Clientsuse the browse Servicesof the View Service Setto navigate through the AddressSpaceto discover theHistoricalNodesand their characteristics. These Servicesprovide the most current information about the AddressSpace. It is possible and probable that the AddressSpaceof a Serverwill change over time (i.e. TypeDefinitionsmay change; NodeIdsmay be modified, added or deleted).

Serverdevelopers and administrators need to be aware that modifying the AddressSpacemay impact a Client’sability to access historical information. If the history for a HistoricalNodeis still required, but the HistoricalNodeis no longer historized, then the Objectshould be maintained in the AddressSpace, with the appropriate AccessLevel Attributeand Historizing Attributesettings (see OPC 10000-3for details on access levels).