=2;
MNP4 + MNP5. (See also S41b0, S38b5)
=3;
V.42 +MNP4.
=4;
V.42 + V.42bis (compatible with &K2, see also S38b5).
S28
Bit-mapped register, default = 068,
Bn
(7)
=0;
Select V.22 for 1200 bps communication.
=1;
Select Bell 212A for 1200 bps communication.
&Bn
(6)
=0;
DTE/DCE rate follows link rate. (See also S18, S44b6)
=1;
DTE/DCE rate fixed at DTE setting, range from 300 to 76.8
Kbps. (See also S44b6)
&Gn
(5,4)
=0;
No guard tone.
=1;
Reserved.
=2;
1800 Hz guard tone.
Yn
(3,2)
=0;
Destructive, expedited break.
=1;
Non-destructive, expedited break.
=2;
Non-destructive, un-expedited break.
*Ln
(1)
=0;
Panel key normal.
=1;
Panel key locked.
&Jn
(0)
=0;
Single phone line, RJ11 phone jack.
=1;
Multiple phone/modem line, RJ12/RJ13 phone jack.
S29
Default dial phone number pointer, default = 000. Use AT&Zn = S to store phone
numbers.
*Dn
=n;
Set default dial phone number pointer at location n (n=0-9) in
the phone directory stored in EEPROM.
S30
Dial-backup phone number pointer, default = 000.
*Bn
=0;
Disable dial backup.
=n;
Enable dial backup and set dial backup phone number pointer at
location n-1 (n=1-9) in the EEPROM. (See also S44b2).
Note: When the leased line has become unoperational, modem will automatically switch to dial
line and the originate mode modem will dial the number according to the pointer saved here if
dial backup was enabled. The answer mode modem will try the leased line and wait for ring if
dial backup is enabled (a non-zero number is selected).
S31
Default=17;
Holds the ASCII decimal value of the XON character.
S32
Default=19;
Holds the ASCII decimal value of the XOFF character.
S33
Reserved.
S34
Default=30;
Dial-backup restoral lookback timer, in minutes.
Note: In dial backup operation, in addition to switching to the dial-up line, the modem will
automatically "lookback" to determine whether the leased line is again operational. This timer will
disconnect current dial-up line and attempt to connect on the original leased line. If it is still
unavailable, the dial-up line will continue to be used.
S35
Bit-mapped register, default = 000,
(7)
=1;
Enable extended numerical result code 30 - 39 when an error