24
Model MT5600ZDXV
2.7.2 The Modem Does Not Respond to Commands
4
Make sure the modem is plugged in and turned on. (See “None of the LEDs
Light When the Modem Is On.”)
4
Make sure you are issuing the modem commands from the data commu-
nications 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.)
4
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.
4
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>.
4
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.
4
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 automatically. 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.
4
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.
4
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.
