Page 63 - Basic Course

KNX BASIC COURSE

21 Informative annex - old line coupler type

Old line coupler type

Secondary line on data rail

Secondary line

Electrical insulation 600 V Spring contacts
Bus coupling
230 V
Logic Filter table 50/60 Hz > 100 ms buffer
SV +
Bus +
Lithium battery Bus ‐
> 10 years SV ‐
Bus coupling Power supply unit Choke Connector LC

640 mA
Main line

Primary line on bus connector

Figure 20: Block Diagram: old line coupler type

In earlier installations (until June 2003) line couplers were installed where power supply
for both bus couplers, logic and the filter table memory were supplied from the secondary
line.

The primary line of this type of coupler, which is 4 respectively 1 unit wide, is connected
via standardized bus connectors and the secondary line by means of a data rail (spring
contacts). The connection to the bus cable is established by means of a data rail
connector (2-pole or 4-pole).

A lithium battery (with a life span of more than 10 years) provides the backup supply for
the memory containing the filter table, also in the case of a bus power down. New line
couplers are equipped with a flash ROM memory and therefore do not need backup
battery power.

Home and Building Management Systems KNX Association
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