CONNECTIONS
Purpose	Location	Purpose	Location
Line in	CN1	DC power	CN4
Line out	CN2	Volume	R1
RS-232/422	CN3	Power switch	SW4

ORIGINATE MODE
Mode	SW3
Originate	Off
Answer	On

DTR MODE
Mode	SW1/1
» DTR normal	On
DTR forced high	Off

FLOW CONTROL
Mode	Async/Sync	SW1/2
» Hardware flow control	Async	On
Software flow control	Async	Off
» SDLC	Sync	On
BSC	Sync	Off

RESULT CODES and LINE ATTENUATION
Mode	Switched/Leased	SW1/3
» Result codes enabled	Switched	Off
Result codes disabled	Switched	On
» Transmit at 0dB	Leased	Off
Transmit at -10dB	Leased	On

UUCP SPOOFING and AS/400 MODE
Mode	Async/Sync	SW1/4
» UUCP spoofing disabled	Async	On
UUCP spoofing enabled	Async	Off
AS/400 disabled	Sync	On
AS/400 enabled	Sync	Off

AUTO-ANSWER and ANSWER/ORIGINATE
Mode	Switched/Leased	SW1/5
» Auto-answer enabled	Switched	On
Auto-answer disabled	Switched	Off
» Answer mode	Leased	On
Originate mode	Leased	Off

EFFICIENCY MODE and SLAVE CLOCK
Mode	Async/Sync	SW1/6
» Modem set to maximum effiency	Async	On
Modem not set to maximum effiency	Async	Off
» Clock controlled remotely	Sync	On
Clock controlled locally	Sync	Off

RTS MODE
Mode	SW1/7
» RTS forced high	Off
RTS normal	On

COMMAND MODE
Mode	SW1/8
» Command mode enabled	Off
Command mode disabled	On

LOOPBACK MODE
Mode	SW1/9
» Remote loopback	Off
Local loopback	On

LINE TYPE
Type	SW1/10
» Switched	On
Leased	Off

RESULT CODE TYPE and CLOCK SOURCE
Mode	Async/Sync	SW1/11
» Multitech result codes	Async	Off
AT result codes	Async	On
» Internal clock	Sync	Off
External clock	Sync	On

ASYNCHRONOUS/SYNCHRONOUS MODE
Mode	SW1/12
» Asynchronous	Off
Synchronous	On

OPERATION SPEED
Speed	SW2/1	SW2/2
» 28.8Kbps	On	On
19.2Kbps	Off	On
14.4Kbps	On	Off
9600bps	Off	Off

CD/DSR MODE
Mode	SW2/3
» CD and DSR normal	On
CD and DSR forced high	Off

FACTORY CONFIGURED - DO NOT ALTER
Switch	Position
SW2/4	N/A

DIAGNOSTIC LED(S)
LED	Color	Status	Condition
SD	Red	On	Modem is transmitting data
SD	Red	Off	Modem is not transmitting data
RD	Red	On	Modem is receiving data
RD	Red	Off	Modem is not receiving data
CD	Red	On	Carrier signal detected
CD	Red	Off	Carrier signal not detected
28.8	Red	On	Modem connected at 28.8Kbps
28.8	Red	Off	Modem not connected at 28.8Kbps
24	Red	On	Modem connected at 24Kbps
24	Red	Off	Modem not connected at 24Kbps
19.2	Red	On	Modem connected at 19.2Kbps
19.2	Red	Off	Modem not connected at 19.2Kbps
14.4	Red	On	Modem connected at 14.4Kbps
14.4	Red	Off	Modem not connected at 14.4Kbps
96	Red	On	Modem connected at 9600bps
96	Red	Off	Modem not connected at 9600bps
96	Red	On	Modem connected at 9600bps
96	Red	Off	Modem not connected at 9600bps
OH	Red	On	Modem is off-hook
OH	Red	Off	Modem is on-hook
TR	Red	On	DTR signal is high
TR	Red	Off	DTR signal is low
EC	Red	On	Error correction enabled
EC	Red	Off	Error correction disabled
EC	Red	Blinking	Error correction activated
FX	Red	On	Modem is connected in FAX mode
FX	Red	Off	Modem is not connected in FAX mode

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.
$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.

CALLBACK ATTEMPTS
Type:	Register
Format:	AT [cmds] S16=n [cmds]
Example:	ATS16=6<CR>
Default:	4
Range:	1-255
Unit:	1 attempt
Description:	Sets the maximum number of login attempts after initial callback connection.

CALLBACK NUMBER
Type:	Configuration
Format:	AT [cmds] [+/-]DT<#>Nnn
Examples:	AT#DB2 +-DT555-1212N10<CR>
Description:	Sets the phone number associated with the password at memory location nn.
Command	Function
+DT	Modem will initiate callback on successful login.
-DT	Modem will allow immediate entry on successful login without callback.
+-DT	If password is followed by a -, modem will allow immediate entry. If password is followed by a + or nothing, modem will initiate callback.

CALLBACK PARITY
Type:	Configuration
Format:	AT [cmds] #Pn [cmds]
Example:	AT #P0 #DB1<CR>
Description:	Sets the parity of the modem when in callback mode.
Command	Function
» #P0	No parity.
#P1	Odd parity.
#P2	Even parity.

CALLBACK PASSWORD
Type:	Configuration
Format:	AT [cmds] #CBNnnxxxx
Example:	AT#DB2 #CBN09snarf<CR>
Description:	Sets the callback password at memory location nn to xxxx. The password must be between 6 and 10 characters, inclusive.

CALLBACK SECURITY
Type:	Configuration
Format:	AT [cmds] #DBn [cmds]
Example:	AT #DB1 S0=1<CR>
Description:	Sets the security level of the callback function.
Command	Function
» #DB0	Disables security and clears callback memory.
#DB1	Enables remote security only.
#DB2	Enables local and remote security.

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.

DIALING MODE
Type:	Configuration
Format:	AT [cmds] $VDn [cmds]
Example:	AT $VD <CR>
Description:	Selects voice/data mode dialing.
Command	Function
» $VD0	Disables voice/data mode.
$VD1	Enables voice/data mode.

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 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 PASSWORD
Type:	Immediate
Format:	AT [cmds] #RCBNn [cmds]
Example:	AT #RCBN05 #RDN05<CR>
Description:	Erases the callback password at the memory location specified.

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.

FACTORY DEFAULTS
Type:	Immediate/Configuration
Format:	AT &F[n]
Example:	AT &F8<CR>
Description:	Loads factory defaults, or sets write protect on NVRAM.
Command	Function
&F	Reloads defaults by setting. (Immediate, see below.)
» &F8	Sets &F to read factory defaults from ROM, and disables NVRAM write protect.
&F9	Sets &F to read defaults from NVRAM, and enables write-protect.

FAILED PASSWORD ATTEMPTS
Type:	Register
Format:	AT [cmds] S26?
Example:	ATS26?<CR>
Default:	Read-only
Range:	0-255
Unit:	1 attempt
Description:	This register stores the number of failed password attempts.

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 2400bps as line quality degrades.
» #F2	Fallback from 2400bps 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 28.8Kbps.
#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 300bps speed.
$SB1200	Sets 1200bps speed.
$SB2400	Sets 2400bps speed.
$SB4800	Sets 4800bps speed.
$SB9600	Sets 9600bps speed.
$SB19200	Sets 19.2Kbps speed.
$SB38400	Sets 38.4Kbps speed.
$SB57600	Sets 57.6Kbps speed.
$SB115200	Sets 115.2Kbps 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.

LOGIN PASSWORD
Type:	Configuration
Format:	AT [cmds] #Ixxxx
Example:	AT #IMicroHouse<CR>
Description:	Sets the login password to xxxx. The password must be between 6 and 10 characters, case sensitive. It defaults to MULTI-TECH.

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
$MB75	Sets V.23 (1200bps/75bps bi-directional).
$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.

SETUP INACTIVITY TIMER
Type:	Register
Format:	AT [cmds] S29=n [cmds]
Example:	ATS29=5<CR>
Default:	20
Range:	1-255
Unit:	1 minute
Description:	Sets the maximum amount of time between commands until the setup password must be re-entered.

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.25 MODE
Type:	Configuration
Format:	AT [cmds] $Vn [cmds]
Example:	AT $V2 CIC<CR>
Description:	Configures V.25bis mode.
Command	Function
» $V0	Disables V.25bis.
$V1	Enables V.25bis.
$V2	Modem will accept one V.25bis command and will then return to AT command mode.
$V5	DSR follows DTR in V.25bis command mode.
$V6	DSR operates normally in V.25bis command mode.

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.

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.

CLEAR MEMORY LOCATION
Type:	Immediate
Format:	CLAn
Example:	CLA05<CR>
Description:	Clears the phone number in memory location nn.

LOCAL SERIAL PORT SPEED
Type:	Configuration
Format:	CSPn
Example:	CSP38400<CR>
Description:	Sets serial port speed.
Command	Function
CSP300	Sets 300bps speed.
CSP1200	Sets 1200bps speed.
CSP2400	Sets 2400bps speed.
CSP4800	Sets 4800bps speed.
CSP9600	Sets 9600bps speed.
CSP19200	Sets 19.2Kbps speed.
CSP38400	Sets 38.4Kbps speed.
CSP57600	Sets 57.6Kbps speed.
CSP115200	Sets 115.2Kbps speed.

CALL REQUESTED NUMBER
Type:	Immediate
Format:	CRI<#>;n
Example:	CRI1-303 555-1212;fubar<CR>
Description:	Same as CRN. Dials the number given. It will ignore spaces and hyphens in the string. If the string is more than fifty characters long, a result of INV will be returned. The identification string n will be ignored.

REQUEST LISTED NUMBERS
Type:	Immediate
Format:	RLN
Example:	RLN<CR>
Description:	Requests the modem to return the list of stored numbers. If no numbers are stored, the modem will return LSN.