Force answer mode/ manual mode answer. The modem goes off-hook in answer mode when it detects a ring on the phone line, and sends an answer tone. If it fails to detect a carrier signal from a calling modem within 60 seconds, it hangs up. Pressing any key after the modem goes off hook aborts the manual answer operation and hangs up the modem.

ITU-T / Bell answer sequence

• n = 0 - ITU-T V.25 answer sequence. Required to connect from 14.4 bits per second (bps) down to 4800 bps. Also required for modems answering overseas calls at 2400 bps and 1200 bps.
• n = 1 - Bell answer tone, used in US and Canada. Set ITU-T or Bell mode.

Dials the specific phone number. Includes the following:

• n = P - Pulse dial (default)
• n = T - Tone Dial
• , - (comma) Pause for two seconds
• ; - (semicolon) Return to command mode after dialing
• " (quot) Dial the letters that follow
• ! - (exclamation) Flash the switch-hook
• W - Wait for second dial tone (with X3 or higher)
• @ - Wait for an answer (with X3 or higher)
• R - Reverse the call / answer frequencies

On-line local echo of transmitted data ON / OFF. Sometimes referred to as the duplex settings

• n = 0 Local echo ON. Sometimes called half duplex. Modem sends a copy to your screen of data it sends to the remote system.
• n = 1 Local echo OFF. Default. Sometimes called full duplex. Receiving (remote) system may send an echo of data it receives.

Modem inquiry. Includes the following:

• n = 0 Display product code
• n = 1 Display results of ROM checksum
• n = 2 Displays results of RAM test
• n = 3 Display modem description and ROM revision
• n = 4 Display current modem settings
• n = 5 Display nonvolatile random access memory (NVRAM) settings
• n = 6 Reserved
• n = 7 Display product configuration

Speaker volume control

• n = 0 Lowest volume
• n = 1 Low volume
• n = 2 Medium volume (default)
• n = 3 High volume

Speaker control

• n = 0 Speaker always OFF
• n = 1 Speaker ON until carrier established (default)
• n = 2 Speaker always ON
• n = 3 Speaker ON after last digit dialed and until carrier is established

Return on-line after command execution.

• n = 0 Return on-line (normal)
• n = 1 Return on-line and retrain. Use if there were errors in a non-ARQ data transfer.

Quiet mode: result codes displayed / suppressed

• n = 0 Result codes displayed
• n = 1 Result codes suppressed (Quiet mode)
• n = 2 Result codes suppressed in answer mode

Software reset / power on defaults

• n = 0 Sets profile 0 in NVRAM
• n = 1 Sets profile 1 in NVRAM

Reset modem

• n = 0 Resets modem to NVRAM profile selected by Y command
• n = 1 Resets modem to NVRAM profile 0
• n = 2 Resets modem to NVRAM profile 1
• n = 3 Resets modem to factory default profile 0 (&F0)
• n = 4 Resets modem to factory default profile 1 (&F1)
• n = 5 Resets modem to factory default profile 2 (&F2)

Enable / Disable additional result code subsets. See also the ATXn Result Code Set Options and Information.

• n = 0 ARQ result codes disabled
• n = 1 ARQ result codes enabled (default)
• n = 2 Additional V.32 modulation indicator
• n = 3 Additional error-control indicator (LAPM, MNP, or NONE) and data-compression type (V.42bis or MNP5)

Serial port rate

• n = 0 Serial port rate switches to follow connection rate (default)
• n = 1 Serial port rate remains fixed at the rate of the last AT command, determined by your software setting. Recommended rates are 38.4K and 19.2K bps. Requires &H (transmit flow control) enabled
• n = 2 Shift to the user-defined, fixed, higher serial port rate for ARQ calls, follow the connection rate for non-ARQ calls. Answer mode only. Requires AT&H flow control.

Carrier Detect (CD) signal, modem-to-computer. DIP switch 6 is factory set so that the modem controls CD, and the override is disabled

• n = 0 CD override (CD always ON)
• n = 1 Modem sends CD signal when it connects with another modem and drops CD on disconnect

Data Terminal Ready (DTR) signal, computer-to-modem. DIP switch 1 is factory set for normal DTR operations, and the override is disabled

• n = 0 DTR override (modem ignores DTR)
• n = 1 Reserved
• n = 2 Computer must send DTR for modem to accept commands. Dropping DTR terminates a call.
• n = 3 Resets modem on receipt of DTR

Load factory (ROM) settings

• n = 0 Factory default
• n = 1 Hardware flow control template
• n = 2 Software flow control template

Set guard tone as part of answer sequence, for 2400 / 1200 bps calls from overseas

• n = 0 No guard tone. U.S. and Canada. (default)
• n = 1 550Hz guard tone. Some European countries. Requires B0 setting.
• n = 2 1800Hz guard tone. U.K. and some Common-wealth countries. Requires B0.

Transmit data flow control

• n = 0 Flow control disabled (default)
• n = 1 Hardware (clear to send) flow control
• n = 2 Software (XON / XOFF) flow control
• n = 3 Hardware and software flow control

Received data software flow control

• n = 0 Flow control disabled (default and recommended setting)
• n = 1 XON / XOFF to local modem and remote computer
• n = 2 XON / XOFF to local modem only (recommended over &I1 / ARQ mode only)
• n = 3 Hewlett Packard: host mode
• n = 4 Hewlett Packard: terminal mode
• n = 5 In ARQ mode, same as AT&12; in non-ARQ, looks for XON/XOFF

Data compression

• n = 0 Disabled
• n = 1 Auto enable / disable (default). Disabled if modem is set to &B0 and serial port rate switches to match connection
• n = 2 Enabled regardless of AT&Bn setting
• n = 3 Selective data compression-MNP Level 5 disabled

Error control (ARQ)

• n = 0 Normal mode, error control disabled
• n = 1,2,3 Reserved
• n = 4 Normal / ARQ mode (default). Normal connection if ARQ connection cannot be made
• n = 5 ARQ mode. Modem hangs up if ARQ connection cannot be made

Connection rate variable or fixed. With fixed rate, modem hangs up if remote modem is operating at a different rate

• n = 0 Variable link operations. Modem tries for highest possible connection rate with other modem (default and recommended setting)
• n = 1 300 bps
• n = 2 1200 bps
• n = 3 2400 bps
• n = 4 4800 bps
• n = 5 7200 bps
• n = 6 9600 bps
• n = 7 12K bps
• n = 8 14.4K bps
• n = 9 16.8K bps
• n = 10 19.2K bps
• n = 11 21.6K bps
• n = 12 24K bps
• n = 13 26.4K bps
• n = 14 28.8K bps

Pulse dialing make / break ratio

• n = 0 U.S. and Canada make / break ratio (default)
LI>n = 1U.K. and some Commonwealth countries make / break ratio

Received Data hardware (RTS) flow control

• n = 1 Ignore RTS (default)
• n = 2 Received data sent to computer only when RTS is high; used only if computer supports RTS signaling

Data Set Ready (DSR) operations

• n = 0 DSR override, always ON (default)
• n = 1 Modem sends computer a DSR when it is ready for a call and drops DTR when it or the remote modem disconnects

Modem testing

• n = 0 End testing
• n = 1 Initiate analog loopback (AL) testing
• n = 2 Reserved
• n = 3 Initiate local digital loopback (LDL) test
• n = 4 Grant remote digital loopback (RDL)
• n = 5 Deny RDL (default)
• n = 6 Initiate RDL testing
• n = 7 Initiate RDL with self-test and error detector
• n = 8 Initiate AL with self-test and error detector

Sets floor connect speed when n is greater than 0 (settings and higher speeds below are good for modems capable of such speeds only)

Write current settings to NVRAM templates

• n = 0 Modifies NVRAM 0 template (Y0)
• n = 1 Modifies NVRAM 1 template (Y1)

Break handling. Destructive breaks clear the buffer; expedited breaks are sent immediately to the remote computer. Under data compression, destructive breaks cause both modems to reset compression tables

• n = 0 Destructive, don't send break
• n = 1 Destructive, expedited (default)
• n = 2 Nondestructive, expedited
• n = 3 Nondestructive, unexpedited; modem sends break in sequence with data received from computer