DeviceHub Data Publishing Formats

Estimated reading time: 1 minute

DeviceHub collects data from PLCs, applies OMA (Open Mobile Alliance) tagging to classify the data, and it sends data to a message broker for further distribution. Data flows trigger via an API call or execute according to a schedule. OT Link Platform supports multiple data formats.

  • DeviceHub Tags generate a Raw Topic, which is a local topic for publishing and subscribing data through the message broker.
  • You can configure the DataHub Cloud Connector to connect to Workload Orchestrator using Raw topics.
  • You can also use OT Link Platform flows to access data from within OT Link Platform. See, Use OT Link Platform Flows to Visualize Data Flows.

Raw Topic Format

  • The raw topic is the local message broker topic. The collected values are the unformatted readings from the PLC register.
  • Values are collected from individual registers. OT Link Platform publishes each value to a register-specific topic, in the following topic format: devicehub.raw.{deviceID}.{registerID}
  • See DeviceHub Add a Tag.

Example of a Raw Topic


OMA IPSO (Standard) Topic Format 

  • If OT Link Platform finds OMA binding/mapping for a collected value, OT Link Platform converts the data into OMA object format and publishes it to the corresponding topic, in the following topic format: devicehub.standard.{deviceID}.{objectID}.{instanceID}.{resourceID}
  • See DeviceHub OMA Binding.

Example of an IPSO Topic


Write Topic Format

  • Use OT Link Platform Flows to create a flow that writes data to a register-specific topic, in the following topic format: devicehub.write.{deviceID}.{registerID}
  • Each device instance on the devicehub.write.{deviceID}.* topic receives all messages for the corresponding device.
  • The device instance executes a write to the specified register on the connected device.
  • See Flow to Write to Tags.

Example of a Write Topic


Poll Once Topic Format

Example of a Poll Once Topic