WorkCentre 3210/3220 Multifunction Printer Service Manual 2-29
Theory of Operation
Fax
Fax is implemented by a conexant DAA (Data Access Arrangement) solution
and is roughly composed of two kinds:
â– CX86710 (SFX336)): A modem chip which adds SSD (System Side
Device) for interfacing between LSD and DIB of FM336Plus Core.
â– CX20493 (LSD): LIU (Line Interface Unit) chip controlled by SSD and
satisfies each PSTN requirements by modulating internal configuration
with connecting telephone line.
Modem (SFX336) Specification
â– 2-wire half-duplex fax modem modes with send and receive data rates up
to 33,600 bps
â– V.17, V.34, V.29, V.27 ter, and V.21 Channel 2
â– Short train option in V.17 and V.27 ter
â– PSTN Session Starting: V.8 and V.8b is signaling
â– HDLC support at all speeds
â– Flag generation, 0-bit stuffing, ITU CRC-16 or CRC-32 calculation
and generation
â– Flag detection, 0-bit deletion, ITU CRC-16 or CRC-32 check sum
error detection
â– FSK flag pattern detection during high-speed receiving
â– Tone modes and features
â– Programmable single or dual tone generation
â– DTMF receiver
â– Tone detection with three programmable tone detectors
â– Receive dynamic range
â– 0 dBm to -43 dBm for V.17, V.29, V.27 ter and V.21 Channel 2
â– 9 dBm to -43 dBm for V.34 half-duplex
â– Digital speaker output to monitor received signal
s3210mfp-143
Modem
CX86710(SFX336)
DSP
SSD
System
Side
Device
Transformer
Transformer
CX20493
LSD
Line
Side
Device
Tel Line
Ext Line
LIU
SDAA
Sound Output
MC14051BD
Volume/Keyclick
Control
MC34119DR2
Speaker
Driver