PI Point Rules

Overview

This chapter defines which PI Points PI Nexus+ inventories and which health checks apply to them, so that issues match how each group of tags is expected to behave.

How rules work

• Rules are checked in order. The first enabled rule that matches a PI Point owns it.
• A rule with Scan and evaluate matching PI Points inventories and checks its points. Without it, its points are excluded and show Not Evaluated, even if a later rule would include them.
• Once rules exist, PI Points that match no enabled rule are not inventoried. Until the first rule exists, a built-in quality-only default applies.

Add or edit a rule

1. Open Admin > PI Point Rules and choose Add Rule, or Edit in a rule's row menu.
2. Leave Enabled and Scan and evaluate matching PI Points ticked for points you want checked.
3. Enter a Name and the match: PI Data Archive, PointSource, Name Include and Name Exclude. Fields take wildcards and comma-separated lists, for example OPC*, R.
4. Choose Preview Matching PI Points to see what the rule matches on its own.
5. On Built-in Health Checks, choose Ignored, Warning or Error per check, and the limits for Stale and Frozen. Add a Rule Reason when you ignore an expected state.
6. Choose Save Rule or Save Changes.

Order rules with Move to top, Move up, Move down and Move to bottom in the row menu. To stop using a rule, choose Disable; it stays in the list.

Changing a rule's match, archive, scan switch or position changes which rule owns which points; the page then asks for a full reconciliation (see Manual Scans and PI Point Rule Reconciliation).

Start Frozen at 24 to 72 hours; it applies to numeric points only.

Naming and attribute checks

These tabs work once the rule is saved. Tag Naming Pattern checks that tag names follow your naming convention:

1. In the rule's editor, open Tag Naming Pattern and choose Add Naming Pattern.
2. Choose the Separator and Segment characters, the Minimum segments and Maximum segments, and optionally the Allowed final tokens. The Advanced Regex follows these choices.
3. Enter tag names under Should Pass and Should Fail, and check that Examples match is shown.
4. Choose the Severity, then Save Naming Pattern and Save Changes.

Point Attribute Checks test PI Point attributes, for example that OPC tags have an instrumenttag or that Scan is on. In a check's menu, Remove only disables the check, like Disable.

Compression Tuning tab

Candidate for compression tuning, on for a new rule, makes the rule's points available to Compression Tuning runs; clear it for calculation outputs and event-like tags. Leave Signal profile override at Auto detect (Recommended) unless the behavior is known. Writing also needs Allow Tuning Writes (see PI Data Archives) and PI write access (see Service Account Rights in the Reference).

Analysis Recalculation tab

Suggest analysis recalculation, off by default, proposes a recalculation for review when a rule's point goes bad or stale and then recovers. It never recalculates by itself. Reviewing suggestions is described in AF Analyses and Recalculation in the User Guide.

Data Flow tab

Data Flow links the rule's points to External Systems as Sources or Targets; see External Systems.

Reference: PI Point Rule Fields