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ISDN TA/V
Before your ISDN TA/V can effect a communications link you have to issue a
number of instructions to it to tell it what number, when, and how to dial or
answer a call. You may also want to instruct the ISDN TA/V to perform a test
of one or another part of the circuit.
If you need to alter the ISDN TA/V’s configuration from its default settings so
that its operating characteristics are compatible with the remote ISDN TA/V,
the line, and the connection to your computer, these changes will also have to
be made by sending one or more instructions to the ISDN TA/V.
The command language used to communicate with the ISDN TA/V is
compatible with the industry-standard AT command set, and in this chapter
we outline the different ways in which you can issue commands to the ISDN
TA/V, explain the rules that apply to the AT language, and show you how
they are applied.
11.1 Via Communication Software Command
In Part I of this manual, Getting Started, we explained how to command
(drive) your ISDN TA/V using a resident communications-software program
in the computer which is connected to the DTE interface. What you were in
effect doing was sending a limited range of AT commands to your ISDN
TA/V, which had a direct effect on its operation.
Remember how, when configuring the communications software, you were
asked to identify the ISDN TA/V command language and you specified it to
be AT compatible. By doing this you were in fact instructing the software to
build an AT command string for you each time an option was selected from
a menu. For example, when you selected the menu option
DIAL
the communications software would have constructed the command string
ATD (plus the specified ISDN number) for you, and sent it to the ISDN
TA/V.
Under normal operating conditions, and providing that the DTE interface is
configured to accept asynchronous commands, this method of ISDN TA/V
control will prove to be adequate. However, using the communications
software to build command strings for you does limit the number of features
to which you have access. When you need to access additional features and
facilities you will have to force the communications software into terminal
mode (usually done by selecting
TERMINAL
11. Commanding the ISDN TA/V
