Rockwell Automation 1757-FFLD Linking Device Configuration Manual - Manual (Page 22)

Publication 1757-PM002A-EN-E - June 2006
2-12 Set Up A System
Figure 2.5 and Figure 2.6 are examples of chicken foot topologies using
Relcom Blocks.
Figure 2.5 Tree Topology (Chicken Foot) Using Relcom Blocks
Figure 2.6 Relcom Blocks in a Chicken Foot or Star Fieldbus
Topology
Bus With Spurs Topology
This topology consists of fieldbus devices that are connected to a multi-drop
bus segment through a length of cable called a spur. A bus with spurs topology
is technically acceptable but not generally a good economic choice.
Figure 2.7 below is an example of a bus with spurs topology. Since it is at the
end of the trunk, the junction box on the right has its internal terminator
enabled.
Figure 2.7 Pepperl + Fuchs F4-JB-I1.CGS FieldConnex
Junction Boxes
To H1 Linking
Device
T T Trunk
Isolated
Terminator
Block
Expansion
Block
Power
Conditioner
D/1 D/3 D/2 D/4 D/5 D/6 D/7
Junction Box
1
ng
ce
T
Junction Box Junction Box