0 - AlwaysInAdvise

OPC UA Block Tag is kept updated if the OPC UA Block Tag's AllowRead property is set to True and the OPC UA Subscription's Enable property is also set to True

1 - AdviseWhenLinked

OPC UA Block Tag is only updated if the OPC UA Block Tag's AllowRead property and the OPC UA Subscription's Enable property are set to True, and this OPC UA Block Tag is linked to an active object, such as a Display on a Screen or an Alarm enabled, among others. The OPC UA Block Tag's link for this purpose can be performed in the properties Value, RawValue, Quality, and Bit00 to Bit31 of OPC UA Block Elements, and Quality and TimeStamp of OPC UA Block Tags (default)