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Data tag messages

Data Tag Messages

Data Tags are used to label Asset time series data. This has many applications such as;

  • For data scientists to use for machine learning training
  • For developers to have additional information beyond the raw data to review and improve Kelvin SmartApps™
  • For Operations to tag events linked to the time series data for historical records

On the Kelvin UI, the data tags will show in the Data Explorer.

Kelvin SmartApps™ can publish a DataTag Message in order to label important events on a certain point in time (or time range) for a certain Asset.

Note

Operations can also their own add Data Tags manually through the Kelvin UI

The DataTag Object supports the following attributes:

Data Tag Attribute Required Description
start_date required Start date for the Data Tag. Time is based on UTC timezone, formatted in RFC 3339.
end_date optional End date for the Data Tag. Time is based on UTC timezone, formatted in RFC 3339.
tag_name required Tag name to categorize the Data Tag.
resource required The Asset that this Data Tag is related to. This is in KRN format (e.g. krn:asset:bp_01).
description optional Detailed description of the Data Tag.
contexts optional A list of associated Kelvin resources with this Data Tag. (e.g. KRNDatastream, KRNApp, etc).

This is how they can be created and published:

Create and Publish Data Tag Python Example
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from datetime import timedelta, datetime

from kelvin.application import KelvinApp
from kelvin.message import DataTag
from kelvin.krn import KRNAsset, KRNDatastream

app = KelvinApp()

@app.timer(interval=10)
async def publish_data():

    now = datetime.now()

    # Create and Publish DataTag
    await app.publish(
        DataTag(
            start_date=now - timedelta(seconds=datatag_duration_secs),
            end_date=now,
            tag_name="My Tag",
            resource=KRNAsset("my_asset"),
            contexts=[KRNApp("app_name"), KRNDatastream("my_datastream")]
        )
    )

app.run()