Multitech MT5600ZDX Benutzerhandbuch

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Make sure the modem is plugged in and turned on. (See “None of the LEDs Light
When the Modem Is On.”)

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Make sure you are issuing the modem commands from the data communications

software, either manually in terminal mode or automatically once you have

configured the software. (You cannot send commands to the modem from the DOS
prompt.)

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Make sure you are in terminal mode in your data communications program, then

type AT and press ENTER. If you get an OK response, your connections are good

and the problem likely is in your phonebook entry or session settings. Be sure your

modem is not in data mode when you type a command.  Use the escape character

sequence to switch to terminal mode.  The default escape sequence must wait

at least one second, enter +++, and pause another second or more before

entering a command.

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The E0 and Q1 commands may be in effect, disabling echo and responses.  Verify
this with the &V command.  To enable echo and responses, enter ATE1Q0<cr>.

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Try resetting your modem by turning it off and on. Make sure there is a reset

command (&F) in your initialization string, or your modem may not initialize
correctly.

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If you don’t get an OK, the problem may still be in the communications software.

Make sure you have done whatever is necessary in your software to make a port

connection. Not all communications programs connect to the COM port automat-

ically. Some connect when the software loads and remain connected until the

program terminates. Others can disconnect without exiting the program.  Many

communications software packages also allow multiple terminals to be open, but only

one can access the modem at a time. If your package reports that it cannot make a

connection, yet the modem’s TR indicator is on, click on the Window menu to see if

more than one terminal is open. The modem’s TR indicator shows that the software

has made a connection with the modem through the COM port.

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Your communications software settings may not match the physical port the modem

is connected to. The serial cable may be plugged into the wrong connector—check

your computer documentation to make sure. Or, you may have selected a COM port

in your software other than the one the modem is physically connected to—compare
the settings in your software to the physical connection.

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If the modem is on, the cable is plugged into the correct port, the communications

software is configured correctly, and you still don’t get an OK, the fault may be in the

serial cable. Make sure it is firmly connected at both ends.

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Is this the first time you have used the cable? If so, it may not be correct. Check

the cable description on the packaging to make sure the cable is the right one for
your computer.

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Peripheral expansion cards, such as bus mouse and sound cards, may include a

serial port preconfigured as COM1 or COM2. The extra serial port, or the card