Lesson 6: Adding support for Alarms & Conditions

Update UaModeler project to add condition object StateCondition to controller

Figure 6.1:

Condition Object OffNormalAlarm is added to ControllerType

Create code update and XML export

• BAIdentifiers.cs
• buildingautomation.xml

Figure 6.2:

Add initialization of Alarm object

After controller object creation

• Create alarm data model object
• Link to alarm nodes

SetComponentUserData(
    new NodeId(block.Name, InstanceNamespaceIndex),
    new QualifiedName(yourorganisation.BA.BrowseNames.StartWithSetPoint, TypeNamespaceIndex),
    new SystemFunction() { Address = block.Address, Function = 3 });

// New Code Begin
// Set alarm condition nodeId
NodeId alarmId = new NodeId(block.Name + "." + yourorganisation.BA.BrowseNames.StateCondition, InstanceNamespaceIndex);
// Create off normal alarm data object
OffNormalAlarmModel alarm = new OffNormalAlarmModel();
alarm.NodeId = alarmId;
alarm.EventType = ObjectTypeIds.OffNormalAlarmType;
alarm.SourceNode = new NodeId(block.Name, InstanceNamespaceIndex);
alarm.SourceName = block.Name;
alarm.Severity = (ushort)EventSeverity.Low;
alarm.ConditionName = "StateCondition";
alarm.ConditionClassId = ObjectTypeIds.ProcessConditionClassType;
alarm.ConditionClassName = BrowseNames.ProcessConditionClassType;
alarm.Retain = false;
alarm.EnabledState.Value = ConditionStateNames.Enabled;
alarm.EnabledState.Id = true;
alarm.AckedState.Value = ConditionStateNames.Acknowledged;
alarm.AckedState.Id = true;
alarm.ActiveState.Value = ConditionStateNames.Inactive;
alarm.ActiveState.Id = false;
alarm.SuppressedOrShelved = false;
// Link alarm data object to nodes in address space
LinkModelToNode(alarmId, alarm, null, null, 500);
// New Code End

foreach (BlockProperty property in block.Properties)

Set Alarm Active State

Change alarm state when controller state changes

Set in BlockStateChanged event

private void UnderlyingSystem_BlockStateChanged(int blockAddress, string blockName, int state)
{
    ...

    // report the event.
    ReportEvent(e.SourceNode, e);

    // New Code Begin
    NodeId alarmId = new NodeId(blockName + "." + yourorganisation.BA.BrowseNames.StateCondition, InstanceNamespaceIndex);
    OffNormalAlarmModel alarm = (OffNormalAlarmModel)GetNodeUserData(alarmId);
    // Change state of StateCondition
    lock (alarm)
    {
        alarm.LastSeverity.Value = alarm.Severity;
        alarm.LastSeverity.SourceTimestamp = alarm.Time;
        if (state == 0)
        {
            // Change state to active and unacknowledged
            alarm.Retain = true;
            alarm.Severity = (ushort)EventSeverity.High;
            alarm.AckedState.Value = ConditionStateNames.Unacknowledged;
            alarm.AckedState.Id = false;
            alarm.Activate(Server.DefaultRequestContext, true);
        }
        else
        {
            // Change state to inactive
            alarm.Severity = (ushort)EventSeverity.Low;
            alarm.Activate(Server.DefaultRequestContext, false);
            if (alarm.AckedState.Id == true)
            {
                alarm.Retain = false;
            }
        }
        e = alarm.CreateEvent(Server.FilterManager);
    }

    // report alarm status as event.
    ReportEvent(alarm.SourceNode, e);
    // New Code End
}

Add Acknowledge handling

Override Acknowledge

public override StatusCode Acknowledge(
    RequestContext context,
    AcknowledgeableConditionModel model,
    byte[] eventId,
    LocalizedText comment)
{
    GenericEvent e = null;

    lock (model)
    {
        StatusCode error = model.Acknowledge(context, eventId, comment);

        if (error.IsBad())
        {
            return error;
        }

        // Check if the alarm is already inactive
        OffNormalAlarmModel alarm = (OffNormalAlarmModel)model;
        if (alarm.ActiveState.Id == false)
        {
            alarm.Retain = false;
        }

        e = model.CreateEvent(Server.FilterManager);
    }

    ReportEvent(model.SourceNode, e);
    return StatusCodes.Good;
}

Alarm View in UaExpert

Figure 6.3:

Alarms view is part of the Event view Alarm condition changes can be triggered with methods Acknowledge can be called from Alarm view