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Use Free OPC UA Modeler to edit UANodeSet files

Last updated on September 1, 2020


Edit UANodeSet files with Free OPC UA Modeler.

This Post is part of the OPC UA Information Model Tutorial.


Starting Free OPC UA Modeler

  1. Execute ///C:/WPy64-3760/WinPython Command Prompt.exe
  2. run the modeler for the same command prompt with ..\python-3.7.6.amd64\Scripts\opcua-modeler.exe

Free OPC UA Modeler is now up and running.

Closing Free OPC UA Modeler

Use the window’s close button [X] to end Free OPC UA Modeler. Using menu Actions -> Quit or Actions -> Close Model has seemingly no effect.

Create a new model

Press Actions -> New Model This will

  • introduce the default nodeset Opc.Ua.NodeSet2.xml with its Namespace, Types and Objects to your model
  • start the opcua.server

Import Reference Nodesets (optional)

The default nodeset contains all basic type and object definitions, which can be used to model your own nodeset. Occasionally, you may want to include models of other nodesets, which are already defined. This is the case if you want to edit UANodeSet files that depend on other models. Such nodeset will declare their dependencies in the <Models> section, like so:

	<Models>
		<Model ModelUri="http://br-automation.com/OpcUa/PLC/PV/" PublicationDate="2018-08-29T08:11:18Z" Version="2.00">
			<RequiredModel ModelUri="http://opcfoundation.org/UA/" PublicationDate="2018-05-15T00:00:00Z" Version="1.04"/>
			<RequiredModel ModelUri="http://opcfoundation.org/UA/DI/" PublicationDate="2013-12-02T00:00:00Z" Version="1.01"/>
			<RequiredModel ModelUri="http://PLCopen.org/OpcUa/IEC61131-3/" PublicationDate="2010-03-24T00:00:00Z" Version="2.01"/>
			<RequiredModel ModelUri="http://br-automation.com/OpcUa/PLC/" PublicationDate="2018-01-30T00:00:00Z" Version="2.01"/>
		</Model>
	</Models>

Note: Above snippet is taken from an UANodeSet file that was generated with Automation Studio 4.7.2

To include an additional, 3rd party nodeset use Actions -> Import XML . Alternatively, a right click into the subwindow Node Sets will offer a pop-up menu to Add Reference Node Set. A commonly imported nodeset is Opc.Ua.Di.NodeSet2, which contains Device Integration Objects.

It may be received from several (equally legit) places:

Note: A collection of UANodeSet files is maintained by the OPC Foundation at https://github.com/OPCFoundation/UA-Nodeset

The OPC Foundation uses this repository as part of their official review process!

Note: Pay attention to the Version attributes of the <RequiredModel> elements!

Download those files in their raw XML format to an arbitrary(?) folder. Then use Action -> Import XML with that file. Free OPC UA Modeler will show

  • a new namespace http://opcfoundation.org/UA/DI/
  • additional objects in Root/Objects

Create a custom namespace for your model

OPC UA separates objects and types into different namespaces to avoid naming conflicts. In order to create your own custom types and object, create your own, custom namespace first. right click into the subwindow NamespaceArray and select Add Namespace

Make sure the index of your custom nodeset is 1. The name/value can be selected arbitrarily, but it’s good practice to select an URL.

Note: The OPC Foundation provides relevant files and/or information at the URLs that name their namespaces. Example:

Note: The standard UA nodeset of the OPC Foundation is always indexed at 0. Custom nodeset are always indexed at 1. Many modelers support only index 1 for custom nodesets (implcitly or explicitly).

Editing a model

Following https://github.com/FreeOpcUa/opcua-modeler#creating-custom-structures I seem to be affected by https://github.com/FreeOpcUa/opcua-modeler/issues/86 (because I imported Opc.Ua.Di before).

When adding new types and objects, make sure to always use your custom namespace.

Save a model

Press the Save button. It’s advisable to git diff now and then to verify correctness of the NodeSet.

Loading a model

Free OPC UA Modeler loses referenced NodeSets, so they have to be re-referenced whenever a model is opened.

You will notice a lost reference in the diff of the .uamodel file.

Loading UANodeSet from B&R Automation Studio

I tried to load the UANodeSet from ECU1 of Broadpeak with Free OPC UA Modeler.

Only with the base nodeset -> fails opcua.ua.uaerrors._auto.BadParentNodeIdInvalid: The parent node id does not to refer to a valid node.(BadParentNodeIdInvalid)

uamodeler.model_manager - INFO - Starting server on opc.tcp://0.0.0.0:48400/freeopcua/uamodeler/')
uamodeler.server_manager - INFO - Starting python-opcua server')
opcua.server.server - WARNING - Endpoints other than open requested but private key and certificate are not set.')
opcua.server.binary_server_asyncio - WARNING - Listening on 0.0.0.0:48400')
uamodeler.namespace_widget - INFO - Writting namespace array: ['http://opcfoundation.org/UA/', 'http://foo.com/']')
uamodeler.namespace_widget - INFO - Writting namespace array: ['http://opcfoundation.org/UA/', 'http://foo.com/zebra/flattening']')
uamodeler.model_manager - INFO - Starting server on opc.tcp://0.0.0.0:48400/freeopcua/uamodeler/')
uamodeler.server_manager - INFO - Starting python-opcua server')
opcua.server.server - WARNING - Endpoints other than open requested but private key and certificate are not set.')
opcua.server.binary_server_asyncio - WARNING - Listening on 0.0.0.0:48400')
opcua.common.xmlimporter - WARNING - failure adding node NodeData(nodeid:NumericNodeId(ns=1;i=300000))')
uawidgets.utils - ERROR - The parent node id does not to refer to a valid node.(BadParentNodeIdInvalid)')
Traceback (most recent call last):
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uawidgets\utils.py", line 21, in wrapper
    result = func(self, *args)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\uamodeler.py", line 247, in open
    self._model_mgr.open(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\model_manager.py", line 178, in open
    self.open_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\model_manager.py", line 110, in open_xml
    self._open_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\model_manager.py", line 116, in _open_xml
    path = self.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\model_manager.py", line 99, in import_xml
    new_nodes = self.server_mgr.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\server_manager.py", line 68, in import_xml
    return self._backend.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\server_manager.py", line 112, in import_xml
    return self._server.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\server\server.py", line 469, in import_xml
    return importer.import_xml(path, xmlstring)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 67, in import_xml
    node = self._add_node_data(nodedata)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 86, in _add_node_data
    node = self.add_variable(nodedata)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 221, in add_variable
    res[0].StatusCode.check()
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\ua\uatypes.py", line 233, in check
    raise UaStatusCodeError(self.value)
opcua.ua.uaerrors._auto.BadParentNodeIdInvalid: The parent node id does not to refer to a valid node.(BadParentNodeIdInvalid)
uamodeler.model_manager - INFO - Starting server on opc.tcp://0.0.0.0:48400/freeopcua/uamodeler/')
uamodeler.server_manager - INFO - Starting python-opcua server')
opcua.server.server - WARNING - Endpoints other than open requested but private key and certificate are not set.')
opcua.server.binary_server_asyncio - WARNING - Listening on 0.0.0.0:48400')
opcua.common.xmlimporter - WARNING - failure adding node NodeData(nodeid:NumericNodeId(ns=1;i=300000))')
uawidgets.utils - ERROR - The parent node id does not to refer to a valid node.(BadParentNodeIdInvalid)')
Traceback (most recent call last):
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uawidgets\utils.py", line 21, in wrapper
    result = func(self, *args)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\uamodeler.py", line 260, in import_xml
    self._model_mgr.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\model_manager.py", line 99, in import_xml
    new_nodes = self.server_mgr.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\server_manager.py", line 68, in import_xml
    return self._backend.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\server_manager.py", line 112, in import_xml
    return self._server.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\server\server.py", line 469, in import_xml
    return importer.import_xml(path, xmlstring)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 67, in import_xml
    node = self._add_node_data(nodedata)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 86, in _add_node_data
    node = self.add_variable(nodedata)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 221, in add_variable
    res[0].StatusCode.check()
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\ua\uatypes.py", line 233, in check
    raise UaStatusCodeError(self.value)
opcua.ua.uaerrors._auto.BadParentNodeIdInvalid: The parent node id does not to refer to a valid node.(BadParentNodeIdInvalid)
opcua.server.address_space - WARNING - AddNodesItem: Requested NodeId NumericNodeId(ns=1;i=100) already exists')
opcua.common.xmlimporter - WARNING - failure adding node NodeData(nodeid:NumericNodeId(ns=1;i=100))')
uawidgets.utils - ERROR - The requested node id is already used by another node.(BadNodeIdExists)')
Traceback (most recent call last):
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uawidgets\utils.py", line 21, in wrapper
    result = func(self, *args)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\uamodeler.py", line 260, in import_xml
    self._model_mgr.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\model_manager.py", line 99, in import_xml
    new_nodes = self.server_mgr.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\server_manager.py", line 68, in import_xml
    return self._backend.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\uamodeler\server_manager.py", line 112, in import_xml
    return self._server.import_xml(path)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\server\server.py", line 469, in import_xml
    return importer.import_xml(path, xmlstring)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 67, in import_xml
    node = self._add_node_data(nodedata)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 92, in _add_node_data
    node = self.add_datatype(nodedata)
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\common\xmlimporter.py", line 392, in add_datatype
    res[0].StatusCode.check()
  File "C:\WPy64-3741\python-3.7.4.amd64\lib\site-packages\opcua\ua\uatypes.py", line 233, in check
    raise UaStatusCodeError(self.value)
opcua.ua.uaerrors._auto.BadNodeIdExists: The requested node id is already used by another node.(BadNodeIdExists)

Open Question

  • Where is the default nodeset Opc.Ua.NodeSet2.xml loaded from and what version is it?
  • Where are downloaded 3rd party nodeset saved preferably?
Published inInformation Modeling

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