Allen-Bradley ControlNet 1786-RPFS Installation Instructions Manual page 9

2. Hold down the latch and insert the other end of the duplex cable into
another module using either Channel 1 or Channel 2 of the other
module.
The duplex cable is manufactured with the fiber reversed on
opposite ends. This automatically connects A of one unit to
B of the other.
Never connect more than one duplex fiber or two simplex
fibers between the same modular repeaters, even if they are
from different modules on the same repeater.
Warning: Do not look directly into the fiber ports.
!
Light levels may cause damage to eyesight.
ControlNet Modular Repeater Short-distance Fiber Module 9
A B
A B
A B
AB PLCs
A B