我如何（仅）使用 Eclipse Milo OpcUa 服务器更新 OPC UA 节点的时间戳？

Question

Thanks for reading this post. I am gratefull for every help!

Goal:

I am trying to write a ValueNode with the same value, but different timestamp on an Eclipse Milo OpcUa Server. I'm doing all this with Java 11 and Milo 0.3.7.

I tested it among others with the example in the github project. I modified the function addScalarNodes in the class ExampleNamespace to write the same value with an updated timestamp once a second. Checking the node with UaExpert, the timestamp remains on the same value. Only if I update the value too, the timestamp updates.

private void addScalarNodes(UaFolderNode rootNode) {
        UaFolderNode scalarTypesFolder = new UaFolderNode(
            getNodeContext(),
            newNodeId("HelloWorld/ScalarTypes"),
            newQualifiedName("ScalarTypes"),
            LocalizedText.english("ScalarTypes")
        );

        getNodeManager().addNode(scalarTypesFolder);
        rootNode.addOrganizes(scalarTypesFolder);

        for (Object[] os : STATIC_SCALAR_NODES) {
            String name = (String) os[0];
            NodeId typeId = (NodeId) os[1];
            Variant variant = (Variant) os[2];

            UaVariableNode node = new UaVariableNode.UaVariableNodeBuilder(getNodeContext())
                .setNodeId(newNodeId("HelloWorld/ScalarTypes/" + name))
                .setAccessLevel(ubyte(AccessLevel.getMask(AccessLevel.READ_WRITE)))
                .setUserAccessLevel(ubyte(AccessLevel.getMask(AccessLevel.READ_WRITE)))
                .setBrowseName(newQualifiedName(name))
                .setDisplayName(LocalizedText.english(name))
                .setDataType(typeId)
                .setTypeDefinition(Identifiers.BaseDataVariableType)
                .build();

            node.setValue(new DataValue(variant));

            node.setAttributeDelegate(new ValueLoggingDelegate());

            getNodeManager().addNode(node);
            scalarTypesFolder.addOrganizes(node);

            if (name.equals("Boolean")) {
                Thread t = new Thread(() -> {
                    while (true) {
                        try {
                            Thread.sleep(1000L);
                            node.setValue(new DataValue(new Variant(Boolean.FALSE)));
                            System.out.println(node.getValue().getSourceTime());
                        } catch (InterruptedException e) {
                            Thread.currentThread().interrupt();
                        }
                    }
                });
                t.start();
            }
        }
    }

My Question(s):

1) Is updating the timestamp only allowed in OPC UA specs.

2) How can I achive this with Milo?

Thanks in advance!

EDIT I check the timestamp by active reading:

Server-side writing:

private void handleValueUpdate(Object value, DateTime dateTime) {
        node.setValue(new DataValue(
            new Variant(value),
            StatusCode.GOOD,
            dateTime));
    }

Client-side reading:

VariableNode variableNode = getOpcClient().getAddressSpace().getVariableNode(new NodeId(namespaceIndex, nodeIdentifier)).get();
return variableNode.readValue().get().getSourceTime();

Answer 1

Are you checking by reading (refreshing attributes pane) or with a subscription and monitored item?

If you're using MonitoredItems the default MonitoringFilter when not otherwise specified uses DataChangeTrigger.StatusValue , which includes changes to value or quality, but not timestamp, so most clients will not ask for or receive timestamp-only changes by default.