4.1 LOCAL OFFLINE COMMAND MODE
When first powered up, the Model 3022 automatically performs a
self-test, configures itself, and enters
Local Offline Command Mode. In
this mode, AT[ commands may be entered to configure the local Model
3022. These commands can be entered through sub-channel 1 or 2 on
a “first come, first served” basis.
The Model 3022 will remain in local offline command mode for 2
minutes (or whatever timeout the user has selected). If the user does
not enter a command within this time period, the local Model 3022 will
connect with the remote Model 3022 and automatically enter Online
Data Mode.
4.2 ONLINE DATA MODE
In
Online Data Mode, sub-channels 1 and 2 are merged together
into one data stream. This single data stream is transmitted through
the modems, and separated back into data channels 1 and 2 at the
remote end. The entire communication process is based upon the
parameters that were set in the command modes.
4.3 PASSTHRU MODE
In
PassThru Mode, the multiplexing function of the local Model
3022 is disabled so that the local modem may be configured or dialed
without disconnecting the Model 3022.
4.4 LOCAL ONLINE COMMAND MODE
In
Local Online Command Mode, the local Model 3022 can listen
to a command while remaining connected to the remote end. This
allows the user to 1) hangup/disconnect the local connection, or 2) go
into Remote Online Command Mode to send commands to the remote
Model 3022.
4.5 REMOTE ONLINE COMMAND MODE
In
Remote Online Command Mode, AT@ commands may be
entered to configure the remote Model 3022. These commands can be
entered through sub-channel 1 or 2 of the local Model 3022 on a “first
come, first served” basis.
5.0 COMMAND ENTRY
Before attempting to configure or operate the Model 3022, it is
important to know how the unit handles command entry. This section
provides rules for command entry, describes result codes, and gives a
complete description of each valid AT command.
5.1 RULES FOR "AT” COMMAND ENTRY
Rule #1. Since the Model 3022 only accepts ASCII characters,
all command lines must start with the attention code "AT" Local
commands follow a [-directive, and are stored in the local command
buffer. Remote commands follow an @-directive, and are stored in the
remote command buffer. The remote commands can only be serviced
when both Model 3022s are synchronized (in Online Data Mode) and
the local Model 3022 is in Online Command Mode (i.e. after /// is
detected). Before a command or string of commands is executed, the
<ENTER> or <CR> must be pressed.
Rule #2. The user may string commands together in one
command line, and separate commands with spaces. However, the
AT[-directive or the AT@-directive may be followed by only
30
characters and spaces. If a command line exceeds 30 characters, the
Model 3022 aborts execution of the command line and will display an
error reply code. This will occur before you press <ENTER/CR>.
Example:
AT[
30 character Model 3022 command <ENTER/CR>
Rule #3. Each command line must end with an <ENTER/CR>.
The Model 3022 will not begin command execution until it receives a
carriage-return character.
Rule #4. If you made an error while keying a command, you can
edit your entry before you press <ENTER/CR>. Pressing
<BACKSPACE> once deletes the last character entered. Pressing
<BACKSPACE> repeatedly deletes the entire command line, except the
AT command at the beginning of the line. Note: Not all modems
support the backspace edit function.
Rule #5. Many commands require a numeric parameter. If you
omit this parameter, it will automatically be set at zero.
Rule #6. To store a new configuration in the Model 3022’s non-
volatile memory, the user must key an AT[W or AT@W command.
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