U.S. ROBOTICS, INC.

COURIER 2400E/PS

Card Type

Modem (Asynchronous)

Chip Set

U.S. Robotics

Maximum Data Rate

2400bps

Data Bus

Unidentified

Data Modulation Protocol

Unidentified

V1983

Proprietary AT Command Set

ABORT

Type:

Immediate

Format:

Any key

Description:

Aborts answering/originating a call; modem hangs up.

ANSWER

Type:

Immediate

Format:

AT [cmds] A

Description:

Enables answer mode, the modem goes off-hook; pressing any key will abort.

ANSWER SEQUENCE

Type:

Configuration

Format:

AT [cmds] Bn [cmds]

Description:

Selects the answer sequence the modem will use

Command

Function

B0

ITU-T answer sequence enabled

í B1

Bell answer sequence enabled

ATTENTION

Type:

Immediate

Format:

AT [cmds]

Description:

Tells the modem that a command follows or use alone to test OK result code

BIT-MAPPED REGISTER S13

Format

AT [cmds] S13=n [cmds]

Default:

0

Range:

0-222

Unit:

Bit-mapped

Description:

Controls auto-answer, result code pause, DTR dialing, reset dialing, MNP3 and hardware reset.

Bit

Value

Function

0

í 0

Not used

1

í 0

1

Auto-answer mode disabled

Auto-answer mode on originate enabled

2

í 0

1

Result code pause enabled

Result code pause disabled

3

í 0

1

DTR dialing disabled

DTR dialing enabled

4

í 0

1

Reset dialing disabled

Reset dialing enabled, dials number at position 0 in NVRAM.

5

í 0

Not used

6

í 0

1

MNP 3 enabled

MNP 3 disabled

7

í 0

1

Hardware reset disabled

Hardware reset enabled

BIT-MAPPED REGISTER S15

Format

AT [cmds] S15=n [cmds]

Default:

0

Range:

0-81

Unit:

Bit-mapped

Description:

Controls escape sequence, MNP4, and MNP compliance.

Bit

Value

Function

0

í 0

1

Normal operation

Hang up on receiving +++

1 - 3

í 000

Not used

4

í 0

1

MNP 4 enabled

MNP 4 disabled

5

í 0

Not used

6

í 0

1

MNP normal

MNP adjusted for non compliant modems

BREAK TYPE

Type:

Configuration

Format:

AT [cmds] &Yn [cmds]

Description:

Configures action of break signal

Command

Function

&Y0

Empty buffer only

í &Y1

Empties buffer and break is sent immediately

&Y2

Do not empty buffer and break is sent immediately

&Y3

Do not empty buffer or send break

CARRIER DETECT (CD)

Type:

Configuration

Format:

AT [cmds] &Cn [cmds]

Description:

Controls the CD signal

Command

Function

&C0

Modem does not respond to CD signal

í &C1

CD signal normal

CARRIER FAILURE CODES

Type:

Register

Format:

AT [cmds] S20=n [cmds]

Description:

Reports codes which correspond to the possible causes of NO CARRIER

Value

Meaning

0

Ant key abort

1

DTR dropped

2

Escape sequence

3

Loss of carrier

4

Inactivity time-out

5

ARQ connection not established, hang-up.

6

ARQ retry time-out

7

Receive link disconnect

COMPRESSION

Type:

Configuration

Format:

AT [cmds] &Kn [cmds]

Description:

Selects data compression

Command

Function

&K0

Data compression disabled

í &K1

Auto enabled/disable data compression

&K2

Data compression enabled

CONNECTION FAILURE CODES

Type:

Register

Format:

AT [cmds] S17=n [cmds]

Default:

0

Description:

Reports codes which correspond to the possible causes of a connection failure

CONNECTION SPEED

Type:

Configuration

Format:

AT [cmds] &Nn [cmds]

Description:

Sets connection speed, modem will hang up if it cannot connect.

Command

Function

í &N0

Normal link

&N1

300bps

&N2

1200bps

&N3

2400bps

DATA TERMINAL READY (DTR)

Type:

Configuration

Format:

AT [cmds] &Dn [cmds]

Description:

Selects modem response to DTR

Command

Function

í &D0

Modem does not respond to DTR

&D1

Modem goes to command mode after DTR toggles

&D2

Modem is initialized after DTR goes off

DIAL

Type:

Immediate

Format:

AT [cmds] D<#> [cmds]

Example:

ATDT 443-3388,,,1111;

Description:

Dials telephone number according to any modifiers included in the string

Note:

Any combination of modifiers can be used to produce the desired dial functions in sequence.

Command

Function

í P

Pulse dialing enabled

T

Tone dialing enabled

,

Dialing paused for 2 seconds to a maximum amount of time specified in S8 register

;

Modem returned to command state after dialing. Can only be placed at the end of the dial command.

"

Dials letters that follow, ATDT"GOMICRO

!

Flash function initiated

W

Dialing resumed following dial tone detection

@

Wait for quiet answer, then proceeds to execute the rest of the dial string.

R

Answer mode enabled; originate mode disabled following handshake initiation.

DIAL - STORED NUMBER

Type:

Immediate

Format:

AT [cmds] DSn [cmds]

Description:

Dial stored number from memory location n

ECHO

Type:

Configuration

Format:

AT [cmds] En [cmds]

Description:

Controls echo function; display keyboard commands when enabled.

Command

Function

E0

Echo function disabled

í E1

Echo function enabled

ECHO - ON-LINE

Type:

Configuration

Format:

AT [cmds] Fn [cmds]

Description:

Selects whether commands sent while in data mode are echoed

Command

Function

F0

Local echo enabled

í F1

Local echo disabled

ERROR CORRECTION MODE (ARQ)

Type:

Configuration

Format:

AT [cmds] &Mn [cmds]

Description:

Selects active error correction protocols

Command

Function

&M0

Normal mode only enabled

í &M4

Normal/ARQ mode enabled

&M5

ARQ mode only enabled

ESCAPE SEQUENCE

Type:

Immediate

Format:

+++AT [cmds] <CR>

Description:

Initiates the escape sequence and returns the modem to the on-line command state if it receives three escape characters set in S2 within the time allotted by S12.

Note: Do not precede this command with AT.

EXTENDED RESULT CODES

Type:

Configuration

Format:

AT [cmds] &An [cmds]

Description:

Selects extended result codes

Command

Function

&A0

ARQ result codes disabled

í &A1

ARQ result codes enabled

FACTORY DEFAULT PROFILE

Type:

Configuration

Format:

AT [cmds] &F [cmds]

Description:

Load default profile in NVRAM

FLOW CONTROL PASSTHROUGH

Type:

Configuration

Format:

AT [cmds] &In [cmds]

Description:

Allows modem to act on, then transmit XON/XOFF characters.

Command

Function

í &I0

Flow control disabled

&I1

XON/XOFF passthrough enabled

&I2

XON/XOFF passthrough disabled

FLOW CONTROL TYPE

Type:

Configuration

Format:

AT [cmds] &Hn [cmds]

Description:

Sets type of flow control used by modem

Command

Function

í &H0

Flow control disabled

&H1

CTS/RTS flow control enabled

&H2

XON/XOFF flow control enabled

&H3

CTS/RTS and XON/XOFF flow control enabled

FLOW CONTROL TYPE

Type:

Configuration

Format:

AT [cmds] &Rn [cmds]

Description:

Controls receive data hardware flow control and RTS signals

Command

Function

í &R1

Modem ignores RTS

&R2

Received data to DTE when RTS is on

GUARD TONE

Type:

Configuration

Format:

AT [cmds] &Gn [cmds]

Description:

Commands the modem to transmit a guard tone

Note: Used primarily for international data transmission

Command

Function

í &G0

Guard tone disabled

&G1

550Hz guard tone enabled

&G2

1800Hz guard tone enabled

HOOK CONTROL

Type:

Immediate

Format:

AT [cmds] Hn [cmds]

Description:

Selects whether the modem is on-hook or off-hook

Command

Function

í H0

Modem commanded to go on-hook (hang-up)

H1

Modem commanded to go off-hook (pick-up)

INACTIVITY TIMER

Type:

Register

Format:

AT [cmds] S19=n [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; S19=0 will disable.

JACK TYPE

Type:

Configuration

Format:

AT [cmds] &Jn [cmds]

Description:

Selects jack type

Command

Jack Type

í &J0

RJ-11C

&J1

RJ-12, RJ-13

LIST AMPERSAND COMMANDS

Type:

Immediate

Format:

AT [cmds] &$ [cmds]

Description:

Displays ampersand (&) commands

LIST DIAL COMMANDS

Type:

Immediate

Format:

AT [cmds] D$ [cmds]

Description:

Displays dial commands

LIST S-REGISTERS

Type:

Immediate

Format:

AT [cmds] S$ [cmds]

Description:

Displays the S-registers

ON-LINE

Type:

Immediate

Format:

AT [cmds] O [cmds]

Description:

Return to on-line command (data transmission) mode

Note: The O command must be placed at the end of the command string.

PULSE DIALING

Type:

Configuration

Format:

AT [cmds] P [cmds]

Description:

Enables pulse dialing

Note: This command can be duplicated with the P modifier in the D (Dial) command.

PULSE DIALING RATIO

Type:

Configuration

Format:

AT [cmds] &Pn [cmds]

Description:

Selects pulse dial make/break ratio

Command

Function

í &P0

39/61ms at 10pps (North America)

&P1

33/67ms at 10pps (Europe)

REPEAT COMMAND STRING

Type:

Configuration

Format:

AT [cmds] > [cmds]

Description:

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

REPEAT PREVIOUS COMMAND

Type:

Immediate

Format:

A/

Description:

Repeats previous command, mainly used for redial

Note: Do not precede this command with AT, or follow it with <CR>.

REPORT INFORMATION

Type:

Immediate

Format:

AT [cmds] In [cmds]

Description:

Displays information requested

Command

Function

I0

Reports product code

I1

Reports ROM checksum

I2

Reports RAM checksum

I3

Reports call duration

I4

Reports current command settings

I5

Reports NVRAM settings

RESULT CODES

Type:

Configuration

Format:

AT [cmds] Qn [cmds]

Description:

Enables modem to send result codes to the DTE

Command

Function

í Q0

Result code sending enabled

Q1

Result code sending disabled

RESULT CODE FORMAT

Type:

Configuration

Format:

AT [cmds] Vn [cmds]

Description:

Selects word or numeric format for information-text and result codes

Command

Function

V0

Numeric format enabled

í V1

Verbose (word) format enabled

SELECT CALL PROGRESS RESULT CODES

Type:

Configuration

Format:

AT [cmds] Xn [cmds]

Description:

Enables selection of tone detection and associated result code format options

Command

Function

X0

Busy and dial tone detection disabled; result codes 0-4 enabled.

í X1

Busy and dial tone detection disabled; result codes 0-5 and 10 enabled

X2

Busy tone detection disabled, dial tone detection enabled; result codes 0-6 and 10 enabled; also adaptive dialing, and fast dialing enabled.

X3

Busy tone detection enabled, dial tone detection disabled; result codes 0-5, 7-10 enabled; also adaptive dialing, wait for second dial tone, and wait for answer enabled.

X4

Busy and dial tone detection enabled; result codes 0-10 enabled; also adaptive dialing, wait for second dial tone, wait for answer, and fast dialing enabled.

X5

Busy tone detection enabled, dial tone detection disabled; result codes 0-5, 7-12 enabled; also adaptive dialing, wait for second dial tone, and wait for answer enabled.

X6

Busy and dial tone detection enabled; result codes 0-10 enabled; also adaptive dialing, wait for second dial tone, wait for answer, and fast dialing enabled.

Note: Valid numeric result codes; 0-8, and 10-12.

SERIAL PORT SPEED

Type:

Configuration

Format

AT [cmds] &Bn [cmds]

Description:

Sets the maximum allowable data exchange rate from the local computer and modem.

Command

Function

&B0

Speed of last AT command

&B1

300bps

&B2

600bps

&B3

1200bps

&B4

2400bps

&B5

4800bps

&B6

9600bps

&B7

19.2Kbps

SOFT RESET

Type:

Immediate

Format:

AT [cmds] Z [cmds]

Description:

Resets modem to profiles saved in non-volatile RAM

SPEAKER MODE

Type:

Configuration

Format:

AT [cmds] Mn [cmds]

Description:

Selects various speaker options

Command

Function

M0

Speaker disabled

í M1

Speaker enabled until carrier signal detected

M2

Speaker enabled

M3

Speaker enabled following dialing, then disabled after carrier signal detected.

SPEAKER VOLUME

Type:

Configuration

Format:

AT [cmds] Ln [cmds]

Description:

Controls speaker volume

Command

Function

L0

Low volume setting

L1

Low volume setting

í L2

Medium volume setting

L3

Highest volume setting

STATUS-REGISTER

Type:

Configuration

Format:

Read: AT [cmds] Sn? [cmds]

Write: AT [cmds] Sn=x [cmds]

Description:

Writes to or reads from a specified register

STORE ACTIVE PROFILE

Type:

Configuration

Format:

AT [cmds] &W [cmds]

Description:

Writes current values to non-volatile RAM templates

STORE TELEPHONE NUMBER

Type:

Configuration

Format:

AT [cmds] &Zn=(phone # & modifiers)

Description:

Writes selected telephone numbers into the non-volatile memory at location n

Note: The characters described in the D command are valid for use in the &Z command.

Command

Function

&Zn?

Displays phone number from non-volatile memory at location n

TEST MODES

Type:

Configuration

Format:

AT [cmds] S16=n [cmds]

Description:

Controls tests. Analog loopback, dial, and self tests (test pattern).

Command

Function

í S16=0

Testing disabled

S16=1

Local analog loopback enabled

S16=2

Dial test enabled

S16=4

Test pattern enabled

S16=5

Local analog loopback and test pattern enabled

TONE DIALING

Type:

Configuration

Format:

AT [cmds] T [cmds]

Description:

Enables tone dialing mode

Note: This command can be duplicated with the T modifier in the D (Dial) command.