ABB AC 800M, User Manual

Page: 62 / 118

Tree Topology Section 3 Fieldbus Topologies
62 3BDS009029R5001 B
Tree Topology
With this topology, devices on a single fieldbus segment are connected via
individual twisted wire pairs to a common junction box, terminal, or I/O card. This
topology can be used at the end of a home run cable as well as in between. It is
practical if devices on the same segment are well separated, but in the general area
of the same junction box. When using this topology, the maximum spur length must
be taken into consideration. Maximum spur lengths are discussed in Line Topology
with spurs.
Figure 17.
Tree Topology
Combinations of the topologies above are possible. However, all rules for
maximum fieldbus segments length, including spurs, must be taken into account
for the calculation of the total bus length.