AT&T 7400B Plus User Manual page 35

DEFINITY Communications System
7400B Plus Data Module
User´s Guide
Command Buffer
Command Line Set Up
Command
Acknowledgement
As you type in a command, each character is saved in a 40-
character buffer. The AT prefix, spaces, and the (
end of the command line are not saved and do not add to the
character count. If you try to type more than 40 countable
characters on one line, the result code ERROR will be displayed on
your terminal screen, and the command line will be ignored.
A command line begins with the AT prefix, includes one or more
commands, and finishes with a line termination character, usually
issued by pressing the (
termination character is an ASCII carriage return.
If you make an error while typing a command line, you can send
the backspace character, usually issued by pressing the
( ) key, as often as needed to delete the error. However,
Backspace
as soon as you enter the AT prefix, the 7400B Plus immediately
reads it and sets up for a command to follow. Hence, you cannot
delete the AT prefix once it is typed. The factory-default
backspace character is an ASCII backspace.
Once you complete a command line by pressing (
7400B Plus will try to interpret all characters on the command line
as valid commands. If the 7400B Plus finds a character that is not
a valid command, it will ignore the erroneous character and any
remaining characters on the command line.
Commands are acted upon immediately and are acknowledged by
a result code. Most commands are acknowledged by OK. This
assumes that the result codes are configured in the verbose form
(command V1 is in effect), and are enabled (Q0 in effect).
Another option for configuring result codes is the short or
numeric form. These result codes are set by the V0 command
which would produce a 0 (zero) instead of the message OK. A
final option for result codes is to configure them for visible
acknowledgement (Q1). Refer to Appendix A, "AT Command Set"
for descriptions of the V and Q commands.
CHAPTER 3: CONFIGURATION AND OPERATION
) key. The factory-default line
Enter
Page 3-3
) at the
Enter
) , the
Enter