Modem & SIM annotated diagnostic test

Note: Before you begin, please ensure your SIM is successfully activated in the Hologram Dashboard.

For instructions on sending AT commands to a device, click here. The instructions are written for Hologram Novas but use basic serial communication and standard AT commands so the same commands can be used on all modems. If you are unable to open a serial communication channel with your modem, contact your original equipment manufacturer for instructions on sending AT commands to your device.

Modem, module, and SIM diagnostic procedure

Using your favorite terminal program (Screen, Teraterm, Putty, GTKTerm, etc.), run the following commands and record their outputs.

Note: The last command below may take up to 5 minutes to complete.

Function Command Sample response
AT Attention
Determines if device can send commands
ATI Module Number
Checks the device type.
AT+CGMI Manufacturer Specific Identity
Checks the manufacturer.
AT+CGMM Manufacturer Specific Model Identity
Returns the manufacturer model identity.
AT+GMM Manufacturer Specific Model Identity
Returns the manufacturer model identity.
AT+CPIN? Check the SIM PIN
Note that Hologram SIMs do not require a SIM PIN.
ICCID is a unique identifier for a profile installed on a SIM.
+CCID: 1234567890123456789
AT+CRSM=176,28539,0,0,12 Read Data File 28539 in Binary Mode
Get forbidden or restricted network list. All F's indicate no networks forbidden.
AT+CFUN? Determine What Mode the Module Is In
Modules should be set to full functionality mode.
+CFUN: 1,0
AT+CSQ Signal Quality
Returns multiple values to indicate signal strength, use device command manual to decipher.
+CSQ: 22,4
AT+CREG? Network Registration Status
Check GSM and SMS network registration.
+CREG: 0,5
AT+CGREG? GPRS Network Registration Status
Check 3G network registration.
+CGREG: 0,5
AT+CEREG? EPS Network Registration Status
Checks 4G LTE network registration.
+CEREG: 2,5,"MI9S","25SS404",8
AT+CGDCONT? Read PDP Context Parameters (APN)
APN should be hologram. AT+CGDCONT=1,"IP","hologram" will set APN, but verify in your device's manual.
+CGDCONT: 1,"IP","hologram","",0,0
AT+CGACT? PDP Context Activation
Indicates which PDP context is being used and if that PDP context is active. The active context (1 in this example) should match the ext ID of the PDP context where the APN is set to hologram for connectivity.
AT+COPS? Operator Selection Status and Current Operator
Displays MCC and MNC of network the modem is connected to. The last number is the RAT (Radio Access technology): 0 for GSM, 2 or 3 for 2G/3G, 7 for LTE, 8 for Cat-M1, 9 for NB-IoT.
+COPS: 1,2,"310260",2
AT+COPS=? Networks In Reach
Network operators or network MCC and MNC are displayed for available networks and their associated region. If the module returns an error, please try again. This command can take up to 3 minutes to run.

Note: If you are not seeing the AT commands you are typing try sending the command ATE. If you prefer, you can run this script for the diagnostics to automatically execute.

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