Signaling Interface; Carrier Interface - Meridian Nortel 1 Option 11C Technical Reference Manual

Page 484 of 544

Signaling interface

Carrier interface

Table 150
Impedance matching switch selection
Cable
75 Ohm
120 Ohm
553-3011-100 Standard 14.00
NTAK79 2.0 Mb PRI card
The Meridian 1 signaling interface consists of the A07 DS-30X signaling
controller. This interface provides an 8 Kbps signaling link via the DS-30X
timeslot zero data bit zero. Messages are 3 bytes in length.
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
The line interface provides for the use of either 75ohm coaxial or 120ohm
twisted pair cable. The impedance is selected by a switch, as shown in the
settings table below.
Note: The ON position for all the switches is towards the bottom of the
card. This is indicated by a white dot printed on the board adjacent to the
bottom left corner of each individual switch.
January 2002
On
S2
S1
Off
S1
S2