CREG – request network registration status

Verifies the current network registration status of the Cinterion® ELS61 Wireless Module. First set the Mode to determine which information is displayed, and if it's displayed automatically when a change occurs.

Type Syntax Returned Result
Test

AT+CREG=?

+CREG: (0-2)

 

OK
Read

AT+CREG?

Perform the Write command first so that you can set the returned details of the Read command.

The response depends on which mode you selected in the write command.

The initial number returned is the mode.

If the mode = 0, the following response occurs:

+CREG: 0,<regStatus>

 

OK

If the mode = 1, the following response occurs:

+CREG: 1,<regStatus>

 

OK

If the mode = 2, the following response occurs:

+CREG: 2,<regStatus>[,<netLac>,<netCellID>[,<AcT>]]

where:

  • <regStatus> is the registration status, either:

    • 0 – Not registered, the device is currently not searching for new operator.
    • 1 – Registered to home network.
    • 2 – Not registered, but the device is currently searching for a new operator.
    • 3 – Registration denied.
    • 4 – Unknown. For example, out of range.
    • 5 – Registered, roaming. The device is registered on a foreign (national or international) network.
  • <netLac> is a two byte location area code in hexadecimal format
  • <netCellID> is the Cell ID in hexadecimal format, either:
    • 16 bit for 2G
    • 28 bit for 3G or 4G
  • <AcT> is radio access technology, either:
    • 0 – GSM
    • 2 – UTRAN
    • 3 – GSM w/EGPRS
    • 4 – UTRAN w/HSDPA
    • 5 – UTRAN w/HSUPA
    • 6 – UTRAN w/HSDPA and w/HSUPA
    • 7 – E-UTRAN

or

ERROR – the command failed.

Write

AT+CREG=<Mode>

where <Mode> is either:

  • 0 – Disable network registration unsolicited result code. You will need to manually check the network registration status.

  • 1 – Enable network registration unsolicited result code. If there is a change in network registration status, the modem will automatically return a response.

  • 2 – Enable network registration and location information unsolicited result code. If there is a change in network registration status or at least one of the additional network information elements, the modem will automatically return a response.

OK - the network registration status mode is successfully set

ERROR - the command failed

Factors contributing to SIM failure to register on the network may include:

  • Missing network coverage
  • Denied network access
  • No valid roaming agreement between the home network and currently available operators

Example

AT+CREG=2

OK

AT+CREG?

+CREG: 2,5,"54DB","0F6B0578",7

OK

Where to next?

Related resources