Specifications

Chapter 7 – Call-Related Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 92
7.2 ATA Answer a Call
Description: TA causes remote station to go off-hook (e.g., answer call).
Syntax: Exec Command: ATA
Responses: In case of data call, if successfully connected (TA switches to data
mode):
CONNECT <text>
In case of voice call, if successfully connected:
OK
When TA returns to command mode after call release:
OK
If no connection:
NO CARRIER
Parameter:
<text>
Connection status
Output only if ATX parameter setting with value greater 0. Connection speed values:
300
1200
2400
4800
9600
14400
Notes:
• Any additional commands on the same command line are ignored.
• The command may be aborted generally by receiving a character during execution. It can’t be aborted in some
connection setup states, such as handshaking.
• The ATA command may be used also to accept a network request for a PDP context activation (see ATA).
• See also ATX for <text>.
• If an incoming call is no longer available (already disconnected/hang up), a “NO CARRIER” result code will be
given.
• This command is PIN protected.
• This command is not supported in airplane mode.
7.3 ATD Mobile Originated Call to a Specified Number
Description: This command can be used to set up outgoing voice or data calls. It also serves to control
Supplementary Services. The termination character “;” is mandatory to set up voice calls or to
send *# codes for Supplementary Services. It must not be used for data calls.
Additional notes on the responses returned after dialing with ATD:
• For voice calls, you have the choice of two different response modes that can be selected
with AT^SM20:
AT^SM20=1 (factory default) causes the ME to respond once the call setup is completed
either successfully ("OK") or unsuccessfully ("NO CARRIER", "NO DIAL TONE", "BUSY").
AT^SM20=0 causes the ME to return "OK" immediately after dialing was completed (i.e.
before call setup terminates successfully or unsuccessfully).
• For data connections, call setup always terminates when the call has been established
(indicated by the result code "CONNECT <text>"), or when it fails (indicated by "NO
CARRIER"). The settings of AT^SM20 do not apply.
Different call release indications:
• Upon termination, an outgoing data call may show a different result code than a voice call
would show under identical conditions. In order to track down the actual reason for call
termination, AT+CEER or ATS18 should be used for all applicable connections.
Using ATD during an active call:
• When a user originates a second voice call while there is already an active voice call, the
first call will automatically put on hold. The second call attempt is acknowledged with “OK”
immediately after dialing with ATD has completed, without relation to a successful call
setup. In case of failure, the additional result codes “NO CARRIER”, “NO DIAL TONE”,
“NO CARRIER” will be presented afterwards (see example below).