ANSWER-BACK
Type:	Configuration
Format:	AT [cmds] &An [cmds]
Example:	AT &A1<CR>
Description:	Controls the modem’s ability to respond with its identification.
Command	Function
» &A0	Disables answer-back.
&A1	Enables answer-back.

AUTO-RELIABLE TIME BUFFER CONFIGURATION
Type:	Configuration
Format:	AT [cmds] $An [cmds]
Example:	AT $A1 &W<CR>
Description:	Controls the handling of incoming data during auto-reliable time period.
Command	Function
» $A0	Data is discarded.x
$A1	Data is buffered.

BIT MODE
Type:	Configuration
Format:	AT [cmds] $EBn [cmds]
Example:	AT $EB1 E1<CR>
Description:	Selects 10- or 11-bit mode.
Command	Function
» $EB0	Sets 10-bit mode.
$EB1	Sets 11-bit mode.

CARRIER MODE
Type:	Configuration
Format:	AT [cmds] &Cn [cmds]
Example:	AT &C0 A<CR>
Description:	Sets the function of the Carrier Detect (CD) signal.
Command	Function
&C0	Forces CD high.
» &C1	CD signal follows carrier.
&C2	Forces CD low for time in S24 when the modem disconnects.
&C4	Resets modem when CD goes low.

COMMAND ESCAPE TYPE
Type:	Configuration
Format:	AT [cmds] %En [cmds]
Example:	AT %E3 &W<CR>
Description:	Sets type and response of command escape sequence.
Command	Function
%E0	Command escape disabled.
» %E1	TIES escape (+++AT...)
%E2	<BREAK>AT method.
%E3	Both TIES and BREAK methods.
%E4	OK response to command escape disabled.
%E5	OK response to command escape enabled.

COMMAND SET
Type:	Configuration
Format:	AT &Qn
Example:	AT &Q1<CR>
Description:	Selects standard Hayes or custom command sets.
Command	Function
» &Q0	Multi-Tech custom command set enabled.
&Q1	Standard Hayes command set enabled.

COMPRESSION
Type:	Configuration
Format:	AT &En
Example:	AT &E15 #L0<CR>
Description:	Selects data compression.
Command	Function
&E14	Data compression disabled.
» &E15	Data compression enabled.

COMPRESSION MODE
Type:	Configuration
Format:	AT #Ln
Example:	AT #L2 DT555-1212<CR>
Description:	Selects active compression protocols.
Command	Function
» #L0	V.42 negotiation enabled.
#L1	MNP negotiation enabled.
#L2	LAP-M negotiation enabled.
#L3	LAP-M enabled, no negotiation.

CTS SIGNAL
Type:	Configuration
Format:	AT [cmds] &RFn [cmds]
Example:	AT &RF0<CR>
Description:	Selects the function of the CTS signal.
Command	Function
&RF0	CTS is set to RTS.
» &RF1	CTS is independent of RTS.

DIAL STORED PHONE NUMBER
Type:	Immediate
Format:	AT [cmds] Nn1 [Nn2, Nn3...]
Example:	ATM0 N1N3N5<CR>
Description:	Dials stored phone number(s). If the first number is busy, the modem will proceed to the next number in the list.

DSR SIGNAL
Type:	Configuration
Format:	AT [cmds] &SFn [cmds]
Example:	AT &SF0<CR>
Description:	Selects the function of the DSR signal.
Command	Function
» &SF0	DSR is set to CD.
&SF1	DSR is independent of CD.

DTR DIALING
Type:	Configuration
Format:	AT [cmds] $Dn [cmds]
Example:	AT $D1 DT555-1212<CR>
Description:	Turns DTR dialing on and off.
Command	Function
» $D0	DTR dialing disabled.
$D1	DTR dialing enabled.

DTR MODE
Type:	Configuration
Format:	AT [cmds] &Dn [cmds]
Example:	AT &D1<CR>
Description:	Sets the function of the DTR signal.
Command	Function
&D0	DTR is ignored.
&D1	Modem returns to command mode on high DTR.
» &D2	DTR normal operation.
&D3	Modem resets on high DTR.

DTR TIMEOUT
Type:	Register
Format:	AT [cmds] S24=n [cmds]
Example:	ATS24=40<CR>
Default:	20
Range:	0-255
Unit:	50 ms
Description:	Sets the time to drop the DTR signal to hangup.

ERASE CALLBACK NUMBER
Type:	Immediate
Format:	AT [cmds] #RDNn [cmds]
Example:	AT #RCBN05 #RDN05<CR>
Description:	Erases the callback phone number at the memory location specified.

ERROR CORRECTION DISABLE ON CONNECT
Type:	Configuration
Format:	AT [cmds] $Fn [cmds]
Example:	AT $F1 DT555-1212<CR>
Description:	Selects whether error correction can be disabled by a <CR> while handshaking.
Command	Function
$F0	Error correction handshake interrupt disabled.
» $F1	Error correction handshake interrupt enabled.

ESCAPE SEQUENCE BUFFER SIZE
Type:	Register
Format:	AT [cmds] S34=n [cmds]
Example:	ATS34=30<CR>
Default:	10
Range:	0-60
Unit:	1 byte
Description:	Sets the size of the buffer used to store commands during an escape sequence.

ESCAPE SEQUENCE - OUT OF BAND
Type:	Immediate
Format:	<BREAK> AT [cmds]<CR>
Example:	<BREAK> AT #F1<CR>
Description:	Puts the modem in Command Mode.
Notes:	Do not precede this command with AT. <BREAK> refers to the hardware modem break signal.

ESCAPE SEQUENCE TIMEOUT
Type:	Register
Format:	AT [cmds] S32=n [cmds]
Example:	ATS32=30<CR>
Default:	20
Range:	0-255
Unit:	1 second
Description:	Sets the maximum amount of time the modem will wait for a <CR> while executing an escape sequence.

FALLBACK MODE
Type:	Configuration
Format:	AT [cmds] #Fn [cmds]
Example:	AT #F1 O<CR>
Description:	Sets direction of fallback.
Command	Function
#F0	Fallback disabled.
#F1	Fallback from 28.8Kbps to 4800bps as line quality degrades.
» #F2	Fallback from 4800bps to 28.8Kbps as line quality improves.

FLOW CONTROL NORMAL MODE
Type:	Configuration
Format:	AT [cmds] &En [cmds]
Example:	AT &E11 O<CR>
Description:	Selects normal flow control.
Command	Function
» &E10	Normal mode disabled.
&E11	Normal mode enabled.

FLOW CONTROL TYPE
Type:	Configuration
Format:	AT [cmds] &En [cmds]
Example:	AT &E4 &W<CR>
Description:	Sets type of flow control used by modem.
Command	Function
&E3	Flow control disabled.
» &E4	CTS/RTS flow control enabled.
&E5	XON/XOFF flow control enabled.

HANDSHAKE ATTEMPTS
Type:	Configuration
Format:	AT [cmds] #An [cmds]
Example:	AT #A1 #L3<CR>
Description:	Configures the initial handshake phase.
Command	Function
#A0	Attempts in order: 28.8Kbps, 24Kbps, 19.2Kbps, 16.8Kbps, 14.4Kbps, 12Kbps, 9600bps, 4800bps, 2400bps, 1200bps, 300bps.
#A1	Attempts only 14.4Kbps.
#A2	Attempts in order: 28.8Kbps, 24Kbps, 19.2Kbps, 16.8Kbps, 14.4Kbps, 12Kbps, 9600bps, 4800bps.
#A3	Attempts in order: 2400bps, 1200bps, 300bps.

HELP SCREENS
Type:	Immediate
Format:	AT $Hn
Example:	AT $H1<CR>
Description:	Shows modem help screens.
Command	Function
$H1	Shows help screen 1.
$H2	Shows help screen 2.
$H3	Shows help screen 3.

LIST CONFIGURATION
Type:	Immediate
Format:	AT Ln
Example:	AT L5<CR>
Description:	Lists modem configuration.
Command	Function
L5	Lists all settings.
L6	Lists the values of all S-registers.
L7	Lists extended parameters.
L8	Lists current diagnostics.

LOCAL SERIAL PORT SPEED
Type:	Configuration
Format:	AT [cmds] $SBnnn [cmds]
Example:	AT $MB9600 $SB19200<CR>
Description:	Sets serial port speed.
Command	Function
$SB300	Sets 300baud speed.
$SB1200	Sets 1200baud speed.
$SB2400	Sets 2400baud speed.
$SB4800	Sets 4800baud speed.
$SB9600	Sets 9600baud speed.
$SB19200	Sets 19.2Kbaud speed.
$SB38400	Sets 38.4Kbaud speed.
$SB57600	Sets 57.6Kbaud speed.
$SB115200	Sets 115.2Kbaud speed.

LOCK SERIAL PORT
Type:	Configuration
Format:	AT [cmds] $BAn [cmds]
Example:	AT $SB57600 $BA0<CR>
Description:	Sets operation of serial port speed.
Command	Function
» $BA0	Serial speed locked at rate set by $SB.
$BA1	Serial speed follows connect speed, ignoring $SB.

LOOPBACK
Type:	Configuration
Format:	AT [cmds] &Tn [cmds]
Example:	AT &T5<CR>
Description:	Enables or disables remote digital loopback response.
Command	Function
&T4	Loopback response enabled.
&T5	Loopback response disabled.

MAXIMUM BLOCK SIZE FOR TRANSMISSION
Type:	Configuration
Format:	AT [cmds] &BSn [cmds]
Example:	AT &BS1 &MB28800<CR>
Description:	Sets the maximum transmittable block size.
Command	Function
&BS0	Maximum block size is 64 characters.
» &BS1	Maximum block size is 128 characters for LAP-M, and 256 characters for MNP.

PACING
Type:	Configuration
Format:	AT [cmds] &En [cmds]
Example:	AT &E13<CR>
Description:	Selects ENQ/ACK pacing.
Command	Function
&E12	Disables ENQ/ACK pacing.
» &E13	Enables ENQ/ACK pacing.

PACING - ENQ/ACK
Type:	Configuration
Format:	AT [cmds] &En [cmds]
Example:	AT &E9<CR>
Description:	Selects ENQ/ACK pacing.
Command	Function
» &E8	Enables ENQ/ACK pacing.
&E9	Disables ENQ/ACK pacing.

REDIAL
Type:	Immediate
Format:	ATA:
Example:	ATA:<CR>
Description:	Redials the last number dialed until it is no longer busy.

REMOTE CONNECT SPEED
Type:	Configuration
Format:	AT $MBnnn
Example:	AT $MB9600 $SB19200<CR>
Description:	Sets maximum remote connect speed.
Command	Function
$MB300	Sets 300bps connect.
$MB1200	Sets 1200bps connect.
$MB2400	Sets 2400bps connect.
$MB4800	Sets 4800bps connect.
$MB9600	Sets 9600bps connect.
$MB14400	Sets 14.4Kbps connect.
$MB19200	Sets 19.2Kbps connect.
$MB28800	Sets 28.8Kbps connect.

RETRANSMIT FAIL ACTION
Type:	Configuration
Format:	AT [cmds] $Rn [cmds]
Example:	AT $R1<CR>
Description:	Sets whether the modem gives up on a bad connection.
Command	Function
» $R0	Hang up after 12 failed retransmissions.
$R1	Do not hang up after 12 failed retransmissions.

STORE PHONE NUMBER IN NVRAM
Type:	Configuration
Format:	AT [cmds] D<#>Nn [dialstring]
Example:	ATD555-1212N1<CR>
Description:	Stores a phone number in the modem’s memory.

TIME UNTIL HANG UP ON LOW DTR
Type:	Register
Format:	AT [cmds] S36=n [cmds]
Example:	ATS36=5<CR>
Default:	0
Range:	0-255
Unit:	1 second
Description:	Sets the maximum amount of time the modem will wait to hang up after the DTR signal goes low.

TIME UNTIL PICK UP ON HIGH DTR
Type:	Register
Format:	AT [cmds] S37=n [cmds]
Example:	ATS37=5<CR>
Default:	0
Range:	0-255
Unit:	1 second
Description:	Sets the maximum amount of time the modem will wait to pick up after the DTR signal goes high.

TRELLIS MODULATION
Type:	Configuration
Format:	AT [cmds] #Tn [cmds]
Example:	AT #T1<CR>
Description:	Controls Trellis Coded Modulation.
Command	Function
#T0	Disables TCM.
» #T1	Enables TCM.

V.42 MODE
Type:	Configuration
Format:	AT [cmds] &En [cmds]
Example:	AT &E0 <CR>
Description:	Configures the operation of V.42 mode.
Command	Function
&E0	Error correction disabled.
» &E1	V.42 set to auto-reliable.
&E2	V.42 set to reliable.

V.42 LOW SPEED
Type:	Configuration
Format:	AT [cmds] $En [cmds]
Example:	AT $E1 <CR>
Description:	Selects whether a V.42 connection will be attempted at 300bps.
Command	Function
» $E0	V.42 disabled at 300bps.
$E1	V.42 enabled at 300bps.

XOFF SEND
Type:	Configuration
Format:	AT [cmds] #Xn [cmds]
Example:	AT #X1<CR>
Description:	Selects how XOFF signal is sent.
Command	Function
» #X0	Single XOFF character sent until ready.
#X1	Multiple XOFF characters sent until ready.

XON/XOFF PASS-THROUGH
Type:	Configuration
Format:	AT [cmds] &En [cmds]
Example:	AT &E7 O<CR>
Description:	Selects whether XON/XOFF signals are sent to remote modem.
Command	Function
» &E6	XON/XOFF signals trapped by local modem.
&E7	XON/XOFF passed through local modem.