NTC-6000 Series V.250 Manual
Page 5 of 32
To suit software version 1.1.0
7/21/2010
Command and configuration reference
Overview
V.250 (AT) commands, issued from your application are used to control and configure the
NTC.
The NTC provides compatibility with legacy applications through compatibility with the
standard V.250 AT command set, these commands can be used to control the basic
functionality of the terminal.
In addition the NTC extends the V.250 command set to include a set of commands that can
be used to configure and operate the NTC‟s unique features without interfering with
operation of the basic V.250 interface.
Operating states
In this manual reference is made to
command state
,
online command state
and
online
data state
, these states are defined as follows: -
command state
:
In Command State, the terminal is not communicating with a remote station, and ready to
accept V.250 commands.
Data from the local DTE are treated as command lines and processed by the terminal and
responses are sent to the local DTE.
The terminal enters this state upon power-up, and when a call is disconnected.
online command state
:
In Online Command State, the terminal is communicating with a remote station, but treats
data from the local DTE as command lines and sends responses to the local DTE.
Data received from the remote station during Online Command State is buffered in the
terminal until Online Data State is once again entered (by a command from the DTE).
Data previously transmitted by the local DTE and buffered by the terminal will be
transmitted from the buffer to the remote station during Online Command State.
Online Command State may be entered from Online Data state through the use of the „+++‟
escape sequence or via change of DTR state as configured by the
&D
command.
online data state
:
In Online Data State, the terminal is communicating with a remote station.
Data signals from the DTE are treated as data and transmitted to the remote station,
and data received from the remote station are delivered to the DTE.
Data and control signals are monitored by the terminal to detect events such as loss of the
remote connection and DTE requests for disconnection or switching to Online Command
state.
Online Data State is entered by successful completion of a command to originate or answer
a call, by automatically answering a call, by a DTE command to return to Online Data state
from Online Command state or in response to the DTR signal as configured by the
&D
command.