2019 - Detailed Changes (PI Web API OMF Services)

New Concept: OMF Endpoint

PI Web API 2019 introduces the PI Web API OMF Services plugin. This plugin adds an Open Message Format (OMF) endpoint to the PI Web API, which can be used to ingress OMF messages to your PI AF and PI Data Archive servers. For more information about OMF, view the OMF Endpoint Notes topic.

New Concept: CREATE Action

The OMF specification defines the CREATE action. When a CREATE message is received, it will be treated as an create-and-assert operation. The PI Web API will attempt to create PI System resources corresponding to the contents of the message. If an existing resource exists, if the resource does not match what the PI Web API is trying to create, the request will fail. The type of resource created by the PI Web API depends on the type of OMF message being used.

New Concept: DELETE Action

The OMF specification defines the DELETE action. When a DELETE message is received, it will be treated as a try-remove operation. The PI Web API will look for the specified resource and compare it to the contents of the message: if the message matches the existing PI System representation, the resource will be deleted. If the resource is not found, no change will occur.

New Concept: Types

The OMF specification introduces the concept of a type. A type describes the contract that later OMF messages should be held to. The PI Web API OMF Services plugin will create an AF Element Template to represent a type.

New Concept: Containers

The OMF specification introduces the concept of a container. A container represents a destination that later OMF messages can write data to. The PI Web API OMF Services plugin will create one or more PI Points to represent a container.

New Concept: Data

The OMF specification introduces the concept of data. Data can be broken down into several types: static, dynamic, and link data.

Static Data

The PI Web API OMF Services plugin will create an AF Element to represent static data.

Dynamic Data

The PI Web API OMF Services plugin will create time-series data, stored in PI Points, to represent dynamic data.

Link Data

Link data is a subset of static data using the reserved OMF type __link. Link data represents hierarchical information. The PI Web API OMF Services plugin only support only implements two types of link data: static-to-static links, and static-to-dynamic links.

Static-to-static links are links that have a static data source and a static data target. The PI Web API OMF Services plugin will create an AF Element hierarchy to represent static-to-static links.

Static-to-dynamic links are links that have a static data source and a container target. The PI Web API OMF Services plugin will create one or more AF Attributes to represent static-to-dynamic links. The created AF Attributes use the PI Point Data Reference to read the time-series data stored in the PI Points that represent the container.

Schema Changes

For detailed information about the PI Web API OMF Services storage schema, refer to the Developer Companion Guide.

Types

• Introduced

Containers

• Introduced

Data

• Introduced