Chapter 4 – Troubleshooting and Frequently Asked Questions
Multi-Tech Systems, Inc. MultiModem GPRS Wireless Modem User Guide
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Situation B: The modem always returns «No carrier» when trying to originate a
call
Solutions for “no carrier” message
If the modem
returns …
Then ask …
Action
no carrier
(esp. for data
communication)
Is the selected bearer
type supported by the
called party?
Is the selected bearer
type supported by the
network?
Type AT+CEER to view the extended error code (see
“Error Results Codes" in the AT Command guide).
Be sure that the selected bearer type is supported by
the called party.
Be sure that the selected bearer type is supported by
the network.
If no success, try bearer selection type: AT+CBST=0,0,3
Be sure SIM card is available for data/fax calls.
no carrier
(esp. for voice
communication
)
Be sure that the semicolon character (“;”) is typed
immediately after the phone number in the AT
command; e.g., ATD######;
Frequently Asked Questions
Which providers can I use?
●
Two major providers are T-Mobile and AT&T.
Does this modem support High-Speed Circuit-Switched Data (HSCSD)?
●
No, our GSM/GPRS modems do not support HSCSD.
The modem is answering, but seems to not be doing anything?
●
The modem is answering in voice mode.
●
If you are trying to make a data call, make sure the account has CSD service. You also need the data number
(separate number from the main phone number that is provided by the provider).
I am trying to make a data connection by dialing from my wireless modem to an analog modem. Why does the analog
modem answer and send tones, but never connect?
●
To make a data call you must use the ATD<number> command.
●
Make sure the account has CSD service.
How do I get the voice portion to work so I can talk to others using the wireless modem?
●
You need a cable that has the speaker pins connected to a speaker and microphone.
●
We have a “Y” cable that splits out to a RJ9 connector that can be used to plug into the receiver of a handset.
●
‘ATD<number>;’ will originate a voice call.
