Add a history extension to any point for which you want to log historical data, that is 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.
Find the history extensions in palette : (Figure 114).
Each history extension has various properties in two major groups:
-
Collector
Determines how or when data is collected, such as active time, and (if applicable) either change tolerance or the collection interval time.
-
History Config
Determines how the data is stored and accessed in the system, such as history name, capacity, and full policy.
For more details, see Configure history extensions.
Table 4 lists all history extension types and the applicable point parents.
Table 4. History extension types
| History extension type | Applies to point types | General description | |
|---|---|---|---|
| (read-only) | Writable | ||
| BooleanChangeOfValue | BooleanPoint | BooleanWritable | Collects upon each change of Boolean value (state) or status. |
| — | any object with single Boolean Out, e.g. kitControl: Logic object type “And” | ||
| BooleanInterval | as above | as above | Collects upon a repeating time interval, as configured. |
| NumericChangeOfValue | NumericPoint | NumericWritable | Collects upon each change of value (outside a specified tolerance) or change of status. |
| — | any object with single Numeric Out, e.g. kitControl: Math object type “Add” | ||
| NumericInterval | as above | as above | Collects upon a repeating time interval, as configured. |
| EnumChangeOfValue | EnumPoint | EnumWritable | Collects upon each change of enumerated state or status. |
| — | any object with single Enum Out | ||
| EnumInterval | as above | as above | Collects upon a repeating time interval, as configured. |
| StringChangeOfValue | StringPoint | StringWritable | Collects upon each change of string value or status. |
| — | any object with single String Out | ||
| StringInterval | as above | as above | Collects upon a repeating time interval, as configured. |
All history extensions have an Update History action available. This popup 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. See About history names for more information about history naming.