Nortel Circuit Card Installation Manual page 121

Table 33
NT8D14 vintages BA/BB jumper strap settings—extended range
Trunk types
CO/FX/WATS
2-way tie (LDR)
2-way tie (OAID)
DID
RAN: pulse start or
level start modes
Note: Jumper strap settings J1.X, J2.X, J3.X, and J4.X apply to all eight units; "X" indicates the
unit number, 0–7. "Off" indicates that no jumper strap is installed on a jumper block.
Table 34
NT8D14 vintages BA/BB trunk types—termination impedance and balance network
(Part 1 of 2)
Trunk types
CO/FX/WATS
2-way tie (LDR)
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 is jumper selectable between 3COM1 and 3COM2.
Loop length
> 1524 m (5000 ft)
> 600 ohms
Not applicable: RAN
trunks should not leave
the building.
Terminating
impedance
Zero–915 m
(Note 1)
(zero–3000 ft)
600 or 900 600 ohms
ohms
600 or 900 600 ohms
ohms
Option settings
Jumper strap settings
J1.X
Off
On
Off
Balance network for loop lengths (Note 2)
915–1524 m
(3000–5000 ft)
3COM1
3COM1
Circuit Card
Page 121 of 906
J2.X J3.X
Off 1–2
On 1–2
Off 2–3
> 1524 m
(> 5000 ft)
3COM2
3COM2
Description and Installation
J4.X
2–3
2–3
1–2