Chapter 3 – Operation
Front
Panel
Overview
The
LED
indicators
on
the
front
panel
indicate
status,
configuration,
and
activity:
TD
–
Transmit
Data.
Flashes
when
the
modem
is
transmitting
data
to
another
modem.
RD
–
Receive
Data.
Flashes
when
the
modem
is
receiving
data.
CD
–
Carrier
Detect.
Lights
when
the
modem
detects
a
valid
carrier
signal
from
another
modem.
It
is
on
when
the
modem
is
communicating
with
the
other
modem,
and
off
when
the
link
is
broken.
OH
–
Off
‐
Hook.
Lights
when
the
modem
is
off
‐
hook,
which
occurs
when
the
modem
is
dialing,
online,
or
answering
a
call.
Flashes
when
the
modem
pulse
‐
dials.
TR
–
Terminal
Ready.
Lights
when
a
communications
program
is
using
the
modem.
It
means
the
modem
is
ready
for
an
outgoing
or
incoming
call.
It
goes
off
when
the
communications
program
disconnects
the
serial
port.
When
it
goes
off,
a
connected
modem
will
also
disconnect.
Power
–
The
Power
led
lights
when
the
system
is
applying
power
to
the
modem.
Leased
Line
Operation
The
MultiModem
ZBA
modem
can
be
used
on
a
two
‐
wire
leased
line.
A
leased
line
is
a
private,
permanent
telephone
connection
between
two
points.
Unlike
normal
dialup
connections,
a
leased
line
is
always
active.
The
modems
automatically
connect
when
they
are
attached
to
the
line
and
are
turned
on.
Because
a
leased
line
is
always
active,
one
of
the
two
modems
on
the
line
must
be
configured
as
the
originate
modem
and
the
other
as
the
answer
modem.
It
does
not
matter
which
is
which.
In
the
event
of
an
interruption,
leased
‐
line
modems
automatically
reconnect
when
the
data
line
or
power
is
restored.
Setup
1.
Open
the
modem
and
change
jumper
J2
to
select
leased
‐
line
operation,
and
jumper
J3
to
select
either
originate
or
answer
operation,
depending
upon
how
you
intend
to
use
the
modem.
See
Chapter
2
for
the
detailed
procedure.
2.
Connect
a
modular
telephone
cable
to
the
LINE
jack.
Connect
the
other
end
of
the
cable
to
a
two
‐
wire
lease
‐
line
jack
or
terminals
supplied
by
the
telephone
company.
3.
Turn
on
the
modem.
14
Multi
‐
Tech
Systems,
Inc.
MT9234ZBA
‐
Series
User
Guide
