Siemens AC75 User Manual
Page 316
AC75 AT Command Set
11.5 AT+CGDATA
s
AC75_ATC_V01.002
Page 316 of 569
10/30/06
Confidential / Released
Notes
• If the MT is in dedicated mode, write command returns "+CME ERROR: operation temporary not allowed".
• It is possible to leave the GPRS data mode and enter the command mode by using the V.250 command
By using the command
again, the data mode is reentered. Which context is used to return to
data mode, depends on the supplied parameter
.
is specified, this is equivalent to using the V.250 command
, which is usable for GPRS con-
nections too. In this case the first context will be used, which is active and already in data mode since it has
been activated.
It is possible to use
to enter the data mode for a context, which is not yet in data mode since it
this is not possible.
11.5.1
Automatic deactivation of PDP context during dial-up PPP
When using the AT+CGDATA write command or
the MT issues the intermediate result
code CONNECT and enters V.250ter online data state. In V.250 online data state, first some LCP protocol
exchange between MT and TE is performed to set up the PPP link. After successfully establishing the PPP link,
the MT performs the PDP context activation procedure if the context is not already activated. As a result, the MT
is in a "PDP context activated" state within the PLMN, the PPP link is established on the mobile side and the
mobile is ready for IP data transfer.
If the TE wants to close the LCP link the MT may perform an LCP termination request procedure on PPP level.
After this LCP termination procedure the MT deactivates the PDP context automatically and the MT returns to
V.250 command mode and issues the final result code NO CARRIER.
During the implicit PDP context deactivation procedure after LCP termination the TE may change into V.250
command state (e.g. by using
or by toggling DTR if
is set to 1) before the result NO CARRIER occurs.
In this case the application should not try to deactivate the PDP context by using the commands
or
. If DTR is configured to disconnect data connections (
2), then the application should not toggle DTR
during the implicit PDP context deactivation and before "NO CARRIER" is received.