Hayes V.92 User Manual page 34

Problem You type an AT command line in a terminal
:
application and press Enter, but your modem
fails to execute the command line. Or there was
no response after executing a command.
Solution
: Be sure you type AT at the beginning of the
command line.
Make sure the communications software is
configured for the same COM port as your modem.
Be sure your modem is not in data mode when you
type the command. Use the escape character
sequence to switch to terminal mode (The default
escape sequence is to wait at least one second,
type +++, and wait another second or more.)
If you typed a command but did not receive an OK
response from your modem, the E0 and Q1
commands may be in effect, disabling echo and
responses. Verify this with the &V command. To
enable echo and responses, type ATE1Q0 and
press Enter.
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