Niagara History Export properties

Properties of Niagara history export descriptors available in the Edit or Add dialog are as follows:

Name

Name for history export descriptor component. Typically left at default. Begins with “Local_” for any history originating from the local station. Or if adding a NiagaraSystemHistoryExport, defaults to “NiagaraSystemHistoryExport” (appending numerals as needed to keep unique).
Editing name does not affect name of resulting history (exported into remote station).
History Id

For a NiagaraHistoryExport descriptor, this property specifies the history name to be created in the remote station’s history space, using two parts: “/<stationName>” and “/<historyName>”. Histories originating in the local station show a “^” (shorthand for local station name), and history name reflects the source history name. Typically, you leave both fields at default values.
For a NiagaraSystemHistoryExport descriptor, the History Id property is not applicable.
Execution Time

Either Daily (default), Interval, or Manual. If Manual, properties below are not available:
- Time of Day (Daily)
  
  Configurable to any daily time. Default is 2:00am.
- Randomization (Daily)
  
  When the next execution time calculates, a random amount of time between zero milliseconds and this interval is added to the Time of Day. May prevent “server flood” issues if too many history archives are executed at the same time. Default is zero (no randomization).
- Days of Week (Daily and Interval)
  
  Select (check) days of week for archive execution. Default is all days of week.
- Interval (Interval)
  
  Specifies repeating interval for archive execution. Default is every 15 minutes.
- Time of Day (Interval)
  
  Specifies start and end times for interval. Default is 24-hours (start 12:00am, end 11:59pm).
Enabled

Default is true. If set to false, history data is not exported.
System Tag Patterns

(Modifiable only for a NiagaraSystemHistoryExport descriptor) Specifies one or more text strings matched against text values in “System Tags” properties of local history extensions, where matching text patterns result in histories exported into the remote history space. For more details, see Using System Tags to export Niagara histories.

The capacity and full policy of any exported history (created on the remote station) is determined by rules under that station’s NiagaraNetwork “History Policies,” and is set at creation time only. For details, see History Policies.