Westermo TDW-33 User manual

Industrial Telephone Modem
www.westermo.com
©Westermo Teleindustri AB • 2007
AT Commands
Interface Guide
6618-3201
TDW-33
TD-36,TR-36
4
3
2
1
4
3
2
1

22 6618-3201
Introduction
This document describes the AT-commands that can be used to configure and control the
TDW-33,TD-36 and TR-36 modem.
The TDW-33,TD-36 and TR-36 different operating modes are controlled by AT-commands.
Modem operation modes:
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 website www.westermo.com.
AT Commands
Responses
1
2
3
5
4
Command
Mode
Online
Command
Mode
Online
Mode

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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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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
Description:
The modem will go off-hook and attempt to answer an incoming call if correct condi-
tions are met. Upon successful completion of answer handshake, the modem will go on-
line in answer mode.
A successful negotiation must be meet 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: TDW-33 TD-36 TD-36 485 TR-36
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
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
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: TDW-33 TD-36 TD-36 485 TR-36
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
and accepted
ERROR Otherwise
S register: None

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66618-3201
&Bn – DTR/TX Dial Option
Supported by: TDW-33 TD-36 TD-36 485 TR-36
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: None
Cn – Carrier control
Supported by: TDW-33 TD-36 TD-36 485 TR-36
Description:
This command is included for compatibility only, and has no effect other than returning
a result code.
Syntax:
ATC<n>
Parameters:
<n>
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
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: TDW-33 TD-36 TD-36 485 TR-36
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
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
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 dia
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
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: TDW-33 TD-36 TD-36 485 TR-36
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
ATE<n> OK The command is valid
and accepted
ERROR Otherwise
S register: The value is written to S14 bit 1