Multi-Tech Systems 7500 User Manual
ION 7500 / ION 7600 User’s Guide
S-Registers
Modem AT Commands Technical Note
Page 285
S-Registers
S-registers are memory locations that store certain modem values or parameters.
S commands are used to read or alter the contents of S-registers.
S commands are used to read or alter the contents of S-registers.
%En
Fallback and Fall
Forward Control
n = 0, 1, or 2
2
%E0 Disable fallback and fall forward.
%E1 Enable fallback, disable fall forward.
%E2 Enable fallback and fall forward.
$MBn
Online BPS Speed
n = speed in bits
per second
28,800
$MB75 Selects CCITT V.23 mode
$MB300 Selects 300 bps on-line
$MB1200 Selects 1200 bps on-line
$MB2400 Selects 2400 bps on-line
$MB4800 Selects 4800 bps on-line
$MB9600 Selects 9600 bps on-line
$MB14400 Selects 14,400 bps on-line
$MB19200 Selects 19,200 bps on-line
$MB28800 Selects 28,800 bps on-line
$MB33600 Selects 33,600 bps on-line
$SBn
Serial Port Baud Rate
n= speed in bits
per second
115200
$SB300 Selects 300 bps at serial port
$SB1200 Selects 1200 bps at serial port
$SB2400 Selects 2400 bps at serial port
$SB4800 Selects 4800 bps at serial port
$SB9600 Selects 9600 bps at serial port
$SB19200 Selects 19,200 bps at serial port
$SB38400 Selects 38,400 bps at serial port
$SB57600 Selects 57,600 bps at serial port
$SB115200 Selects 115,200 bps at serial port
$SB230400 Selects 230,400 bps at serial port
Command
Values
Default
Description
Register
Unit
Range
Default
Description
S6
seconds
2-65*
2*
Sets the time the modem waits after it goes off-hook before it begins to dial the
telephone number.
S7
seconds
1-255*
50*
Sets the time the modem waits for a carrier signal before aborting a call. Also sets
the wait for silence time for the @ dial modifier.
S8
seconds
0-65
2
Sets the length of a pause caused by a comma character in a dialing command.
S10
100 ms
1-254
20
Sets how long a carrier signal must be lost before the modem disconnects.
S11
1ms
50-150*
95*
Sets spacing and duration of dialing tones.
S28
decimal
0, 1-255
1
0 disables, 1.255 enables V.34 modulation.
S30
1 minute
0, 1-255
0
Sets the length of time that the modem waits before disconnecting when no data is
sent or received. A value of zero disables the timer. See also the \T command
S35
decimal
0-1
0
0 disables, 1 enables the V.25 calling tone, which allows remote data/fax/voice
discrimination.
S36
decimal
0-7
7
Specifies the action to take in the event of a negotiation failure when error control is
selected. (See S48.)