Subscriptions

The subscriptions API allows customers to create timeseries data subscriptions to various IMS sources. When subscriptions to specific tags have been made, timeseries datapoints will be streamed to the Omnia Timeseries DB. The data will then be accessible from the Omnia Timeseries API.

From version 1.2 and onwards the API also supports creating subscriptions for the data lake. The data will be exported to the data lake daily. Creating a subscription for the Omnia Timeseries DB will automatically create a subscription for the data lake. The converse however, does not apply. The idea being that all Omnia Timeseries DB IMS data should be accompanied by data in the data lake extending further back in history. This backfilling is timeconsuming. Therefore it might take some time before the historical data is accessible.

Before subscriptions can be made to a specific IMS source. This source will have to be setup and initialized by the Omnia Ind IoT Team. The source will be given a source quota. When this is done customers can subscribe to specific tags on that IMS. When the source quota has been met, no more subscriptions to that source will be allowed. The Omnia Ind IoT Team will have to review the export performance and subsequently increase the quota.

Realtime Subscriptions

Similar to Streaming API, the IMS Subscriptions API also supports streaming tag data to a customer specified event-hub. Customers can specify the output event-hub using the Set real-time destination endpoint, and then add temporary real time subscriptions by using the Create real-time subscription endpoint. Existing subscriptions can be viewed using the List real-time subscriptions endpoint.

Real-time subscriptions by default have a 10 minute duration, but this can be overridden using the lifeTime query parameter.

Use cases for this type of streaming is end user applications where user initiate need for showing live data from a sensor/equipment, eg in a Field app or digital twin app. Data is streamed from the main source for Omnia Industrial IoT, for most assets the process historian (IMS) on corporate network.

Applications must be granted Subscriptions.Realtime on omnia-iiot-subscriptions-api-production to be able to use this function.

Realtime subscriptions are available for data from historians on these plants:

• Aasta Hansteen
  
• Gina Krog
  
• Gudrun
  
• Heidrun
  
• Johan Sverdrup
  
• Kristin
  
• Mariner
  
• Martin Linge
  
• Norne
  
• Sleipner
  
• Snorre A. NB, only default map/terminal supported
  
• Statfjord A, B, C
  
• Valemon
  
• Visund
  
• Åsgard A
  
• Åsgard B