Chapter 4 – Troubleshooting and Frequently Asked Questions
Chapter 4 – Troubleshooting and
Frequently Asked Questions
Troubleshooting Examples
Before calling the
•The right antenna is connected to the modem
•The serial cable connection is correct
•The power is connected correctly and the power lights on the modem are on
•Verify your signal strength
•Verify your network registration
•Use the following situation examples to troubleshoot the modem not answering and the modem returning a No Carrier message.
Situation A: The modem does not answer
If the Wireless MultiModem does not answer through the serial link upon an attempted transmission of data or voice signals, see the table below for possible causes and solutions.
Solutions for ‘no connection through serial link’ situation
If the | Then ask … | Action |
modem |
|
|
returns … |
|
|
(nothing) | Is the communication program | In communications program, verify that modem |
| properly configured? | parameters have been set to the values shown here: |
|
| Data bits = 8 |
|
| Parity = none |
|
| Stop Bits = 1 |
|
| Baud = 115200 bps |
| Is another program interfering | Close any such application program. |
| with the communication |
|
| program? |
|
| Is the modem set to | Type ATS0=1 (to set to auto answer on the first ring) |
| autoanswer? | Type ATA (to set to manual answer) |
| Is the communication program | Type ATS0=1 (to set to auto answer on the first ring) |
| receiving RING responses? | Type ATA (to set to manual answer) |
Situation B: The modem always returns «No carrier» when trying to originate a call
Solutions for “no carrier” message
If the modem | Then ask … | Action |
returns … |
|
|
no carrier | Is the selected bearer type | Type AT+CEER to view the extended error code (see |
(esp. for data | supported by the called | “Error Results Codes" in the AT Command guide). |
communication) | party? | Be sure that the selected bearer type is supported by the |
|
| called party. |
| Is the selected bearer type | Be sure that the selected bearer type is supported by the |
| supported by the network? | 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 |
| Be sure that the semicolon character (“;”) is typed |
(esp. for voice |
| immediately after the phone number in the AT command; |
communication) |
| e.g., ATD######; |
29 |
