Hello,

The Client code shows that you’re attempting to read the value of some Attribute of Node with the specified NodeId (ns=3,85/0:Simulation). If the Server you’re testing with is the SampleConsoleServer sample application and not some other Server using that similar connection address, then there won’t be a Node with such NodeId in its AddressSpace and the read operation will fail with StatusCode Bad_NodeIdUnkown.

1) For SampleConsoleServer, you can add a Node by entering “a” to command line interface and then deciding a name that will be used as the new Node’s DisplayName and BrowseName. The created Node is added under MyObjects folder and it will be a Property Variable Node. Its NodeId will be of GUID type and the identifier is generated by the application automatically when the Node is created.

If you need the command line interface to support more options when adding Nodes, you will have to implement that yourself. You can use MyNodeManager’s addNode(String name) method as an example of how to add Nodes to the AddressSpace.

2) For sample code on reading and writing, see the read(NodeId nodeId) and write(NodeId nodeId) methods of the SampleConsoleClient sample application found in samples folder of the SDK distribution.

Hello,

The GUID for the created Node is generated when the Node is created. If you restart the SampleConsoleServer application and create the Node again, it will have a different NodeId as a new GUID is generated. What exactly are you trying to do by adding new Nodes to SampleConsoleServer?

1) I’m not sure what you mean with “read value added nodeID” but you can read the NodeId Attribute of the added Node by entering 1 and the Value Attribute by entering 13.

2) Newly added Nodes will not have any initial Values. The DataType of the Node is BaseDataType so any Value can be written to the Node.

Hello,

The DataType of the created Node is BaseDataType. This is the abstract “root” DataType which means that the Node will accept a Value of any DataType. However, SampleConsoleClient is attempting to convert the String entered via the command line to a proper Java class, which is failing since there is no Java class that corresponds to BaseDataType.

To write a Value to such Node, you must call writeAttribute(NodeId nodeId, UnsignedInteger attributeId, Object value, boolean autoConvert) method of UaClient class in write(NodeId nodeId) method of SampleConsoleClient with autoConvert set to false instead of true. On the other hand, autoConvert must be true if you’re attempting to write Values to Variables with other DataTypes and the method needs to convert Strings entered via the command line to proper Java classes.

Though, in a real Client you would probably be using proper Java classes for the values instead of using only Strings. SampleConsoleClient and SampleConsoleServer are just simplified samples that don’t consider all real world scenarios that might require more specific handling.

But why are you testing your Client with a created Node when there already are plenty of Nodes with non-abstract DataTypes in the SampleConsoleServer’s AddressSpace?

Hello,

AutoConvert is not a flag, it is a parameter of writeAttribute(NodeId nodeId, UnsignedInteger attributeId, Object value, boolean autoConvert) method of UaClient class. See write(NodeId nodeId) method of SampleConsoleClient class for an example of using this method with autoConvert parameter set to true:

boolean status = client.writeAttribute(nodeId, attributeId, value, true);

Variables with DataTypes that support conversion from String to the matching JavaClass can be written to using SampleConsoleClient. We do not have an exact list of such DataTypes so you will have to see for yourself which Variables support reading and writing. And as I said before, a proper Client application wouldn’t be working with only Strings since converting them to Structures or Arrays would be very inconvenient. The writing mechanism of SampleConsoleClient is simply intended to demonstrate how writing is done in OPC UA.

For monitoring Variables for data changes with Subscriptions and MonitoredItems, see subscribe(NodeId nodeId) method of SampleConsoleClient class. For more information, see the Client tutorial in tutorial folder of the SDK distribution.