Specifications

SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 20 12/24/2010
after dialing was completed, otherwise TA will returns "OK",
"BUSY", "NO DIAL TONE", "NO CARRIER".
Using ATD during an active voice call:
z When a user originates a second voice call while there is already an
active voice call, the first call will be automatically put on hold.
z The current states of all calls can be easily checked at any time by
using the AT+CLCC Command.
2.2.4 ATD><n> Originate Call to Phone Number in Current Memory
ATD><n> Originate Call to Phone Number in Current Memory
Execution
Command
ATD><n>[<clir>
][ <cug>][;]
Response
This Command can be used to dial a phone number from current phonebook
memory.
Note: This Command may be aborted generally by receiving an ATH
Command or a character during execution. The aborting is not possible
during some states of connection establishment such as handshaking.
If error is related to ME functionality
+CME ERROR: <err>
If no dial tone and (parameter setting ATX2 or ATX4)
NO DIALTONE
If busy and (parameter setting ATX3 or ATX4)
BUSY
If a connection cannot be established
NO CARRIER
If the remote station does not answer
NO ANSWER
If connection successful and non-voice call.
CONNECT<text> TA switches to data mode.
Note: <text> output only if ATX<value> parameter setting with the
<value> >0
When TA returns to Command mode after call release
OK
If successfully connected and voice call