Specifications

AT Command Set for L55 Platform 2003-11-21
Copyright  Siemens AG 2003 All Rights Reserved Page 113 of 131
2.5.4 Using special characters in certain commands ( e. g., +CPBR/+CPBW)
String parameters like <text> in certain commands (like, for instance, AT+CPBW) should be entered
using quotation marks `"` (Ascii=Windows=GSM=0x22), since the following problems may occur if the
quotation marks are left out:
- SPACEs (Space, Blank, Ascii=Windows=GSM=0x20) are skipped.
E.g. at+cpbw=1,"123",,K. H. results in "K.H." 
at+cpbw=1,"123",,"K. H." spaces are retained ☺
- Commas (`,`) (Ascii=Windows=GSM=0x2C) and semicolons (`;`)(Ascii=Windows=GSM=0x3B) are
prohibited and must not be used in <text>, because they are used as separators between
parameters and commands.
E.g. at+cpbw=1,"123",,Kurz,Helmut results in ERROR 
at+cpbw=1,"123",,"Kurz,Helmut" ☺
To be able, however, to enter quotation marks (and some other special characters) in string
parameters you will have to use the Escape character (hex value 0x5c). While “0x5c” denotes the
backslash (`\`) in the ASCII character set (Ascii=Windows=0x5C), in the GSM character set “0x5C”
denotes the `Ö` character.
The escape sequence thus has the following structure:
- The sequence begins with the escape character 0x5C
(ASCII=Windows=`\', GSM=`Ö`)
- The special character follows and is entered as a 2 Byte representation of the GSM chacter set
value .
e.g. the 2 Byte representation of the `@` (GSM=0x00) is `00`
Table 2-12 lists the special characters that should be entered using the escape sequence:
GSM Char GSM hex value ASCII char. 3 byte esc. seq.(hex) Note
Ö 0x5C \ 0x5C 0x35 0x43 Backslash
" 0x22 “ 0x5C 0x32 0x32 String delimiter
ò 0x08 BSP 0x5C 0x30 0x38 Backspace
@ 0x00 NULL 0x5C 0x30 0x30 GSM NULL
Table 2-12: Using escape characters in commands
Examples of using escape characters in GSM commands are listed in Table 2-13:
Desired phonebook entry <text> in AT+CPBW command (hex)
Ölhändler 0x22 0x5C 0x35 0x43 0x6C 0x68 0x7B 0x6E 0x64 0x6C 0x65
0x72 0x22
“Eddi" Kurz 0x22 0x5C 0x32 0x32 0x45 0x64 0x64 0x69 0x5C 0x32 0x32
0x20 0x4B 0x75 0x72 0x7A 0x22
Oòo 0x22 0x4F 0x5C 0x30 0x38 0x6F 0x22
0x22 0x5C 0x30 0x30 0x41 0x64 0x72 0x2E 0x22
[no problems with strlen()]
@Adr.
22 00 41 64 72 2E 22
(may cause problems with strlen() in application)
Table 2-13: Using escape characters in GSM commands
Note:
When reading phonebook records, there is NO replacement. Every character will appear in normal
GSM character set notation (like the left column in the example above).