Page 142 - Advanced Course

KNX ADVANCED COURSE

2 The TP1 Coupler

The coupler for TP1 can be used as a:
Line coupler
Backbone coupler
Line repeater

The selected application software determines the function of the coupler (for further
information see basic KNX course). Only when the coupler is used as a line repeater
special application software can be selected. This is however not strictly necessary as the
coupler software recognises the type of the device through the selected physical address.

In June 2003, the first generation coupler was replaced by a new variant. A distinction is
therefore made in the following section between the “old” and “new” coupler. As the old
coupler type has been used in a large number of installations, underneath also its
characteristics are described.

2.1 Structure of the TP1 Coupler

The TP1 coupler essentially contains:
Two microcontrollers in the old coupler generation or a common controller in the new
coupler generation
Two transmission modules
Memory for the filter table and for buffering telegrams
 Old coupler: 4 Kbyte static “dual-ported“ SRAM, buffered against voltage failure for
more than 10 years via a lithium battery

 Filter table in upper memory area (3.5 K) for 28,672 group addresses (in
view of this, main groups 14/15 cannot be individually filtered)
 Telegram buffer (0.5 K) for 20 telegrams in the lower memory area, each
23 bytes long with a flag byte before and a status byte after the telegram.
10 telegram buffers are reserved for each direction.

 New coupler: In this coupler type, the memory is implemented as a flash memory
so that buffering via a battery is not necessary.
The coupler has three LEDs in addition to the programming LED; a green operating LED
and a yellow LED for each line. The yellow LEDs only flicker on receipt of a telegram and
not when a telegram is sent.

2.2 Connection of TP1 Couplers

The terms “primary line” or “main line” correspond to the upper segment while the terms
“secondary line” or “line” correspond to the lower segment.
The primary line is connected via a bus connector on the front of the coupler while the
secondary line is connected via pressure contacts on the data rail. A version of the new
coupler is also available which allows the secondary line to be connected via a bus
connector on the front of the coupler.

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