US Patent 7917857 Direct subscription to intelligent I/O module

Systems and methods that supply direct access (e.g., bypassing the controller) to embedded historian via a subscription and notification component. By modeling the notification related information (e.g., subscription queries, subscriber information, event information . . . ) as data and leveraging the power of database systems to perform set-oriented manipulations on this data efficiently, the subject innovation enables for a highly scalable and efficient subscription and notification system for direct access to the historians.