L2SS-392: Support calling OPC-UA methods.

tangostationcontrol/tangostationcontrol/clients/opcua_client.py

@@ -153,15 +153,18 @@ class OPCUAConnection(AsyncCommClient):
         return read_function, write_function
 
 
-    async def call_method(self, method_path, *args):
-        node = await self.obj.get_child(method_path[:-1])
-        return await node.call_method(method_path[-1], *args)
+    async def _call_method(self, method_path, *args):
+        method_path = self.get_node_path(method_path)
+
+        try:
+            node = await self.obj.get_child(method_path[:-1])
+            result = await node.call_method(method_path[-1], *args)
+        except Exception as e:
+            raise Exception(f"Calling method {method_path} failed") from e
 
 
     def call_method(self, method_path, *args):
-        method_path = self.get_node_path(method_path)
-
-        raise NotImplementedError
+        return asyncio.run_coroutine_threadsafe(self._call_method(method_path, *args), self.event_loop).result()
 
 
 class ProtocolAttribute: