Oki OKIOFFICE 84 Service Manual page 390

A3.1.5 R51 Circuit Diagram (Page 5/12)
1. Block diagram
The circuit diagram shown on page 5/12 consists of Modem (14.4 kbps).
Modem consists the following functions:
l
Modulation/demodulation
Modulation type:
1) ITU-T Rec. V17 (14400/12000/9600/7200 bps) for G3 picture data.
2) ITU-T Rec. V29 (9600/7200 bps) for G3 picture data.
3) ITU-T Rec. V27 ter (4800/2400 bps) for G3 picture data.
4) ITU-T Rec. V21 channel 2 (300 bps) for binary signals defined in ITU-T Rec. T.30.
l
Automatic adaptive equalizer for G3 receive data with 300 bps data excluded.
l
Generation of signal tones
l
PB tone (multi-frequency tone) generation
l
Detection of single tones
l
D/A converter for send data (TX)
l
A/D converter for receive data (RX)
l
Amplitude equalizer for RX
l
Selectable attenuation for TX
l
Automatic gain control
Figure A3.1.5 shows the related signals of Modem.
Service Guide OKIOFFICE 84
Chapter A Board Descriptions
Page: 233