Ricoh M281 Series Service Manual page 944

Bit Switches - 4
4-7 Modem types available for reception
The setting of these bits is used to inform the transmitting terminal of the available
modem type for the machine in receive mode.
If V.34 is not selected, V.8 protocol must be disabled manually.
Cross reference
V.8 protocol on/off - G3 switch 03, bit 2
Bit 7 Bit 6
0 0
0 0
0 0
0 1
0 1
Other settings - Not used
No
0-1 PSTN cable equalizer
(TX mode: Internal)
Bit 1 Bit 0
0 0
0 1
1 0
1 1
2-3 PSTN cable equalizer
(RX mode: Internal)
D255/D256 FAX OPTION
Bit 5 Bit 4
0 1
1 0
1 1
0 0
0 1
G3 Switch 07 (SP No. 1-105-008)
Function
Setting
None
Low
Medium
High
Types
V.27ter
V.27ter, V.29
V.27ter, V.29, V.33
V.27ter, V.29, V.17
V.27ter, V.29, V.17, V.34
Comments
Use a higher setting if there is signal loss
at higher frequencies because of the
length of wire between the modem and
the telephone exchange.
Use the dedicated transmission
parameters for specific receivers.
Also, try using the cable equalizer if one
or more of the following symptoms
occurs.
Communication error
Modem rate fallback occurs frequently.

This setting is not effective in
V.34 communications.
Use a higher setting if there is signal loss
at higher frequencies because of the
110 SM