AC75 AT Command Set
13.8 AT+CMGW s
AC75_ATC_V01.002 Page 375 of 569 10/30/06
Confidential / Released
• If writing fails due to timeout, then
AT^SM20 <CmgwMode>=1 causes "+CMS ERROR: Unknown error" to be returned;
AT^SM20 <CmgwMode>=0 causes "+CMS ERROR: timer expired" to be returned.
• Note that some providers do not recognize an @ symbol used in a short message. A widely used alternative
is typing "*" as defined in GSM 03.40 (GPP TS 23.40).
• For baudrates lower than 19200 it is recommended to use the line termination character only (refer to ATS3=
<n>, default <CR>) before entering the text or PDU. Use of the line termination character followed by the
response formating character (see ATS4= <n>, default <LF>) may cause problems.
• SMS-COMMANDs and SMS-STATUS-REPORTs cannot be stored in text mode.
• All characters entered behind the ">" prompt will be recognized as GSM characters. For example, "Back-
space" (ASCII character 8) does not delete a character, but will be inserted into the short message as an addi-
tional physical character. As a result, the character you wanted to delete still appears in the text, plus the GSM
code equivalent of the Backspace key.
• Message Length in Text Mode
The maximum length of a short message depends on the used coding scheme: It is 160 characters if the 7
bit GSM coding scheme is used, and 140 characters according to the 8 bit GSM coding scheme.
In case UCS2 character set selected it is highly recommended to set Data Coding Scheme (<dcs> of
AT+CSMP) to 16-bit data, otherwise the length of sms user data is restricted to 88 octets. Even better for mes-
sages with UCS2 character set is the PDU Mode.
• The length of 8-bit data code d short messages has to be greater than 0.