3Com U.S. Robotics 56K Voice, Command Reference Manual

Page: 185 / 210

S-Registers I-3
S15 0 Bit-mapped register. (See Chapter 1, Using the AT
Command Set, for instructions about how to set
bit-mapped registers.)
Bit Value Result
0 1 Disable the Business Modem's extra
high-frequency equalization if it
causes problems on shorter-link calls
(for HST modulation only).
1 2 Disable online fallback.
2 4 Disable 450 bps back channel* HST
only.
3 8 Reset non-ARQ mode Transmit buffer
from 1.5K bytes to 128.* (for the
convenience of BBS operators taking
calls from remote users of slower
modems).
4 16 Disable MNP Level 4; retransmitting
the larger Level 4 data blocks may be
a problem if you expect a great
number of errors during a call.
5 32 Set Backspace key to delete.
6 64 Some earlier 2400 bps MNP modems,
not made by 3Com, U.S. Robotics, or
Microcom, were not fully compatible
with the MNP protocol. If you have
difficulty making a successful 2400
bps MNP connection with a remote
MNP modem, it may be because of
this incompatibility. Set S15 to 64 and
try again to make the connection.
7 128 Custom applications only.
* The default 1.5K byte non-ARQ
buffer allows data transfer with X-
and Y-modem-type File Transfer
Protocols without using flow control.
The 128-byte option allows remote
users with slower modems to stop
your transmitted data from scrolling
off their screens. When remote users
send your computer an XOFF
(<Ctrl-S>) and you stop transmitting,
the data in transit doesn’t exceed the
size of their screen.
Register Default Function