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Glossary

A quick reference for the KNX and ETS terms used throughout the documentation. Terms link back to the Academy page that explains them in depth.

Actuator​

A device that receives telegrams and drives a physical load (relay, dimmer, blind motor, valve). Multi-channel: one device, many switchable circuits. See Devices.

Application program​

The manufacturer-supplied "driver" for a device, imported into ETS. It defines the device's parameters and group objects.

Area​

The top level of the KNX topology below the backbone; groups up to 15 lines. Part of the individual address.

Backbone​

The line that joins all areas via backbone couplers.

Bus​

The shared medium (TP cable, IP, RF, PL) carrying power and data between KNX devices. See The bus.

Bus monitor / Group monitor​

ETS diagnostic tools that show live traffic — raw frames (bus monitor) or decoded group communication (group monitor).

Channel​

One independently controllable output/input of a multi-channel device. The thing you link a group address to.

Commissioning (download)​

Writing the engineered configuration from ETS into the physical devices over the bus. See The ETS workflow.

Coupler​

A device joining two topology segments (line/area/backbone) and filtering traffic between them.

Datapoint type (DPT)​

The format and meaning of a value on the bus, written main.sub (e.g. 9.001 = temperature °C). See Datapoint types.

EIB​

European Installation Bus — KNX's main predecessor. EIB and KNX are backward compatible; treat them as the same bus. See What is KNX?.

ETS​

Engineering Tool Software — the manufacturer-independent tool every KNX project is built and commissioned with. See What is ETS?.

FDSK​

Factory Default Setup Key — the per-device key (printed on the device) ETS uses to take ownership of a KNX Secure device.

Flags (C R W T U I)​

Per-group-object settings (Communication, Read, Write, Transmit, Update, Init) that govern how the object behaves on the bus. See Telegrams & group addresses.

Group address​

A logical "mailing list" devices send to and listen on, written main/middle/sub (e.g. 1/1/0). The unit of building logic. See Telegrams & group addresses.

Group object / communication object​

A device's linkable endpoint (e.g. "Switch", "Status") that you connect to a group address in ETS.

Individual address (physical address)​

A device's unique area.line.device address (e.g. 1.2.14), used for engineering/diagnostics — not normal operation. See Topology.

KNX Association​

The member organisation maintaining the KNX standard and certification, and publishing ETS.

KNX Data Secure​

End-to-end authentication/encryption of application telegrams. See KNX Secure.

KNX IP Secure​

Encryption of KNXnet/IP transport. See KNX Secure.

KNXnet/IP​

KNX carried over Ethernet/IP — tunnelling (point-to-point) or routing (multicast between lines).

Keyring (.knxkeys)​

The exported, password-protected file holding a secure project's keys. Required to maintain a KNX Secure installation. See KNX Secure.

.knxproj​

The single file ETS exports: a ZIP of XML holding the whole project — topology, devices, parameters, group addresses, building structure. The asset KNX Clarity versions. See What is ETS? and ETS files.

.knxprod​

A manufacturer product-data file imported into ETS to make a device available for engineering.

Line​

One bus segment with its own power supply (~64 devices). 15 lines per area. See Topology.

Line/area repeater​

A device extending a segment's device capacity without adding a topology level.

Parameter​

A configurable setting on a device (timings, modes, thresholds) set in ETS and written during commissioning.

Power supply​

The device feeding a line's bus voltage (typically 30 V DC). One per line.

Sensor​

A device that detects something and sends a telegram (button, presence, temperature…). See Devices.

Telegram​

The short message a device puts on the bus: sender, target group address, and a DPT-encoded payload. See Telegrams & group addresses.

Topology​

The hierarchical structure of a KNX network (backbone → areas → lines → devices). See The bus & topology.

TP (twisted pair)​

The dominant wired KNX medium — the green two-core bus cable carrying power and data.