Nortel Networks Circuit Card - Manual (Page 621)

NT8D14 Universal Trunk card Page 621 of 906
Circuit Card Description and Installation
Table 193
Trunk types – termination impedance and balance network (NT8D14BA, NT8D14BB)
Trunk types
Terminating
impedance
(Note 1)
Balance network for loop lengths (Note 2)
0–915 m
(0–3000 ft)
915–1524 m
(3000–5000 ft)
> 1524 m
(> 5000 ft)
CO/FX/WATS 600 or 900
ohms 600 ohms 3COM 3CM2
2-way TIE (LDR) 600 or 900
ohms 600 ohms 3COM 3CM2
2-way TIE (OAID) 600 or 900
ohms 600 ohms 3COM 3CM2
DID (loop length
< 600 ohms) 600 or 900
ohms 600 ohms 3COM 3CM2
DID (loop length
Š 600 ohms) 600 or 900
ohms 600 ohms N/A 3CM2
RAN: continuous
operation mode 600 or 900
ohms 600 or 900 ohms N/A N/A
Paging 600 ohms 600 ohms N/A N/A
Note 1: The terminating impedance of each trunk unit is software selectable in LD 14 and
should match the nominal impedance of the connecting equipment.
Note 2: The balance network of each trunk unit is software selectable between resistive 600 or
900 ohms or 3COM and jumper selectable between 3COM and 3CM2. Jumper selection for
3COM/3CM2 restriction does not apply to NT8D14BB.