Data Tags

Data Tag Messages

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.

The DataTag Object supports the following attributes:

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:

from datetime import timedelta, datetime

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

(...)

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")]
    )
)