Question

Why is the KNX RF free-field range limited to approximately 100 m?

KNX BasicLearnKNX RFMedium
Answer

A — Because of the maximum allowed transmission power and the limited energy available in battery-operated or battery-free devices

Correct: the source names transmission-power limits and the limited energy of battery/battery-free devices.

Source

KNX Basic Course Documentation — 2 — p. 139

All proposed choices (exam context)
  1. A.Because of the maximum allowed transmission power and the limited energy available in battery-operated or battery-free devices
  2. B.Because the 868 MHz band physically cannot travel further
  3. C.Because ETS caps the transmission distance at 100 m
  4. D.Because encryption of telegrams shortens the range
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Last updated: 19 May 2026

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