CalAmp SMC-GPRS Series, User Manual

Page: 24 / 84

001-0004-829 Rev00
Page 24 of 84
Select ATV0 to set the short format (numeric code) or ATV1 to set the long format (verbose code)
of result codes. In case of using the command without parameter the value will be set to 0.
Generally, only
AT+CBST=0 (auto bauding) and AT+CBST = 7 (9600 bps, [V.110]) are supported
and provide reliable performance. All other settings can be tried, but depending on
the network problems may be encountered.
Once a data connection is established, the ME first enters the data mode (online mode). With the
escape se++ you can switch from data to command mode without dropping the line. The
command ATO returns from command to data mode.
The escape sequence must be preceded and followed by a pause of at least 1000 ms. The +++
characters must be entered in quick succession, all within 1000 ms.
To end a call, the caller or the called party may use the commands ATH or AT+CHUP. The response
to ATH and AT+CHUP is “OK” while the remote party is given “NO CARRIER”.
CSD Incoming Calls
Depending on the basic initialization, an incoming CSD call is indicated either by the URC “RING”
(if AT+CRC=0) or the extended URC format “+CRING: REL ASYNC” (if AT+CRC=1).
An incoming data call can be accepted by entering the command
ATA or by using the
autoanswer mode if enabled with ATS0≠000. Depending on the module's basic initialization,
connection setup is indicated by the result code "CONNECT" (if ATX0) or "CONNECT <text>" (if
ATX>0), where <text> gives the transmission speed, for example "CONNECT 9600/RLP". In
addiditon, the CONNECT result code may be preceded by the intermediate result code “+CR: REL
ASYNC” if the ME is initialized with AT+CR=1.
CSD Outgoing Calls
The commands used to dial out are ATD, ATDI and ATDL. Do not attach a semicolon “;” at the
end of the dial string. Dialing from the phonebooks is not supported for data connections.
When dialing a data call number, the following responses can be returned:
CONNECT (if ATX0) or CONNECT <text> (if ATX>0)
NO CARRIER
BUSY
NO DIALTONE
The response is given when the connection has been set up successfully ("CONNECT"), or when it
fails ("NO CARRIER", "BUSY", "NO DIALTONE").
If the module is initialized with AT+CR=1, the additional intermediate result “+CR: REL ASYNC”
appears before the CONNECT result code.
When the TA-TE link is reserved (data mode), any URCs, for example an incoming SMS, will be
indicated by a BREAK only. The URC itself will be transmitted as soon as the TA-TE link is free
again. This means, the URC will be output either when the user switches from data to command
mode with +++, or when the line is dropped.