Differences between OMF PI Web API and OMF Relay

OMF with PI Web API differs from the previous version of OMF that utilizes the PI Data Collection Manager (DCM) and PI Connector Relay in the following aspects:

• The PI Web API does not support a per-application root AF Element; AF Elements are created at database root.

• Resource naming conventions have changed.

• PI Data Collection Manager (DCM) is no longer used to uniquely identify resources through application ID.

• PI Connector Relay is no longer used.

• A PI Web API installation with the OMF Ingress Services feature is required (available in PI Web API 2019 and later).

The relay has its own interface for provisioning OMF clients. PI Web API does not have a corresponding concept. OMF clients need to be able to be authenticated through PI Web API, at which point PI Web API will impersonate the Windows Identity associated with the OMF client. For more information, see Authentication and Authorization.