Nortel Networks Circuit Card 311 - Manual (Page 980)

980 NTBK50 2.0 Mb PRI card
Carrier interface
For the E1 interface, the connection to the external digital carrier is provided
by the line interface chip. This device provides accurate pulse shaping
to meet the CCITT pulse mask requirements. It provides clock recovery
functions on the receive side, as well as tolerance to jitter and wander in the
received bit stream.
For the E1 interface, the connection to the external digital carrier is provided
by the line interface chip. This device provides accurate pulse shaping
to meet the CCITT pulse mask requirements. It provides clock recovery
functions on the receive side as well as tolerance to jitter and wander in the
received bit stream.
For the E-1 interface, the connection to the external digital carrier is provided
by the line interface chip. This device provides accurate pulse shaping
to meet the CCITT pulse mask requirements. It provides clock recovery
functions on the receive side, as well as tolerance to jitter and wander in the
received bit stream.
Impedance matching (Switch SW2)
The line interface provides for the use of either 75 ohms coaxial or 120
ohms twisted pair cable. The impedance is selected by SW2, as shown in
Table 408 "Impedance matching switch settings" (page 980) .
Table 408
Impedance matching switch settings
Cable Type SW 2-1
75 ohms Down (On)
120 ohms Up (Off)
Note: The ON position for all the switches is toward the bottom of the
card. This is indicated by a white dot printed on the board next to the
bottom left corner of each individual switch.
The line interface provides for the use of either 75ohm coaxial or 120ohm
twisted pair cable. The impedance is selected by SW2, as shown in the
settings table below.
Table 409
Impedance matching switch settings
Cable Type SW 2-1
75 3 /
4
Down (On)
120 3 /
4
Up (Off)
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.