Page 61 - Basic Course

KNX BASIC COURSE

19 Line couplers replaced by KNXnet/IP routers

Line coupler replaced by KNXnet/IP Router

Line 1.5 KNXnet/ KNXnet/ Line 2.5
IP‐Router Floor 5 IP‐Router
1.5.0 2.5.0

KNXnet/ KNXnet/
Line 1.4 Floor 4 Line 2.4
IP‐Router IP‐Router
1.4.0 2.4.0

KNXnet/ KNXnet/
Line 1.3 IP‐Router Floor 3 IP‐Router Line 2.3
1.3.0 2.3.0

Line 1.2 KNXnet/ KNXnet/ Line 2.2
IP‐Router Floor 2 IP‐Router
1.2.0 2.2.0

KNXnet/ KNXnet/
Line 1.1 Line 2.1
IP‐Router Floor 1 IP‐Router
1.1.0 2.1.0
Area 1 Area 2
(West wing) Network (East wing)
(LAN)
Figure 19: Our picture again: line couplers have now been replaced by KNXnet/IP routers.
This picture represents the underneath explained case 1.

Just like the TP/TP coupler, the KNXnet/IP router can be used as a line coupler as well as
a backbone coupler. If the KNXnet/IP router replaces the line coupler, all main lines and
basically also the backbone line are replaced by Ethernet (Case 1).
If backbone couplers are replaced by KNXnet/IP routers, the normal line couplers can
remain, as only the backbone line is replaced by the LAN (Case 2).
Which case is more appropriate depends more or less on the - to be expected telegram
rate requirements on main – and backbone lines. Theoretically, a third case is possible, as
a combination of case 1 and 2, with normal TP areas with a KNXnet/IP router on top and
also with lines with IP routers instead of line couplers. This option should however be
chosen in exceptional cases. The topic is described in more detail in the KNX advanced
course.

Home and Building Management Systems KNX Association
KNX TP Topology Topology_E1213a 22/24