User's Manual

56 MDS TransNET I&O Guide MDS 05-2708A01, Rev. D
connections where wire lines were the only communications link available at
the time. Most of these older system implemented support for the AT
commands needed in the host software, so TransNET units can be used
without software modifications.
In this mode, the Master’s DATA port is parsed for a subset of AT commands.
(See Supported Commands below). When an ATDTxxxxx data sequence is
detected, and xxxxx is a unit address of a radio in the network, the TransNET
Master will establish a virtual link to that unit. It will remain in that state until
either another ATDTxxxxx or ATH (hang-up/disconnect) is detected. (Note:
Unaddressed Remotes in the network will not respond to user data. Data will
only be exchanged between the equipment connected to the addressed
Remote unit and the network or device connected to the Master’s DATA port.
In order to use this mode, the command AT ON must be selected at the Master
Radio. The acknowledgment to an ATDT command is simulated by the
Master; there is no true verification that the far-end connection is valid.
Please consider the following additional information before using the AT
commands:
• Radio commands and AT commands are independent with unique
syntax and functional objectives.
• ATDT is not a radio command; it is part of the payload data input and
follows the syntax for Hayes-compatible modems.
• TransNET commands are entered through the RJ11 DIAGNOSTIC port
on Master and Remote radios. AT ON and UNIT are examples of
TransNET commands.
• AT commands are only entered through the Master’s DB-9 DATA port,
and only when the TransNET command AT ON has been previously
issued. The radio supports a subset of the Hayes-compatible modem AT
set. Each command is entered without spaces, and always begins with
AT, and ends with a carriage return key press.
Supported AT Commands
Supported modem commands on the payload port are:
AT <attention>
Replies with OK (Code 0).
ATDT[xxxxx] <dial>
The command xxxxx represents 5-digit unit address with a leading zero (0)
if applicable. This command replies with CONNECT (Code 1). Once
connected, all characters are passed through until a
+++ is seen.
ATH <hang up> or +++
This command replies with OK (Code 0) and deletes any virtual connection
to the currently addressed Remote station.
ATV[x] <change verbosity>
x = 0
, means use numeric messages
x = 1 , means use text messages (Default)
Replies with OK (Code 0)