Data flow

Here is an example of a typical data flow that occurs as different architecture elements interact to provide the client with PI System data.

When searching for data in a new display:

1. When a user performs a search for a data item (asset, attribute, or PI point), the client sends a request for that data item to the AVEVA PI Vision application server. The request is relayed to the AF SDK, which populates the search results retrieved from the Data Archive and PI AF server.

2. Based on the search results, the user can create a symbol for the data item by dragging it onto the display. The symbol on the display does not yet contain any PI data values. The maximum number of returned assets per data source is based on the AFDBMaxSearchResults system parameter; however, you may receive more results since the parent of any returned asset is not counted as part of the maximum.

3. Symbol creation triggers a request for PI data, which the AVEVA PI Vision application server relays to Data Archive server or PI AF server. When PI data returns to the client, the symbols on the display are populated with data values.

4. When a user saves the display, the display definition (display settings) is sent to the Microsoft SQL Server and stored in the AVEVA PI Vision database.

When opening an existing display:

5. When a user opens an existing display, the client sends a request for a display definition to the AVEVA PI Vision application server, which is relayed to the Microsoft SQL Server. The SQL Server returns the display definition from which the client generates a display with symbols. The symbols do not yet contain any data values.

6. Symbol creation triggers a request for PI data, which the AVEVA PI Vision application server relays to Data Archive server or PI AF server. When PI data returns to the client, the symbols are populated with data values.