Canon FACSIMILE BASIC 2000 Service Manual page 280

FACSIMILE SYSTEM
6–8
T1 Off-hook
detection circuit
B
HS
T2
L1
Exchange
L2
Fig. 6-7 Formation of DC Loop on Facsimile Side
H relay
ON
CML relay
DC seize
circuit
ON
To 2-wire/4-wire
conversion circuit
NCU board