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What is ETS?

ETS — the Engineering Tool Software — is the single, manufacturer-independent program used to design, configure, and commission every KNX installation. It is published by the KNX Association, not by a device vendor. Whatever brands are in the building, the project was built in ETS.

If KNX is the standard, ETS is how the standard is applied to a specific building. The file it produces — the .knxproj — is the artefact KNX Clarity is built around.

What ETS actually does​

ETS is where an integrator:

  1. Imports product data. Manufacturers publish their devices' application programs and parameters. ETS pulls these from the online KNX catalog (or imported .knxprod files).
  2. Builds the topology. Areas, lines, and the devices on them.
  3. Assigns individual addresses. Each device gets its unique area.line.device address.
  4. Parameterises devices. Channel modes, timings, thresholds, logic — the behaviour, set per device.
  5. Creates and links group addresses. The actual logic of the building: which button controls which actuator.
  6. Commissions (downloads). ETS connects to the bus through an interface and writes the individual address, application, and parameters into every physical device.
  7. Diagnoses. Group monitor, bus monitor, and device read-out for fault-finding.

The first six steps are engineering (data). Step 6's download is the moment that data becomes the physical building's behaviour.

ETS versions​

VersionNotes
ETS6Current generation. Project format read by modern tooling.
ETS5Still extremely common in the field; many live projects.
ETS4 / 3Legacy. Projects are usually migrated forward.

ETS6 can open ETS5 projects (migrating them). KNX Clarity targets ETS5/6 project exports — see ETS files.

Licensing (why it is not just "free software")​

ETS is licensed by the number of devices you can commission in one project:

  • ETS Demo — free, up to a handful of devices. Learning only.
  • ETS Lite — limited device count.
  • ETS Professional — unlimited; the integrator's working licence.
  • ETS Home — aimed at end users for their own home.

The licence governs commissioning, not whether a project file exists. This licensing reality is part of why a building owner often cannot "just open the project themselves" — and why a neutral, readable record of the installation has value independent of who holds an ETS licence.

The .knxproj file​

When an integrator exports a project, ETS produces a single .knxproj file. It is, technically, a ZIP archive containing XML: the topology, every device and its parameters, the full group address structure and links, the building/room structure, and metadata.

For KNX Secure projects it can be password protected, and the secure keys live in a companion .knxkeys (keyring) export.

This file is the building's logic

A .knxproj is not a backup of "settings" — it is the only complete, authoritative description of how the building behaves. Lose it and the next integrator is reverse-engineering the installation device by device. That single risk is the reason KNX Clarity exists: it stores, versions, and hands over the .knxproj so the building's engineering survives people and laptops. See ETS files and Escrow & transfers.

Continue to The ETS workflow to see how a project goes from empty to commissioned — and exactly what ends up in that file.