Westermo TD-32 - Manual (Page 14)

14 6178-2203
DTE Command Lines
In order to send commands to the modem, a prefix must be entered before the actual command(s).
This prefix is the ASCII string ‘AT’, which is an abbreviation for attention.
Commands may be entered in either upper or lowercase characters. The only exception is the prefix
‘AT’; both characters in this string must be of the same case.
Several commands may be entered on the same command line with or without space in between.
The command lines shall always be terminated by a carriage return (with the exception of the
‘A/’command).
The command consists of a single letter or a letter with the characters %, &, \, ( or * in front.
At Swedish terminals which lack \ in the character set Ö is used instead. After each command there
might be a parameter, most often a numerical value. Most parameter values are written to a memory
in the modem, an S-register. Different registers are effected depending on which command has been
used.
Commands and appurtenant parameters are sent to the modem through the serial port on the modem.
This must be connected to a terminal, a computer with a communication software or other equipment
which is able to send asynchronous, serial information. Each time ”AT” is sent to the modem it will
analyse which speed and parity is being used and will then switch to the serial port. In this modem it
is also possible to use DIP-Switches to set the most common parameters and also set the modem so
that it will not react on commands coming through the serial port.
In the description of commands it is written ”Default” within brackets after some commands, this
means that the command has this value when reset to the factory parameters (AT&F).
When communication is established with another modem it is still possible to reach the command
mode by sending an ”escape” sequence to the modem. This sequence consists of an interruption in
communication, after which three characters is sent, most often plus (+++) and after which it is silent
again. The silent periods are there to prevent that a text, containing this sequence, when sent will
interrupt the connection. The silence is usually 1 second, but can be changed in register S12.
Also the character can be changed, in register S2.