AT&T 28.8 (EXTERNAL) modem/telephone/ISDN Settings and Configuration

Card Type	Modem (synchronous/asynchronous)
Chip Set	AT&T
I/O Options	Voice
Maximum Data Rate	28.8Kbps
Maximum Fax Rate	14.4Kbps
Data Bus	External
Fax Class	Class I & II
Data Modulation Protocol	Bell 103A/212A ITU-T V.21, V.22, V.22bis, V.23, V.32, V.32bis, V.32terbo, V.34
Fax Modulation Protocol	ITU-T V.17, V.21CH2, V.27ter, V.29
Error Correction/Compression	MNP5, V.42, V.42bis

CONNECTIONS
Function	Label		Function		Label
Line in		CN1		DC power		CN4
Line out		CN2		Power switch		SW1
RS-232/422		CN3

DIAGNOSTIC LED(S)
LED	Color	Status	Condition
MR	Red	On	Power is on
MR	Red	Off	Power is off
TR	Red	On	DTR signal is high
TR	Red	Off	DTR signal is low
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
OH	Red	On	Modem is off-hook
OH	Red	Off	Modem is on-hook
CD	Red	On	Carrier signal detected
CD	Red	Off	Carrier signal not detected
AA	Red	On	Auto-answer enabled
AA	Red	Off	Auto-answer disabled
EC	Red	On	Error correction enabled
EC	Red	Off	Error correction disabled

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

AUTO-RELIABLE FALLBACK CHARACTER
Type:	Register
Format:	AT [cmds] S29=n [cmds]
Default:	0
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]
Description:	Controls the handling of incoming data during auto-reliable time period
Command	Function
í \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 - FALLBACK/FALLFORWARD
Type:	Configuration
Format:	AT [cmds] %En [cmds]
Description:	Controls auto-retrain mode and fallback/fall forward
Command	Function
%E0	Auto-retrain disabled
%E1	Auto-retrain enabled
í %E2	Fallback/fall forward enabled

BIT MAPPED REGISTERS
Register	Default
S14	137
S15	83
S16	0
S17	75
S19	3
S20	0
S21	48
S22	246
S23	12
S24	72
S27	0
S28	16

BREAK SEND
Type:	Configuration
Format:	AT [cmds] \Bn [cmds]
Default:	3
Range:	0-9
Unit:	.1 second
Description:	Sends break to modem

BREAK TYPE
Type	Configuration
Format	AT [cmds] \Kn [cmds]
Default	5
Range	0-5
Description	Configures action of break signal

COMPRESSION
Type:	Configuration
Format:	AT [cmds] %Cn [cmds]
Description:	Controls data compression
Command	Function
%C0	Data compression disabled
í %C1	Data compression enabled

CONNECT MODE
Type:	Configuration
Format:	AT [cmds] \Nn [cmds]
Description:	Sets connect mode
Command	Function
\N0	Normal mode enabled
\N1	Direct mode enabled
\N2	MNP mode only enabled
í \N3	LAP-M/MNP/Normal mode enabled
\N4	LAP-M mode only enabled
\N5	LAP-M/Normal mode enabled
\N6	LAP-M/MNP mode enabled.
\N7	MNP/Normal mode enabled

CONNECTION SPEED UPPER LIMIT
Type:	Immediate
Format:	AT [cmds] %Bn [cmds]
Description:	Selects the maximum DCE connection speed
Command	Function
%B300	Select 300bps speed
%B1200	Select 1200bps speed
%B2400	Select 2400bps speed
%B4800	Select 4800bps speed
%B7200	Select 7200bps speed
%B9600	Select 9600bps speed
%B12000	Select 12Kbps speed
%B14400	Select 14.4Kbps speed
%B16800	Select 16.8Kbps speed
%B19200	Select 19.2Kbps speed
%B21600	Select 21.6Kbps speed
%B24000	Select 24Kbps speed
%B26400	Select 26.4Kbps speed
%B28800	Select 28.8Kbps speed

DTE BAUD RATE
Type:	Configuration
Format:	AT [cmds] %Nn [cmds]
Description:	Controls DTE baud rate
Command		Function
í %N0		IBM PC
%N1		NEC PC98 set 1
%N2		NEC PC98 set 2
Note: For use with external models

EXTENDED RESULT CODES
Type:	Configuration
Format:	AT [cmds] \Vn [cmds]
Description:	Selects extended result codes
Command	Function
\V0	Modem speed result codes enabled
\V1	Modem speed and basic REL result codes enabled
í \V2	All extended result codes enabled
\V3	Computer speed result codes enabled

FLOW CONTROL
Type:	Configuration
Format:	AT [cmds] \Gn [cmds]
Description:	Selects modem port flow control
Command	Function
í \G0	Flow control disabled
\G1	Flow control enabled

FLOW CONTROL TYPE
Type:	Configuration
Format:	AT [cmds] \Qn [cmds]
Description:	Sets type of flow control used by modem
Command	Function
\Q0	Flow control disabled
\Q1	Bidirectional XON/XOFF flow control enabled
\Q2	CTS flow control by DCE enabled
í \Q3	CTS/RTS flow control enabled
\Q4	Unidirectional XON/XOFF flow control enabled

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

LINE SIGNAL QUALITY
Type:	Immediate
Format:	AT [cmds] %Q [cmds]
Description:	Displays line signal quality and receive level in dBm

DUMB MODE
Type:	Configuration
Format:	AT [cmds] %Dn [cmds]
Description:	Controls smart/dumb mode
Command	Function
í %D0	Smart mode enabled
%D1	Dumb mode enabled

LOCK SERIAL PORT
Type:	Configuration
Format:	AT [cmds] \Jn [cmds]
Description:	Sets operation of serial port speed
Command	Function
í \J0	Serial speed locked
\J1	Serial speed follows connect speed

MAXIMUM BLOCK SIZE FOR TRANSMISSION
Type:	Configuration
Format:	AT [cmds] \An [cmds]
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
í \A3	MNP block size is 256 characters

MODULATION SELECTION
Type:	Configuration
Format:	AT [cmds] \Mn [cmds]
Description:	Controls V.34 and V.32terbo modulation selection
Command		Function
í \M0		V.34 and V.32terbo enabled
\M1		V.32terbo disabled
\M2		V.34 disabled

SLEEP TIMER
Format	AT [cmds] S13=n [cmds]
Default:	6
Range:	0-255
Unit:	1 second
Description:	Maximum duration of DTE and DCE inactivity allowed prior to initiating low-power sleep mode

TRANSMIT ATTENUATION
Type:	Register
Format:	AT [cmds] S91=n [cmds]
Default:	12
Range:	0-15
Unit:	-1dBm
Description:	Controls attenuation for transmit level

XON/XOFF PASS-THROUGH
Type:	Configuration
Format:	AT [cmds] \Xn [cmds]
Description:	Selects whether XON/XOFF signals are sent to remote modem
Command	Function
í \X0	XON/XOFF signals trapped by local modem
\X1	XON/XOFF passed through local modem