get_node('ns=4;i=7822').write_value(ua.LocalizedText("Manufacturer Name", "de_CH")) #Manufacturer
+        await self.server.get_node('ns=4;i=7823').write_value(ua.LocalizedText("Machine Model", "de_CH")) #Model
+        await self.server.get_node('ns=4;i=7824').write_value('Product_Instance_Uri') #ProductInstanceUri
+        await self.server.get_node('ns=4;i=7825').write_value('422111516848641789') #SerialNumber
+        await self.server.get_node('ns=4;i=7826').write_value(ua.Variant(1972, ua.VariantType.UInt16)) #YearOfConstruction
+
+    async def __aenter__(self):
+        await self.init()
+        await self.server.start()
+        return self.server
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb):
+        await self.server.stop()
+
+
+async def main():
+    script_dir = os.path.dirname(__file__)
+    async with HelloServer(
+        "opc.tcp://0.0.0.0:4840",
+        "FreeOpcUa Example Server",
+        script_dir,
+    ) as server:
+        
+        while True:
+            await asyncio.sleep(1)  
+            a, b = random.randint(0,5), random.randint(0,4)
+            # Update variables
+            await server.get_node('ns=4;i=7830').write_value(a) #CurrentMode
+            await server.get_node('ns=4;i=7831').write_value(b) #CurrentState
+            await asyncio.sleep(5)
+            
+
+
+if __name__ == "__main__":
+    logging.basicConfig(level=logging.INFO)
+    asyncio.run(main())
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