Abstract: A control system database server is disclosed that includes a data compression facility that implements a compression test sequence on streams of time stamped data points rendered by components of a control system. A deadband/time override is incorporated into the compression test sequence to ensure that a previously received data point, within the stream of received data points, is saved within a designated time period even if the compression test sequence would have determined that the data point be discarded. The series of compressed/tabled data points, corresponding to the received steams of data points, are thereafter provided by the historian to requesting client applications that, by way of example, retrieve the compressed, time stamped data point streams for the purpose of constructing and displaying trend graphs.

Abstract: Disclosed are techniques for synchronizing software objects in one namespace with software objects in another namespace. When a change is detected in the first namespace (such as the addition, deletion, or movement of a software object), only as much information as is needed to characterize the change is sent to the second namespace. The second namespace then replicates the changed status of the first namespace. In one embodiment of the invention, an Archestra namespace is synchronized with an InSQL namespace by applying the public/private namespace capability of InSQL.

Abstract: A database server for handling steams of time stamped data points for tagged variables is disclosed herein that supports a set of advanced data retrieval operations/queries invoked by clients of the database server. The advanced data retrieval operations are invoked by client queries to provide, on demand, secondary information by processing previously tabled data corresponding to received data streams rendered by a variety of data sources in a supervisory control/monitoring, process control and/or automated equipment environment. Calculations, on previously stored data, for rendering the secondary information are performed within the database server at the time the secondary information is requested by a client of the historian that maintains a database containing the previously stored data.

Abstract: A data acquisition service on a network node is disclosed for forwarding received process data to a process history database over a potentially slow and/or intermittent network connection. A store and forward functionality within the networked node receives incoming process data via a first network interface and forwards outgoing process data via a second network interface. The disclosed store and forward functionality includes an immediate transmission cache and a store and forward storage. The store control enters, in response to detecting an entry condition, an activated mode wherein incoming process data is directed to the store and forward storage. A read control forwards outgoing process data to the second network interface from the immediate transmission cache and store and forward storage. The read control includes at least a first configurable parameter that constrains a rate at which data retrieved from the store and forward storage is forwarded via the second network interface.