As defined in OPC 40083, the root node of the specific interface, e.g. an instance of LDS_InterfaceType, set the SubscribeToEvents flag in the EventNotifier attribute.
The client subscribes to events at this root node and receives the events already defined in this specification, such as temperature limit alarms or diagnostic events.
A LDS may optionally generate additional manufacturer-specific alarms, warnings or information displayed on the user interface of the device and can publish these events via two special AlarmTypes.
Component-related messages should be represented by instances of ComponentAlarmType, additive-related messages should be represented by instances of AdditiveAlarmType, other device information is of type HelpOffNormalAlarmType.
All are subtypes of OffNormalAlarmType, can be synchronized via ConditionRefresh and contain a Severity for error handling according to OPC 40083.
The ComponentAlarmType represent component-related text messages (alarms, error messages, warnings, information) of the peripheral device and is a subtype of HelpOffNormalAlarmType as defined in OPC 40083.
NOTE: For messages related to the whole device, the HelpOffNormalAlarmType shall be used.
Table 24 – ComponentAlarmType Definition
|References||Node Class||BrowseName||DataType||TypeDefinition||Modelling Rule|
|Subtype of 3:HelpOffNormalAlarmType defined in OPC 40083|
The SourceNode (included in BaseEventType) shall contain the NodeId of the related component. In case of medium or high severity, the IMM can sort out bad parts or stop production.