getting started lessons: Subscription and Monitoritem

[diana]

Hi Supported Team,

I've a problem with the function Subscription and Monitoritem in the lesson06 of client_gettingstarted.
I'd like calls two clients and one server.
The first client calls the subscription function for monitoring a variable. At the same time, I'd like that the second client call the function "write" for the variable that the first client is monitoring. Can I monitoring the variables AirConditioner_1.HumiditySetPoint
and AirConditioner_1.TemperatureSetPoint?

Thank you,

[Support Team]

Hello Diana,
I guess what you want is
- monitor one node with client A
- write values to the very same node with client B
- see the written values change in client A

You have to use the same NodeId for monitoring and writing. You can use either of the 2 NodeIds you posted above.

Best Regards,
Unified Automation Support Team

[diana]

ok, perfect! I'd like print the value of either variable when the subscription is called; in the code there is:

Code: Select all

        else
        {
           
 printf("** UaSession::createMonitoredItems result **********************n");


 for ( i=0; i<count; i++ )
            {

                UaNodeId node(monitoredItemCreateRequests[i].ItemToMonitor.NodeId);


                if ( 


OpcUa_IsGood(monitoredItemCreateResults[i].StatusCode) )
                {

                    printf("** Variable %s MonitoredItemId = %dn", node.toString().toUtf8(), monitoredItemCreateResults[i].MonitoredItemId);
                }


                else
                {
                    
printf("** Variable %s failed!n", node.toString().toUtf8());
                }
            }

            if ( OpcUa_IsGood(monitoredItemCreateResults[count].StatusCode) )
            {
      

	      printf("** Event MonitoredItemId = %dn", monitoredItemCreateResults[count].MonitoredItemId);

      }
           
 else
            {

                printf("** Event MonitoredItem for Server Object failed!n");
            }

In the last "printf", the funcion print the "monitoredItemCreateResults[count].MonitoredItemId".
My question is: How I can print the other attributes of the monitoring variable?

thank you!

Diana

[Support Team]

Hello Diana,
in the same way you can print the other parameters.
Looking at the ExtensionObject is a bit tricky. We're currently working on an easier way to work with ExtensionObjects.

Code: Select all

if ( OpcUa_IsGood(monitoredItemCreateResults[count].StatusCode) )
{
    printf("** Event MonitoredItemId = %dn", monitoredItemCreateResults[count].MonitoredItemId);
    printf("** Event RevisedQueueSize = %dn", monitoredItemCreateResults[count].RevisedQueueSize);
    printf("** Event RevisedSamplingInterval = %dn", monitoredItemCreateResults[count].RevisedSamplingInterval);
    printf("** Event StatusCode = %sn", UaStatusCode(monitoredItemCreateResults[count].StatusCode).toString().toUtf8());

    // check if we have an EventFilterResult
    if( monitoredItemCreateResults[count].FilterResult.Encoding == OpcUa_ExtensionObjectEncoding_EncodeableObject &&
        monitoredItemCreateResults[count].FilterResult.Body.EncodeableObject.Type->TypeId == OpcUaId_EventFilterResult &&
        monitoredItemCreateResults[count].FilterResult.Body.EncodeableObject.Object != OpcUa_Null)
    {
        OpcUa_EventFilterResult *pEventFilterResult = (OpcUa_EventFilterResult*)monitoredItemCreateResults[count].FilterResult.Body.EncodeableObject.Object;

        OpcUa_Int32 j;
        for(j = 0; j < pEventFilterResult->NoOfSelectClauseResults; j++)
        {
            printf("** SelectClause[%d] Status = %sn", j, UaStatusCode(pEventFilterResult->SelectClauseResults[j]).toString().toUtf8());
        }
    }
}

Best Regards,
Unified Automation Support Team