Chapter
5
–
Callback
Security
7.
To
store
a
callback
phone
number
in
the
first
memory
location,
type
AT&Z0=
[
+
][
‐
]
AT
xxxxxxxx
[
,
???
],
where
xxxxxxxx
is
the
dialing
string.
Press
E
NTER
.
The
phone
number
must
be
preceded
by
DT
for
tone
dialing
or
DP
for
pulse
dialing.
The
dialing
string
can
also
include
other
AT
commands.
Example:
AT&Z0=+
‐
ATM0DT5551212
.
Up
to
35
characters
can
be
used.
The
+,
‐
,
and
???
characters
are
optional:
+
Number
entry.
Enables
a
mobile
caller
to
enter
his
current
phone
number
for
callback.
‐
Direct
connection.
Enables
a
caller
to
choose
direct
connection
without
being
called
back.
,???
Extension
entry.
Must
be
used
with
the
+
command.
Enables
a
caller
to
enter
an
extension
number
for
callback.
The
number
of
?
characters
must
equal
the
number
of
digits
in
the
extension.
8.
To
store
a
callback
phone
number
in
the
second
memory
location,
type
AT&Z1=
[
+
][
‐
]
AT
xxxxxxxx
[
,
???
],
where
xxxxxxxx
is
the
dialing
string,
and
press
E
NTER
.
Note
that
the
memory
location
number
in
the
command
is
incremented
by
one.
9.
Repeat,
through
memory
location
29,
until
all
dialing
strings
are
entered.
10.
To
review
your
entries,
type
AT&V
and
press
E
NTER
.
Note:
A
form
is
provided
on
the
last
page
of
this
chapter
to
help
you
plan
or
keep
track
of
password
and
phone
number
assignments.
Calling
Procedures
Use
the
following
procedures
to
call
a
modem
that
has
callback
security
enabled.
Note
that
Autoanswer
must
be
enabled
on
the
calling
modem
(
S0=1
).
Password
Only
Callback
Use
this
procedure
when
calling
from
a
fixed
location.
1.
Using
a
data
communications
program
such
as
HyperTerminal,
dial
the
number
of
the
callback
modem.
2.
When
the
connection
is
established,
the
callback
modem
responds
with
the
following
message:
Password>
3.
Type
the
password
corresponding
to
the
phone
number
for
your
modem.
Press
E
NTER
.
You
have
three
attempts
or
one
minute
to
enter
a
valid
password.
4.
If
the
password
is
valid,
the
following
message
appears,
and
the
modems
disconnect:
OK
Disconnecting
5.
After
the
delay
specified
by
the
#CBD
n
command,
the
callback
modem
calls
the
number
associated
with
the
password.
If
the
callback
modem
is
unable
to
establish
a
connection,
it
tries
again,
up
to
the
number
of
attempts
specified
by
the
#CBA
n
command.
6.
After
the
modems
reconnect,
the
following
message
reappears:
Password
>
7.
Type
the
same
password
that
you
used
to
initiate
the
call.
You
are
allowed
three
attempts
to
enter
the
password,
after
which
you
will
be
disconnected.
8.
If
the
password
is
valid,
the
following
message
appears
and
the
modems
establish
a
working
connection:
OK
Connecting
20
Multi
‐
Tech
Systems,
Inc.
MT9234ZBA
‐
Series
User
Guide
