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Echelon segments

Echelon/Echelon Network are all the wire, fiber and devices connected.
A Segment is one wired section. If you used your ohm meter you would read zero ohms between all parts of a segment. A segment is a wired piece of the Echelon.
A Echelon Segment can be wired two ways - Bus or Free Topology
Each Segment needs to be terminated, both ends for Bus, once in the center of the wire for Free Topology.
Max of 64 nodes/devices/Electrical Drops
The Segment wire is non-polarized (no positive or negative)
There is no baud rate settings on the Echelon Network or the Echelon Segment, the baud is set at 78.5k
Routers, repeaters and regenerates help separate segments.

BUS topology

Bus topology is a wired segment of the Echelon where all the nodes are wired in and out, like a RS485 bus would be wired,
it would be wired into one node then to the next Wired in series.
Max of 64 nodes per segment, terminated on both ends of the segment (2 terminations).
Any Bus segment that is less then 2,000ft is treated as Free Topology and is terminated once in the center.
Bus Topology will run 2,000ft to 6,000ft with 3 or more nodes, 8,000ft with a node on each end.

Free topology or FT

As the picture shows the nodes are tapped anywhere on the wired segment.
Terminated once in the center of the nodes/wire.
No two nodes can be separated by more then 1,500ft of wire.
Free topology is also known as FT