Note: Before you begin, please ensure your SIM is successfully activated in the Hologram Dashboard.
For an introduction to AT commands, click here. 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 |
OK |
ATI |
Module Number Checks the device type. |
SARA-U201-03B-00 |
AT+CGMI |
Manufacturer Specific Identity Checks the manufacturer. |
u-blox |
AT+CGMM |
Manufacturer Specific Model Identity Returns the manufacturer model identity. |
SARA-U201 |
AT+GMM |
Manufacturer Specific Model Identity Returns the manufacturer model identity. |
SARA-U201 |
AT+CPIN? |
Check the SIM PIN Note that Hologram SIMs do not require a SIM PIN. |
+CPIN: READY |
AT+CCID |
Check the SIM ICCID 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. |
+CRSM: 144,0,"FFFFFFFFFFFFFFFFFFFFFFFF" |
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","0.0.0.0",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. |
+CGACT:1,1 |
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. |
+COPS:(1,"AT&T","AT&T","310410",2) |
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.