Question
The Group Address space in KNX TP1 allows up to 65 536 different Group Addresses (2^16).
Answer
True
A Group Address is encoded on 16 bits inside the telegram, giving 65 536 possible values. In practice, the address 0/0/0 is reserved as a broadcast, so 65 535 addresses remain available for application use. Whether the project uses the 2-level (main/sub) or 3-level (main/middle/sub) representation does not change the underlying 16-bit address space — it only changes how the bits are visually grouped in ETS.
Preparation tip
Even on huge projects the limit is rarely reached — long before exhausting 65 535 addresses, you will have hit ETS performance bottlenecks. Worry about naming clarity, not about running out of addresses.
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