Equipment-class.schema.json gains an `extends` field for class inheritance — child classes inherit signals, alarms, and stateModel from the parent and can add new ones or override individual entries by name. Convention: `_` prefix on classId marks an abstract base class (e.g. `_base`) intended only to be extended, not assigned directly to equipment via Equipment.EquipmentClassRef.
FANUC CNC class updated to extends: "_base"; redundant identity signals (Version, ActiveAlarmCount) removed since they're now in the base; remaining FANUC-specific signals updated with cross-references showing how they feed into the base signals at Layer 3 (RunState → canonical Running/Idle/Faulted derivation; AlarmActive → HasActiveAlarms / HighestActiveAlarmSeverity; PartsCount → TotalCycles; MainProgramNumber → CurrentRecipe).
Format-decisions.md adds D9 (rationale for `_base` + `extends` inheritance, with references to OPC 40010 / Part 9 / ISO 22400 / handoff) and D10 (signal `category` drives OPC UA folder placement, per OPC 40010 Identification + Status pattern, with a category-to-folder mapping table).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Includes: README explaining purpose / scope / temporary-location framing / format decision, CONTRIBUTING.md with proposed workflow + per-class semver versioning policy + validation commands, format/equipment-class.schema.json defining the shape of a class template (classId, version, displayName, applicability, signals, alarms, optional stateModel), format/tag-definition.schema.json defining the shape of a single canonical signal (name, dataType, category, unit, isArray, accessLevel, writeIdempotent, isHistorized, scaling), format/uns-subtree.schema.json defining the shape of a per-site UNS subtree (enterprise + site + areas + lines), classes/fanuc-cnc.json as the worked pilot class with 16 signals + 3 alarms + suggested state-derivation notes (per OtOpcUa corrections doc D1), uns/example-warsaw-west.json as a worked UNS subtree example, docs/overview.md (what / why / lifecycle / what's NOT in this repo), docs/format-decisions.md (8 numbered decisions covering JSON Schema choice per corrections D2, per-class semver, additive-only minor bumps, _default placeholder reservation, signal-name vs UNS-segment regex distinction, stateModel-as-informational, no per-equipment overrides at this layer, applicability.drivers as OtOpcUa driver enumeration), docs/consumer-integration.md (how OtOpcUa / Redpanda / dbt each integrate). $id URLs in the JSON schemas resolve at the actual current path so validators don't 404.
Top-level README adds a row to the Component Detail Files table pointing to schemas/. Corrections doc B2 (schemas-repo dependencies) marked partially RESOLVED with the seed location and a list of what still needs the plan team or cross-team owner to decide (owner team naming, dedicated repo migration, format-decision ratification, FANUC CNC pilot confirmation, CI gate setup, Redpanda + dbt consumer integration plumbing).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
