PI Nexus+ / Reference
AF Issues and Thresholds
This reference lists the issues PI Nexus+ raises for AF attributes and AF analyses, the analysis thresholds and the attribute scan modes. The User Guide chapters AF Attributes, Elements and Templates and AF Analyses and Recalculation link here.
Overview
This reference lists the issues PI Nexus+ raises for AF attributes and AF analyses, the analysis thresholds and the attribute scan modes. The User Guide chapters AF Attributes, Elements and Templates and AF Analyses and Recalculation link here.
AF attribute issues
Category AF Attributes on the Issues page.
| Issue | Severity | Raised when | Typical fix |
|---|---|---|---|
| Attribute Missing PI Point | Error | The attribute's PI Point data reference points to a PI Point that does not exist | Create the point or correct the data reference |
| AF Attribute Error | Error | The attribute's health is Error for another reason, for example a data reference that cannot be resolved | Read the health message; correct the data reference or configuration string |
| Attribute With No Data | Error or Warning, from the attribute's health | The current value is No Data | Check the linked PI Point and its source |
| Uninitialized Attribute | Error or Warning | The linked PI Point has never received a value (Pt Created) | Start the data flow to the PI Point |
| Bad AF Attribute Value, or a specific name such as Attribute Collection Timeout, Attribute Access Denied, Attribute Source Shutdown, Attribute Requires Configuration, Attribute Calculation Failed, Attribute Calculation Disabled, Attribute Scanning Disabled, Attribute Scan State Warning | Error or Warning | The current value has bad quality | Fix the source the message names |
| Unknown AF Attribute Health | Warning | The attribute's health could not be determined | Run a scan of the database; check the AF connection |
When an attribute becomes not evaluated (see the scan modes below), its open issue resolves after the next successful scan; the issue history stays. The linked PI Point keeps its own issues.
AF attribute scan modes
Set per AF server by an administrator (see AF Servers and Databases in the Administration Guide).
| Value evaluation mode | Current value read for |
|---|---|
| Operational attributes (default) | Attributes with a data reference, including configuration items and manual data entry. Attributes without a data reference, hidden attributes and excluded attributes are inventoried but Not Evaluated |
| All attributes | Every attribute |
| Inventory only | No attribute; AF metadata and dependencies only |
AF analysis issues
Category AF Analyses on the Issues page.
| Issue | Severity | Raised when | Typical fix |
|---|---|---|---|
| Broken AF Analysis | Error | The analysis health is Error: its definition cannot be evaluated, an input or output is broken, or more than half of the captured executions failed | Read the health message on Overview; correct the analysis in PI System Explorer |
| AF Analysis Health Warning | Warning | The health is Warning, for example at least one captured execution failed or was skipped | Read the health message; check the inputs and the trigger |
| AF Analysis Status Warning | Warning | The analysis status is neither enabled, good, disabled nor stopped, for example an error state of the Analysis Service | Check the analysis in PI System Explorer |
| Disabled or Stopped AF Analysis | Per AF server: Ignored, Info (default), Warning or Error | The analysis is disabled or stopped | Enable it, or delete it if it is no longer needed |
| High AF Analysis Service Load | Error | Service load above the threshold, when its severity is set to Error | Lengthen the trigger interval or simplify the expression |
| AF Analysis Service Load Warning | Warning | Service load above the threshold (default 5 %) | As above |
Disabled, stopped and not-ready analyses stay in the list with their configuration and dependencies, but PI Nexus+ does not evaluate their rules.
Analysis performance
| Figure | Calculation |
|---|---|
| Service load | Average elapsed time divided by average trigger interval, in percent |
| Runtime per day | 86,400 seconds divided by the average trigger interval, times the average elapsed time |
| Error ratio / skip ratio | Failed / skipped executions as a share of all captured executions |
| Setting (per AF server, Analysis Settings) | Default |
|---|---|
| Service load check | On |
| Service load threshold | 5 % |
| Service load severity | Warning (shown as Moderate); Error is shown as High |
| Minimum executions before thresholds apply | 25; below that the service load shows Insufficient Data |
| Error ratio | Above 50 %: health Error. Above 0 %: health Warning |
| Skip ratio | Above 0 %: health Warning |
No Runtime Data means the Analysis Service returned no runtime statistics for the analysis.
AF element and template states
| State | Meaning |
|---|---|
| Element Good / Warning / Bad | Worst health of its child attributes and analyses |
| No Health Sources | The element has no attribute or analysis that PI Nexus+ evaluates |
| Not Evaluated | The element cannot be evaluated at the moment |
| Template With Issues | At least one element built from the template has an open issue |
