Nortel Circuit Card Installation Manual page 621

Table 193
Trunk types – termination impedance and balance network (NT8D14BA, NT8D14BB)
Trunk types
CO/FX/WATS
2-way TIE (LDR)
2-way TIE (OAID)
DID (loop length
< 600 ohms)
DID (loop length
Š 600 ohms)
RAN: continuous
operation mode
Paging
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.
Terminating
impedance
(Note 1)
(0–3000 ft)
600 or 900
ohms
600 or 900
ohms
600 or 900
ohms
600 or 900
ohms
600 or 900
ohms
600 or 900 600 or 900 ohms
ohms
600 ohms
NT8D14 Universal Trunk card
Balance network for loop lengths (Note 2)
0–915 m 915–1524 m
(3000–5000 ft)
600 ohms
600 ohms
600 ohms
600 ohms
600 ohms
600 ohms
Circuit Card
Page 621 of 906
> 1524 m
(> 5000 ft)
3COM
3COM
3COM
3COM
N/A
N/A
N/A
Description and Installation
3CM2
3CM2
3CM2
3CM2
3CM2
N/A
N/A