Some Notes About At Commands - SimpleTech STI-FAX/28.8 User Manual

Some Notes About AT Commands

• Some AT commands override other AT commands. For
example, issuing AT &K3 &K4 <Enter> will not enable
both hardware flow control (&K3) and software flow
control (&K4), it will only enable software flow control.
The latter command overrides the former.
• If you do not specify a number on commands that end in a
number, the modem will take the number to be 0. So, for
example, AT B and AT B0 achieve the same effect: setting
communications to the CCITT standard. This feature can
be useful if you wish to save space when issuing com-
mands.
• If your modem is on-line and you want to issue an AT
command string to your modem without disrupting your
connection, you can bring your modem into command
mode by typing a special escape sequence. To issue the
escape sequence you must first not transmit any data for a
period equal to the guard time, which by default is one
second. Then type +++ quickly. Do NOT press <Enter>.
Instead, wait for another second. The modem will respond
to this step with an OK message. Now your modem is
ready to accept AT command strings. When you want to
resume your on-line connection, type ATO <Enter>.
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