Chapter 5 - Troubleshooting; No Response To At Commands; The Modem Does Not Execute The Command Line; The Modem Does Not Give A Response After An Executed At Command - Multitech MultiMobile MT5634ZLX/FE User Manual

Chapter 5 – Troubleshooting Chapter 5 – Troubleshooting
Chapter 5 – Troubleshooting Chapter 5 – Troubleshooting
This chapter provides general and specific problem solving steps. Below are a number of examples of
problems, probable causes, and solutions. If your MultiMobile PC Card is not working properly, look up
the problem and solution here. If you cannot solve the problem, Technical Support (see the Copyright
page – it's the page after the cover). There are some specific steps for resolving IRQ and COM port
conflicts listed at the end of this chapter.

No Response to AT Commands

Cause: The COMx port may be in use by another device in the computer.
Solution: Change the COMx port of MultiMobile PC Card to a different, unused port. It might be
best to set it to COM3 or COM4. Even if you are not using a serial port that is set to the same
COMx port as the modem, it can still interfere with the modem. Be sure to update your software
COMx port setting as well.
Cause: The
Interrupt
Solution: Change the IRQ settings to a different, unused, IRQ. Even if you are not using a serial
port that is set to the same IRQ as the modem, it can still interfere with the modem.

The Modem Does Not Execute the Command Line

Cause: Make sure you are typing
end).
Cause: Make sure the modem is not in Data Mode. Type +++ if necessary.
Cause: Make sure your software is set to the same COMx port as your MultiMobile PC Card.

The Modem Does Not Give a Response After an Executed AT Command

Cause: The echo and/or responses may be turned off by the ATE0Q1 commands.
Solution: Use ATE1Q0 then Enter to change them back.
Cause: Make sure the modem is in Command Mode and not Data Mode when you enter AT
commands.

The Modem Gives an 'ERROR' Response After an Executed AT Command

Cause: Make sure you did not type an invalid command.
Cause: Make sure your command line is 40 characters or less.

The Modem Goes Off-Hook and Disables the Telephone Line

Cause: The modem may be set to auto-answer the phone when it rings.
Solution: Disable auto-answer by typing ATS0=0 then Enter at the command line.

The Modem Does Not Auto-Answer the Phone

Cause: If necessary, make sure the software is configured to auto-answer the phone.
Solution: To set auto-answer mode on from AT command mode, type ATS0=n then press Enter.
The n stands for number of rings the modem answers. For example: ATS0=3 causes the modem
to answer on the third ring.
MT5634ZLX, MT5634ZLXI, MT5634ZLX/FE User Guide
the modem is using may be the same
at the beginning of the command line (and hit Enter at the
AT
Chapter 5 – Troubleshooting
used by another device.
Interrupt
26