ACCEPT AUTO-RELIABLE MODE
Type:	Immediate
Format:	AT [cmds] \U
Example:	AT \U<CR>
Description:	Accepts remote modem’s request for reliable link.

AUTO FALL FORWARD/FALLBACK
Type:	Configuration
Format:	AT [cmds] %Gn [cmds]
Example:	AT %G0 &W <CR>
Description:	Selects auto fallback.
Command	Function
» %G0	Fallback disabled.
%G1	Fallback enabled.

AUTO-RELIABLE FALLBACK CHARACTER
Type:	Register
Format:	AT [cmds] %An [cmds]
Example:	AT%A13<CR>
Default:	13
Range:	0-127
Unit:	ASCII
Description:	Sets the character used as the auto-reliable fallback character. %A0 will disable this function.

AUTO-RELIABLE TIME BUFFER CONFIGURATION
Type:	Configuration
Format:	AT [cmds] \Cn [cmds]
Example:	AT \C1 &W<CR>
Description:	Controls the handling of incoming data during auto-reliable time period.
Command	Function
» \CO	Data is discarded.
\C1	Data is buffered.
\C2	Data is discarded, sets to normal mode and sends auto-reliable character to serial port.

AUTO-RETRAIN
Type:	Configuration
Format:	AT [cmds] %En [cmds]
Example:	AT %E0 <CR>
Description:	Selects auto-retrain mode.
Command	Function
» %E0	Auto-retrain disabled.
%E1	Auto-retrain enabled.

BAUD RATE ADJUST
Type:	Configuration
Format:	AT [cmds] \Jn [cmds]
Example:	AT %L3 %B14 \J0<CR>
Description:	Allows baud rate to follow serial port speed
Command	Function
» \J0	Baud rate adjust disabled.
\J1	Baud rate adjust enabled.

BIT-MAPPED REGISTER S14
Format		AT [cmds] S14? [cmds]
Example:		ATS14?<CR>
Default:		Read only
Range:		0-174
Unit:		Bit-mapped
Description:		Displays 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? [cmds]
Example:		ATS21?<CR>
Default:		Read only
Range:		0 - 253
Unit:		Bit-mapped
Description:		Displays 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? [cmds]
Example:		ATS22?<CR>
Default:		Read only
Range:		0 - 255
Unit:		Bit-mapped
Description:		Displays volume and speaker settings, result codes, and make/break pulse ratio.
Bit	Value		Function
1, 0	00 01 10 11		Not used. Low volume setting. Medium volume setting Highest volume setting.
3, 2	00 01 10 11		Speaker disabled. Speaker enabled until carrier signal detected Speaker enabled. Speaker enabled following dialing, then disabled after carrier signal detected.
6, 5 ,4	000 100 101 110 111		Busy and dialtone detection disabled, result codes 0-4 enabled. Busy and dialtone detection disabled, result codes 0-5, 10 enabled. Busy tone detection disabled, dialtone detection enabled, result codes 0-6, 10 enabled. Busy tone detection enabled, dialtone detection disabled, result codes 0-5, 7, 10 enabled. Busy and dialtone detection enabled, result codes 0-7, 10 enabled.
7	0 1		Pulse dialing at 39/61ms at 10pps. Pulse dialing at 33/67ms at 10pps.

BIT-MAPPED REGISTER S23
Format		AT [cmds] S23? [cmds]
Example:		ATS23?<CR>
Default:		Read only
Range:		0-255
Unit:		Bit-mapped
Description:		Displays 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	000 001 010 011 100 101 110 111		Sets serial port speed to 0-300bps. Sets serial port speed to 1200bps. Sets serial port speed to 2400bps. Sets serial port speed to 4800bps. Sets serial port speed to 7200bps. Sets serial port speed to 9600bps. Sets serial port speed to 19.2Kbps. Sets serial port speed to 38.4Kbps.
5,4	00 01 10 11		Parity even. No Parity. Parity odd. Mark.
7, 6	00 01 10		Guard tone disabled. Guard tone disabled. Guard tone 1800Hz enabled.

BIT-MAPPED REGISTER S27
Format		AT [cmds] S27? [cmds]
Example:		AT S27? <CR>
Default:		Read only
Range:		0 - 127
Unit:		Bit-mapped
Description:		Displays synchronous/asynchronous mode, Line type, internal clock, and ITU-T/Bell modes.
Bit	Value		Function
3, 1, 0	000 001 010 011 100		Asynchronous mode, serial port speed follows connect speed. Asynchronous command mode and synchronous connect mode. Asynchronous command mode and synchronous connect mode, DTR dialing enabled. Asynchronous command mode on low DTR, synchronous connect mode on high DTR. Hayes AutoSync™ mode - serial port locked at 9600bps.
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.

BREAK SEND
Type:	Configuration
Format:	AT [cmds] \Bn [cmds]
Example:	AT \B3 &W<CR>
Range:	0-9
Unit:	.1 second
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 Reliable/Normal mode		Break from DTE Direct mode	Modem receives \B	Break from remote modem
\K0	Enter command mode, do not send break to remote modem.		Send break to remote modem immediately, then enter command mode.	Buffers cleared and break sent to remote modem.	Buffers cleared and break sent to DTE.
\K1	Buffers cleared and break sent to remote modem.		Send break to remote modem immediately.	Buffers cleared and break sent to remote modem.	Buffers cleared and break sent to DTE.
\K2	Enter command mode, do not send break to remote modem.		Send break to remote modem immediately, then enter command mode.	Send break to remote modem immediately.	Send break to DTE immediately.
\K3	Send break to remote modem immediately.		Send break to remote modem immediately.	Send break to remote modem immediately.	Send break to DTE immediately.
\K4	Enter command mode, do not send break to remote modem.		Send break to remote modem immediately, then enter command mode.	Send break to remote modem with transmitted data.	Break sent with received data to the DTE.
» \K5	Send break with transmitted data.		Send break to remote modem immediately.	Send break to remote modem with transmitted data.	Break sent with received data to the DTE.

BUFFER CONTROL
Type:	Confiuration
Format:	AT [cmds] Kn [cmds]
Example:	AT K1 *L2 #E1<CR>
Description:	Selects SRAM for use in Fax mode.
Command	Function
K0	SRAM buffer disabled.
» K1	SRAM buffer enabled.

CALLING TONE
Type:	Configuration
Format:	AT [cmds] -Cn [cmds]
Example:	AT -C0 &W<CR>
Description:	Controls whether the DTE will allow the modem to send a 1300Hz calling tone when originating.
Command	Function
» -C0	Disable calling tone.
-C1	Enable calling tone.

COMPRESSION
Type:	Configuration
Format:	AT [cmds] %Cn [cmds]
Example:	AT *EC0 %C1 *AP0<CR>
Description:	Selects data compression.
Command	Function
%C0	Data compression disabled.
» %C1	Data compression enabled.

CONNECT MODE
Type:	Configuration
Format:	AT [cmds] \Nn [cmds]
Example:	AT \N1 DT555-1212<CR>
Description:	Sets connect mode.
Command	Function
\N0	Normal mode.
\N1	Direct mode.
\N2	MNP reliable mode.
» \N3	V.42 auto-reliable mode.
\N4	V.42 reliable mode.

CONVERT TO RELIABLE MODE
Type:	Immediate
Format:	AT [cmds] \Y [cmds]
Example:	AT \Y<CR>
Description:	Initiates reliable mode link.

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 TYPE
Type:	Configuration
Format:	AT [cmds] \Qn [cmds]
Example:	AT \Q0 A <CR>
Description:	Sets type of flow control used by modem.
Command	Function
\Q0	Flow control disabled.
\Q1	XON/XOFF flow control enabled.
\Q2	CTS flow control to DTE enabled.
» \Q3	RTS/CTS flow control enabled.

INACTIVITY TIMER
Type:	Configuration
Format:	AT [cmds] \Tn [cmds]
Example:	AT\T20<CR>
Default:	0
Range:	0-90
Unit:	1 minute
Description:	Sets the length of time that the modem does not receive information before it disconnects.

INACTIVITY TIMER
Type:	Register
Format:	AT [cmds] S90=n [cmds]
Example:	ATS90=20<CR>
Default:	Unidentified
Range:	0-255
Unit:	1 minute
Description:	Sets the length of time that the modem does not receive information before it disconnects. S90=0 will disable.

MAXIMUM BLOCK SIZE FOR TRANSMISSION
Type:	Configuration
Format:	AT [cmds] \An [cmds]
Example:	AT \A3 &MB28800<CR>
Description:	Sets the maximum transmittable block size.
Command	Function
\A0	Maximum MNP block size is 64 characters.
\A1	Maximum MNP block size is 128 characters.
\A2	Maximum MNP block size is 192 characters.
» \A3	Maximum MNP block size is 256 characters.

ON-LINE IN RELIABLE MODE
Type:	Immediate
Format:	AT [cmds] \O [cmds]
Example:	AT \O <CR>
Description:	Returns to on-line and requests reliable mode connection.

REPORT SIGNAL QUALITY
Type:	Immediate
Format:	AT [cmds] %Q [cmds]
Example:	AT %Q<CR>
Description:	Reports signal quality. If the value is greater than 7, the modem will retrain.

RESULT CODES
Type:	Configuration
Format:	AT [cmds] \Vn [cmds]
Example:	AT \V0 Q0 <CR>
Description:	Controls result codes the modem will display.
Command	Function
\V0	Basic result code enabled.
\V1	Modified MNP result code enabled.
» \V2	Extended V.42 result code enabled.

REPORT INFORMATION
Type:	Immediate
Format:	AT [cmds] In [cmds]
Example:	AT I1 &W<CR>
Description:	Displays modem properties.
Command	Function
I0	Reports product code.
I1	Reports firmware version number.
I2	Reports ROM checksum.
I3	Reports device set name.
I4	Reports current configuration (see rows below, default is 31).
		Bit	Value	Meaning
		0	0 » 1	Hayes escape sequence. TIES escape sequence.
		1	0 » 1	No error corection firmware. Error corection firmware.
		2	0 » 1	Serial host interface. Parallel host interface.
		3	0 » 1	No external static RAM present. External static RAM present.
		4	0 » 1	8K x 8 static RAM present. 32K x 8 static RAM present.

RETURN TO RELIABLE MODE
Type:	Immediate
Format:	AT [cmds] \Z [cmds]
Example:	AT \Z <CR>
Description:	Ends reliable mode link, initiate return to normal mode.

TEST MODES
Format		AT [cmds] S16? [cmds]
Example:		ATS16?<CR>
Default:		Ready-only
Range:		0-125
Unit:		Bit-mapped
Description:		Displays 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 w/ self-test not in progress. Remote digital loopback w/ self-test in progress.
6	0 1		Local analog loopback w/ self-test not in progress. Local analog loopback w/ self-test in progress.

V.42 DETECTION PHASE
Type:	Configuration
Format:	AT [cmds] -Jn [cmds]
Example:	AT -J1 &W<CR>
Description:	Controls V.42 detection.
Command	Function
-J0	V.42 detection disabled.
» -J1	V.42 detection enabled.

V.42bis COMPRESSION CONTROL
Type:	Configuration
Format:	AT [cmds] "Hn [cmds]
Example:	AT "H3 &W<CR>
Description:	Controls V.42bis data compression.
Command	Function
"H0	V.42bis disabled.
"H1	V.42bis when transmitting enabled.
"H2	V.42bis when receiving enabled.
» "H3	V.42bis when transmitting/receiving enabled.

V.42bis MAXIMUM STRING LENGTH
Type:	Immediate
Format:	AT [cmds] "On [cmds]
Example:	AT "O16 <CR>
Default:	16
Range:	6 - 250
Unit:	Unidentified
Description:	Selects string size for V.42bis compression.

XON/XOFF PASS-THROUGH
Type:	Configuration
Format:	AT [cmds] \Xn [cmds]
Example:	AT \X7 O<CR>
Description:	Selects whether XON/XOFF signals are sent to remote modem.
Command	Function
» \X0	XON/XOFF signals trapped by local modem.
\X1	XON/XOFF passed through local modem.