User Guide

Command Set: 3Com Modem User's Guide

Typing Commands

• In terminal mode, type commands in either upper or lower case, not a combination. Use the Backspace key to delete errors. (You cannot delete the original AT command because it is stored in the modem buffer.)
• If a command has numeric options and you do not include a number, zero is assumed. For example, if you type ATB, the command ATB0 is assumed.
• Every command except A/, +++, and A must begin with the AT prefix and be entered by pressing ENTER.
• The maximum command length is 58 characters. This does not include the AT prefix, carriage returns, or spaces.

All defaults are based on the &F1 Hardware Flow Control template loaded in NVRAM when the modem is shipped.

Basic Data Commands

<control key>S - Stop or restart help screens.

<control key>C
<control key>K -Stop help screens.

$ -Use in conjunction with D, S, or & commands (or just AT) to display a basic command list; online help.

A -Manual Answer: goes off hook in answer mode. Pressing any key aborts the operations.

A / -executes the last issued command. Used mainly to redial. This does not require the AT prefix or a Carriage Return.

A> Re-executes the last issued command continuously, until the user intervenes or the command is executed forever. Does not require the AT prefix or a Carriage Return.Any key Aborts off-hook dial/answer operation and hangs up.

AT -Required command prefix, except with A/, +++, and A. Use alone to test for OK result code.

Bn -U.S.ITU-T answer sequence

• B0 ITU-T answer sequence
• B1 U.S. answer tone

Dn -Dials the specified phone number, includes the following:

• 0-9 Numeric digits
• #, * Extended touch-tone pad tones
• L Dials the last dialed number
• P Pulse (rotary) dial
• R Originates call using answer (reverse) frequencies
• Sn Dials the phone number string stored in NVRAM at position n (n = 03). Phone numbers are stored with the &Zn=s command
• T Tone dial
• , (Comma) Pause, see the definition of the S8 register to which it is linked
• ; (Semicolon) Return to Command mode after dialing
• " (Quotation Marks) Dials the letters that follow (in an alphabetical phone number)
• ! (Exclamation point) Flashes the switch hook
• / (Back Slash) Delays for 125 ms. before proceeding with dial string
• W Waits for second dial tone (X2 or X4); linked to S6 register
• @ (At Symbol) Dials, waits for quiet answer, and continues (X3 or higher)
• $ (Dollar Sign) Displays a list of Dial commands

En -Sets local echo

• E0 Echo OFF
• E1 Modem displays keyboard commands

Fn -Sets online local echo of transmitted data ON/OFF

• F0 Local echo ON; modem sends a copy of data, it sends to the remote system to your screen
• F1 Local echo OFF; receiving system may send a remote echo of data it receives

Hn -Controls ON/OFF hook

• H0 Hangs up (goes on hook)
• H1 Goes off hook

In -Displays the following information:

• I0 Four-digit product code
• I1 Results of ROM checksum
• I2 Results of RAM checksum
• I3 Product type
• I4 Current modem settings
• I5 Nonvolatile memory (NVRAM) settings
• I6 Link diagnostics
• I7 Product configuration
• I9 Plug and Play information
• I11 Extended link diagnostics

Ln -Controls speaker volume (available on internal modems only)

• L0 Low volume
• L1 Low volume
• L2 Medium volume
• L3 High volume

Mn -Operates speaker

• M0 Speaker always OFF
• M1 Speaker ON until CONNECT
• M2 Speaker always ON
• M3 Speaker ON after dial, until CONNECT

On -Returns online

• O0 Returns online
• O1 Returns online and retrains

P -Sets pulse dial (for phone lines that do not support touch-tone dialing)

Qn -Displays/suppresses result codes

• Q0 Displays result codes
• Q1 Quiet mode; no result codes
• Q2 Displays result codes only in Originate mode

Sr.b=n -Sets bit .b of register r to n (0/OFF or 1/ON)

Sr=n -Sets register r to n

Sr? -Displays contents of S-Register r

S$ -Displays a list of the S-Registers

T -Sets tone dial

Vn -Displays verbal/numeric result codes

• V0 Numeric codes
• V1 Verbal codes

Xn -Sets result code displayed, default is X4 (Note: Result codes 0 through 155 are for 33.6 products and V.90 products. Result codes above 155 apply only to V.90 products.)

*Requires @ in dial string; replaces NO CARRIER

Yn -Selects power-on/reset default configuration

• Y0 Use profile 0 setting in NVRAM
• Y1 Default is profile 1 setting in NVRAM
• Y2 Use factory configuration 0
• Y3 Use factory configuration 1
• Y4 Use factory configuration 2

Z -Resets modem

• Z0 Resets modem to NVRAM profile selected by Y command or dip 7
• Z1 Resets modem to NVRAM profile 0
• Z2 Resets modem to NVRAM profile 1
• Z3 Resets modem to factory default profile 0 (&F0)
• Z4 Resets modem to factory default profile 1 (&F1)
• Z5 Resets modem to factory default profile 2 (&F2)

Extended Data Commands

&$ -Displays a list of ampersand (&) commands

&An -Enables/disables additional result code subsets, see Xn

• &A0 ARQ result codes disabled
• &A1 ARQ result codes enabled
• &A2 V.32 modulation indicator added
• &A3 IProtocol indicators addedLAPM/MNP/NONE (error control) and V42bis/MNP5 (data compression)

&Bn -Manages modem's serial port rate

• &B0 Variable, follows connection rate
• &B1 Fixed serial port rate
• &B2 Fixed in ARQ mode, variable in non-ARQ mode

&Cn -Controls Carrier Detect (CD) signal

• &C0 CD override
• &C1 Normal CD operations

&Dn -Controls Data Terminal Ready (DTR) operations

• &D0 DTR override
• &D1 DTR toggle causes online Command mode
• &D2 Normal DTR operations
• &D3 SResets on receipt of DTR

&Fn -Loads a read-only (non-programmable) factory configuration

• &F0 Generic template
• <&F1 Hardware flow control template
• &F2 Software flow control template

&Gn -Sets Guard Tone

• &G0 No guard tone, U.S. and Canada
• &G1 550 Hz guard tone, some European countries, requires B0 setting
• &G2 1800 Hz guard tone, U.K., requires B0 setting

&Hn -Sets Transmit Data (TD) flow control, see also &Rn

• &H0 Flow control disabled
• &H1 Hardware flow control, Clear to Send (CTS)
• &H2 Software flow control, XON/XOFF
• &H3 Hardware and software flow control

&In -Sets Receive Data (RD) software flow control, see also &Rn

• &I0 Software flow control disabled
• &I1 XON/XOFF signals to your modem and remote system
• &I2 Signaux XON/XOFF XON/XOFF signals to your modem only

&Kn -Enables/disables data compression

• &K0 Data compression disabled
• &K1 Auto enable/disable
• &K2 Data compression enabled
• &K3 MNP5 compression disabled

&Mn -Sets Error Control (ARQ) for connections at 1200 bps and higher

• &M0 Normal mode, error control disabled
• &M1 Reserved
• &M2 Reserved
• &M3 Reserved
• &M4 Normal/ARQ
• &M5 ARQ mode

&Nn -Sets connect speed, if connection cannot be made at this speed, the modem will hang up. When used in conjunction with &Un and &Un is greater than 0, &Nn sets the ceiling connect speed. &Un sets the floor connect speed. (See also the table in the &Un section.) (Note: Result codes 0 through 155 are for 33.6 products and V.90 products. Result codes above 155 apply only to V.90 products.)

• &N0 Connection speed is determined by the remote modem
• &N1 300 bps
• &N2 1200 bps
• &N3 2400 bps
• &N4 4800 bps
• &N5 7200 bps
• &N6 9600 bps
• &N7 12000 bps
• &N8 14400 bps
• &N9 16800 bps
• &N10 19200 bps
• &N11 21600 bps
• &N12 24000 bps
• &N13 26400 bps
• &N14 28800 bps
• &N15 31200 bps
• &N16 33600 bps
• &N17 28000 bps
• &N18 29333 bps
• &N19 30666 bps
• &N20 32000 bps
• &N21 33333 bps
• &N22 34666 bps
• &N23 36000 bps
• &N24 37333 bps
• &N25 38666 bps
• &N26 40000 bps
• &N27 41333 bps
• &N28 42666 bps
• &N29 44000 bps
• &N30 45333 bps
• &N31 46666 bps
• &N32 48000 bps
• &N33 49333 bps
• &N34 50666 bps
• &N35 52000 bps
• &N36 53333 bps
• &N37 54666 bps
• &N38 56000 bps
• &N39 57333 bps

&Pn -Sets pulse (rotary) dial make/break ratio

• &P0 U.S./Canada ratio, 39%/61%
• &P1 U.K. ratio, 33%/67%

&Rn -Sets Receive Data (RD) hardware flow control, Request to Send (RTS), see also &Hn

• &R0 Reserved
• &R1 Modem ignores RTS
• &R2 Received Data to computer only on RTS

&Sn -Controls Data Set Ready (DSR) operations

• &S0 DSR override; always ON
• &S1 Modem controls DSR

&Tn -Begins test modes

• &T0 Ends testing
• &T1 Analog Loopback
• &T2 Reserved
• &T3 Local Digital Loopback
• &T4 Enables Remote Digital Loopback
• &T5 Prohibits Remote Digital Loopback
• &T6 Initiates Remote Digital Loopback
• &T7 Remote Digital with self-test and error detector
• &T8 Analog Loopback with self-test and error detector

&Un -When set above 0, the value chosen from the table sets the floor connect speed (the lowest acceptable connect speed). If a connection cannot be made at or above this speed, the modem will hang up. This command can also be used in conjunction with &Nn. Note: &U17 through &U39 apply only to V.90 products.

&Un -&U0 No restrictions on the minimum speed for the connection

• &U1 300 bps
• &U2 1200 bps
• &U3 2400 bps
• &U4 4800 bps
• &U5 7200 bps
• &U6 9600 bps
• &U7 12000 bps
• &U8 14400 bps
• &U9 16800 bps
• &U10 19200 bps
• &U11 21600 bps
• &U12 24000 bps
• &U13 26400 bps
• &U14 28800 bps
• &U15 31200 bps
• &U16 33600 bps
• &U17 28000 bps
• &U18 29333 bps
• &U19 30666 bps
• &U20 32000 bps
• &U21 33333 bps
• &U22 34666 bps
• &U23 36000 bps
• &U24 37333 bps
• &U25 38666 bps
• &U26 40000 bps
• &U27 41333 bps
• &U28 42666 bps
• &U29 44000 bps
• &U30 45333 bps
• &U31 46666 bps
• &U32 48000 bps
• &U33 49333 bps
• &U34 50666 bps
• &U35 52000 bps
• &U36 53333 bps
• &U37 54666 bps
• &U38 56000 bps
• &U39 57333 bps

&Wn -Writes current configuration to NVRAM templates

• &W0 Modifies the NVRAM 0 template (Y0)
• &W1 Modifies the NVRAM 1 template (Y1)

&Yn -Sets break handling

• &Y0 Destructive, but does not send break
• &Y1 Destructive, expedited
• &Y2 Nondestructive, expedited
• &Y3 Nondestructive, unexpedited

&Zn=s -Writes phone number string s to NVRAM at position n (n = 03)

• &Zn=L Writes last executed dial string to NVRAM at position n (n = 03)
• Displays the phone number stored at position n (n = 03)
• &ZL? Displays the last executed dial string

#CID=n -Controls Caller ID feature

• #CID=0 Caller ID disabled
• #CID=1 Caller ID enabled with formatted information
• #CID=2 Caller ID enabled with unformatted information

+++ Escapes to online-command mode

Fax Commands

+FCLASS=n -Sets the mode of operation

• FCLASS=0 Data mode
• FCLASS=1 Group 3 Facsimile Service Class 1 mode
• FCLASS=2.0 Group 3 Facsimile Service Class 2.0 mode

FCLASS? -Displays the current FCLASS mode (see mode descriptions above)

+FCLASS=? -Displays the FCLASS mode options (see mode descriptions above)

+FTS=n -Stops the fax transmission. Then the modem waits for a specified time before OK appears on screen. The pause is set in 10 millisecond intervals. n is the number of 10 millisecond intervals that pass before OK appears. (n=0-255)

+FRS=n -Makes the modem wait for a specified length of silence before sending OK to the screen. The pause is set in10 millisecond intervals. n is the number of 10 millisecond intervals that pass before OK appears.(n=0-255) Note: This command terminates with OK when either the specified amount of silence is detected or when the user types anything (which is ignored).

+FTM=n -Transmits data using the modulation specified by n.(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146) Note: See the "Screen Messages" table at the end of this section for an explanation of messages that appear in response to this command.

+FRM=n -Receives data using the modulation specified byn.(n = 3, 24, 48, 72, 96, 97, 98, 121, 122, 145, or 146) Note: See the "Screen Messages" table at the end of this section for an explanation of messages that appear in response to this command.

+FTH=n -Transmits data framed in the HDLC protocol using the modulation specified by n.(n = 3, 24, 48, 72, 96, 97, 98, 121, 22, 145, or 146) Note: See the "Screen Messages" table at the end of this section for an explanation of messages that appear in response to this command.