HwMuseum | Index

AT&T PARADYNE

COMSPHERE 3910

Modem Type

Data (synchronous/asynchronous)

Maximum Data Rate

19.2Kbps

Data Bus

External

Data Modulation Protocol

AT&T V.32terbo, Point to Point diagnostic, Trellis Multipoint

Bell 103A/212A

ITU-T V.21, V.22, V.22bis, V.23, V27bis, V.29, V.32, V.32bis

Error Correction/Compression

MNP5, V.42, V.42bis

CONNECTIONS

Purpose

Location

Purpose

Location

Switched line

CN1

Power switch

SW1

Leased line

CN2

Scroll left

CN6

RS-232/422

CN3

Scroll right

CN7

DC power

CN4

Go up one level

CN8

Network Management (proprietary)

CN5

Go to top level

CN9

DIAGNOSTIC LED(S)

LED

Color

Status

Condition

PWR

Green

On

Power is on

PWR

Green

Off

Power is off

ALRM

Red

Blinking

Major alarm detected in a remote 391x series modem

ALRM

Red

Off

Normal operation

DIAG

Green

On

Modem is receiving diagnostic messages

DIAG

Green

Off

Modem is not receiving diagnostic messages

DTR/108

Green

On

DTR signal is high

DTR/108

Green

Off

DTR signal is low

RTS/105

Green

On

RTS signal is high

RTS/105

Green

Off

RTS signal is low

CTS/106

Green

On

CTS signal is high

CTS/106

Green

Off

CTS signal is low

TXD/103

Green

On

Modem is receiving data from DTE

TXD/103

Green

Off

Modem is not receiving data from DTE

LSD/109

Green

On

Carrier signal detected

LSD/109

Green

Off

Carrier signal not detected

RXD/104

Green

On

Modem is transmitting data to DTE

RXD/104

Green

Off

Modem is not transmitting data to DTE

SQ

Yellow

Blinking

Line signal is degraded or data path is being blocked

SQ

Yellow

Off

Normal operation

TEST/142

Yellow

On

Test connection established

TEST/142

Yellow

Blinking

Modem is upgrading firmware

TEST/142

Yellow

Off

No test connection established

RATE

Yellow

On

Modem is connected at less than configured speed

RATE

Yellow

Off

Modem is connected at configured speed

DIAL

Yellow

On

Modem is establishing a switched line connection

DIAL

Yellow

Blinking

Switched line connection established

DIAL

Yellow

Off

No switched line connection

Proprietary AT Command Set

ANTISTREAMING

Type:

Register

Format:

AT [cmds] S72=n [cmds]

Example:

AT S72=0 &W<CR>

Description:

Selects antistreaming option

Command

Function

» S72=0

Disabled

S72=1

10 seconds

S72=2

30 seconds

S72=3

1 minute

S72=4

2 minutes

S72=5

3 minutes

S72=6

5 minutes

AT COMMAND RESPONSE

Type:

Register

Format:

AT [cmds] S84=n [cmds]

Example:

AT S84=0 &W<CR>

Description:

Sets the response to AT commands.

Command

Function

» S84=0

Normal operation

S84=1

Execute valid commands, suppress error codes.

S84=2

Ignore configuration commands, always return OK error code.

AUTO BAUD

Type:

Register

Format:

AT [cmds] S78=n [cmds]

Example:

AT S78=0 &W<CR>

Description:

Allows modem to connect at remote modem’s modulation.

Command

Function

» S78=0

Auto baud enabled.

S78=1

Auto baud disabled.

AUTO-RELIABLE FALLBACK CHARACTER

Type:

Configuration

Format:

AT [cmds] %An [cmds]

Example:

AT%A20<CR>

Default:

19

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]

Example:

AT \C1 &W<CR>

Description:

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

Command

Function

» \CO

Data is discarded.

\C1

Data is buffered.

\C2

Data is discarded, resets to \C1 on receipt of autoreliable fallback character.

BREAK TYPE

Type:

Configuration

Format:

AT [cmds] \Kn [cmds]

Example:

AT \K5 &W<CR>

Description:

Selects response to DTE break command.

Command

Function

\K0

Send break, clear buffer, enter command mode.

\K1

Send break, clear buffer

\K2

Send break, send data, enter command mode.

\K3

Send break. send data,

\K4

Send data, send break, enter command mode.

» \K5

Send data, send break.

BUFFER REDUCED ASYNCRONOUS

Type:

Register

Format:

AT [cmds] S97=n [cmds]

Example:

AT S97=0 &W<CR>

Description:

Limits asynchronous buffer size to a 20 character maximum

Command

Function

» S97=0

Buffer size limit disabled.

S97=1

Buffer size limit enabled

BUSY OUT ON LOW DTR

Type:

Register

Format:

AT [cmds] S69=n [cmds]

Example:

AT S69=0 &W<CR>

Description:

Modem goes off hook on low DTR (use only in PBX mode).

Command

Function

» S69=0

Busy out disabled.

S69=1

Busy out enabled.

CALLBACK SECURITY

Type:

Register

Format:

AT [cmds] S67=n [cmds]

Example:

AT S67=0 &W<CR>

Description:

Enables callback security option

Command

Function

» S67=0

Disabled

S67=1

Enabled

CD SIGNAL

Type:

Configuration

Format:

AT [cmds] &Cn [cmds]

Example:

AT &C3 *RS1 *SR1<CR>

Description:

Configures the behavior of the carrier detect signal.

Command

Function

&C0

CD forced high.

» &C1

CD normal.

&C2

CD forced high except during handshaking and disconnecting.

&C3

CD momentary follows DTR.

&C4

CD follows remote RTS signal.

&C5

CD Follows DTR signal. Forced low on disconnect.

CELLULAR ENHANCEMENTS

Type:

Register

Format:

AT [cmds] S91=n [cmds]

Example:

AT S91=0 &W<CR>

Description:

Configures modem to enhanced cellular mode

Command

Function

» S91=0

Disabled

S91=1

Enabled

COMPRESSION

Type:

Configuration

Format:

AT %Cn

Example:

AT I2 %C1 &B0 <CR>

Description:

Selects data compression.

Command

Function

%C0

Data compression disabled.

» %C1

Data compression enabled.

CTS SIGNAL

Type:

Configuration

Format:

AT [cmds] \Dn [cmds]

Example:

AT \D0<CR>

Description:

Selects the function of the CTS signal.

Command

Function

» \D0

CTS forced high.

\D1

CTS normal.

\D2

CTS interrupted for 2 seconds on disconnect.

\D3

CTS follows DTR.

\D4

CTS follows RTS

DISCONNECT BUFFER DELAY

Type:

Register

Format:

AT [cmds] S49=n [cmds]

Example:

AT S49=0<CR>

Default:

10

Range:

0-255

Unit:

1 second

Description:

Selects how long the modem will continue to transmit data in transmit buffer after receipt of disconnect signal

DISCONNECT IMMEDIATELY

Type:

Register

Format:

AT [cmds] S85=n [cmds]

Example:

AT S85=0 &W<CR>

Description:

Disconnect immediately on receipt of disconnect signal from DTE or diagnostic control panel.

Command

Function

» S85=0

Disabled.

S85=1

Enabled.

DISCONNECT ON LOSS OF CURRENT

Type:

Register

Format:

AT [cmds] S65=n [cmds]

Example:

AT S65=0<CR>

Description:

Causes the modem to disconnect if the telephone line’s current drops.

Command

Function

» S65=0

Disconnect after 8ms if current is lost.

S65=1

Disconnect after 90ms if current is lost.

S65=2

Disabled

DTE RATE CONTROL

Type:

Register

Format:

AT [cmds] S61=n [cmds]

Example:

AT S61=0 &W<CR>

Description:

Sets result of DTE CT111 rate control signal.

Command

Function

» S61=0

Disabled.

S61=1

Fallback 1.

S61=2

Fallback 2.

FLOW CONTROL

Type:

Configuration

Format:

AT [cmds] \Gn [cmds]

Example:

AT \G1 &K3<CR>

Description:

Selects modem port flow control.

Command

Function

» \G0

Flow control disabled.

\G1

Flow control enabled.

FLOW CONTROL TYPE

Type:

Configuration

Format:

AT [cmds] \Qn [cmds]

Example:

AT \Q5<CR>

Description:

Sets type of flow control used by modem.

Command

Function

\Q0

Flow control disabled.

\Q1

Bidirectional XON/XOFF flow control enabled.

» \Q2

CTS flow control by DCE enabled.

\Q3

Bidirectional CTS/RTS flow control enabled.

\Q4

XON/XOFF flow control by DTE enabled.

\Q5

XON/XOFF flow control by DCE enabled.

\Q6

RTS flow control by DTE enabled.

INACTIVITY TIMER

Type:

Configuration

Format:

AT [cmds] \Tn [cmds]

Example:

AT\T20<CR>

Default:

0

Range:

0-255

Unit:

1 minute

Description:

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

LAP-M FRAME SIZE

Type:

Configuration

Format:

AT [cmds] \An [cmds]

Example:

AT \A3 %C1<CR>

Description:

Sets the maximum frame size for V.42 and MNP connections.

Command

Function

\A0

Maximum frame size is 64

\A1

Maximum frame size is 128

\A2

Maximum frame size is 192

» \A3

Maximum frame size is 256

\A4

Maximum frame size is 32

\A5

Maximum frame size is 16

LAP-M FRAME WINDOW

Type:

Register

Format:

AT [cmds] S89=n [cmds]

Example:

ATS89=6<CR>

Default:

0

Range:

1-9

Unit:

1 frame (beginning with 0=6 frames)

Description:

Sets the number of frames used in V.42 and V.42bis transmissions

LEASED LINE AUTO-RETRAIN

Type:

Register

Format:

AT [cmds] S82=n [cmds]

Example:

AT S82=0 &W<CR>

Description:

Allows modem to retrain to compensate for bad line quality in V.32bis or V.32terbo

Command

Function

» S82=0

Retrain enabled.

S82=1

Retrain disabled.

LEASED LINE BACKUP SPECIAL STANDBY

Type:

Register

Format:

AT [cmds] S98=n [cmds]

Example:

AT S98=0 &W<CR>

Description:

Allows leased line dial backup using a third modem.

Command

Function

» S98=0

Disabled

S98=1

Enabled

LEASED LINE DIAL BACKUP

Type:

Register

Format:

AT [cmds] S46=n [cmds]

Example:

AT S46=0 &F1<CR>

Description:

Automatically establishes switched line connection if leased line fails

Command

Function

» S46=0

Disabled.

S46=1

Enabled.

LEASED LINE BACKUP RECOVERY DELAY

Type:

Configuration

Format:

AT [cmds] S47=n &F1 [cmds]

Example:

AT S47=0 &F1 <CR>

Description:

After leased line failure, modem attempts to reconnect after specified delay.

Command

Function

» S46=0

Disabled.

S46=1

15 minute delay.

S46=2

60 minute delay.

S46=3

4 hour delay

S46=4

2 minute delay (test)

S46=5

Adv 15 minutes

S46=6

Adv 30 minutes

S46=7

Adv 60 minutes

S46=8

Adv 2 minutes (test)

LEASED LINE DISCONNECT LEVEL

Type:

Register

Format:

AT [cmds] S48=n [cmds]

Example:

AT S48=0 &W<CR>

Description:

Sets level carrier signal drops to before disconnect.

Command

Function

» S48=0

Disconnect at -43dBm

S48=1

Disconnect at -26dBm

S48=2

Disconnect at -33dBm

LEASED LINE SPEED

Type:

Register

Format:

AT [cmds] S44=n [cmds]

Example:

ATS44=18<CR>

Default:

18

Description:

Sets maximum leased line speed

Command

Function

S44=1

14.4Kbps V.32bis

S44=2

12.0Kbps V.32bis

S44=3

9600bps V.32bis

S44=4

7200bps V.32bis

S44=5

4800bps V.32bis

S44=6

2400bps V.22bis

S44=11

14.4Kbps V.33

S44=12

12.0Kbps V.33

S44=13

9600bps V.29

S44=14

7200bps V.29

S44=15

4800bps V.29

S44=16

4800bps V.27

S44=17

2400bps V.27bis

» S44=18

19.2Kbps V.32terbo

S44=19

16.8Kbps V.32terbo

S44=20

19.2Kbps TMp

S44=21

14.4Kbps TMp

S44=22

9600bps TMp

S44=23

7200bps TMp

S44=24

4800bps TMp

S44=25

2400bps TMp

LEASED LINE TRANSMISSION LEVEL

Type:

Register

Format:

AT [cmds] S45=n [cmds]

Example:

AT S45=15<CR>

Default:

0

Range:

0 - 15

Unit:

1 dBm

Description:

Sets the signal level for transmission when in leased line mode.

LINE TYPE

Type:

Configuration

Format:

AT [cmds] &Ln [cmds]

Example:

AT &L0 H1 DT555-1212<CR>

Description:

Selects line type.

Command

Function

» &L0

Switched line.

&L1

2-wire originate mode leased line.

&L2

4-wire originate mode leased line.

&L3

2-wire answer mode leased line.

&L4

4-wire answer mode leased line.

LOCAL ANALOG LOOPBACK

Type:

Register

Format:

AT [cmds] S52=n [cmds]

Example:

AT S52=0 &W<CR>

Description:

Modem executes local analog loopback on receipt of CT141 signal from DTE

Command

Function

» S52=0

Loopback disabled.

S52=1

Loopback enabled.

LOCK SERIAL PORT

Type:

Register

Format:

AT [cmds] S90=n [cmds]

Example:

AT S90=0<CR>

Description:

Sets operation of serial port speed.

Command

Function

» S90=0

Disabled.

S90=1

Serial speed follows connect speed.

NETWORK POSITION IDENTIFICATION

Type:

Register

Format:

AT [cmds] S74=n [cmds]

Example:

AT S74=0 &W<CR>

Description:

Identifies modem as either tributary or control

Command

Function

» S74=0

Identify as tributary

S74=1

Identify as control

PASSWORD REMOTE ACCESS

Type:

Register

Format:

AT [cmds] S56=n [cmds]

Example:

ATS56=06<CR>

Default:

None

Range:

00-99

Unit:

Password digits

Description:

Allows entry of the first two digits of remote access password.

PASSWORD REMOTE ACCESS

Type:

Register

Format:

AT [cmds] S57=n [cmds]

Example:

ATS57=06<CR>

Default:

None

Range:

00-99

Unit:

Password digits

Description:

Allows entry of the second two digits of remote access password.

PASSWORD REMOTE ACCESS

Type:

Register

Format:

AT [cmds] S58=n [cmds]

Example:

ATS58=06<CR>

Default:

None

Range:

00-99

Unit:

Password digits

Description:

Allows entry of the third two digits of remote access password.

PASSWORD REMOTE ACCESS

Type:

Register

Format:

AT [cmds] S59=n [cmds]

Example:

ATS59=06<CR>

Default:

None

Range:

00-99

Unit:

Password digits

Description:

Allows entry of the fourth two digits of remote access password.

REMOTE CONFIGURATION

Type:

Register

Format:

AT [cmds] S55=n [cmds]

Example:

AT S55=0 &W<CR>

Description:

Allows remote configuration by 3800 series modem.

Command

Function

» S55=0

Remote configuration enabled.

S55=1

Remote configuration disabled.

REMOTE DIGITAL LOOPBACK

Type:

Register

Format:

AT [cmds] S51=n [cmds]

Example:

AT S51=0 &W<CR>

Description:

Modem executes remote digital loopback on receipt of CT140 signal from DTE

Command

Function

» S51=0

Loopback disabled.

S51=1

Loopback enabled.

REPORT INFORMATION

Type:

Immediate

Format:

AT [cmds] In [cmds]

Example:

AT I1 O<CR>

Description:

Displays modem properties.

Command

Function

I0

Reports product code.

I1

Reports firmware 3 digit version number.

I2

Performs EPROM check

STORED PROFILE

Type:

Register

Format:

AT [cmds] S88=n [cmds]

Example:

AT S88=0 &W<CR>

Description:

Loads stored profile on disconnect.

Command

Function

» S88=0

Disabled.

S88=231

Disabled.

S88=1

Enabled.

S88=232

Enabled.

SWITCHED LINE SPEED

Type:

Register

Format:

AT [cmds] S41=n [cmds]

Example:

ATS41=20<CR>

Default:

20

Description:

Sets maximum line speed

Command

Function

S41=1

14.4Kbps V.32bis

S41=2

12.0Kbps V.32bis

S41=3

9600bps V.32bis, V.32

S41=4

7200bps V.32bis

S41=5

4800bps V.32bis, V.32

S41=6

2400bps V.22bis

S41=11

14.4Kbps V.33

S41=12

12000bps V.33

S41=13

9600bps V.29

S41=14

7200bps V.29

S41=15

4800bps V.29

S41=16

4800bps V.27

S41=17

2400bpsV.27bis

S41=18

19.2Kbps V.32terbo

S41=19

16.8Kbps V.32terbo

» S41=20

19.2Kbps TMp

S41=21

14.4Kbps TMp

S41=22

9600bps TMp

S41=23

7200bps TMp

S41=24

4800bps TMp

S41=25

2400bps TMp

TRANSMISSION LEVEL

Type:

Configuration

Format:

AT [cmds] &In [cmds]

Example:

AT &I26 &W<CR>

Default:

Unidentified

Range:

0-32, 99, 100

Unit:

-1 dBm

Description:

Sets the signal level for transmission

Note: 0-9 invalid in North America.

TRELLIS MULTIPOINT TRANSMIT PREEMPHASIS

Type:

Register

Format:

AT [cmds] S96=n [cmds]

Example:

AT S96=0 &W<CR>

Description:

Compensates for high frequency attenuation with amplification

Command

Function

» S96=0

Enabled

S96=1

Disabled

TRELLIS MULTIPOINT TRAIN TIME

Type:

Register

Format:

AT [cmds] S95=n [cmds]

Example:

AT S95=0 &W<CR>

Description:

Selects train time from tributary to control modem.

Command

Function

» S95=0

10 milliseconds

S95=1

20 milliseconds

S95=2

50 milliseconds

S95=3

100 milliseconds

S95=4

200 milliseconds

S95=5

300 milliseconds

V.25bis CODE SET

Type:

Register

Format:

AT [cmds] S62=n [cmds]

Example:

AT S62=0 &W<CR>

Description:

Sets coding type used in V.25bis mode.

Command

Function

» S62=0

ASCII

S62=1

EBCDIC

V.25bis IDLE CHARACTER

Type:

Register

Format:

AT [cmds] S63=n [cmds]

Example:

AT S63=0 &W<CR>

Description:

Sets V.25 idle fill type

Command

Function

» S63=0

Fill character is mark.

S63=1

Fill character is flag.

V.25bis NEW LINE CHARACTER

Type:

Register

Format:

AT [cmds] S64=n [cmds]

Example:

AT S64=0 &W<CR>

Description:

Sets V.25 new line character.

Command

Function

» S64=0

Carriage return and line feed.

S64=1

Carriage return.

S64=2

Line feed.

V.27 TRAIN

Type:

Register

Format:

AT [cmds] S72=n [cmds]

Example:

AT S72=0 &W<CR>

Description:

Sets train length.

Command

Function

» S43=0

Short

S43=1

Long

V.29 LINK TYPE

Type:

Register

Format:

AT [cmds] S94=n [cmds]

Example:

AT S94=0 &W<CR>

Description:

Selects point to point or multipoint operation

Command

Function

» S94=0

Point to point operation

S94=1

Multipoint operation

V.29 RETRAIN

Type:

Register

Format:

AT [cmds] S93=n [cmds]

Example:

AT S93=0 &W<CR>

Description:

Modem transmits training sequence on receipt of training sequence

Command

Function

» S93=0

Disabled

S93=1

Enabled

V.29 TRAIN

Type:

Register

Format:

AT [cmds] S92=n [cmds]

Example:

AT S92=0 &W<CR>

Description:

Allows retrain based on incoming data or training sequence. Required for tributary modem.

Command

Function

» S92=0

Disabled

S92=1

Enabled

V.32bis AUTO-RETRAIN

Type:

Register

Format:

AT [cmds] S76=n [cmds]

Example:

AT S76=0 &W<CR>

Description:

Selects action the modem will take during bad line quality on 32bis connection.

Command

Function

» S76=0

Auto retrain enabled.

S76=1

Auto retrain disabled.

V.32bis TRAIN

Type:

Register

Format:

AT [cmds] S43=n [cmds]

Example:

AT S43=0 &W<CR>

Description:

Sets train length for V.32bis and V32.

Command

Function

» S43=0

Long

S43=1

Short

V.42bis COMPRESSION CONTROL

Type:

Configuration

Format:

AT [cmds] "Hn [cmds]

Example:

AT "H3 &W<CR>

Description:

Controls V.42bis data compression

Command

Function

"H0

V.42bis disabled.

"H1

V.42bis when transmitting enabled.

"H2

V.42bis when receiving enabled.

» "H3

V.42bis when transmitting/receiving enabled.

V.54 DEVICE ADDRESS

Type:

Register

Format:

AT [cmds] S53=n [cmds]

Example:

ATS53=6<CR>

Default:

0

Range:

0-34

Unit:

Device address 0= disabled

Description:

Identifies the address of the modem in loopback test.

V.54 DEVICE TYPE

Type:

Register

Format:

AT [cmds] S54n [cmds]

Example:

AT S54=0 &W<CR>

Description:

Identifies modem’s network position.

Command

Function

» S54=0

Peripheral

S54=1

Intermediate

XON/XOFF PASS-THROUGH

Type:

Configuration

Format:

AT [cmds] \Xn [cmds]

Example:

AT \X7 O<CR>

Description:

Selects whether XON/XOFF signals are sent to remote modem.

Command

Function

» \X0

XON/XOFF signals trapped by local modem.

\X1

XON/XOFF passed through local modem.

Proprietary V.25bis Command Set

DISPLAY STORED NUMBERS

Type:

Immediate

Format:

RLNn

Example:

RLN2<CR>

Description:

Display number in memory location n. If no number is given, all stored numbers will be displayed.