Ricoh B264 Service Manual page 820

BIT SWITCHES
G3 Switch 02
7 Short preamble
0: Disabled 1: Enabled
G3 Switch 03
No FUNCTION
0 DIS detection number
(Echo countermeasure)
0: 1
1: 2
1 Not Used
2 V.8 protocol
0: Disabled
1: Enabled
3 ECM frame size
0: 256 bytes
1: 64 bytes
4 CTC transmission conditions
0: After one PPR signal
received
1: After four PPR signals
received (ITU-T standard)
5 Modem rate used for the next
page after receiving a negative
code (RTN or PIN)
0: No change 1: Fallback
6 Not Used
7 Select detection of reverse
polarity in ringing
0: Off
1: On
B779
Refer to Appendix B in the Group 3 Facsimile
Manual for details about Short Preamble.
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.
≤ Re
N Transmit N send
N Number of transmitted frames
Transmit-
N - Number of frames to be retransmitted
Resend
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.
1: The machine's tx modem rate will fall back before
sending the next page if a negative code is
received. This bit is ignored if ECM is being used.
Do not change the settings
This switch is used to prevent reverse polarity in
ringing on the phone line (applied to PSTN-G3
ringing). Do not change this setting
0: No detection Outside Japan
1: Detection Inside Japan only
68
SP No. 1-105-003
SP No. 1-105-004
SM