The local digital twins is the component that sits between the cloud and the local message broker at the edge. Its role is to provide connectivity to the cloud, as well as to ensure that digital twin state is available on a local level even in offline mode (no matter of the connection state).
Such capabilities were implemented to support offline scenarios and advanced edge computing involving synchronization with the cloud after disruptions or outages. The synchronization mechanisms were also designed in a way to significantly reduce data traffic, and efficiently prevent data loss due to long-lasting disruptions.