Ricoh B079, Service Manual

Page: 782 / 948

BIT SWITCHES
B547 74 SM
G3-1 Switch 07 SP No. 1-105-008
No FUNCTION COMMENTS
2
to
3
PSTN cable equalizer
(rx mode: Internal)
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 not effective in V.34
communications.
4 PSTN cable equalizer
(V.8/V.17 rx mode: External)
0 : Disabled
1 : Enabled
Keep this bit at “1”.
5 PSTN cable equalizer
(V.34 rx mode; External) Keep this bit at “1”.
6-7 Not used Do not change the settings.
G3-1 Switch 08 - Not used (do not change the settings)
G3-1 Switch 09 SP No. 1-105-010
No FUNCTION COMMENTS
0
to
1
ISDN cable equalizer
(tx mode: Internal)
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 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 not effective in V.34
communications.