0 - AlwaysInAdvise

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

1 - AdviseWhenLinked

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