26
Network Communications—N2 Communications Bus
Twisted
Two Twisted Pair Telephone Cable
3-wire Twisted Cable
TBCWIRE2
3 6
2 5
1 4
HRD
GND
SFT
GND
SFT
GND
Twisted
OUT (-)
REF-OUT
IN (-)
IN (+)
REF-IN
OUT (+)
3
6
2 5
1
4
HRD
GND
SFT
GND
SFT
GND
TB2
Twisted
Twisted
IN (-)
OUT (-)
REF-IN
REF-OUT
OUT (+)
IN (+)
TBC821
Notes:
We recommend 22 AWG or heavier wire.
Experience has shown that 24/26 AWG wire
is prone to breakage during installation.
If shielded wire is used, wire shield to SFT GRD
(soft ground) terminal for devices other than the NCM.
one location, preferably at the NCU.
To hard ground
N2 Bus, wire shield to HRD GRD (hard ground).
Wires that are labeled "OUT" and "REF OUT"
are only used if the N2 Bus must continue
to another device.
For two twisted pair cable, terminate one pair
to (+) and (-). Terminate the other pair
by terminating one wire to REF and folding back
and taping the remaining wire.
= Tape Back
T
UNUSED
UNUSED
6
5
3
2
1
4
TB1
6
5
3
2
1
4
Figure 11: Wiring N2 Bus to the Communication Terminal Board
(TBC821)