Escape Sequences - Multitech CommPlete MT3334HD8 User Manual

Escape Sequences

Escape sequences are also known as escape codes. They are used to cause the modem to enter command
mode from online mode without disconnecting the call. There are two local escape sequences used by the
modem, +++AT<CR> and <BREAK>AT<CR>, and one remote escape sequence, %%%AT<CR> (see
"Remote Configuration.").
+++AT<CR> In-Band Escape Sequence
If the modem is online with a remote modem, you can cause the modem to enter command mode, without
disconnecting the call, by typing an escape code. The default escape code used by the modem is three plus
signs ( +++) followed by the letters AT , up to 10 command characters (most typically H , to hang up), and
E
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command mode. For example, to hang up the modem at the end of a call, type +++ATH <CR>.
<BREAK>AT<CR> Out-of-Band Escape Sequence
The MT3334HD8 provides an alternate escape method that uses a break signal as the escape code. The
break signal— ten or more zero bits issued by data communications software—allows the DTE to signal
the modem without the risk of the modem interpreting data characters as modem control characters. The
break signal is followed by the letters AT , up to 60 command characters, and E
used, the modem executes the command and immediately returns to online mode, unless the command is
to hang up and/or reset the modem (an H or Z command). In the latter case, the modem escapes to
command mode after executing the H or Z command.
%En Escape Sequence Options
n = 0–5
Defaults: %E1 and %E4
The default setting is for the modem to respond to the +++ escape method. Optional settings are for the
modem to respond to the <BREAK> method, for the modem to respond to either the +++ or the
<BREAK> methods, and for the modem to ignore both methods and not escape. The %E command is
used to select these options as follows:
%E0
%E1
%E2
%E3
%E4
%E5
%E1 %E5
%E3 %E5
A Force Answer Mode
You can use the A command to force the modem into answer mode. Type ATA when in command mode
to immediately bring your modem off-hook, out of command mode, and into online answer mode, and to
cause it to transmit its carrier signal over the phone line. If no responding carrier tone is received by your
modem within forty-five seconds (or by the time you have specified in register S7), your modem stops
transmitting its tone, hangs up, and goes back into command mode.
CommPlete Communications Server
. The modem then escapes to command mode, executes the command (if any), and remains in
Modem won't escape
+++ AT<CR> escape method (factory default).
<BREAK> escape method.
Either +++ or <BREAK> escape methods.
Disables OK response to +++ (factory default).
Enables OK response to +++.
Enables +++ method and OK responses to +++.
Enables +++ or <BREAK> method and OK responses to +++.
3 AT Commands
. When this sequence is
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