Following are sub-types of SystemEventTypethat will be generated in response to a Refresh Methodscall. They are illustrated in Figure 23.

image026.png

Figure 23– Refresh Related Event Hierarchy

This EventTypeis used by a Serverto mark the beginning of a Refresh Notificationcycle. Its representation in the AddressSpaceis formally defined in Table 99.

Table 99– RefreshStartEventType definition

Attribute

Value

BrowseName

RefreshStartEventType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the SystemEventTypedefined in OPC 10000-5, i.e. it has HasProperty Referencesto the same Nodes.

This EventTypeis used by a Serverto mark the end of a Refresh Notificationcycle. Its representation in the AddressSpaceis formally defined in Table 100.

Table 100– RefreshEndEventType definition

Attribute

Value

BrowseName

RefreshEndEventType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the SystemEventTypedefined in OPC 10000-5, i.e. it has HasProperty Referencesto the same Nodes.

This EventTypeis used by a Serverto indicate that a significant change has occurred in the Serveror in the subsystem below the Serverthat may or does invalidate the Conditionstate of a Subscription. Its representation in the AddressSpaceis formally defined in Table 101.

Table 101– RefreshRequiredEventType definition

Attribute

Value

BrowseName

RefreshRequiredEventType

IsAbstract

True

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the SystemEventTypedefined in OPC 10000-5, i.e. it has HasProperty Referencesto the same Nodes.

When a Serverdetects an Eventqueue overflow, it shall track if any Condition Events have been lost, if any Condition Events were lost, it shall issue a RefreshRequiredEventType Eventto the Clientafter the Eventqueue is no longer in an overflow state.