Muratec MFX-3595 Field Engineering Manual page 104

Network Control Unit (NCU) board
The NCU board provides the connection to the telephone line. It consists of the interface circuit, ring signal
detector and telephone control circuit.
SURGE
ABSORBER
H Relay
OH
Detector
~
- +
AGND
~
Electronic Inductor,
Off-Hook, Pulse Dial,
and TIP, and RINGVI
Control
Receive
Coupling
Impedance
Matching and
24V
Transmitter
IC1
SmartDAA
CONT24
2-30
IC2
Modem
OH
28.224
MHz
CS
SDI
SDO
SCK
PWM
CI
IRQ
RESET
H