Network Communications—N2 Communications Bus
27
The N2 Bus is wired to the dedicated terminal block on each ASC. For
details, refer to the technical bulletin for the particular ASC.
You can use the N2 Bus repeater in three different configurations: station,
branch, or star. As these configurations show in Figures 12, 13, and 14, the
maximum N2 Bus length from the NCU to the farthest device
cannot
be
longer than 4572 m (15,000 ft). This is the farthest distance the N2 Bus
signal can travel. Note, however, that the grand total of all N2 Bus
segments can be much longer than 4572 m (15,000 ft). For example, in
Figure 13, the grand total is 7315 m (24,000 ft); however, the longest
single run is 4115 m (13,500 ft).
The station configuration, shown in Figure 12, has repeaters wired in
between the devices.
NEU
ASC
NCU
N2 Bus
ASC
NEU
NEU
NEU
NEU
NEU
Repeater
1524 m (5000 ft)
50 Devices
A B
or
A B
Repeater
4572 m (15,000 ft)
REPEATCN
NCM's
EOL In
EOL Out
Self
Termination
EOL Out EOL Out
A: EOL In
B: EOL In
EOL Out
EOL Out
EOL Out EOL In
A: EOL In
B: EOL In
Figure 12: Repeater Station Configuration
Wiring--ASCs
to N2 Bus
Installing the
Repeater