Ricoh D158 Service Manual page 939

PSTN cable equalizer
(rx mode: Internal)
Bit 3 Bit 2
0
0
1
2-3 1
PSTN cable equalizer
(V.8/V.17 rx mode: External)
4
0: Disabled
1: Enabled
Parameter selection for dial tone
detection
6
0: Normal parameter
1: Specific parameter
SM
Use a higher setting if there is signal
loss at higher frequencies because of
Setting the length of wire between the modem
0 None and the telephone exchange.
1 Low Also, try using the cable equalizer if one
0 Medium or more of the following symptoms
1 High occurs.
Communication error with error codes
such as 0-20, 0-23, etc.
Modem rate fallback occurs frequently.
Keep this bit at "1".
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.
97

This setting is not effective in
V.34 communications.
Bit Switches - 4
D702