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venfree/Wiki/KNX RF – KNX Radio Frequency

KNX RF – KNX Radio Frequency

KNX RF is the wireless transmission medium for KNX devices without TP bus wiring. Ideal for retrofit installations in existing buildings where cables cannot be laid.

Technology and Range

KNX RF transmits on 868 MHz (Europe) or 915 MHz (USA/Canada) with a maximum transmit power of 25 mW. Range within a building is typically 10–30 m, depending on walls, concrete and other obstacles. Range can be extended with repeaters.

KNX RF Multi (from 2016) is the current generation with improved bidirectionality, longer range and better coexistence with other 868 MHz systems (e.g. alarm systems). All modern KNX RF devices support RF Multi.

Differences from KNX TP

RF devices receive no bus voltage via cable, they require their own power supply (230 V) or batteries. Battery-operated devices (buttons, window contacts) typically have a 2–5 year battery life. A KNX RF coupler connects RF devices to a TP line; RF devices appear in ETS like normal TP devices.

Key Facts

  • Frequency: 868 MHz (Europe)
  • Range: 10–30 m within building
  • No bus voltage supply via RF
  • KNX RF Multi: bidirectional, current generation
  • RF coupler connects RF devices to TP line
  • Ideal for retrofitting without cable work

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