Nortel Networks Circuit Card User Manual
Page 552

Page 552 of 906
NT8D09 Analog Message Waiting Line card
553-3001-211 Standard 3.00 August 2005
Figure 110
Analog message waiting line card – block diagram
Input/output
interface
control
Micro-
controller
DS-30X
interface
5.12 MHz
clock
Tx PCM
Async card
LAN link
Front
panel
LED
Card LAN
interface
Line interface unit power
Rx PCM
1 kHz
frame sync
Card slot
address
Backplane
Controller
card
Line
signaling
interface
Control
logic
Reg
Signaling
and status
Address/
data bus
553-6168
Power
supplies
Ring
generator
–150 V dc
light
power
+8.5 V dc
+ 5 V dc power
Reg
+15 V dc
+12 V dc power
Ringing
– 48 V dc
battery
Rsync
XFMR
Signaling relays
(ringing, battery
reversal)
Line interface units 0–3
Tip
Ring
Analog
telephone
lines
Loop current/
dialpulse detect
Message
waiting
XFMR
Signaling relays
(ringing, battery
reversal)
Line interface units 4–7
Tip
Ring
Analog
telephone
lines
Loop current/
dialpulse detect
Message
waiting
XFMR
Signaling relays
(ringing, battery
reversal)
Line interface units 8–11
Tip
Ring
Analog
telephone
lines
Loop current/
dialpulse detect
Message
waiting
XFMR
Signaling relays
(ringing, battery
reversal)
Line interface units 12–15
Tip
Ring
Analog
telephone
lines
Loop current/
dialpulse detect
Message
waiting
Analog
hybrid
Analog
hybrid
Analog
hybrid
Analog
hybrid
PCM
Codec
PCM
Codec
PCM
Codec
PCM
Codec