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4.3.4 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 recommenda-
tions.
Dependent on the selected topology, the maximum transmission distances
achievable are different.
4.3.4.1 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%)
Cable type
Bus length if only FTT-10 is used in a
segment
Bus length if FTT-10 and LPT-
10 are used in a segment
Belden 85102
≤
2700 m
≤
2200 m
Belden 8471
≤
2700 m
≤
2200 m
Level IV, 22AWG
≤
1400 m
≤
1150 m
JY (St) Y 2x2x0,8
≤
900 m
≤
750 m
Tab. 4-2: Bus lengths with FTT-10 transceivers/bus topology, with terminations on both ends
When using a physical repeater, max. 5400 m can be reached.
4.3.4.2 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%)
Overall cable length with
Cable type
Distance of two nodes
10, 5 and 2.5 MHz clock
1.25 MHz clock
Belden 5102
≤
500 m
≤
500 m
≤
400 m
Belden 8471
≤
400 m
≤
500 m
≤
400 m
UL Level IV, 22AWG
≤
400 m
≤
500 m
≤
400 m
JY(St)Y 2x2x0,8
≤
320 m
≤
500 m
≤
400 m
Tab. 4-3: 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:
1.
If there are different signal paths, e.g. in a ring-shaped topology, the longer transmission
path has to be taken into account.
2.
The maximum cable length is the total of all network conductors connected in the bus
segment.