NFPA Style 4 Configurations
12
NOTI•FIRE•NET™ PN 50257:E 7/5/01
reconfigures to permit communication among the nodes within the fragment.
Figure 4 Style 4 Configurations
In an NFPA Style 4 fiber-optic system, a single break will result in loss of communication between
network nodes within the fragment of the network that can only receive signals from the other
fragment (refer to Figure 5). In Figure 5, the fragment to the left of the break cannot receive
information from the fragment to the right of the break. However, the fragment to the right of the
break can receive information from the fragment to the left of the break.
Figure 5 Fiber-Optic Style 4 System Break
Note:
A wire-to-wire short
here results in loss of
communication between all
four nodes/repeaters on this
bus connection as well as
fragmentation of the
network. Bus connections
should be no longer than 100
feet within conduit or
located within the same
enclosure.
These two nodes continue to
communicate with each other.
These two nodes continue to
communicate with each other.
However, they will not transmit
to the first two nodes.
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