Specifications

AT Command Set

TC35-ATC-01-V02.10 Page 10/145 02.10 / 23.05.2001

1.3 Supported character sets

The ME uses 2 character sets: GSM 03.38 (7 bit, see character tables in annex 7.10 „Alphabet ta-

bles“, pg. 144) and UCS2 (16 Bit, refer ISO/IEC 10646). Also refer to subclause „AT+CSCS Set TE

character set", pg. 83.

With the intention of using an ASCII terminal to enter characters which are coded differently in ASCII

and GSM (e.g. Ä, Ö, Ü), these characters have to be entered via escape sequences. Such a character

is translated into the corresponding GSM character value and if output later, the GSM character value

is issued. Any ASCII terminal then will have to show wrong responses.

For instance:

GSM 03.38

character

GSM character

hex. value

Corresponding

ASCII character

ASCII

Esc sequence

Hex

Esc sequence

Ö 5C \ \5C 5C 35 43

" 22 “ \22 5C 32 32

ò 08 BSP \08 5C 30 38

@ 00

NULL \00 5C 30 30

Use of the GSM Null character may cause problems on application level when using a ´C´-function

as „strlen()“ and should thus be represented by an escape sequence.

1.4 Autobauding

The serial interface of the ME supports autobauding. Therefore it is possible to detect the baud rate

used by the TE while receiving the strings „AT“ or „at“ (Attention). This two-character abbreviation is

always used to start a command line to be sent from TE to TA.

There are certain rules to be followed when autobauding is active:

1. Only the strings „AT“ or „at“ can be detected (neither „aT“ nor „At“!).

2. Autodetection works in the range from 1200 to 115200 baud.

3. The serial interface has to be used with 8 data bits, no parity and 1 stop bit anyway.

If autobauding is active

• the multiplex mode (see +CMUX, pg. 67) cannot be activated (and if multiplex mode has been en-

tered, AT+IPR=<rate> is not possible).

• the command A/ (and a/) cannot be used.

The device is shipped with autobaud mode enabled.

For further implications regarding the autobaud mode and baud rate selection see the following AT

Commands:

1. AT+ILRR Set TE-TA local rate reporting , pg. 30

2. AT+IPR Set fixed local rate, pg. 32