Chapter 4 – Safety
Situation C: The modem always returns «No carrier» when trying to issue a communication
Solutions for “no carrier” message
If the modem returns … | Then ask … | Action |
no carrier | Is the selected | Type AT+CEER to view the extended |
(esp. for data communication) | bearer type | error code (see “Error Results Codes" |
| supported by the | in the AT Command guide). |
| called party? | Be sure that the selected bearer type |
|
| is supported by the called party. |
| Is the selected | Be sure that the selected bearer type |
| bearer type | is supported by the network. |
| supported by the | If no success, try bearer selection |
| network? | type: AT+CBST=0,0,3 |
|
| Be sure SIM card is available for |
|
| data/fax calls. |
no carrier |
| Be sure that the semicolon character |
(esp. for voice communication) |
| (“;”) is typed immediately after the |
|
| phone number in the AT command. |
|
| E.g., ATD######; type |
|
| AT+CBST=0,0,3 |
|
| Configure the SIM card for data/fax |
|
| calls. |
| Is the received | See “Signal Strength Verification.” |
| signal strong |
|
| enough? |
|
| Is the antenna | See “Antenna/RF Specifications.” |
| properly |
|
| connected? |
|
23 |
