Ricoh D127 Service Manual page 500

Bit Switches
G3 Switch 03 [SP No. 1-105-004]
No FUNCTION
DIS detection number
(Echo countermeasure)
0
0: 1
1: 2
1 Not Used
V.8 protocol
2 0: Disabled
1: Enabled
ECM frame size
3 0: 256 bytes
1: 64 bytes
CTC transmission conditions
0: After one PPR signal
4 received
1: After four PPR signals
received (ITU-T standard)
D127/D128
COMMENTS
0: The machine will hang up if it receives the same
DIS frame twice.
1: Before sending DCS, the machine will wait for
the second DIS which is caused by echo on the
line.
Do not change the settings.
0: V.8/V.34 communications will not be possible.
Note:
Do not set to 0 unless the line condition is always
bad enough to slow down the data rate to 14.4
kbps or lower.
Keep this bit at "0" in most cases.
0: When using ECM in non-standard (NSF/NSS)
mode, the machine sends a CTC to drop back the
modem rate after receiving a PPR, if the following
condition is met in communications at 14.4, 12.0,
9.6, and 7.2 kbps.
NTransmit- Number of transmitted frames
NResend- Number of frames to be retransmitted
1: When using ECM, the machine sends a CTC to
drop back the modem rate after receiving four
PPRs.
PPR, CTC: These are ECM protocol signals.
This bit is not effective in V.34 communications.
5-48 SM Appendix