CN2 (1/2)
TEL1
TEL2
CN2 (2/2)
SR
8
CN1
LINE
AR
, AR
1
2
arresters
1
IC
2
F
OFF HOOK Detector
D
Ring Detector
RL
2
C
C31 R5
CML
C4
7
DP
RL3
RL
1
B
R
,
10
11
4
Figure A3.5.1 Block Diagram of UNC
IC1
E
T
5
1
Impedance
matching
NT
PP
R
574
RL6
Receiving
A
Sensitivity
6
CN3
OH2
RI
S
, R
504
to Modem
Adj
Rp
R