Specifications

Chapter 11 – GPRS Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 211
11.21 ATS0 Automatic Response to a Network Request for
PDP Context Activation
Description: The V.250 ATS0=<n> (Automatic answer) command may be used to turn off (n=0) and on (n>0)
the automatic response to a network request for a PDP context activation.
When the ATS0=<n> (<n> > 0) command is received, the MT will attempt to perform a GPRS
attach if not yet attached and if configured to do so (see AT^SCFG, parameter <gs0aa>). Failure
will result in ERROR being returned to the TE. Subsequently, the MT will announce a network
request for PDP context activation by issuing the URC RING or CRING to the TE, followed by the
intermediate result code CONNECT. The MT then enters V.250 online data state and follows the
same procedure as it would after having received a AT+CGANS=1 command with no <L2P> or
<cid> values specified.
ATS0=0 does not perform an automatic GPRS detach.
Syntax: Read Command: ATS0?
Response: <n>
OK
Write Command: ATS0=<n>
Response: OK
Parameter:
<n> This parameter can be stored with AT&W and can be displayed with AT&V.
000 Disables automatic answer mode. Default. (This is the factory default value and can be restored
to '000' with AT&F).
001-255 Enables automatic answering after specified number of rings.
Notes:
• If different settings are used on each interface, and a request for PDP context activation is received, the interface
‘wins’ which is idle and uses the smallest ATS0 value.
• When a network request for PDP context activation is answered automatically and another AT command is
issued at the same time on the same interface then this AT command will not be executed. Any response relates
to the automatic context activation procedure. If the AT command which caused the collision was a CS data call,
the CONNECT response does not pertain to this data call but to GPRS. This can be detected if ATX is not set to
0. The CS data call will issue CONNECT <text>; GPRS will issue CONNECT only.
• A network request for PDP context activation has a maximum duration of approximately 40 seconds (for details
see GSM 04.08). A RING/CRING URC is issued every 5 seconds, so setting parameter <n> to values greater
than 7 will not allow a successful context activation and is not recommended.
• Automatic GPRS attach will not be performed on recalling a stored user profile with ATZ or on power up, even
though a value <n> greater than 0 was stored in the user profile with AT&W.
• If the automatic GPRS attach fails (e.g., the network rejects the attach request), the write command returns error,
though the new value takes effect. This is necessary because ATS0 is used for circuit switched calls too.
• If AT^SCFG="GPRS/ATS0/withAttach","on" is selected, but the automatic GPRS attach attempt fails (e.g., the
network rejects the attach request), the ATS0 write command ends up with "ERROR" or "+CME ERROR:
unknown" after approx. 5 minutes, though the new <n> value takes effect. This is necessary because ATS0 is
used for circuit switched calls too.
• The ATS0 write command is PIN protected. Usage of the PIN is dependent on conditions specified for the
command. Not all command types are PIN protected (for example a write command can be PIN protected while
the read command is not).
Note: The table provided in Section 19.3, Available AT Commands and Dependency on SIM PIN uses the same
symbols.
• This command is not supported in airplane mode.