Chapter 4 - Troubleshooting And Frequently Asked Questions; Troubleshooting Examples - Multitech MTCBA-G-U-F1 User Manual

Chapter 4 – Troubleshooting and
Frequently Asked Questions

Troubleshooting Examples

Before calling the Multi-Tech Technical Support, check to the following connections:
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 ...
modem
returns ...
(nothing) Is the communication program
properly configured?
Is another program interfering
with the communication
program?
Is the modem set to
autoanswer?
Is the communication program
receiving RING responses?
Situation B: The modem always returns «No carrier» when trying to originate a call
Solutions for "no carrier" message
If the modem Then ask ...
returns ...
no carrier
(esp. for data
communication)
no carrier
(esp. for voice
communication)
Multi-Tech Systems, Inc. MultiModem GPRS USB Wireless Modem User Guide
Is the selected bearer type
supported by the called
party?
Is the selected bearer type
supported by the network?
Chapter 4 – Troubleshooting and Frequently Asked Questions
Action
In communications program, verify that modem
parameters have been set to the values shown here:
Data bits = 8
Parity = none
Stop Bits = 1
Baud = 115200 bps
Close any such application program.
Type ATS0=1 (to set to auto answer on the first ring)
Type ATA (to set to manual answer)
Type ATS0=1 (to set to auto answer on the first ring)
Type ATA (to set to manual answer)
Action
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.
Be sure that the semicolon character (";") is typed
immediately after the phone number in the AT command;
e.g., ATD######;
44