Dynamic Attributes Check

Use these questions to prepare for the Kanoa Ops certification exam.

What is the difference between a dynamic attribute and a custom property?

A dynamic attribute stores a value that changes over time as time-stamped events, so you can ask what the value was at any moment. A custom property is configuration that rarely changes and has no event history. See Dynamic Attributes.

What has to be done before a dynamic attribute can record values for an asset?

The attribute must be defined and then linked to the asset. Events are recorded against that attribute-asset link. See Create Dynamic Attributes.

Name two ways a dynamic attribute value can be recorded without a script.

Collected automatically from a PLC tag configured as the attribute's data source, or entered by a person, either on the Attribute Events screen or through an operator screen built from the dropdownSelector or textEntry views. See Create Dynamic Attributes.

Why give operators an entry screen instead of the Attribute Events screen?

Attribute Events is an administrative screen for reviewing and correcting history. Kanoa's kanoa/mes/asset/attributes views give operators a simple control that records a time-stamped event for the right asset and attribute. See Dynamic Attributes.

Which function returns the value of a dynamic attribute at a given moment?

system.kanoa.attribute.getPreviousAttributeEvent(assetId, attributeId, tStamp) returns the most recent event before tStamp; pass system.date.now() to get the value in effect right now. Use getAttributeEvents for the full history over a time range. See Dynamic Attributes.

When should you not use a dynamic attribute?

When Kanoa already has a natural home for the data: counters for counts, state events for downtime, item states for scrap, and custom properties for stable configuration. Use a dynamic attribute when the value is custom, changes over time, and the time it changed matters. See Dynamic Attributes.