Ricoh D146 Service Manual page 1920

1
PSTN cable equalizer
(rx mode: Internal)
Bit 3
0
0
2-3
1
1
PSTN cable equalizer
(V.8/V.17 rx mode: External)
4
0: Disabled
1: Enabled
5 Not used
Parameter selection for dial tone
detection
6
0: Normal parameter
1: Specific parameter
7 Not used
D163
1 High
Bit 2 Setting
0 None
1 Low
0 Medium
1 High
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
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.

This setting is not effective in
V.34 communications.
Keep this bit at "1".
Do not change the settings.
0: This uses the fixed table in the ROM
for dial tone detection.
1: This uses the specific parameter
adjusted with SRAM (69ECBEH -
69ECDEH). Select this if the dial tone
cannot be detected when the "Normal
parameter: 0" is selected.
Do not change the settings.
144 SM