Ricoh B022, Service Manual, Page: 709 / 878

F
ax Un
it
B418
OVERVIEW
SM 4-1 B418
4. DETAILED SECTION DESCRIPTIONS
4.1 OVERVIEW
The basic fax unit consists of three PCBs: an FCU, an MBU and an NCU.
The FCU controls all the fax communications and fax features, in cooperation with
the controller board. The MBU contains the ROM and SRAM. The NCU switches
the analog line between the fax unit and the external telephone.
Fax Options:
1. Extra G3 Interface option: This provides one more analog line interface. This
allows full dual access. Only one extra G3 interface option can be installed. The
optional G3 unit consists of two PCBs: G3 board and NCU.
2. ISDN unit: This allows the fax unit to communicate over an ISDN line.
3. Fax Function Upgrade Unit: JBIG compression becomes available. In addition,
this expands the system’s SRAM capacity to hold programmed telephone
numbers, memory files, etc.
4. Memory Expansion: This expands the SAF memory and the page memory
(used for image rotation); without this expansion, the page memory is not big
enough for image rotation at 400 dpi, so transmission at 400 dpi is not possible.
F C U
C C U IF
E xp a nsion
M e m o ry
G 3
G 4
N C U
N C U
F a x F u n ctio n
U p g rad e
M B U
C o n tro ller
B418D501.WMF