The available coupler types are: TP1/TP1, TP1/PL, TP1/RF and IP/TP1.
The allowed and by ETS supported coupler concatenations are:
Without backbone:
- TP1/TP1 (Line Coupler) + TP1/TP1 (Line Repeater)
- IP/TP1 (IP Router) + TP1/TP1 (Line Repeater)
With backbone:
- TP1/TP1 (Backbone Coupler) + TP1/PL
- TP1/TP1 (Backbone Coupler) + TP1/RF
- TP1/TP1 (Backbone Coupler) + TP1/TP1 (Line Coupler) + TP1/TP1 (Line Repeater)
- IP/TP1 (IP Router) + TP1/PL
- IP/TP1 (IP Router) + TP1/RF
- IP/TP1 (IP Router) + TP1/TP1 (Line Coupler) + TP1/TP1 (Line Repeater)
The following concatenations are technically possible, but NOT supported by ETS:
Without backbone:
- TP1/TP1 (Line Coupler) + TP1/PL
- TP1/TP1 (Line Coupler) + TP1/RF
- IP/TP1 (IP Router) + TP1/PL
- IP/TP1 (IP Router) + TP1/RF
With backbone:
- IP/TP1 (IP Router) + TP1/TP1 (Line Coupler) + TP1/PL
- IP/TP1 (IP Router) + TP1/TP1 (Line Coupler) + TP1/RF
These concatenations are not allowed because all segments of a line need to be of the same medium type.
World coupler
Theoretically it is also possible to make the following concatenations:
- IP/TP1 (IP Router) + TP1/TP1 (Backbone Coupler) + TP1/PL
- IP/TP1 (IP Router) + TP1/TP1 (Backbone Coupler) + TP1/RF
- IP/TP1 (IP Router) + TP1/TP1 (Backbone Coupler) + TP1/TP1 (Line Coupler)
- IP/TP1 (IP Router) + TP1/TP1 (Backbone Coupler) + TP1/TP1 (Line Coupler) + TP1/TP1 (Line Repeater)
The IP Router connects the installation (with TP1 backbone) to an IP network and can only have the Individual Address 0.0.0, because the address ranges: 0.1.0 -> 0.15.0 & 1.0.0 -> 15.0.0 are only allowed for TP1. The Individual Address 0.0.0 is however is not allowed and hence not supported by ETS.