About history extensions

Add a history extension to any point to log historical data, that is, to collect a history. In a point history, each collected sample of slot Out has a date-timestamp, point status and value. Point history data is viewable in both a table and chart format.

These components are found in the Extensions folder of the history palette.

In Niagara 4.6 and later, if the Enable property is set to false, a copied history extension does not revert.

Each history extension has various properties in two major groups:

Collector properties determine how or when data are collected, such as active time, and (if applicable) either change tolerance or the collection interval time.
History Config properties determine how the system stores the data. These properties include History Name, Capacity, and Full Policy.

The following lists all history extension types and the applicable point parents.


History extension type	Applies to point types		General description
History extension type	(read-only)	Writable	General description
NumericInterval	as above	as above	Collects upon a repeating time interval, as configured.
NumericCov	NumericPoint	NumericWritable	Collects upon each change of value (outside a specified tolerance) or change of status.
NumericCov	—	any object with single Numeric Out, e.g. kitControl: Math object type “Add”
BooleanInterval	as above	as above	Collects upon a repeating time interval, as configured.
BooleanCov	BooleanPoint	BooleanWritable	Collects upon each change of Boolean value (state) or status.
BooleanCov	—	any object with single Boolean Out, e.g. kitControl: Logic object type “And”
EnumInterval	as above	as above	Collects upon a repeating time interval, as configured.
EnumCov	EnumPoint	EnumWritable	Collects upon each change of enumerated state or status.
EnumCov	—	any object with single Enum Out	Collects upon each change of enumerated state or status.
StringInterval	as above	as above	Collects upon a repeating time interval, as configured.
StringCov	StringPoint	StringWritable	Collects upon each change of string value or status.
StringCov	—	any object with single String Out	Collects upon each change of string value or status.

All history extensions have an Update History action available. This menu item provides a way to refresh the History Id after a rename. It applies the formatting property (as designated by enclosing % signs) of the Name Format field to the Id of the History Config Id. For example, if the History Name property under a history extension is set to %parent.name%, then the History Config Id is initially named based on this parent display name. However, if you rename the parent component, the History Config Id property does not automatically or immediately change. The Update History Id action invokes a renaming of the History Config Id based on the formatting property, so if the parent component (in this example case) is changed, the Update History Id action changes the Id property and, if different from the history name, it results in a change in the history name as well.