Manual

Smart Machine Smart Decision
SIM800 Series_AT Command Manual_V1.09 24 2015-08-03
beginning of the command line. Please note to use a semicolon as the command delimiter after
an extended command; in basic syntax or S parameter syntax, the semicolon need not enter, for
example: ATE1Q0S0=1S3=13V1X4;+IFC=0,0;+IPR=115200;&W.
The Command line buffer can accept a maximum of 556 characters (counted from the first
command without “AT” or “at” prefix). If the characters entered exceeded this number then none
of the Command will executed and TA will return "ERROR".
1.4.5 Entering successive AT commands on separate lines
When you need to enter a series of AT commands on separate lines, please Note that you need to
wait the final response (for example OK, CME error, CMS error) of last AT Command you
entered before you enter the next AT Command.
1.5 Supported character sets
The SIM800 Series AT Command interface defaults to the IRA character set. The SIM800 Series
supports the following character sets:
GSM format
UCS2
HEX
IRA
PCCP
PCDN
8859-1
The character set can be set and interrogated using the "AT+CSCS" Command (3GPP TS
27.007). The character set is defined in GSM specification 3GPP TS 27.005.
The character set affects transmission and reception of SMS and SMS Cell Broadcast messages,
the entry and display of phone book entries text field and SIM Application Toolkit alpha strings.
1.6 Flow control
Flow control is very important for correct communication between the GSM engine and DTE.
For in the case such as a data or fax call, the sending device is transferring data faster than the
receiving side is ready to accept. When the receiving buffer reaches its capacity, the receiving
device should be capable to cause the sending device to pause until it catches up.
There are basically two approaches to achieve data flow control: software flow control and
hardware flow control. SIM800 Series support both two kinds of flow control.
In Multiplex mode, it is recommended to use the hardware flow control.
1.6.1 Software flow control (XON/XOFF flow control)
Software flow control sends different characters to stop (XOFF, decimal 19) and resume (XON,
decimal 17) data flow. It is quite useful in some applications that only use three wires on the