CimViewer

A single-file web tool for inspecting IEC CIM / CIM100 RDF/XML power-network exports in the browser. Loads any CIM XML file, draws components on a real map and on a non-crossing schematic, and flags common data-quality problems (like AcLineSegments with the wrong number of Terminals).

▶ Try it online

Launch CimViewer →

No install, no clone, no sign-up — click the link, pick your CIM XML file, and it parses entirely in your browser. Nothing is uploaded anywhere.

Prefer to run it locally? See Running it locally below.

Features

• Two views
  • Geographic — components placed on an OpenStreetMap background using their real PositionPoint coordinates.
  • Relationship — a schematic that lays every component out as a radial tree, with black dotted lines drawn along the CIM topology (Equipment ─ Terminal ─ ConnectivityNode ─ Terminal ─ Equipment). Nodes never overlap, so it's easy to see what's connected to what when components share a location on the map. Associations are followed in both directions, so classes that name their counterpart themselves (LvFeeder.Terminal, Feeder.Substation, Equipment.EquipmentContainer) are connected too, not stranded.
• Click any component to see every attribute from the source XML in a table — one click copies a value to the clipboard.
• Dynamic layers — every class found in the file gets its own checkbox with a count.
• Class scope — the relationship view shows Recommended classes by default (conducting equipment plus containers such as Feeder, LvFeeder, Substation, VoltageLevel), or switch to All classes to include reference data (BaseVoltage, WireInfo, UsagePoint, alias and address records). Containers are drawn as dashed boxes so they read as grouping rather than as devices.
• Vendor extension namespaces — objects outside the main CIM namespace (e.g. Zepben EWB's zb:LvFeeder) are parsed and shown, with the extra namespaces listed in the Format panel. Only RDF and model-description metadata are ignored.
• Validation checkboxes with an issues panel: highlights AcLineSegments with ≠2 terminals (pulsing red so they're impossible to miss), Terminals missing a ConnectivityNode, and Equipment missing a Location.
• Search by component name or mRID; pressing Enter zooms and selects in either view.
• Resizable sidebar, drag-to-pin nodes in the schematic, and zoom/pan on both views.

Running it locally

If you'd rather not use the hosted version, or you want to work offline:

1. Download CimViewer.html.
2. Serve the folder with any local HTTP server. The simplest way is Python (included with most systems):

   python -m http.server 8000
   

3. Open http://localhost:8000/CimViewer.html in any modern browser (Chrome, Edge, Firefox).
4. Click Load CIM XML file… and pick your CIM RDF/XML export.

That's it. Nothing is uploaded anywhere — parsing happens entirely in your browser.

Why a local server? OpenStreetMap's tile servers require a valid HTTP Referer header. If you open the HTML file directly by double-clicking it, the browser uses the file:// protocol which sends no referer, so map tiles will show a 403 error. Serving from localhost fixes this. The Relationship (schematic) view works either way since it doesn't use map tiles.

Other ways to serve locally

Tool	Command
Python 3	python -m http.server 8000
Python 2	python -m SimpleHTTPServer 8000
Node.js	npx serve .
PHP	php -S localhost:8000
VS Code	Install the "Live Server" extension, right-click the file → Open with Live Server

Supported CIM shape

• Namespaces: http://iec.ch/TC57/CIM100# (plus Zepben Evolve extensions).
• Any top-level CIM element with a PowerSystemResource.Location is recognised as equipment automatically — the type list is built from the file, so PowerTransformers, BusbarSections, custom types, etc. all appear without code changes.
• Equipment with ≥2 PositionPoints is drawn as a polyline; everything else as a point marker.
• The schematic topology is reconstructed from Terminal.ConductingEquipment and Terminal.ConnectivityNode references.

Dependencies

The page pulls these from public CDNs at load time:

• Leaflet 1.9.4 — map rendering
• OpenStreetMap tiles
• D3 v7 — schematic layout (force + radial tree)

If you're behind a strict corporate proxy that blocks unpkg.com, cdn.jsdelivr.net or tile.openstreetmap.org, the relevant part of the page will fail silently. Easiest workaround: vendor the library files locally and update the <script>/<link> tags.

Browser support

Any modern Chromium-based browser, Firefox, or Safari. The tool uses plain DOM + SVG + fetch + DOMParser — no polyfills required.

Limitations / not yet supported

• CIM-level assets that aren't PowerSystemResource-located (e.g. catalog data) are skipped.
• The schematic layout builds a BFS spanning tree per connected component, so cycles in the topology are rendered without their extra edges (cycles are rare in distribution networks but common in transmission).
• Single-file tool — no persistence, no backend, no diff between files.

Contributing

Issues and pull requests welcome. Keep the tool as a single HTML file with CDN dependencies unless there's a strong reason to add a build step.

License

MIT — do whatever you like, no warranty.

Support

If this tool saves you time, you can buy me a coffee ☕. Entirely optional — the code stays free.