Question

When a tool wants to read or write the memory of a System 2, 7 or B device, how must it authorize itself?

KNX BasicLearnKNX Bus DevicesMedium
Answer

B — With an authorization key of 4 bytes

Correct: Access requires the tool to first authorize itself with a 4-byte authorization key.

Source

KNX Basic Course Documentation — 3.2.1 — p. 128

All proposed choices (exam context)
  1. A.With an authorization key of 2 bytes
  2. B.With an authorization key of 4 bytes
  3. C.With an authorization key of 6 bytes
  4. D.No authorization is needed for System 2, 7 or B devices
Full bank

Keep going with the full KNX Basic bank

Keep going with the full KNX Basic bank: unlimited timed mock exams, detailed answers, history. From €9 (one-time payment).

See pricing — from €9
Want more?

See the 9 other KNX Basic practice questions

Related questions

Question from our independent practice bank. KNX Basic is a registered trademark of KNX Association, not affiliated with CertifBus.

Last updated: 19 May 2026

See pricing — from €9
KNX Basic pack · from €9
KNX BASIC & ADVANCED

Ready to find out where you really stand?

10 free questions every day, no account needed. Full access only if you decide to go all the way.

+1/−0,5 official scoringFR·EN·DE interface and explanations9 from · one-time payment
Newsletter

Get launch announcements

We'll email you when new KNX questions, a guide or a tool is published. No spam.

Unsubscribe in 1 click. No sharing with third parties.