Specifications
SIM900 AT Command Manual       
SIM900_AT Command Manual_V1.03  109  12/24/2010 
supported <bm>s),(list of supported <ds>s),(list of supported <bfr>s) 
OK 
Parameters 
See Write Command 
Response 
+CNMI: <mode>,<mt>,<bm>,<ds>,<bfr>  
OK 
Read Command 
AT+CNMI? 
Parameters 
See Write Command 
Response 
TA selects the procedure for how the receiving of new messages from the 
network is indicated to the TE when TE is active, e.g. DTR signal is ON. If 
TE is inactive (e.g. DTR signal is OFF), message receiving should be done 
as specified in GSM 03.38. 
OK 
ERROR 
Write Command 
AT+CNMI=<mo
de>[,<mt>[,<bm
>[,<ds>[,<bfr>]]]
] 
Parameters 
<mode>  0  Buffer unsolicited result codes in the TA. If TA result 
code buffer is full, indications can be buffered in some 
other place or the oldest indications may be discarded 
and replaced with the new received indications. 
  1  Discard indication and reject new received message 
unsolicited result codes when TA-TE link is reserved 
(e.g. in on-line data mode). Otherwise forward them 
directly to the TE. 
  2  Buffer unsolicited result codes in the TA when TA-TE 
link is reserved (e.g. in on-line data mode) and flush 
them to the TE after reservation. Otherwise forward 
them directly to the TE. 
  3  Forward unsolicited result codes directly to the TE. 
TA-TE link specific inband technique used to embed 
result codes and data when TA is in on-line data mode.
<mt>  (the rules for storing received SMs depend on its data coding 
scheme (refer GSM 03.38 [2]), preferred memory 
storage (+CPMS) setting and this value): 
  0  No SMS-DELIVER indications are routed to the TE. 
  1  If SMS-DELIVER is stored into ME/TA, indication of 
the memory location is routed to the TE using 
unsolicited result code: +CMTI: <mem>,<index> 
  2  SMS-DELIVERs (except class 2) are routed directly to 










