CONNECTIONS
Purpose	Location	Purpose	Location
Line out	CN1	Line in	CN2

BASE I/O ADDRESS SELECTION
Port	SW1/A	SW1/C	SW1/E	SW1/F
» COM1: (3F8h)	Off	On	Off	On
COM2: (2F8h)	On	Off	Off	On
COM3: (3E8h)	Off	On	On	Off
COM4: (2E8h)	On	Off	On	Off

INTERRUPT SELECTION
IRQ	SW/B	SW1/D	JP1
3	On	Off	Pins 2 & 4 closed
» 4	Off	On	Pins 2 & 4 closed
5	Off	Off	Pins 3 & 4 closed
7	Off	Off	Pins 1 & 2 closed
Note: Location of JP1 is unidentified.

BIT-MAPPED REGISTER S14
Format		AT [cmds] S14=n [cmds]
Example:		ATS14=0<CR>
Default:		Unidentified
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 1		Smart mode. Dumb mode.
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=0<CR>
Default:		Unidentified
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 jack. Not used.
1	0 1		Serial Parallel
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=0<CR>
Default:		Unidentified
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=0<CR>
Default:		Unidentified
Range:		0-189
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		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.
5,4	00 01 10 11		Parity even. Space Parity. Parity odd. Mark/No Parity.
7, 6	00 01 10		Guard tone disabled. Guard tone 550Hz enabled. Guard tone 1800Hz enabled.

BIT-MAPPED REGISTER S27
Format		AT [cmds] S27=n [cmds]
Example:		AT S27=0 <CR>
Default:		Unidentified
Range:		0 - 108
Unit:		Bit-mapped
Description:		Selects sync/async mode, Line type, internal clock, and ITU-T/Bell modes.
Bit	Value		Function
3, 1, 0	000 001 010 011 100		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 DCE transmit clock source. External DTE transmit clock source. Remote DCE transmit clock source.
6	0 1		CCITT mode. Bell mode.

ENTRY FORMAT
Type:	Configuration
Format:	AT [cmds] +En [cmds]
Example:	AT +E1 &W<CR>
Description:	Selects format flag.
Command	Function
+E0	Reset format flag enabled.
+E1	Binary format flag enabled.
+E2	Hex format flag enabled.

FAX MODE
Type:	Configuration
Format:	AT [cmds] +Fn [cmds]
Example:	AT +F1 &W<CR>
Description:	Controls fax mode.
Command	Function
+F0	Fax mode disabled.
+F1	Fax mode enabled, DTE rate set to nbps.

FLOW CONTROL
Type:	Configuration
Format:	AT [cmds] +Kn [cmds]
Example:	AT +K4 &W<CR>
Description:	Sets type of flow control used by DTE.
Command	Function
+K0	Flow control disabled.
+K3	CTS flow control to DTE enabled.
+K4	XON/XOFF flow control enabled.

ON/OFF FAX TRANSMITTER
Type:	Configuration
Format:	AT [cmds] +Dn [cmds]
Example:	AT +D2 &W<CR>
Description:	Controls fax transmitter.
Command	Function
+D0	Fax transmitter disabled.
+D1	Fax transmitter V.21 enabled.
+D2	Fax transmitter V.27/2400bps enabled.
+D3	Fax transmitter V.27/4800bps enabled.

PAGES TO TRANSMIT
Type:	Configuration
Format:	AT [cmds] +Pn [cmds]
Example:	AT+P6<CR>
Default:	Unidentified
Range:	1-255
Unit:	1 page
Description:	Sets the number of pages to be transmitted.

RESOLUTION
Type:	Configuration
Format:	AT [cmds] +Rn [cmds]
Example:	AT +R0 &W<CR>
Description:	Controls the resolution of fax transmission and receiving.
Command	Function
+R0	Normal resolution enabled.
+R1	Fine resolution enabled.

SPEED
Type:	Configuration
Format:	AT [cmds] +Bn [cmds]
Example:	AT +B5 &W<CR>
Description:	Selects fax baud rate.
Command	Function
+B4	Transmit at 2400bps
+B5	Transmit at 4800bps
+B6	Transmit at 7200bps.
+B7	Transmit at 9600bps.

TEST MODES
Format		AT [cmds] S16=n [cmds]
Example:		ATS16=0<CR>
Default:		Unidentified
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 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.

TEST MODES
Type:	Immediate
Format:	AT [cmds] +Tn [cmds]
Example:	AT +T1 &W<CR>
Description:	Selects the type of test the fax will perform.
Command	Function
+T0	Test mode disabled.
+T1	Test mode 1, reports frames received in ASCII Hex.
+T2	Test mode 2; reports frames received in ASCII Hex, KDV output follows CD in fax CPM mode.