Specifications

SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 76 12/24/2010
Read Command
AT+CREG?
Response
TA returns the status of result code presentation and an integer <stat>
which shows whether the network has currently indicated the registration
of the ME. Location information elements <lac> and <ci> are returned
only when <n>=2 and ME is registered in the network.
+CREG: <n>,<stat>[,<lac>,<ci>]
OK
If error is related to ME functionality:
+CME ERROR: <err>
Response
TA controls the presentation of an unsolicited result code +CREG: <stat>
when <n>=1 and there is a change in the ME network registration status.
OK
Parameters
<n> 0 Disable network registration unsolicited result code
1 Enable network registration unsolicited result code
+CREG: <stat>
2 Enable network registration unsolicited result code with
location information +CREG: <stat>[,<lac>,<ci>]
<stat> 0 Not registered, MT is not currently searching a new
operator to register to
1 Registered, home network
2 Not registered, but MT is currently searching a new
operator to register to
3 Registration denied
4 Unknown
5 Registered, roaming
<lac> String type (string should be included in quotation marks);
two byte location area code in hexadecimal format
<ci> String type (string should be included in quotation marks);
two byte cell ID in hexadecimal format
Unsolicited Result Code
If <n>=1 and there is a change in the MT network registration status
+CREG: <stat>
If <n>=2 and there is a change in the MT network registration status or a
change of the network cell:
+CREG: <stat>[,<lac>,<ci>]
Write Command
AT+CREG=[<n>
]
Parameters
See Write Command
Reference
GSM 07.07 [13]
Note