Page 216 - Basic Course

KNX BASIC COURSE

10.5 Line coupler or IP router?

IP router as a line coupler
Line 1.5 Line 2.5
Floor 5

Line 1.4 Line 2.4
Floor 4
Line 1.3 Line 2.3
Floor 3
Line 1.2 Line 2.2
Floor 2
Line 1.1 Line 2.1
Floor 1

Area 1 (West wing) Area 2 (East wing)
Data network (LAN)

Figure 51: IP routers replacing line couplers

For many years now, more and more IP routers are installed, next to the classic TP-TP
line couplers. Nowadays, they are still significantly more expensive but offer several
benefits that should not be underestimated:

In addition to the standard multicast routing function, each IP router offers one or more
so-called IP tunneling links.
These tunnelling links can be used for ETS remote access as well as for access by
visualisation programs.
If you access the associated line directly with ETS via an IP tunnelling connection, you
always have the fastest possible communication link available.
The visualisation can also be made considerably quicker if it can be linked to all IP
routers simultaneously via a single data interface.
In the vertical communication KNX to Visualisation, speeds of up to factor 225 can be
achieved (225 lines in parallel equals 225 x 9.6 kbit/s = 2.16 Mbit/s)

In principle one can say that the more lines that are needed and the more data points that
are centrally monitored, the more worthwhile the use of IP routers becomes.

Home and Building Management Systems KNX Association
KNX Project Design with ETS: Advanced ETS4_Planning complex_E0411c 40/59