Service manual

Bit Switches
SM Appendix 5-53 D127/D128
Appendix:
Fax Trouble-
Shooting
Guide
G3 Switch 07 [SP No. 1-105-008]
No FUNCTION COMMENTS
0-1
PSTN cable equalizer
(tx mode: Internal)
Bit 1: 0, Bit 0: 0 = None
Bit 1: 0, Bit 0: 1 = Low
Bit 1: 1, Bit 0: 0 = Medium
Bit 1: 1, Bit 0: 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.
 This setting is not effective in V.34
communications.
2-3
PSTN cable equalizer
(rx mode: Internal)
Bit 3: 0, Bit 2: 0 = None
Bit 3: 0, Bit 2: 1 = Low
Bit 3: 1, Bit 2: 0 = Medium
Bit 3: 1, Bit 2: 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.
 This setting is not effective in V.34
communicatio
4
PSTN cable equalizer
(V.8/V.17 rx mode: External)
0: Disabled
1: Enabled
Keep this bit at “1”.