Nortel Networks Circuit Card ユーザーズマニュアル

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 NT8D14 Universal Trunk card
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Electrical specifications
Table 185 gives the electrical characteristics of the NT8D14 Universal Trunk 
card.
Table 185
Universal trunk card – trunk interface electrical characteristics (Part 1 of 2)
Trunk Types
Characteristic
CO / FX / WATS
DID / TIE
RAN
Paging
Terminal impedance
600 or 900 ohms 
(Note 1)
600 or 900 ohms 
(Note 1)
600/900 ohms 
(Note 1)
600 ohms
Balance impedance
600 or 900 ohms 
(Note 1),
3COM, or 3CM2 
(Note 2)
600 or 900 ohms 
(Note 1),
3COM, or 3CM2 
(Note 2)
N/A
N/A
Supervision type
Ground or 
loop start 
(Note 3)
Loop start 
(with ans sup) 
(Note 3)
Continuous, level, or 
pulse
N/A
DC signaling loop 
length (max)
1700-ohm loop with 
near-end battery of 
–42.75 V
2450-ohm loop with 
near-end battery of 
–44 V
600/900-ohm loop
600 ohm 
loop
Far-end battery
–42 to –52.5 V 
(Note 4)
–42 to –52.5 V
–42 to –52 V
N/A
Minimum detected 
loop current
20 mA
10 mA
10 mA
N/A
Ground potential 
difference
±3 V
±3 V
±1 V
±1 V
Low DC loop 
resistance during 
outpulsing
<300 ohms
N/A
N/A
N/A
High DC loop 
resistance
Ground start 
Š 30k ohms; 
loop start 
Š 5M ohms
N/A
N/A
N/A
Ring detection
17 to 33 Hz
40 to 120 V rms
N/A
N/A
N/A