Question

Which information does the control field of the first data block carry?

KNX BasicLearnKNX RFMedium
Answer

C — Telegram length, device type (uni-/bidirectional), transmission quality (signal strength) and battery status

Correct: the control field holds the telegram length, the device type, the transmission quality and the battery status of battery-operated devices.

Source

KNX Basic Course Documentation — 3.4 — p. 147

All proposed choices (exam context)
  1. A.Only the CRC used for error detection
  2. B.The switching or dimming command to be executed
  3. C.Telegram length, device type (uni-/bidirectional), transmission quality (signal strength) and battery status
  4. D.The group address assigned by ETS
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Last updated: 19 May 2026

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