AUTO-RETRAIN
Type:	Configuration
Format:	AT %En
Example:	AT %E1 <CR>
Description:	Selects auto-retrain mode.
Command	Function
» %E0	Auto-retrain disabled.
%E1	Auto-retrain enabled.
%E2	Fallback/fall forward enabled.
%E3	Auto-retrain enabled, fast hang-up when line quality is poor.

BIT-MAPPED REGISTER S14
Format		AT [cmds] S14=n [cmds]
Example:		ATS14=138<CR>
Default:		138
Range:		0-174
Unit:		Bit-mapped
Description:		Controls echo, result codes, result code display, dial mode, and answer/originate mode.
Bit	Value		Function
0	0		Not used.
1	0 » 1		Command echo disabled. Command echo enabled.
2	» 0 1		Result codes enabled. Result codes disabled.
3	0 » 1		Display result codes in numeric format. Display result codes in verbose format.
4	0		Not used.
5	» 0 1		Tone dial enabled. Pulse dial enabled.
6	0		Not used.
7	0 » 1		Answer mode enabled. Originate mode enabled.

BIT-MAPPED REGISTER S21
Format		AT [cmds] S21=n [cmds]
Example:		ATS21=4<CR>
Default:		4
Range:		0 - 253
Unit:		Bit-mapped
Description:		Selects jack type, CTS signal, low DTR action, DCD signal, DSR signal, and the Long Space Disconnect function.
Bit	Value		Function
0	» 0 1		Selects RJ-11, RJ-41S, or RJ45S jack. Selects RJ-12 or RJ-13 jack.
1	0		Not used.
2	0 » 1		CTS follows RTS. CTS forced high.
4, 3	» 00 01 10 11		DTR signal ignored. Modem goes to command mode on low DTR. Modem disconnects on low DTR. Auto-Answer is disabled. Modem is initialized on low DTR.
5	» 0 1		DCD forced high. DCD normal.
6	» 0 1		DSR forced high. DSR normal.
7	» 0 1		Long Space Disconnect function disabled. Long Space Disconnect function enabled.

BIT-MAPPED REGISTER S22
Format		AT [cmds] S22=n [cmds]
Example:		ATS22=118<CR>
Default:		118
Range:		0-127
Unit:		Bit-mapped
Description:		Controls speaker volume and controls, and limits results codes.
Bit	Value		Function
1, 0	00 » 01 10 11		Off volume. On volume. Medium level volume. High level volume.
3, 2	00 » 01 10 11		Speaker off. Speaker off on carrier. Speaker always on. Speaker on during handshake.
6, 5, 4	000 100 101 110 » 111		Basic result codes only enabled. Basic and connection speed result codes enabled. Basic and connection speed result codes and dialtone detection enabled. All result codes except dialtone detection enabled. All result codes enabled.

BIT-MAPPED REGISTER S23
Format		AT [cmds] S23=n [cmds]
Example:		ATS23=55<CR>
Default:		55
Range:		0-255
Unit:		Bit-mapped
Description:		Grants/denies remote digital loopback, controls DTE rate and parity, and sets guard tone.
Bit	Value		Function
0	0 » 1		Remote digital loopback denied. Remote digital loopback allowed.
3, 2, 1	000 001 010 » 011 100 101 110		Sets serial port speed to 0-300bps. Sets serial port speed to 600bps. Sets serial port speed to 1200bps. Sets serial port speed to 2400bps. Sets serial port speed to 4800bps. Sets serial port speed to 9600bps. Sets serial port speed to 19200bps.
5,4	00 01 10 » 11		Parity even. Not used. Parity odd. No Parity.
7, 6	00 01 » 10		Guard tone disabled. Guard tone disabled. Guard tone 1800Hz enabled.

BIT-MAPPED REGISTER S27
Format		AT [cmds] S27=n [cmds]
Example:		ATS27=73<CR>
Default:		73
Range:		0-127
Unit:		Bit-mapped
Description:		Selects sync/async mode, Line type, internal clock, and ITU-T/Bell modes.
Bit	Value		Function
3, 1, 0	000 001 101 » 110		Asynchronous mode, serial port speed follows connect speed. Asynchronous off-line command mode and synchronous connect mode. Error-correcting mode. Asynchronous mode, serial port speed locked.
2	» 0 1		Dial up line. Leased line.
5, 4	» 00 01 10		Internal DTE transmit clock source. External DTE transmit clock source. Slave DTE transmit clock source.
6	» 0 1		CCITT mode. Bell mode.

BIT-MAPPED REGISTER S28
Format		AT [cmds] S28=n [cmds]
Example:		ATS28=0<CR>
Default:		0
Range:		0
Unit:		Bit-mapped
Description:		Controls V.23 split speed, V.23 split screen, V.23 half duplex, and pulse dialing.
Bit	Value		Function
0	» 0 1		V.23 split speed operation disabled. V.23 split speed operation enabled.
1	» 0 1		Select 75bps transmit, 1200bps receive. Select 1200bps transmit, 75bps receive.
2	0		Not used.
4, 3	» 00 01 10 11		39ms make/61ms break at 10pps. 33ms make/67ms break at 10pps. 39ms make/61ms break at 20pps. 33ms make/67ms break at 20pps.
5	0		Not used
7, 6	» 00 01 10		MNP at highest speed MNP at 1200bps MNP at 1200bps

BIT-MAPPED REGISTER S31
Format		AT [cmds] S31=n [cmds]
Example:		ATS31=40<CR>
Default:		194
Range:		0-255
Unit:		Bit-mapped
Description:		Controls auto-baud function and result codes.
Bit	Value		Function
0	0		Not used.
1	0 » 1		Auto-baud disabled. Auto-baud enabled.
3, 2	» 00 01 10		DTE speed displayed in result codes. Extended result codes enabled; DCE speed displayed in result codes. DCE speed displayed in result codes.

BIT-MAPPED REGISTER S40
Format		AT [cmds] S40=n [cmds]
Example:		ATS40=104<CR>
Default:		104
Range:		0 - 255
Unit:		Bit-mapped
Description:		Controls power level and break handling; selects MNP extended services, link negotiation, and block size.
Bit	Value		Function
0	í0 » 1		MNP10 disabled. MNP10 enabled.
1	0 1		Link will be negotiated at highest possible speed. Link will be negotiated at 1200bps.
2	» 0 1		Power level adjustment enabled. Power level adjustment disabled.
5, 4, 3	000 001 010 011 100 » 101		\K0 \K1 \K2 \K3 \K4 \K5
7, 6	00 » 01 10 11		MNP block size is 64 characters. MNP block size is 128 characters. MNP block size is 192 characters. MNP block size is 256 characters.

BIT-MAPPED REGISTER S41
Format		AT [cmds] S41=n [cmds]
Example:		ATS41=131<CR>
Default:		131
Range:		0 - 255
Unit:		Bit-mapped
Description:		Selects compression, auto-retrain, flow control, and MNP mode.
Bit	Value		Function
1 - 0	00 01 10 » 11		Data compression disabled. MNP5 enabled. V.42bis enabled. MNP5 and V.42bis enabled.
6, 2	» 00 01 10		Auto-retrain disabled. Auto-retrain enabled. Fallback/fall forward enabled.
3	» 0 1		Flow control disabled. Flow control enabled.
4	» 0 1		Stream mode for MNP. Block mode for MNP.
5	0		Not used.
7	0 » 1		Fallback to V.22bis/V.22 disabled. Fallback to V.22bis/V.22 enabled.

BREAK SEND
Type:	Configuration
Format:	AT [cmds] \Bn [cmds]
Example:	AT \B3 &W<CR>
Range:	1-9
Unit:	100 ms
Description:	Sends break to modem.

BREAK TYPE
Type:	Configuration
Format:	AT [cmds] \Kn [cmds]
Example:	AT \K1 <CR>
Description:	Configures action of break signal.
Command		Break from DTE	Modem receives \B	Break received from remote modem
\K0		Online command mode enabled, send no break to remote modem.	Break sent to remote modem and buffered cleared.	Buffers cleared, break sent to DTE.
\K1		Break sent to remote modem and buffered cleared.	Break sent to remote modem and buffered cleared.	Buffers cleared, break sent to DTE.
\K2		Online command mode enabled, send no break to remote modem.	Send break to remote modem immediately.	Break sent immediately to DTE.
\K3		Send break to remote modem immediately.	Send break to remote modem immediately.	Break sent immediately to DTE.
\K4		Online command mode enabled, send no break to remote modem.	Send break with transmitted data.	Break sent with received data to the DTE.
\K5		Send break with transmitted data.	Send break with transmitted data.	Break sent with received data to the DTE.

CELLULAR TRANSMISSION LEVEL
Type:	Configuration
Format:	AT [cmds] @Mn [cmds]
Example:	AT @M26 &W<CR>
Default:	26
Range:	10 - 31
Unit:	-1 dBm
Description:	Sets the signal level for transmission when in leased line mode.

COMPRESSION AND ERROR CORRECTION
Type:	Configuration
Format:	AT %Cn
Example:	AT %C3 *Y1<CR>
Description:	Selects data compression and error correction.
Command	Function
%C0	Data compression disabled.
%C1	MNP5 enabled.
%C2	V.42bis enabled.
» %C3	V.42bis and MNP5 enabled.

COMPROMISE EQUALIZER
Type:	Configuration
Format:	AT [cmds] :En [cmds]
Example:	AT :E &W<CR>
Description:	Controls V.32 compromise equalizer.
Command	Function
:E0	Equalizer disabled.
» :E1	Equalizer enabled.

CONFIGURATION PROFILES
Type:	Immediate
Format:	AT [cmds] \Sn [cmds]
Example:	AT \S0<CR>
Description:	Displays active configuration profiles.

CONNECT MODE
Type:	Configuration
Format:	AT [cmds] \Nn [cmds]
Example:	AT \N1 DT555-1212<CR>
Description:	Sets connect mode.
Command	Function
\N0	Normal mode enabled.
\N2	Reliable mode enabled.
» \N3	Auto-reliable mode enabled.
\N4	LAPM mode enabled.
\N5	MNP mode enabled.

FLASH DIAL MODIFIER TIME
Format	AT [cmds] S29=n [cmds]
Example:	ATS29=0<CR>
Default:	70
Range:	0-70
Unit:	10 ms
Description:	Time the modem will go on-hook upon receiving the ! dial modifier in dial string.

FLOW CONTROL
Type:	Configuration
Format:	AT [cmds] \Gn [cmds]
Example:	AT G1 &K3<CR>
Description:	Selects modem port flow control.
Command	Function
» \G0	Flow control disabled.
\G1	Flow control enabled.

FLOW CONTROL CHARACTER - XOFF
Type:	Register
Format:	AT [cmds] S33=n [cmds]
Example:	ATS33=20<CR>
Default:	19
Range:	0-255
Unit:	ASCII
Description:	Sets the character used to represent XOFF.

FLOW CONTROL CHARACTER - XON
Type:	Register
Format:	AT [cmds] S32=n [cmds]
Example:	ATS32=20<CR>
Default:	17
Range:	0-255
Unit:	ASCII
Description:	Sets the character used to represent XON.

HANDSHAKE OPTIONS
Type:	Configuration
Format:	AT [cmds] S48=n [cmds]
Example:	AT S48=7<CR>
Description:	Controls the V.42 handshake sequence.
Command	Function
S48=0	V.42 negotiation disabled.
» S48=7	V.42 negotiation enabled.
S48=128	V.42 disabled; fallback according to S36.

HDLC ADDRESS
Type:	Register
Format:	AT [cmds] S20=n [cmds]
Example:	ATS20=6<CR>
Default:	0
Range:	0-255
Unit:	1 second
Description:	Sets the HDLC address/BSC character.

LINE SIGNAL LEVEL
Type:	Configuration
Format:	AT [cmds] %L [cmds]
Example:	AT %L <CR>
Description:	Returns value of signal level for transmission at the MDP.

LINE SIGNAL QUALITY
Type:	Configuration
Format:	AT [cmds] %Q [cmds]
Example:	AT %Q &W<CR>
Description:	Reports line signal quality.

MNP10 LINK NEGOTIATION
Type:	Configuration
Format:	AT [cmds] *Hn [cmds]
Example:	AT *H0 -Q1 <CR>
Description:	Sets the speed at which MNP10 link negotiation will occur.
Command	Function
» *H0	Link will be negotiated at highest possible speed.
*H1	Link will be negotiated at 1200bps.
*H2	Link will be negotiated at 4800bps.

MNP10 PARAMETERS
Format		AT [cmds] S201=n [cmds]
Example:		ATS201=58<CR>
Default:		58
Range:		10 - 63
Unit:		Bit-mapped
Description:		Controls MNP10 parameters.
Bit	Value		Function
4 - 0	01011 … 11010 … 11111		Sets leased line transmit attenuation level to -11dBm. Sets leased line transmit attenuation level to -26dBm. Sets leased line transmit attenuation level to -31dBm.
5	0 1		Equalizer disabled. Equalizer enabled.

MAXIMUM BLOCK SIZE FOR TRANSMISSION
Type:	Configuration
Format:	AT [cmds] \An [cmds]
Example:	AT \A3 %C1<CR>
Description:	Sets the maximum transmittable block size.
Command	Function
\A0	MNP block size is 64 characters.
\A1	MNP block size is 128 characters.
\A2	MNP block size is 192 characters.
» \A3	MNP block size is 256 characters.

MNP10 COMPRESSION
Type:	Configuration
Format:	AT [cmds] -Kn [cmds]
Example:	AT %C1 -K1 -Q0 <CR>
Description:	Selects MNP10 data compression.
Command	Function
» -K0	MNP10 disabled.
-K1	MNP10 enabled.
-K2	MNP10 enabled on originate mode only.

MNP10 FALL-BACK
Type:	Configuration
Format:	AT [cmds] -Qn [cmds]
Example:	AT *H0 -Q1 <CR>
Description:	Allows MNP10 to fall back to speeds slower than 4800bps.
Command	Function
-Q0	MNP10 at 2400 and 1200bps disabled.
» -Q1	MNP10 at 2400 and 1200bps enabled.

MNP10 POWER LEVEL ADJUST
Type:	Configuration
Format:	AT [cmds] )Mn [cmds]
Example:	AT )M1 %C1<CR>
Description:	Controls automatic transmit power level adjustment during MNP 10 link negotiation.
Command	Function
» )M0	Power level adjustment disabled.
)M1	Power level adjustment enabled.

MNP STREAM/BLOCK MODE
Type:	Configuration
Format:	AT [cmds] \Ln [cmds]
Example:	AT \L1 DT555-1212<CR>
Description:	Selects the transfer mode for MNP.
Command	Function
» \L0	Stream mode for MNP enabled.
\L2	Block mode for MNP enabled.

REMOTE ACCESS ESCAPE CHARACTER
Format	AT [cmds] S202=n [cmds]
Example:	ATS202=40<CR>
Default:	170
Range:	0 - 255
Unit:	Bit-mapped
Description:	Holds value of ASCII character used as the escape character.

SLEEP TIMER
Format	AT [cmds] S24=n [cmds]
Example:	ATS24=40<CR>
Default:	0
Range:	0 - 255
Unit:	1 seconds
Description:	Maximum duration of DTE and DCE inactivity allowed prior to initiating low-power sleep mode.

TEST MODES
Format		AT [cmds] S16=n [cmds]
Example:		ATS16=40<CR>
Default:		0
Range:		0-125
Unit:		Bit-mapped
Description:		Controls loopback tests, analog, digital, remote digital, and self tests.
Bit	Value		Function
0	» 0 1		Local analog loopback not in progress. Local analog loopback in progress.
1	0		Not used.
2	» 0 1		Local digital loopback not in progress. Local digital loopback in progress.
3	» 0 1		Modem not in remote digital loopback. Remote digital loopback in progress.
4	» 0 1		Remote digital loopback not requested. Remote digital loopback requested.
5	» 0 1		Remote digital loopback with self-test not in progress. Remote digital loopback with self-test in progress.
6	í 0 1		Local analog loopback with self-test not in progress. Local analog loopback with self-test in progress.

TEST MODE - PTT
Type:	Configuration
Format:	AT [cmds] %TT [cmds]
Example:	AT %TT &W<CR>
Description:	Send PTT test signals for European line test.