User's Manual

Telit TRIZIUM Product Description

80264ST10007a Rev. 4– 09/09/04

5 AT Command

The Telit TRIZIUM module can be driven via the serial interface using the standard AT commands

. The Telit TRIZIUM

module is compliant with:

1. Hayes standard AT command set, in order to maintain the compatibility with existing SW programs.

2. ETSI GSM 07.07 specific AT command and GPRS specific commands.

3. ETSI GSM 07.05 specific AT commands for SMS (Short Message Service) and CBS (Cell Broadcast Service)

4. FAX Class 1 compatible commands

Moreover the Telit TRIZIUM module supports also Telit proprietary AT commands for special purposes.

In the following the dedicated description of how to use the AT commands with the Telit TRIZIUM module.

5.1 Definitions

The following syntactical definitions apply:

<CR> Carriage return character, is the command line and result code terminator character, which value, in decimal

ASCII between 0 and 255,is specified within parameter S3.

The default value is 13.

<LF> Linefeed character, is the character recognised as line feed character. Its value, in decimal ASCII between 0

and 255, is specified within parameter S4. The default value is 10.

The line feed character is output after carriage return character if verbose result codes are used (V1 option used )

otherwise, if numeric format result codes are used (V0 option used) it will not appear in the result codes.

<...> Name enclosed in angle brackets is a syntactical element. They do not appear in the command line.

[...] Optional subparameter of a command or an optional part of TA information response is enclosed in square

brackets. Brackets themselves do not appear in the command line. When subparameter is not given in AT commands

which have a read command, new value equals to its previous value. In AT commands which do not store the values of

any of their subparameters, and so have not a read command, which are called action type commands, action should be

done on the basis of the recommended default setting of the subparameter.

5.2 AT Command Syntax

GSM commands use syntax rules of extended commands.

Every extended command has a test command (trailing =?) to test the existence of the command and to give

information about the type of its subparameters. There are two types of extended command:

- Parameter type commands which also have a read command (trailing ?) to check the current values of

subparameters.

- Action type commands do not store the values of any of their possible subparameters, and therefore do not have a

read command.

5.2.1 Command lines

The basic structure of the command lines are:

• ATCMD1<CR> where AT is the command line prefix, CMD1 is a basic command (i.e. it have not + prefix) and

CR is the command line terminator character

• ATCMD2=10<CR> where 10 is a subparameter

• AT+CMD1;+CMD2=, ,10<CR> These are two examples of extended commands (which have a + prefix). They are

delimited with semicolon. In the second command the subparameter is omitted

• +CMD1?<CR> This is a read command for checking current subparameter values

The AT is an ATTENTION command and is used as a prefix to other parameters in a string. The AT command

combined with other parameters can be set up in the communications package or typed in manually as a command line

instruction.