The value of Nodes with readable history (marked as HR in the Other column) shall be persisted for a period of 8 hours, meaning the last 8 (eight) hours of data will be available.

The server shall implement historization of events for all events, accessible by client via the OPC UA service history read. The historization internal storage shall be sized to persist at least 1 (one) hour of events generated at the average server generation rate.

The Value of Nodes with NodeClass Variable shall be persisted in the control system in such a way that, in case of a hardware failure or replacement, the TMC server values will not be reset.