Ricoh LD013, Service Manual

Page: 458 / 513

F
ax Un
it
B4
04
BIT SWITCHES
SM 5-41 B404
G3 Switch 07
No FUNCTION COMMENTS
0
to
1
PSTN 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.
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) This function should only be turned on in
environments where reception signal levels tend to
be low.
6-7 Not used Do not change the settings.