VEN-TEL, INC.

VT24V42FAX

Modem Type

Data (synchronous/asynchronous)/Fax

Maximum Data Rate

2400bps

Maximum Fax Rate

9600bps

Data Bus

External

Fax Class

Class I & II

Data Modulation Protocol

Bell 103A/212A

ITU-T V.21, V.22, V.22bis, V.23

Fax Modulation Protocol

Unidentified

Error Correction/Compression

MNP5, MNP10, V.42, V.42bis

CONNECTIONS

Purpose

Location

Purpose

Location

Line out

CN1

RS-232/422

CN4

Line in

CN2

Power switch

SW1

DC power

CN3

   

DIAGNOSTIC LED(S)

LED

Color

Status

Condition

HS

Red

On

Modem is operating at 2400bps

HS

Red

Off

Modem is operating at less than 2400bps

AA

Red

On

Auto answer enabled

AA

Red

Off

Auto answer disabled

CD

Red

On

Carrier signal detected

CD

Red

Off

Carrier signal not detected

OH

Red

On

Modem is off-hook

OH

Red

Off

Modem is on-hook

RD

Red

On

Modem is receiving data

RD

Red

Off

Modem is not receiving data

SD

Red

On

Modem is transmitting data

SD

Red

Off

Modem is not transmitting data

TR

Red

On

DTR signal is high

TR

Red

Off

DTR signal is low

TM

Red

Blinking

Test mode enabled

TM

Red

Off

Test mode disabled

Proprietary Command Set

BIT-MAPPED REGISTER S14

Format

AT [cmds] S14=n [cmds]

Example:

ATS14=139<CR>

Default:

171

Range:

0 - 255

Unit:

Bit-mapped

Description:

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

Bit

Value

Function

0

1

Not used.

1

0

» 1

Command echo function disabled.

Command echo function enabled.

2

» 0

1

Result code sending disabled.

Result code sending enabled.

3

0

» 1

Numeric format enabled.

Verbose format enabled.

4

0

Not used.

5

0

» 1

Tone dialing mode enabled.

Pulse dialing mode enabled.

6

» 0

1

Result codes normal.

Result codes disabled in answer mode.

7

0

» 1

Answer mode enabled.

Originate mode enabled.

BIT-MAPPED REGISTER S21

Format

AT [cmds] S21=n [cmds]

Example:

ATS21=1<CR>

Default:

0

Range:

0 - 255

Unit:

Bit-mapped

Description:

Controls low DTR action, DCD signal, and the Long Space Disconnect function.

Bit

Value

Function

0

0

Not used.

1

» 0

1

Restore profile 0 on power-up.

Restore profile 1 on power-up.

2

0

Not used.

4, 3

» 00

01

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

1

DCD signal forced high.

DCD signal normal.

6

» 0

1

DSR signal forced high.

DSR signal normal.

7

» 0

1

Long Space Disconnect function disabled.

Long Space Disconnect function enabled.

BIT-MAPPED REGISTER S22

Format

AT [cmds] S22=n [cmds]

Example:

ATS22=114<CR>

Default:

118

Range:

0 - 255

Unit:

Bit-mapped

Description:

Controls volume and speaker settings, result codes, and make/break pulse ratio.

Bit

Value

Function

1, 0

00

01

» 10

11

Lowest volume setting.

Low volume setting.

Medium volume setting

Highest volume setting.

3, 2

00

» 01

10

11

Speaker disabled.

Speaker enabled until carrier signal detected

Speaker enabled.

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

6, 5 ,4

000

100

101

110

» 111

Busy and dialtone detection disabled, result codes 0-4 enabled.

Busy and dialtone detection disabled, result codes 0-5, 10 enabled.

Busy tone detection disabled, dialtone detection enabled, result codes 0-6, 10 enabled.

Busy tone detection enabled, dialtone detection disabled, result codes 0-5, 7, 10 enabled.

Busy and dialtone detection enabled, result codes 0-7, 10 enabled.

7

» 0

1

39/61ms pulse ratio at 10pps (North America)

33/67ms pulse ratio at 10pps (Europe)

BIT-MAPPED REGISTER S23

Format

AT [cmds] S23=n [cmds]

Example:

ATS23=114<CR>

Default:

0, read-only (see note)

Range:

0 - 255

Unit:

Bit-mapped

Description:

Controls guard tones. Also indicates detected serial port speed and parity. Also provides storage for remote digital loopback tests.

Note:

All bits except bits 6 and 7 are read-only.

Bit

Value

Function

0

0

1

Remote digital loopback response disabled.

Remote digital loopback response enabled.

3, 2, 1

000

001

010

011

100

» 101

Local speed detected at 300bps.

Local speed detected at 600bps.

Local speed detected at 1200bps.

Local speed detected at 2400bps.

Local speed detected at 4800bps.

Local speed detected at 9600bps.

5, 4

00

01

11

Even parity detected.

Odd parity detected.

No parity detected.

7, 6

» 00

01

10

Guard tone disabled.

550Hz guard tone enabled.

1800Hz guard tone enabled.

BIT-MAPPED REGISTER S27

Format

AT [cmds] S27=n [cmds]

Example:

ATS27=77<CR>

Default:

73

Range:

0 - 255

Unit:

Bit-mapped

Description:

Controls communications mode, line type, and protocol type.

Note:

Be aware that bits 2 and 3 are out of order.

Bit

Value

Function

3, 1, 0

000

001

010

011

100

101

110

Asynchronous mode, serial port speed follows connect speed.

Asynchronous command mode and synchronous connect mode.

Asynchronous command mode - modem autodials first number in directory on high DTR, then synchronous connect mode.

Asynchronous command mode on low DTR, synchronous connect mode on high DTR.

Hayes AutoSync™ mode - serial port locked at 9600bps.

Error-correcting mode.

Asynchronous mode, serial port speed locked.

2

» 0

1

Select dial-up line.

Select leased line.

5, 4

00

01

10

Modem generates clock

Modem generates clock from the receive carrier signal.

DTE generates clock

6

» 0

1

Select CCITT protocols.

Select Bell protocols.

7

0

Not used.

COMPRESSION

Type:

Register

Format:

AT [cmds] S41=n [cmds]

Example:

AT S41=1<CR>

Description:

Selects data compression.

Command

Function

S41=0

Data compression disabled.

» S41=1

Data compression enabled.

COMPRESSION MODE

Type:

Configuration

Format:

AT #Ln

Example:

AT #L2 -K1 <CR>

Description:

Selects active compression protocols.

Command

Function

#L0

Compression disabled.

#L1

MNP compression only enabled.

#L2

V.42bis compression only enabled.

» #L3

MNP and V.42bis compression enabled.

FLOW CONTROL

Type:

Configuration

Format:

AT [cmds] \Gn [cmds]

Example:

AT \G1 &K3<CR>

Description:

Selects flow control.

Command

Function

» \G0

Flow control disabled.

\G1

Flow control enabled.

INACTIVITY TIMER

Type:

Configuration

Format:

AT [cmds] \Tn [cmds]

Example:

AT\T20<CR>

Default:

0

Range:

0-42

Unit:

1 minute

Description:

Sets the length of time that the modem does not receive information before it disconnects.

LOOPBACK TESTS

Format

AT [cmds] S16=n [cmds]

Example:

ATS16=32<CR>

Default:

0

Range:

0 - 255

Unit:

Bit-mapped

Description:

Enables loopback tests.

Note:

Bit 3 is read-only.

Bit

Value

Function

0

» 0

1

Local analog loopback test disabled.

Local analog loopback test enabled.

1

0

Not used.

2

» 0

1

Local digital loopback test disabled.

Local digital loopback test enabled.

3

» 0

1

Modem is not performing remote digital loopback test.

Modem is performing remote digital loopback test.

4

» 0

1

Remote digital loopback test disabled.

Remote digital loopback test enabled.

5

» 0

1

Remote digital loopback with local self-test disabled.

Remote digital loopback with local self-test enabled.

6

» 0

1

Local analog loopback with local self-test disabled.

Local analog loopback with local self-test enabled.

7

0

Not used.

MNP10 COMPRESSION

Type:

Configuration

Format:

AT [cmds] -Kn [cmds]

Example:

AT %C1 -K1 -Q0 <CR>

Description:

Selects MNP10 data compression.

Command

Function

-K0

MNP10 disabled.

» -K1

MNP10 enabled.