Chapter 3 – Troubleshooting
The modem will not answer.
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To have modem auto-answer, set modem with ‘ATS0=1’. Use ‘AT&W’ to store the setting.
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Send ‘ATA’ to the modem once the RING is indicated on the terminal screen.
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If you aren’t providing DTR, you may need to set the modem to ignore DTR by using this command:
‘AT&D0’ .
Which providers can I use?
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T-Mobile, AT&T, and Cingular
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AT&T doesn’t support CSD (wireless to analog connection)
I am trying to make a GPRS connection using a Windows dial-up session. It connects and then
immediately disconnects. What’s wrong?
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Make sure the APN is stored in the modem (the APN is given by the provider).
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Check the APN with ‘AT+CGDCONT?’ to make sure it is correct.
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If no APN is inserted, then insert the correct APN: ‘AT+CGDCONT=1,”IP”,”<APN>”’.
When I try to make a GPRS connection using Windows dial-up I get this error: “Hardware Failure”.
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Check the modem to make sure it is installed. Check the Modem Properties screen to be sure the
modem can be queried.
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Make sure the modem is not being held by another application. Look for the TR light indication. If it is
on, most likely another application is holding onto the port.
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Try rebooting the system.
What is the maximum number of characters I can use to send a SMS message?
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The modem supports up to 160 characters max.
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In PDU mode using 7-bit, the modem still supports 160 characters. But in 8-bit mode the modem will
only support 70 characters.
Multi-Tech Systems, Inc. MultiModem
®
GPRS with USB User Guide
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