Westermo TDW-33 User Manual

AT Commands

Reference Guide

6618-3202

TDW-33

TD-36, TD-36 485

TR-36, TR-36B

4 3 2 1 4 3 2 1

Westermo Teleindustri AB

Industrial Telephone Modem

www.westermo.com

Introduction

This document describes the AT-commands that can be used to configure and control the TDW-33, TD-36, TD 36 485 and TR-36 modem.

AT Commands

Responses

The TDW-33, TD-36, TD-36 485 and TR-36 different operating modes are controlled by AT-commands. Modem operation modes:

Command

Mode

Online

Command

Mode

Online

Mode

Example of commands/events that can trigger a change of the modems operation modes

1 – ATD command 2 – Hangup from the remote end 3 – Escape sequence +++ 4 – ATO command 5 – ATH command

For more information about Westermo, please visit out websit

e www.westermo.com.

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Abbreviations and definitions

Abbreviations

ASCII American Standard Code for Information Interchange

AT ATtention; this two-character abbreviation is always used to start a command line to

be sent from TE to Modem

BCD Binary Coded Decimal

ETSI European Telecommunications Standards Institute

IRA International Reference Alphabet (ITU-T T.50 [13])

ISO International Standards Organisation

ITU-T International Telecommunication Union – Telecommunications Standardization Sector

TE Terminal Equipment, e.g. a computer (equal to DTE; Data Terminal Equipment)

TIA Telecommunications Industry Association

Definitions

<CR> Carriage return character, which value is specified with command S3.

<LF> Linefeed character, which value is specified with command S4.

<...> Name enclosed in angle brackets is a syntactical element.

Brackets themselves do not appear in the command line.

[...] Optional subparameter of a command or an optional part of ME information

response is enclosed in square brackets. Brackets themselves do not appear in the command line. When subparameter is not given in parameter type commands, new value equals to its previous value. In action type commands, action should be done on the basis of the recommended default setting of the subparameter

underline Underlined defined subparameter value is the recommended default setting of this

subparameter. In parameter type commands, this value should be used in factory settings that are configured by V.25ter command &F0. In action type commands, this value should be used when subparameter is not given.

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List of AT-commands

Commands always start with AT (which means ATtention) and finish with a <CR> character.

Information responses and result codes

Responses normally start and end with <CR><LF>, except when the modem is set to “short result code format” with the command ATV0, or when the ATQ1 (no result codes) command is used.

If command syntax is incorrect, an ERROR string is returned. If extended error result codes are configured (+CMEE) and if command syntax is correct but with some incorrect parameters, the +CME ERROR: <Err> or +CMS ERROR: <SmsErr> strings are returned with different error codes. If the command line has been performed successfully, an OK string is returned. In some cases, such as “AT+CPIN?” or (unsolicited) incoming events, the product does not return the OK string as a response. In the AT-command list below, <CR> and <CR><LF> are intentionally omitted.

Special AT-commands

In addition to the commands listed below there are two special commands that do not start with AT.The first command is “A/” without any <CR>.This command makes the modem repeat the last entered command.The second special command is the “+++” (also without <CR>).This command is called “escape sequence” and is used when the modem is in dedicated mode (online mode).When entering “+++” in dedicated mode, the modem will switch from “online mode” to “online command mode”.This means that it is possible to send commands to the local modem.The escape sequence is useful when disconnecting the active call.The disconnection is made with the ATH command (see the list of AT-commands below).The ATO command can also be used when in “online command mode”.

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General commands

The AT command line accepts up to 65 characters.

A – Answer a call

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

The modem will go off-hook and attempt to answer an incoming call if correct conditions are met. Upon successful completion of answer handshake, the modem will go online in answer mode.

A successful negotiation must be met during time set by register S7

Syntax:

ATA

Parameters:

No parameters

Command example Possible responses Note

ATA CONNECT<speed> Answer to this incoming

call, call accepted

S register: S7 sets time allowed to connect

&An – Dial Abort Option

Supported by:

Description:

The modem normally aborts the option the connection negotiation if a character is received from DTE during the connection phase. This command gives the user the option to let the modem ignore characters.

Syntax:

&A<n>

Parameters:

<n> 0: Enables Abort (Default) 1: Disable Abort

Command example Possible responses Note

AT&A<n> OK The command is valid

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

and accepted

ERROR Otherwise

S register: The value is written to S14 bit 4

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Bn – ITU-T or BELL

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

When the modem is configured to allow either option, the modem willl select Bell or ITU-T modulation for a line speed connection of 300 or 1200 bit/s. Any other line speed will use a ITU-T modulation standard.

Syntax:

B<n>

Parameters:

<n> 0: Selects ITU-T Modulation (Default) 1: Selects Bell Modulation

Command example Possible responses Note

ATB<n> OK The command is valid

and accepted

ERROR Otherwise

S register: The value is written to S27 bit 6

\Bn – Transmit Break to Remote

Supported by:

Description:

In non-error correction mode, the modem will transmit a break signal to to the remote modem with a length in multiples of 100 ms according to parameter specified. The command works in conjunction with the \K command.

Syntax:

\B<n>

Parameters:

<n> Corresponds to the break length in 100 ms units (Default = 3).

Command example Possible responses Note

AT\B<n> OK The command is valid

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

and accepted

ERROR Otherwise

S register: None

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&Bn – DTR/TX Dial Option

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command enables the modem to dial a number which is stored with AT&Z0 commands. This is performed when the DTR signal goes from inactive to active signal level or when data is received on the DTE TX line (in command mode). After enabling the Hotcall functionality the modem must be restarted for the function to take affect. Disable the TX Hotcall function by sending an escape sequence ’+++’ to enter command mode and then set the &Bn command. See also AT&D and AT&K

Syntax:

&B<n>

Parameters:

<n> 0: Disable DTR/TX Hotcall ( Default ) 1: Enable DTR Hotcall 2: Enable TX Hotcall (buffered data)

Command example Possible responses Note

AT&B<n> OK The command is valid

and accepted

ERROR Otherwise

S register: S210 bit 5 and 6

Cn – Carrier control

Supported by:

Description:

This command is included for compatibility only, and has no effect other than returning a result code.

Syntax:

ATC<n>

Parameters:

<n>

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Command example Possible responses Note

ATC<n> OK The command is valid and

accepted

ERROR Otherwise

S register: None

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%Cn – Select data compression

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command enables or disables data compression. The modem can only perform data compression on an error corrected link. The parameter value, if valid, is written to S41 bit 0 and 1.

Syntax:

AT%C<n>

Parameters:

<n> 0: No compression. Resets S46 bit 1. 1: Enables MNP 5 data compression. Resets S46 bit 1. 2: Enables V42bis data compression. Sets S46 bit 1 3: Enables both V.42bis and MNP5 data compression. Sets S46 bit 1. (Default)

Command example Possible responses Note

AT%C<n> OK The command is valid

and accepted

ERROR Otherwise

S register: The value is written to S41 bits 0 and 1 and S46 bit 1

&Cn – DCD Option

Supported by:

Description:

This command controls the DCD output in accordance with the parameter supplied

Syntax:

&C<n>

Parameters:

<n> 0: DCD remains ON at all times 1: DCD follows the state of a carrier (Default)

Command example Possible responses Note

AT&C<n> OK The command is valid

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

and accepted

ERROR Otherwise

S register: The value is written to S21 bit 5

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D – Dial command

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

The ATD command is used for data or fax call. For a data or a fax call, the application sends the following ASCII string to the product:

ATD<nb> where <nb> represents a dial string composed of dial characters and

dial modifiers.

The dial characters include the decimal values 0 through 9, letters A,B,C,D, and the symbols “*” and “#”.

Dial modifier description:

Separator Name Functionality

, Commaseparator Insert a pause in dialing procedure $ Bongtonesepator A bong tone needs to be detected before

dialing continues ; Returncmdseparator Return to command state / waitsepator Waits for 0.125 seconds : PABX Wait for PABX tone + Insert shortkey ? Delimiter Delimiter between number to be dialed (P#)

and PSTN security access password W Wait Wait for dial tone before processing to next

character in the dial string = Secdialsep. Wait for second dialtone & Wait for credit card Wait for credit card dialing tone before

dialing tone continuing with the dial string. If the tone is

not detected within the time specified by S6

or S7, the modem will abort the rest of the

sequence, return on-hook, and generate an

error message. @ Quietseparator Wait for second dialtone L RE-dial The L must be immediately after the D with

last dialed number all characters ignored. P Select pulse dialing Pulse dial the numbers that follow until a “T”

is encountered. \ Select pulse dialing T Select Tone dialing Pulse dial the numbers that follow until a “P”

is encountered. S = n Dial Stored Number Dial the number stored in the directory

n = 0 to 3 ! Flash The modem will go on-hook the time

specified in S29.

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^ Toggle call tone Applicable to current dial enable/disable only

R This modifier needs to be

accepted, but not acted on

() Ignored; may be used to format dial string

- Ignored; may be used to format dial string

<space> Ignored; may be used to format dial string

<i> Ignored; may be used to format dial string

Syntax:

ATD<nb>

Response:

The response to the ATD command is one of the following:

Result code Numeric result code Description

CONNECT <speed> Refer to description If the call succeeds, for of result codes data calls only, <speed>

takes the value negotiated by the product

NO CARRIER 3 Call setup failed or

remote user release

NO DIALTONE 6 Generate whenthe

modem does not detect a valid dialtone during the dial procedure

BUSY 7 If the called party is

already in communication

NO ANSWER 8 If no hang up is detected

after a fixed network time-out

Parameters:

<nb> is the dial string

S register: None

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&Dn – DTR Control

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This commands controls the Data Terminal Ready (DTR) signal.

Syntax:

AT&D<n>

Parameters:

<n> 0: The DTR signal is ignored (Default) 1: Modem switches from data to command mode when DTR switches from ON

to OFF 2: Upon DTR switch from ON to OFF, the call is hang up 3: DTR drop causes the modem to perfom a soft reset.

Command example Possible responses Note

AT&D<n> OK The command is valid

and accepted

ERROR Otherwise

S register: The value is written to S21 bits 3 and 4.

En – Echo

Supported by:

Description:

This command is used to determine whether the modem echoes characters received by an external application (DTE) or not.

Syntax:

ATE<n>

Parameters:

<n> 0: Characters are not echoed 1: Characters are echoed (Default)

Command example Possible responses Note

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

ATE<n> OK The command is valid

and accepted

ERROR Otherwise

S register: The value is written to S14 bit 1

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%En – Enable/Disable Line Quality Monitor and Auto-Retrain or

Fallback/Fall Forward

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

Enable/disable Line quality Monitor and Auto-Retrain or Fall back/fall forward. This command controls if the modem automatically monitors the line quality and requests a retrain (%E1) or fall back when line quality is insufficient or a fall forward when line quality is sufficient (%E2). Set S41 bits 2 and 6.

Syntax:

AT%E<n>

Parameters:

<n> 0: Disable Line Quality and auto-retrain 1: Enable Line Quality and auto-retrain 2: Enable Line Quality Monitor and Fallback/Fall Forward / (Default)

Command example Possible responses Note

AT%E<n> OK The command is valid

and accepted

ERROR Otherwise

S register: The value is written to S41 bits 2 and 6.

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Fn – Select Line Modulation

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

This command selects which type of modulation will be used on the phone line. If this parameter is set to something other than F0, the line speed will be fixed. (See also the +MS command)

Syntax:

ATF<n>

Parameters:

<n> 0: Selects Auto V8 automatically line speed according to the preference of the remote

modem. (Default) 1: Selects 300 bit/s, V.21 (if B0 is set) or Bell 103 (if B1 is set). 2: Selects V.22 600 bit/s 3: Selects V.23 , see %Fn for speed. 4: Selects V.22 (if B0 is set) or Bell 212A (if B1 is set). 1 200 bit/s. 5: Selects V.22bis,.2 400 bit/s, 6: Selects V.32bis 4 800 bit/s or V.32 4 800 bit/s. 7: Selects V.32bis 7 200 bit/s. 8: Selects V.32bis 9 600 bit/s or V.32. 9 600 bit/s. 9 : Selects V.32bis 12 000 bit/s. 10: Selects V.32bis 14 400 bit/s. 14: Selects V.34 15: Auto

Command example Possible responses Note

ATF<n> OK The command is valid

and accepted

ERROR Otherwise

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%Fn –V23 Speed selection

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

The direction and speed of forward and backchannels for V23C modulation are set with this command.

Syntax:

AT%F<n>

Parameters:

<n> 1: Selects 75Tx/1200Rx 2: Selects 1200Tx/75Rx 3: Selects 1200Tx/1200Rx. (Default)

Command example Possible responses Note

AT%F<n> OK The command is valid and accepted

ERROR Otherwise

&Fn – Restore Factory Configuration

Supported by:

Description:

The modem loads factory default configuration (profile). A configuration (profile) consists of a subset of S-registers.

Syntax:

AT&F<n>

Parameters:

<n> 0: Load factory default settings for all commands except Westermo specific commands. 1: Load factory default settings for all commands except Westermo specific commands. 2: Load factory default for Westermo specific commands.

Command example Possible responses Note

AT&F<n> OK The command is valid

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

and accepted

ERROR Otherwise

S register: None

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+FCLASS – Select Active Service Class

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command selects the active service class

Syntax

+FCLASS=<n> +FCLASS? +FCLASS=?

Parameters

<n> 0: Select Data Mode (Default.) 1: Select Facsimile Class 1 8: Select Voice Mode

Command example Possible responses Note

AT+FCLASS<n> OK The command is valid

and accepted

ERROR Otherwise

S register: None

&Gn – Select Guard Tone

Supported by:

Description:

The modem Generates the guard tone selected by this command according to the parameter supplied (DPSK modulation modes only).

Syntax:

&G<n>

Parameters:

<n> 0: Disables Guard Tone (Default) 1: Disables Guard Tone 2: Selects 1800 Hz Guard Tone.

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Command example Possible responses Note

AT&G<n> OK The command is valid

and accepted

ERROR Otherwise

S register: The value is written to S23 bits 6 and 7.

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*Gn – Password control

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command controls whether or not the modem will handle Password and/or Call back functionality. For compatibility reasons only. See also AT*WCB

Syntax:

*G<n>

Parameters:

<n> 0: Disables Password Control ( Default ), corresponds to AT*WCB = 0 1: Enables Password Control, corresponds to AT*WCB = 3

Command example Possible responses Note

AT*G<n> OK The command is valid

and accepted

ERROR Otherwise

S register: The value is written to S14 bit 6.

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+GCI – Country Parameters

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command selects the country code for modem.

Syntax:

AT+GCI = <value> AT+GCI = ? AT+GCI?

Parameters:

<Value>

Please refer to Country table i.e.

A5: Selects country code for Sweden B5: Selects country code for America C7: Universal country code (Default)

Command example Possible responses Note

AT+GCI = <value> OK The command is valid

and accepted

ERROR Otherwise

S register: None

Hn – Disconnect (Hang-Up)

Supported by:

Description:

This command initiates a hang-up sequence. Syntax: ATH<n>

Parameters:

<n> 0: The modem will release the line if the modem currently is on-line. 1: If on-hook, the modem will go off-hook and enter command mode.

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Command example Possible responses Note

ATH<n> OK The command is valid

and accepted

ERROR Otherwise

S register: None

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In – Request identification information

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command causes the product to transmit one or more lines of specific information text.

Syntax:

ATI<n>

Parameters:

<n> 0: Display max line speed. 1: Reserved 2: Reserved 3: Reserved 4: Display manufacturer identification. 5: Display country code. 6: Display revision identification for modem modulation code 7: Reserved 8: Display switch settings

9: Display Westermo Application Software revision identification. Other values: “ERROR” string is sent back.

Command example Possible responses Note

ATI0 33600 Max line speed OK

ATI4 WESTERMO Modem manufactor TELEINDUSTRI AB identifier OK

ATI6 BSMW310_BF533_bfbsmw310_5457OK Revision identification OK for modem modula-

tion code

ATI8 000 000 000 000 Switch settings OK Each DIP switch

displayed as a decimal value. S1 S2 S3 S4 Notice switch setting is only reed at powerup and ATZ

ATI9 4101-0201 Westermo SW OK release

ERROR Otherwise

S register: None

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+ICF – Fixed DTE format

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This commands specifies the data format between the modem and the DTE. Notice that format can’t be set with rate set to auto.

Syntax

AT+ICF = <format> AT+ICF = ? AT+ICF?

Parameters:

<format> 0 Auto 5,4 7NI 4,4 7N2 5,1 7E1 5,0 7O1 3,4 8N1 2,1 8E1 2,0 8O1 4,1 7E2 4,2 7O2 1,4 8N2 1,1 8E2 1,2 8O2

Command example Possible responses Note

AT+ICF? +ICF: (3,4) OK Current format is 8N1

AT+ICF = ? +ICF(0-5),(0-4) OK Allowed values

AT+ICF = (3,4) OK AT+ICF = <n> ERROR If n is not valid

S register: None

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+IPR – Fixed DTE rate

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This commands specifies the data rate between the modem and the DTE.

Syntax

AT+IPR = <rate> AT+IPR = ? AT+IPR?

Parameters:

<rate>: baud rates that can be used by the DCE 0 (enables autobauding) 200 300 600 1200 2400 4800 9600 19200 38400 57600 115200 230400

Command example Possible responses Note

AT+IPR? +IPR: 9600 OK Current rate is 9600 bit/s

AT+IPR = ? +IPR: (0, 300, 600, 1200,

2400, 4800, 9600, 19200, 38400, 57600,

115200), OK

AT+IPR = 38400 OK Disable autobauding and

set rate to 38400 bit/s AT+IPR = 0 OK Enable autobauding AT+IPR = n ERROR If n is not valid

S register: None

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\Kn – Break Control

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command controls the response of the modem to a break signal received from the terminal equipment, from the remote modem or through the \B command. The modem can respond in three different ways depending on the state of the modem. The value is written to S40 bit 3,4 and 5.

Syntax:

AT\K<n>

Parameters:

<n>

Mode 1

Modem is in on line data mode and a break is received from the DTE. <n>

0: Enter on-line command modem, no break sent to the remote modem. 1: Clear data buffers and send break to remote modem. 2: Same as 0. 3: Send break to remote modem immediately. 4: Same as 0. 5: Send break to remote modem in sequence with transmitted data (Default).

Mode 2

Modem is in on line command mode and a \B is received in order send as a break to the remote modem. <n>

0: Clear data buffers, send break to the remote modem. 1: Same as 0. 2: Send break to remote modem immediately. 3: Same as 2. 4: Send break to remote modem in sequence with transmitted data. 5: Same as 4.

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Mode 3

A break is received from a remote modem during a non-error corrected connection. <n>

0: Clear data buffers, send break to the DTE. 1: Same as 0. 2: Send break immediately to DTE. 3: Same as 2. 4: Send break to remote modem in sequence with transmitted data. 5: Same as 4. (Default)

Command example Possible responses Note

AT\K<n> OK The command is valid

and accepted ERROR Otherwise

S register: The value is written to S40 bits 3, 4 and 5.

&Kn – DTE-DCE flow control

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command controls the operation of local flow control between the DTE and DCE.

Syntax:

AT&K<n>

Parameters:

<n> 0: Disables Flow Control (Default) 3: Enables RTS/CTS 4: Enables XON/XOFF

Command example Possible responses Note

AT&K<n> OK <n>= 0 to 4 ERROR Otherwise

S register: The value is written to S39 bits 0, 1 and 2.

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Ln – Speaker Volume

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

Sets the speaker volume control.

Syntax:

ATL<n>

Parameters:

L0: Low Volume L1: Low Volume L2: Medium Volume L3: High Volume ( Default )

Command example Possible responses Note

ATL<n> OK ERROR Otherwise S register: The value is written to S22 bits 0 and 1.

%L – Report Line Signal Level

Supported by:

Description:

This command returns a value which indicates the received signal level.

Syntax:

AT%L

Parameters:

None

Command example Possible responses Note

AT&L 009 OK –9 dBm signal level

ERROR Otherwise

S register: None

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

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*L – Display Stored Passwords and Callback numbers

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command displays stored Password and Callback numbers.

Syntax:

AT*L

Parameters:

None

Command example Possible responses Note

AT*L 0 – Password, Callback number 1 – Password, Callback number OK

ERROR Otherwise

S register: None

Mn – Speaker Control

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

Speaker Control command.

Syntax:

ATM<n>

Parameters:

<n> 0: Speaker off 1: Speaker is on during call establishment, but off when receiving a carrier. (Default) 2: Speaker is always on

Same as 1 but only when answering, and not during call establishment.

Command example Possible responses Note

ATM<n> OK ERROR Otherwise

S register: The value is written to S22 bits 2 and 3.

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+MS – Select Modulation

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command selects the modulation, enables or disables automode, specifies the receive rates and specifies the transmit rates using six subparameters.

Syntax:

+MS = <carrier>,<automode>,<min_tx_rate>,<max_tx_rate>,<min_rx_rate>,<max_rx_ rate>

+MS = ? +MS ?

Parameters:

V21 300 bit/s or 200 bit/s V22 1200 bit/s V22B 1200 or 2400 bit/s V23C 75/1200, 1200/75 bit/s PSTN-mode dialled connections V23HDX 1200/1200 half duplex PSTN dialled connections (TD-36 and TD-36 485 also 2 wire leased line) V23FDX 1200/1200 bit/s full duplex 4 wire leased line (only TD-36 485) V32 4800 or 9600 bit/s V32B 4800, 7200, 9600, 12000 or 14400 bit/s V34 2400, 4800, 7200, 9600, 12000, 14400, 16800, 19200, 21600, 24000, 26400,

28800, 31200, 33600 bit/s V34FC 2400, 4800, 7200, 9600, 12000, 14400, 16800, 19200, 21600, 24000, 26400, 28800, 31200, 33600 bit/s V90A up to tx = 33600, rx = 56000 bit/s (client mode) Only TDW-33 V90D up to tx = 56000, rx = 33600 bit/s (server mode) Only TDW-33 B103 300 bit/s B212 1200 bit/s

0: Disable 1: Enable

<min_xx_rate>, <max_xx_rate>

Minimum and maximum data rate depending on modulation used.

Command example Possible responses Note

AT+MS = ? The modem sends a

string of information to the DTE consisting of supported options

AT+MS? List current configuration

S register: None

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\Nn – Select Operating mode

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

This command controls the preferred error correcting mode for a data connection

Syntax:

AT\N<n>

Parameters:

<n> 0: Selects normal speed buffered mode (disables error-correction mode). 1: Selects direct mode and is equivalent to &M0, &Q0 mode of operation. In this mode the serial port is directly connected to the data pump, which results in the lowest possible delay time. This is useful in i.e. the case of polled PLC systems where the response time is critical. 2: Selects reliable (error-correction) mode. The modem will first attempt a LAPM connection and then an MNP connection. Failure to make a reliable connection results in the modem hanging up. 3: Selects auto reliable mode. This operates the same as \N2 except failure to make a reliable connection results in the modem falling back to the speed buffered normal mode, \n0. 4: Selects LAPM error-correction mode. Failure to make an LAPM error-correctio connection results in the modem hanging up. Note: The -K1 command overrides the \n4 command. 5: Selects MNP error-correction mode. Failure to make an MNP error-correction connection results in the modem hanging up.

Command example Possible responses Note

AT\N<n> OK ERROR Otherwise

S register: The value is written to S36 and S48 (see description).

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On – Back to online mode

Supported by:

TDW-33 TD-36 TD-36 485 TR-36 TR-36B

Description:

If a connection has been established and the modem is in online command mode, this command allows you to return to online data mode either with or without a retrain.

Syntax:

ATO<n>

Parameters:

<n> 0: Enters on-line mode without a retrain (Default). 1: Enters on-line mode with a retrain.

Command example Possible responses Note

ATO0 OK Enters on-line mode

without a retrain.

ATO1 OK Enters on-line mode with a retrain

ERROR Otherwise or if not

connected

S register: None

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