Samsung SCX-4521F Series Service Manual page 168

4. Fax Modem Part
1) Modem Part
The modem part is consist of FM336(FAX Modem chip), LIU(Line Interface
Unit) and modem analog front end(AFE) functional part.
* The feature of the SFM336 modem chip is as below;
① Communication Mode : Half Duplex
② Modem Method
- GROUP 3
- Tonal Signal
- Binary Signal
③ Image Transmission Time : 3sec ( ITU-T NO.1 CHART/Memory Tx/ECM )
④ Data Compress
⑤ Modem Speed
bps
⑥ Receive Level
⑦ Output Level
- Adjustable
- Initial Setting : -12dBm
⑧ Receive dynamic range:
-. 0 dBm to -43 dBm for V.17, V.29, V.27 ter and V.21
-. -9 dBm to -43 dBm for V.34 halfduplex
2) The Gain of the Line signal can be adjusted by setting the register value of
the FAX modem chip ,Tx and Rx path is almost directly connected to the impedance
matching transformer of the LIU.
- Adjust Tx Level within Setting Level+0,-2dB range.
- Adjust Rx Level that has the same level as the TIMS out level if possible, and
must not exceed the TIMS out level.
3) Speaker Driving Part
Analog Switch(MC14053BD) makes a path for FAX Tone, Ring, Key click sound
and Analog MUX (MC14051) makes a different signal level so that the the
Speaker driver chip(MC34119) can driving the Speaker with different sound volume.
5. Printing Process Part
Printing Process part is made of PC-Interface part, PVC(Priter Video Controller), LSU
control part, High Voltage control part and Fuser Unit control part.
PC-interface core is included in the Chorus2 ASIC and controls the PC-interface.
LSU control part controls the LSU polygon motor, Laser diode, video data output so
that the printing image can be made up on the OPC Drum.
- Phase : 2-2 Phase 2000PPS at Quick Scan,
2-2 Phase 1000PPS AT Fine Scan,
2-2 Phase 667PPS AT Super Fine Scan
: ITU-T V34, V17, V29, V27ter
: ITU-T T.30
: ITU-T V.21, T.30
: MH, MR, MMR, JPEG
: 33600 / 28800 / 14400 / 12000 / 9600 / 7200 / 4800 / 2400
: 0 ~ -48dBm
: -6 ~ -15dBm ( 1dBm Step )