21 May, 1999
BIT SWITCHES
4-39
Service
Tables
G3 Switch 06
FUNCTION
COMMENTS
4
to
7
Modem types available for
reception
Bit 7 6 5 4 Setting
0 0 0 1 V.27ter
0 0 1 0 V.27ter, V.29
0 0 1 1 V.27ter, V.29,
V.33
0 1 0 0 V.27ter, V.29,
V33, V17
0 1 0 1 V.27ter, V.29,
V.33, V.17, V.34
Other settings - Not used
The settings of these bits inform the transmitting
terminal of the available modem type for the
receiving machine.
V.33 is an exclusive Ricoh mode (NSF).
G3 Switch 07
FUNCTION
COMMENTS
0
1
PSTN cable equalizer
(TX mode)
Bit 1 Bit 0 Setting
0 0 None
0 1 Low
1 0 Medium
1 1 High
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 if
you need to change this 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.
Note: This setting is ineffective in V.34
communications.
2
3
PSTN cable equalizer
(RX mode)
Bit 3 Bit 2 Setting
0 0 None
0 1 Low
1 0 Medium
1 1 High
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.
Also, try using the cable equalizer if one or more
of the following symptoms occurs:
•
Communication error with error codes such as
0-20, 0-23, etc.
•
Modem rate fallback occurs frequently.
Note: This setting is ineffective in V.34
communications.
4
PSTN external cable equalizer
(V.27ter, V.29, V.33/V.17, V.8
rx mode)
0: Disabled 1: Enabled
Keep this bit at “1” in most cases.
5
PSTN external cable equalizer
(V.34 rx mode)
0: Disabled 1: Enabled
Set this bit to 0 when the line quality is good.
(e.g. digital PABX)
The V.34 modem rate may decrease from
equalizer over correction.
6-7
Not used
Do not change these settings.
