history-HistoryConfig
This component configures a history in the History database.
Figure 21. History Config properties
The History Config component is available in the history palette under LogHistoryService. The following table summarizes the History Config properties.
| Property | Value | Description |
|---|---|---|
| HistoryConfig | Container for sub-properties used to configure the attributes of the history record stored in the History space. | |
| Id | Text string | Read only value. String results from value configured in history extension’s History Name property. An error string here indicates the History Name property is incorrectly configured .
|
| Source | ORD | Read only value. Displays the ORD of the active history extension. |
| Time Zone | Text string | Read only value. Displays the time zone of the active history extension. |
| Record Type | Text | Read only values. Displays the data that the record holds in terms of: extension type (history) and data type (BooleanTrendRecord, NumericTrendRecord, and so on). |
| Capacity | Record Count: nnn (500 default), Unlimited | Specifies local storage capacity for histories. In general, 500 (default record count) or less is adequate for a controller
station because those records are usually archived (exported) to a
Unlimited is not the wisest choice even for a
|
| Full Policy | Roll (default), Stop | Applies only if Capacity is set to “Record Count”. Upon specified record count, the oldest records are overwritten by newest
records. Roll ensures that the latest data are recorded. Stop terminates recording when the number of stored records reaches specified history capacity.
Full policy has no effect if |
| Interval | Text string | Read only value. For Interval-based data collection, the cycle time, or how often the history properties are checked. Any time you change this property, a new history is created (or “split-off”) from the original history because histories with different intervals are not compatible. |
| System Tags | Text | This property allows you to assign additional metadata (the System Tag) to a history extension. This identifier is then available for selective import or export of histories using the Niagara System History Import or Niagara System History Export option (using the System Tag Patterns). Each System Tag is separated by a semicolon. For example: NorthAmerica;Region1;Cities. |