Ncu - Ricoh FAX550 Service Manual

DETAILED SECTION DESCRIPTIONS
PCBs AND THEIR FUNCTIONS

2.3.5. NCU

TIP
To
Network
RING
To
Handset
T1
R1
T2
R2
To
Answering
Machine
NCU
•
For simplification, relay drive signals and detector outputs to/from the
FCU are not shown on this diagram.
•
In the above diagram, the relays are shown in the standby position for
Auto Receive (Fax) Mode.
Protection
Circuit
Line
Current
Detector
FG
Oh
Relay
2-11
November 30th, 1991
Tx/Rx Data
Di Switch
To/From FCU
Ringing
Signal
Detector
Auto
Mode
Relay
From FCU
Off-Hook
Detector
2
To FCU
+24V
To FCU