Protocol Reference - Tandy DCM212 Operation Manual

Hayes
protocol reference
15
Programming
commands
AT
Attention code
Every
command
line starts
with the
attention code.
Always
enter
this
code
in
uppercase
letters.
Other
commands may
be typed
in
lower- or
uppercase
letters.
[
enter
)
Carriage return
Ends
the
comm
and
line
.
The
Modem
does not
execute a
command
until
you
press
(
ENTER
) .
The
carriage return
key
is
defined
as 13 in
ASCII
value.
To
redefine
it,
change
the value
of
register S3.
BS
Backspace
You
can
edit
a
command
line
with the
(BS)
key,
but the attention
code
at
the
beginning of a
command
line
cannot be
deleted.
The
(BS) key
is
defined
as 8 in
ASCII
value.
To
redefine
it,
change
the value
of
register
S5.
+ + +
Escape code
Use
the escape
code
to return to
command mode
from communica-
tions
mode.
When
you
input escape
code
+ + +
,
the
Modem
returns
to
command mode
and
displays the
result
code
OK. The
telephone
line will
still
be connected
until
you
input
HO
(ON
HOOK
command),
or
Z
(Reset
command).
The
escape code
character
can be
redefined with
register S2,
and
the
character
should be
entered three consecutive times.
When
you
rede-
fine
the escape character,
do
not
select
characters that are frequently
used
in the data
line.
The
escape
code
is
marked
off
from
data
by
the
escape guard
time.
This guard time
is
inserted
between
the
last
character transmitted
and
the
first
character of the escape code.
It is
also inserted after
the
third
character
of
the escape
code.
As
a
result,
the
escape code
is
sandwiched
by
the escape
guard
time.
The
escape
guard time can be
redefined with
register SI
2.
Its
default
value
is
50
(1
second).
When
entering the
escape
code
with
default
values,
wait
at least
1
second, input
+ + +
,
then
wait
1
second
more
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