Phase 4: Interface connection

The final phase of installation focuses on connecting interfaces to your new Data Archive. A PI interface is a software program that collects data from the data source and sends data to Data Archive. Some interfaces also have the ability to read data from Data Archive and write back to the data source.

Note: If you are planning on deploying Data Archive as a collective, perform these tasks first on the primary server. Then, perform the tasks for each secondary Data Archive server within your collective.

There are hundreds of different PI interfaces and each interface is fully documented in its own dedicated manual. However, most interfaces share a common set of features.

For most interfaces, it is important to configure buffering on the interface node. This prevents loss of data when Data Archive is not available for some reason (such as during an upgrade). The exceptions are:

• Some interfaces do not require buffering because the data source itself is buffered.

• There are a very few interfaces that should not be run with buffering. Consult the documentation for your interface.

The majority of AVEVA interfaces use the PI Application Programming Interface (PI API) to retrieve configuration information from Data Archive and to write data to the Data Archive server. A few non-batch interfaces also use the PI Software Development Kit (PI SDK) to retrieve configuration information from Data Archive and to create PI points, digital states, and so on. Almost all batch interfaces use the PI SDK to write batch data to Data Archive.

PI interfaces typically run on a dedicated system, called an Interface node, which connects both to the data source and to Data Archive. The Interface node might be a machine that is a part of the foreign data system, or a stand-alone dedicated interface machine, or even a Data Archive server (PI to PI). Interface nodes can run multiple interfaces and connect to multiple Data Archive servers.

Since data sources run without human intervention, user logins are not applicable. To allow PI interfaces to connect to Data Archive, configure a PI mapping to a PI identity.

Note: You will see the following error in Pipc.log: No Write Access - Secure Object if the interface does not have permission to write to PI Data Archive. In order to give the interface the proper permissions to write data to the PI Data Archive, you must set up a mapping to an identity on the PI Data Archive for the interface. The PI mapping can be configured to assign a PI User account (or PI Identity in 3.4.380 or later) to any program that logs in from the interface computer. The interface will then get all the privileges assigned to that PI User. The PI User or PI Identity must have explicit data access write permissions for the relevant points.