Specifications

SIM900 AT Commands Set
SIM900_ATC_V1.01 59 23.06.2010
Parameter
<n> 0 Releases all held calls or sets User Determined User
Busy (UDUB) for a waiting call
1 Releases all active calls (if any exist) and accepts the
other (held or waiting) call.
1x Releases a specific active call x
2 Place all active calls on hold (if any) and accept the
other (held or waiting) call.
2x Places all active calls on hold except call X with
which
communication shall be supported.
3 Adds a held call to the conversation.
4 Connects the two calls and disconnects the subscriber
from both calls(ECT)
6 Swap operation(retrieves the held call and holds the
active call). Not applicable for calls engaged in a
multiparty operation(+CME ERROR returned)
6x Retrieves the specified held call x. Not applicable for
calls engaged in a multiparty operation (+CME
ERROR returned)
7x Holds the specified active call x. Not applicable for
calls engaged in a multiparty operation (+CME
ERROR returned)
8x Releases the specified call x (whatever its state).
9x Aborts MO speech call x setup without releasing other
calls. Possible if OK result code is sent before call is
connected: allowed if *PSCSSC mode = enabled and
+COLP = disabled.
Reference Note
3.2.15 AT+CIMI Request International Mobile Subscriber Identity
AT+CIMI Request International Mobile Subscriber Identity
Test Command
AT+CIMI=?
Response
OK
Parameter
Execution
Command
AT+CIMI
Response
TA returns <IMSI>for identifying the individual SIM which is attached to
ME.
<IMSI>