Learn about mappings of value streams to PI points

Connectors and OMF applications create value streams that carry time-series measurements as a sequence of time-stamped events. Each value stream is associated with one or more measurements in the data source.

Each event in a value stream contains a time stamp, one or more measurement properties, and, optionally, a quality property (currently not supported for OMF applications). The relay creates a PI point for each measurement property in a value stream. The points are assigned to the Base point class.

When processing an event from a value stream, the relay normally creates archive update events for the value in each measurement property, which are written to the associated PI points. However, null property values and the optional quality property change the relay behavior as described in the following sections for connectors.

Note: The user guide for each connector explains the circumstances that result in null property values and whether values streams have the quality property.