3COM CORPORATION

US ROBOTICS 2400

Modem Type

Data (synchronous/asynchronous)

Maximum Data Rate

2400bps

Data Bus

External

Fax Class

Class I & II

Data Modulation Protocol

Bell 103A/212A

ITU-T V.22bis

CONNECTIONS

Purpose

Location

Purpose

Location

Line out

CN1

Power in

CN4

Line in

CN2

Volume

R1

RS-232/422

CN3

Power switch

SW2

DIAGNOSTIC LED(S)

LED

Color

Status

Condition

LED1

Red

On

Analog loopback self test mode

LED1

Green

On

Data mode

LED2

Red

Blinking

Modem is transmitting/receiving data

LED2

Green

On

Carrier signal detected

DTR SIGNAL

Setting

SW1/1

» On

DTR forced high

Off

DTR normal

RESULT CODES

Setting

SW1/2

» Off

Extended result codes enabled

On

Extended result codes disabled

RESULT CODES DISPLAY

Setting

SW1/3

» On

Display disabled

Off

Display enabled

ECHO DISPLAY

Setting

SW1/4

» Off

Local echo enabled

On

Local echo disabled

AUTO ANSWER

Setting

SW1/5

» On

Modem doe not answer on first ring

Off

Modem answers on first ring

CARRIER DETECT

Setting

SW1/6

» Off

CD normal

On

CD forced high

MULTIPLE PHONE INSTALLATION

Setting

SW1/7

» Off

Single phone connected

On

Multiple phones connected

AT COMMAND SET

Setting

SW1/8

» On

AT command set recognized

Off

AT command set disabled

Proprietary AT Command Set

TIME DISPLAY

Type:

Immediate

Format:

AT [cmds] Kn [cmds]

Example:

AT K1 *L2 #E1<CR>

Description:

Displays the current call time or clock time.

Command

Function

K0

Display length of last call.

K1

Display actual time.

HELP SCREENS

Type:

Immediate

Format:

AT <prefix>$

Example:

AT &$<CR>

Description:

Shows command help screens for all commands beginning with the given prefix, or no prefix if none is given.

Command

Function

$

Shows ATx help screen.

D$

Shows ATDx help screen.

S$

Shows S-register help screen.

REPEAT COMMAND STRING

Type:

Configuration

Format:

AT [cmds] >

Example:

AT DT1(303) 443-3388 > <CR>

Description:

Causes modem to repeat command string until a keyboard key is pressed.

ANALOG LOOPBACK SELF TEST

Type:

Register

Format:

AT [cmds] S16=n [cmds]

Example:

ATS16=139<CR>

Description:

Selects the tone dialing test.

Command

Function

0

Data mode.

1

Analog loopback.

2

Dial testing.

4

Test pattern.

5

Analog loopback and test pattern.