UNIDENTIFIED

2400U/BU MODEM

Card Type

Modem (asynchronous)

Chip Set

Unidentified

Maximum Data Rate

2400bps

Data Bus

8-bit ISA

Data Modulation Protocol

Bell 103/212A

ITU-T V.21, V.22, V.22bis

Error Correction/Compression

MNP5, V.42

CONNECTIONS

Function

Label

Function

Label

Line in

CN1

Line out

CN2

SERIAL PORT ADDRESS

Setting

SW1/1

SW1/2

COM1 (3F8h)

On

On

COM2 (2F8h)

Off

On

COM3 (3E8h)

On

Off

COM4 (2E8h)

Off

Off

INTERRUPT

Setting

SW2/1

SW2/2

2

Off

Off

3

On

Off

4

Off

On

5

Off

Off

Proprietary AT Command Set

AUTO-RELIABLE FALLBACK CHARACTER

Type:

Configuration

Format:

AT [cmds] %An [cmds]

Default:

0

Range:

0-127

Unit:

ASCII

Description:

Sets the character used as the auto-reliable fallback character; %A0 will disable this function.

AUTO-RELIABLE TIME BUFFER CONFIGURATION

Type:

Configuration

Format:

AT [cmds] \Cn [cmds]

Description:

Controls the handling of incoming data during auto-reliable time period

Command

Function

í \C0

Data is discarded

\C1

Data is buffered

\C2

Data is discarded; modem returns to normal mode on receiving auto-reliable fallback character.

BIT-MAPPED REGISTER S14

Format

AT [cmds] S14=n [cmds]

Default:

42

Range:

0-174

Unit:

Bit-mapped

Description:

Controls echo, result codes and display, dial mode, and answer/originate mode.

Bit

Value

Function

0

0

Not used

1

0

í 1

Command echo disabled

Command echo enabled

2

í 0

1

Result codes enabled

Result codes disabled

3

0

í 1

Display result codes in numeric format

Display result codes in verbose format

4

0

Not used

5

0

í 1

Tone dial enabled

Pulse dial enabled

6

0

Not used

7

í 0

1

Answer mode enabled

Originate mode enabled

BIT-MAPPED REGISTER S21

Format

AT [cmds] S21=n [cmds]

Default:

48

Range:

0-252

Unit:

Bit-mapped

Description:

Selects jack type, CTS/DCD/DSR signals, low DTR action, and the long space disconnect function.

Bit

Value

Function

1, 0

0

Not used

2

í 0

1

CTS follows RTS

CTS forced high

4, 3

00

01

í 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

í 1

DCD forced high

DCD normal

6

í 0

1

DSR forced high

DSR normal

7

í 0

1

Long space disconnect function disabled

Long space disconnect function enabled

BIT-MAPPED REGISTER S22

Format

AT [cmds] S22=n [cmds]

Default:

118

Range:

0-255

Unit:

Bit-mapped

Description:

Controls speaker volume and controls, limits results codes, and make/break ratio.

Bit

Value

Function

1, 0

00

01

í 10

11

Off volume

Low level volume

Medium level volume

High level volume

3, 2

00

í 01

10

11

Speaker off

Speaker off on carrier

Speaker always on

Speaker on during handshake

6, 5, 4

000

100

101

110

í 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

7

í 0

1

39/61ms at 10pps (North America)

33/67ms at 10pps (Europe)

BIT-MAPPED REGISTER S23

Format

AT [cmds] S23=n [cmds]

Default:

6

Range:

0-183

Unit:

Bit-mapped

Description:

Grants/denies remote digital loopback, controls DTE rate and parity, and sets guard tone.

Bit

Value

Function

0

í 0

1

Remote digital loopback allowed

Remote digital loopback denied

2, 1

00

10

í 11

Sets serial port speed to 0-300bps

Sets serial port speed to 1200bps

Sets serial port speed to 2400bps

3

0

Not used

5,4

í 00

01

10

11

Parity even

Space Parity

Parity odd

Mark Parity

7, 6

í 00

01

10

Guard tone disabled

Guard tone 550Hz enabled

Guard tone 1800Hz enabled

BIT-MAPPED REGISTER S27

Format

AT [cmds] S27=n [cmds]

Default:

64

Range:

0-68

Unit:

Bit-mapped

Description:

Selects line type, and ITU-T/Bell modes.

Bit

Value

Function

1, 0

0

Not used

2

í 0

1

Switched line

Leased line

5 - 3

0

Not used

6

0

í 1

ITU/T mode

Bell mode

BREAK SEND

Type:

Configuration

Format:

AT [cmds] \Bn [cmds]

Default:

3

Range:

1-9

Unit:

.1 second

Description:

Sends break to modem

BREAK TYPE

Type:

Configuration

Format:

AT [cmds] \Kn [cmds]

Description:

Configures action of break signal

Command

Break from DTE

Reliable/Normal mode

Modem receives \B

Break from DTE

Direct mode

\K0

Online command mode enabled, send no break to remote modem

Break sent to remote modem and buffered cleared

Send break to remote modem immediately, Online command mode enabled

\K1

Break sent to remote modem and buffered cleared

Break sent to remote modem and buffered cleared

Send break to remote modem immediately

\K2

Online command mode enabled, send no break to remote modem

Send break to remote modem immediately

Send break to remote modem immediately, Online command mode enabled

\K3

Send break to remote modem immediately

Send break to remote modem immediately

Send break to remote modem immediately

\K4

Online command mode enabled, send no break to remote modem

Send break with transmitted data

Send break to remote modem immediately, Online command mode enabled

í \K5

Send break with transmitted data

Send break with transmitted data

Send break to remote modem immediately

BAUD RATE ADJUST

Type:

Configuration

Format:

AT [cmds] \Jn [cmds]

Description:

Allows baud rate to follow serial port speed

Command

Function

í \J0

Baud rate adjust disabled

\J1

Baud rate adjust enabled

COMPRESSION

Type:

Configuration

Format:

AT [cmds] %Cn [cmds]

Description:

Selects data compression

Command

Function

%C0

Data compression disabled

í %C1

Data compression enabled

CONFIGURATION PROFILES

Type:

Immediate

Format:

AT [cmds] \Sn [cmds]

Description:

Displays active configuration profiles and stored profile 0 and 1.

CONNECT MODE

Type:

Configuration

Format:

AT [cmds] \Nn [cmds]

Description:

Controls the type of connection the modem will operate in

Command

Function

í \N0

Normal mode enabled

\N1

Direct mode enabled

\N2

MNP reliable mode enabled

\N3

MNP auto-reliable mode enabled

\N4

LAP-M reliable mode with detection enabled

\N5

LAP-M auto-reliable mode with detection enabled

\N6

LAP-M reliable mode without detection enabled

\N7

LAP-M auto-reliable mode without detection enabled

DISPLAY STORED NUMBERS

Type:

Immediate

Format:

AT [cmds] \F [cmds]

Description:

Displays all stored phone numbers

ECHO DATA

Type:

Configuration

Format:

AT [cmds] \En [cmds]

Description:

Enables modem to echo received data

Command

Function

í \E0

Data echo disabled

\E1

Data echo enabled

EXTENDED RESULT CODES

Type:

Configuration

Format:

AT [cmds] \Vn [cmds]

Description:

Selects extended result codes

Command

Function

\V0

Extended result codes disabled

í \V1

Extended result codes enabled

EXTENDED RESULT CODES - MNP

Type:

Configuration

Format:

AT [cmds] -Mn [cmds]

Description:

Selects the display of MNP result codes with extended result codes

Command

Function

-M0

Disable display of MNP connection service class

í -M1

Enable display of MNP connection service class while extended result codes are enabled

FLOW CONTROL TYPE

Type:

Configuration

Format:

AT [cmds] \Qn [cmds]

Description:

Sets type of flow control used by modem

Command

Function

\Q0

Flow control disabled

\Q1

XON/XOFF flow control enabled

í \Q2

CTS Unidirectional flow control enabled

\Q3

Bidirectional CTS/RTS flow control enabled

INACTIVITY TIMER

Type:

Configuration

Format:

AT [cmds] \Tn [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.

MAXIMUM BLOCK SIZE FOR TRANSMISSION

Type:

Configuration

Format:

AT [cmds] \An [cmds]

Description:

Sets the maximum transmittable block size

Command

Function

\A0

MNP block size is 64 characters

\A1

MNP block size is 128 characters

\A2

MNP block size is 192 characters

í \A3

MNP block size is 256 characters

PROTOCOL/SPEED

Type:

Configuration

Format:

AT [cmds] %Bn [cmds]

Description:

Selects the initial DCE speed

Command

Function

%B0

Select 300bps speed

%B1

Select 1200bps speed

í %B2

Select 2400bps speed

TEST MODES

Format

AT [cmds] S16=n [cmds]

Default:

0

Range:

0-125

Unit:

Bit-mapped

Description:

Controls loopback tests, analog, digital, remote digital, and self tests.

Bit

Value

Function

0

í 0

1

Local analog loopback not in progress

Local analog loopback in progress

1

0

Not used

2

í 0

1

Local digital loopback not in progress

Local digital loopback in progress

3

í 0

1

Modem not in remote digital loopback

Remote digital loopback in progress

4

í 0

1

Remote digital loopback not in progress

Remote digital loopback in progress

5

í 0

1

Remote digital loopback w/ self-test not in progress

Remote digital loopback w/ self-test in progress

6

í 0

1

Local analog loopback w/ self-test not in progress

Local analog loopback w/ self-test in progress

XON/XOFF PASS-THROUGH

Type:

Configuration

Format:

AT [cmds] \Xn [cmds]

Description:

Selects whether XON/XOFF signals are sent to remote modem

Command

Function

í \X0

XON/XOFF signals trapped by local modem

\X1

XON/XOFF passed through local modem