Glossary
| Term | Meaning |
|---|---|
| Project | Engineering root. Creating one opens the main workspace and a local deployment target |
| Workspace | Draft / copy-on-write area. Edits are delta rows |
| Revision | Immutable engineering document after publish. UPDATE/DELETE are rejected |
| Resource | folder, tag, screen, equipmentType, equipment, udt, udtInstance, connection, report |
| Snapshot | Compiled runtime document; sealed with a content hash |
| Deployment target | Per-project deploy target; may bind to a runtime |
| Runtime | Live process. One process per tenant (Model A) |
| Tag | Measurement or command point; carries behaviour, source, and alarm limits |
| Connection | Endpoint catalogue (host/port/auth). Not stored in the snapshot |
| UDT | User-defined type; instances expand to tags |
| Equipment | Type + instance; compiler emits tags and a faceplate screen |
| Screen | HMI scene (JSON → SVG). No separate scene format |
| Publish | Validate + immutable revision + compile |
| Activate | gRPC StageSnapshot then ActivateSnapshot |
| SOE | Sequence of Events ring |
| Select / Operate | Select-before-operate command protection (lease) |
| Spool | Local JSONL historian queue (ready/ rotation) |
| Principal | User account (roles: admin, engineer, viewer, operator) |
| Session | Opaque session token (~12 hours) |
| API token | vion_at_* personal access token |
| Tenant | Isolation unit when multi-tenant mode is on |
| vion.toml | Server config file (env > file > default) |