CONNECTIONS
Purpose	Location	Purpose	Location
Line out	CN1	DC power	CN4
Line in	CN2	Volume	R1
RS-232/422	CN3	Power switch	SW2

MI/MIC POLARITY
Setting	J6	J8
» Normal	Pins 1 & 2 closed	Pins 1 & 2 closed
Reversed	Pins 2 & 3 closed	Pins 2 & 3 closed

TX/RX PIN ASSIGNMENT
Setting	SW3
Normal operation	» Off
Reverse TX/RX pin assignments	On

DTR SIGNAL
Setting	SW1/1
DTR forced high	On
» DTR normal	Off

RESULT CODES
Setting	SW1/2
» Verbose result codes enabled	Off
Numeric result codes enabled	On

RESULT CODES DISPLAY
Setting	SW1/3
» Display enabled	On
Display disabled	Off

ECHO COMMANDS DISPLAY
Setting	SW1/4
» Local echo enabled	Off
Local echo disabled	On

AUTO ANSWER
Setting	SW1/5
» Modem answers on first ring	On
Modem does not answer on first ring	Off

CARRIER DETECT
Setting	SW1/6
» CD normal	Off
CD forced high	On

RESULT CODES DISPLAY
Setting	SW1/7
» Display result codes in originate and answer modes	Off
Display result codes in Answer mode	On

AT COMMAND SET
Setting	SW1/8
» AT command set enabled	On
AT command set disabled	Off

ESCAPE CODE
Setting	SW1/9
» Off	Disconnect, go to command mode and display NO CARRIER when escape character is received
On	Go to command mode and display OK result code when escape character is received

USER PROFILE
Setting	SW1/10
» Off	Use stored profile
On	Use factory default

VOICE/DATA
Setting	SW4
Note: for switch functions see table for register S32.

DIAGNOSTIC LED(S)
LED	Color	Status	Condition
HS	Red	On	Modem is operating at 4800bps or faster
HS	Red	Off	Modem is operating at slower than 4800bps
AA	Red	On	Auto-answer enabled
AA	Red	Off	Auto-answer disabled
CD	Red	On	Carrier signal detected
CD	Red	Off	Carrier signal not detected
OH	Red	On	Modem is off-hook
OH	Red	Off	Modem is on-hook
RD	Red	Blinking	Modem is receiving data
RD	Red	Off	Modem is not receiving data
TD	Red	Blinking	Modem is transmitting data
TD	Red	Off	Modem is not transmitting data
TR	Red	On	DTR signal is high
TR	Red	Off	DTR signal is low
MR	Red	On	Power is on
MR	Red	Off	Power is off
MR	Red	Blinking	Retraining/test mode
RS	Red	On	RTS signal is high
RS	Red	Off	RTS signal is low
CS	Red	On	CTS signal is high
CS	Red	Off	CTS signal is low
EC	Red	On	Error control enabled
EC	Red	Off	Error control disabled
EC	Red	Blinking	Modem is retransmitting data
SYN	Red	On	Synchronous mode
SYN	Red	Off	Asynchronous mode

BIT-MAPPED REGISTER S13
Format		AT [cmds] S13=n [cmds]
Example:		ATS13=139<CR>
Default:		0
Range:		0 - 255
Unit:		Bit-mapped
Description:		Controls DTR reset, DTR dialing, auto answer, result code delay, reset dialing, HST and MNP3.
Bit	Value		Function
0	» 0 1		DTR normal. Reset on low DTR.
1	» 0 1		Auto answer operation normal. When ring detected, enter originate mode and listen for answer tone.
2	» 0 1		Pause 250 msec. before displaying result codes. Display result codes immediately.
3	» 0 1		DTR dialing disabled. DTR dialing enabled.
4	» 0 1		Reset dialing disabled. Reset dialing enabled.
5	» 0 1		HST enabled. HST disabled.
6	» 0 1		MNP 3 enabled. MNP 3 disabled.

BIT-MAPPED REGISTER S15
Format:		AT [cmds] S15=n [cmds]
Example:		ATS15=139<CR>
Default:		0
Range:		0 - 127
Unit:		Bit-mapped
Description:		Controls HST high frequency equalization, online fallback, back channel, non-error-correcting mode buffer, MNP4, and BS/DEL switch and MNP compliance
Bit	Value		Function
0	» 0 1		HST high frequency equalization enabled. HST high frequency equalization disabled.
1	» 0 1		Online fallback enabled. Online fallback disabled.
2	» 0 1		450bps back channel enabled. 450bps back channel disabled.
3	» 0 1		Non-error-correcting mode transmit buffer set to 1.5KB. Non-error-correcting mode transmit buffer set to 128 bytes.
4	» 0 1		MNP 4 enabled. MNP 4 disabled.
5	» 0 1		Use backspace key for delete disabled. Use backspace key for delete enabled.
6	» 0 1		MNP normal. MNP adjusted for non compliant modems.

BIT-MAPPED REGISTER S27
Format:		AT [cmds] S27=n [cmds]
Example:		ATS27=139<CR>
Default:		0
Range:		0 - 191
Unit:		Bit-mapped
Description:		Controls V.21, V.42 answer tone and handshake, and 9600 result codes.
Bit	Value		Function
0	» 0 1		V.21 disabled. V.21 enabled.
1	» 0		Not used.
2	» 0		Not used.
3	» 0 1		2100Hz answer tone enabled. 2100Hz answer tone disabled.
5, 4	» 00 01 10 11		V.42 detect, LAPM and MNP enabled. V.42 detect and LAPM enabled. MNP enabled. LAPM enabled.
6	» 0		Not used.
7	» 0 1		Actual result codes displayed. Force 9600 result codes.

BREAK LENGTH
Type:	Register
Format:	AT [cmds] S21=n [cmds]
Example:	ATS21=20<CR>
Default:	10
Range:	Unidentified
Unit:	10 ms
Description:	Sets the length of error control mode breaks sent from DCE to DTE.

BREAK TYPE
Type:	Configuration
Format:	AT [cmds] &Yn [cmds]
Example:	AT &Y0<CR>
Description:	Configures action of break signal.
Command	Function
&Y0	Break empties buffer.
» &Y1	Break empties buffer and is sent immediately.
&Y2	Break does not empty buffer and is sent immediately.

COMPRESSION
Type:	Configuration
Format:	AT [cmds] &Kn [cmds]
Example:	AT &K1<CR>
Description:	Controls data compression.
Command	Function
&K0	Data compression disabled.
&K1	Data compression disabled when serial port is locked.
&K2	Data compression enabled.
&K3	MNP 5 disabled.

CONNECTION SPEED UPPER LIMIT
Type:	Configuration
Format:	AT [cmds] &Nn [cmds]
Example:	AT &N1 DT555-1212<CR>
Description:	Sets required connection speed if &U is set to 0. Otherwise, sets fastest allowed connection speed.
Command	Function
» &N0	Variable.
&N1	300bps
&N2	1200bps
&N3	2400bps
&N4	4800bps
&N5	7200bps
&N6	9600bps
&N7	12Kbps
&N8	14.4Kbps
&N9	16.8Kbps
&N10	19.2Kbps
&N11	21.6Kbps
&N12	24Kbps
&N13	26.4Kbps
&N14	28.8Kbps

EXTENDED RESULT CODES
Type:	Configuration
Format:	AT [cmds] &An [cmds]
Example:	AT &A1 %C1<CR>
Description:	Selects extended result codes.
Command	Function
&A0	Extended result codes disabled.
&A1	ARQ result codes enabled.
» &A3	Error control and compression result codes enabled.

FLOW CONTROL CHARACTER - XON
Type:	Register
Format:	AT [cmds] S22=n [cmds]
Example:	ATS22=20<CR>
Default:	17
Range:	11-127
Unit:	ASCII
Description:	Sets the character used to represent XON.

FLOW CONTROL CHARACTER - XOFF
Type:	Register
Format:	AT [cmds] S23=n [cmds]
Example:	ATS23=20<CR>
Default:	19
Range:	11-127
Unit:	ASCII
Description:	Sets the character used to represent XOFF.

FLOW CONTROL PASSTHROUGH
Type:	Configuration
Format:	AT [cmds] &In [cmds]
Example:	AT &I0 &W<CR>
Description:	Allows modem to act on, then transmit XON/XOFF characters.
Command	Function
» &I0	Software flow control disabled.
&I1	XON/XOFF passthrough enabled.
&I2	XON/XOFF passthrough disabled.

FLOW CONTROL TYPE
Type:	Configuration
Format:	AT [cmds] &Hn [cmds]
Example:	AT &H0 A<CR>
Description:	Sets type of flow control used by modem.
Command	Function
&H0	Flow control disabled.
» &H1	CTS/RTS flow control enabled.
&H2	XON/XOFF flow control enabled.
&H3	CTS/RTS and XON/XOFF flow control enabled.

HELP SCREENS
Type:	Immediate
Format:	AT <prefix>$
Example:	AT &$<CR>
Description:	Shows command help screens for all commands beginning with the given prefix, or no prefix if none is given.
Command	Function
$	Shows ATx help screen.
&$	Shows AT&x help screen.
D$	Shows ATDx help screen.
S$	Shows S-register help screen.

INACTIVITY TIMER
Type:	Register
Format:	AT [cmds] S19=n [cmds]
Example:	ATS19=20<CR>
Default:	0
Range:	Unidentified
Unit:	1 minute
Description:	Sets the length of time that the modem does not receive information before it disconnects.

NETWORK ACCESS
Type:	Configuration
Format:	AT [cmds] %Rn [cmds]
Example:	AT %R1 &W<CR>
Description:	Used with USR network management system.
Command	Function
» %R0	Network access disabled.
%R1	Network access enabled.

REPEAT COMMAND STRING
Type:	Configuration
Format:	AT [cmds] > [cmds]
Example:	AT *D1 > #E1<CR>
Description:	Causes modem to repeat command string until a keyboard key is pressed.

REPORT INFORMATION
Type:	Immediate
Format:	AT [cmds] In [cmds]
Example:	AT I1 O<CR>
Description:	Displays modem properties.
Command	Function
I0	Reports product code.
I1	Reports ROM checksum result.
I2	Reports RAM checksum result.
I3	Reports firmware version.
I4	Reports current command settings.
I5	Reports current NVRAM settings.
I6	Reports current connection’s statistics.
I7	Reports configuration.

STATUS REGISTER BIT
Type:	Configuration
Format:	Read: AT [cmds] Sn.m=0 or 1 [cmds] Write: AT [cmds] Sn.m=? [cmds]
Example:	AT S40.4=1 S51.3?<CR>
Description:	Sets/clears or reads bit m of register n.

TESTING
Format		AT [cmds] S16=n [cmds]
Example:		ATS16=32<CR>
Default:		0
Range:		0 - 15
Unit:		Bit-mapped
Description:		Enables loopback tests.
Note:		Bit 3 is read-only.
Bit	Value		Function
0	» 0 1		Analog loopback test disabled. Analog loopback test enabled.
1	» 0 1		Dial test disabled. Dial test enabled.
2	» 0 1		Test pattern disabled. Test pattern enabled.
3	» 0 1		Remote digital loopback test disabled. Remote digital loopback test enabled.

TIME DISPLAY
Type:	Immediate
Format:	AT [cmds] Kn [cmds]
Example:	AT K1 *L2 #E1<CR>
Description:	Displays the current call time or clock time.
Command	Function
K0	Display length of last call.
K1	Display actual time.

TOUCH TONE RECOGNITION
Type:	Configuration
Format:	AT [cmds] %Tn [cmds]
Example:	AT %T &W<CR>
Description:	Controls recognition of touch tones while off hook.
Command	Function
%T	Enabled.

BIT MAPPED REGISTER S34
Format:		AT [cmds] S34=n [cmds]
Example:		ATS34=139<CR>
Default:		0
Range:		0 - 56
Unit:		Bit-mapped
Description:		Controls V.23, MR LED function and MI/MIC.
Bit	Value		Function
3	» 0 1		V.23 disabled. V.23 enabled.
4	» 0 1		MR LED normal. MR LED reflects DSR signal.
5	» 0 1		MI/MIC disabled. MI/MIC enabled.

VOICE/DATA SWITCH
Type:	Register
Format:	AT [cmds] S32=n [cmds]
Example:	ATS32=6<CR>
Default:	1
Unit:	1-7
Description:	Controls the function of SW4.
Command	Function
0	Disabled.
1	Switch between voice and originate mode.
2	Switch between voice and answer mode.
3	Redial.
4	Dial number stored at position 0.
5	Enable and disable Auto Answer.
6	Reset.
7	Start remote digital loopback test.