Monitoring OpcUa nodes does not work always

Mark81

I'm trying to enable the monitoring of the value of several QpcUa nodes, but I receive the handleAttribute slot only for one.

Here I set up my nodes:

typedef struct
{
    QOpcUaNode *node;
    QVariant value;
    bool updated;
    bool enableRead;
} Node_t;

void MyOpcUa::insertNode(QString key, QString id, bool enableRead)
{
    Node_t node; // my internal struct
    node.node = _opcUaClient->node(id); // the actual OpcUa node
    node.value = QVariant();
    node.updated = false;
    node.enableRead = enableRead;

    Q_ASSERT(node.node); // check the node is valid
    _mapOpcNodes.insert(key, node);
    connect(node.node, &QOpcUaNode::attributeRead, this, &MyOpcUa::handleAttributes);
    connect(node.node, &QOpcUaNode::attributeUpdated, this, &MyOpcUa::handleAttributes);
}

After connection, I enable the monitoring:

void MyOpcUa::enableMonitoring()
{
   QMapIterator<QString, Node_t> i(_mapOpcNodes);
    while (i.hasNext())
    {
        i.next();
        Node_t node = i.value();
        if (node.enableRead)
        {
            qDebug() << node.node->enableMonitoring(QOpcUa::NodeAttribute::Value, QOpcUaMonitoringParameters(1000));
        }
    }
}

all the calls for enableMonitoring() return true.
But, say, I enable the monitoring for 5 nodes, only one is actually read periodically.

All of the nodes are of class variable hence they support monitoring. Furthermore using Qt OPA UA Viewer example application I can monitoring them.

Instead with my application I can monitor only one, the others are not periodically read. Of course I can read them manually.

I don't see any differences among them:

I can monitor only udiActualOrderLengthRT with my application.

Mark81

@Mark81 I tried to check the signal enableMonitoringFinished and I get a success:

void MyOpcUa::enableMonitoringFinished(QOpcUa::NodeAttribute attr, QOpcUa::UaStatusCode statusCode)
{
    qDebug() << attr << statusCode;
}

QOpcUa::NodeAttribute::Value QOpcUa::Good