Ricoh B230 Service Manual

Service RAM Addresses 
SM 121 B786 
B786 
Fax Option 
 Defaults 
Area 6BEC03  6BEC04 
NA F4  01 
EU F4  01 
ASIA F4  01 
 
6BEC05(H) – Dial tone detect judge time (20 ms) 
Defaults: NA: 64, EU: 1B, ASIA: 32 
6BEC06(H) – Dial tone disconnect permission time (20 ms) 
Defaults: NA: 11, EU: 0F, ASIA: 11  

Overview 
B786 122  SM 
5. DETAILED SECTION DESCRIPTIONS 
5.1 OVERVIEW 
 
The basic fax unit consists of two PCBs: an FCU and an MBU. 
The FCU controls all the fax communications and fax features, in cooperation with the 
controller board. The MBU contains the ROM and SRAM. Also, the FCU has an NCU 
circuit. 
Fax Options: 
1.  Extra G3 Interface option: This provides one more analog line interface. This allows 
full dual access. Two extra G3 interface options can be installed. 
2.  Memory Expansion: This...

Boards 
SM 123 B786 
B786 
Fax Option 
5.2 BOARDS 
5.2.1 FCU 
 
The FCU (Facsimile Control Unit) controls fax communications, the video interface to the 
base copier’s engine, and all the fax options.. 
FACE3 (Fax Application Control Engine) 
ƒ CPU 
ƒ  Data compression and reconstruction (DCR) 
ƒ DMA control 
ƒ Clock generation 
ƒ  DRAM backup control 
Modem (FAME) 
ƒ  V.34, V33, V17, V.29, V.27ter, V.21, and V.8 
DRAM 
ƒ  The 16 MB of DRAM is shared as follows. 
SAF memory        : 4MB 
Working memory...

Boards 
B786 124  SM 
5.2.2 MBU 
On this board, the flash ROM contains the FCU firmware, and the SRAM contains the 
system data and user parameters. Even if the FCU is changed, the system data and user 
parameters are kept on the MBU board. 
ROM 
ƒ  3MB flash ROMs for system software storage  
2MB (16bit x 1MB) + 1MB (16bit x 512K) 
SRAM 
ƒ  The 256KB SRAM for system and user parameter storage is backed up by a lithium 
battery. 
Memory Back-up 
ƒ  A lithium battery backs up the system parameters and...

Boards 
SM 125 B786 
B786 
Fax Option 
5.2.3 SG3 BOARD 
 
The SG3 board allows up to three simultaneous communications when used in 
combination with the FCU and optional G3 boards. The NCU is on the same board as the 
common SG-3 board. This makes the total board structure smaller. But, the specifications 
of the SG3 board do not change. 
NCCP (New Communication Control Processor) 
ƒ  Controls the SG3 board. 
ƒ CPU (RU30) 
ƒ  DPRAM (Dual Port RAM): Handshaking with the FCU is done through this block. 
ƒ...

Boards 
B786 126  SM 
AFE (Analog Front End) 
ƒ Analog processing 
CODEC (COder-DECoder) 
ƒ  A/D & D/A conversions for modem 
REG 
ƒ  Generates +3.3 V from the +5V from the FCU  

Video Data Path 
SM 127 B786 
B786 
Fax Option 
5.3 VIDEO DATA PATH 
5.3.1 TRANSMISSION 
 
Memory Transmission and Parallel Memory Transmission 
The base copiers scanner scans the original at the selected resolution in inch format. The 
BICU processes the data and transfers it to the FCU. 
 
ƒ  When scanning a fax original, the BICU uses the MTF, independent dot erase and 
thresholding parameter settings programmed in the fax unit’s scanner bit switches, 
not the copiers SP modes. 
Then, the FCU converts...

Video Data Path 
B786 128  SM 
and/or reduces the data if necessary for transmission. The NCU transmits the data to the 
line. 
Immediate Transmission 
The base copiers scanner scans the original at the resolution agreed with the receiving 
terminal. The BICU video processes the data and transfers it to the FCU. 
 
ƒ  When scanning a fax original, the BICU uses the MTF, independent dot erase and 
thresholding parameter settings programmed in the fax unit’s scanner bit switches, 
not the copiers SP modes....

Video Data Path 
SM 129 B786 
B786 
Fax Option 
5.3.2 RECEPTION 
 
First, the FCU stores the incoming data from either an analog line to the SAF memory. 
(The data goes to the FACE3 at the same time, and is checked for error lines/frames.) 
The FCU then decompresses the data and transfers it to page memory. If image rotation 
will be done, the image is rotated in the page memory. The data is transferred to the BICU. 
If the optional G3 unit is installed, the line that the message comes in on depends on...

Fax Communication Features 
B786 130  SM 
5.4  FAX COMMUNICATION FEATURES 
5.4.1 MULTI-PORT 
When the optional extra G3 Interface Unit is installed, communication can take place at 
the same time through the two or three lines at once. 
 
Option Available Line Type Available protocol 
Combinations 
Standard only  PSTN  G3 
Extra G3 Interface Unit (single)  PSTN + PSTN  G3 + G3 
Extra G3 Interface Unit 
(double) PSTN + PSTN +PSTN  G3 + G3 +G3 
 
5.4.2 DOCUMENT SERVER 
 
The base copiers scanner scans the...