236 • LON

Network architecture – Principles and Regulations

5.3.4 Recommended bus and cable lengths

Note

If components of different manufacturers are used in one network, there might be diverging indications. The following information is based on the specifications of Echelon® and are to be understood merely as recommendations.

Dependent on the selected topology, the maximum transmission distances achievable are different.

5.3.4.1 Bus shaped wiring

For a bus shaped wiring with a bus termination on both ends, the following cable lengths are permissible:

(Bus termination on both ends: 105 Ω +/- 1%)

Tab. 5-2: Bus lengths with FTT-10 transceivers/bus topology, with terminations on both ends

When using a physical repeater, max. 5400 m can be reached.

5.3.4.2 Free Wiring

With a free wiring (tree, star) with a bus termination at one end, the following cable lengths are permissible:

(Bus termination on one end: 52 Ω +/- 1%)

Tab. 5-3: Bus lengths with FTT-10 transceivers/Free wiring (tree, star), with termination on one end

For a safe transmission in bus segments with a tree topology the following points are to be observed:

•If there are different signal paths, e.g. in a ring-shaped topology, the longer transmission path has to be taken into account.

•The maximum cable length is the total of all network conductors connected in the bus segment.

Modular I/O System

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