...
The
...
FAC-2100
...
contains
...
ten
...
optically
...
isolated
...
digital
...
inputs.
...
Eight
...
of
...
those
...
inputs
...
are
...
classified
...
as
...
standard
...
inputs
...
and
...
the
...
remaining
...
two
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as
...
universal
...
inputs.
...
The
...
main
...
difference
...
between
...
the
...
two
...
types
...
is
...
the
...
input
...
voltage
...
range.
...
The
...
figure
...
above
...
shows
...
the
...
equivalent
...
circuit
...
for
...
these
...
inputs.
...
Notice
...
that
...
each
...
input
...
drives
...
an
...
isolating
...
infrared
...
light
...
emitting
...
diode
...
(LED).
...
When
...
current
...
is
...
supplied
...
to
...
the
...
LED,
...
the
...
digital
...
input
...
is
...
said
...
to
...
be
...
in
...
a
...
logic
...
high
...
state.
...
When
...
current
...
is
...
removed
...
from
...
the
...
LED,
...
the
...
digital
...
input
...
is
...
in
...
a
...
logic
...
low
...
state.
...
Table
...
1
...
shows
...
the
...
signal
...
range
...
associated
...
with
...
each
...
logic
...
state
...
for
...
each
...
digital
...
input
...
type.
...
Both
...
the
...
universal
...
and
...
standard
...
digital
...
inputs,
...
when
...
used
...
with
...
a
...
voltage
...
source
...
(such
...
as
...
the
...
FAC-2100's
...
auxiliary
...
output
...
),
...
can
...
be
...
used
...
to
...
indicate
...
a
...
switch
...
or
...
contact
...
closure.
...
Use
...
the
...
universal
...
digital
...
input
...
to
...
interface
...
with
...
logic
...
circuits.
...
Use
...
the
...
standard
...
digital
...
input
...
to
...
interface
...
with
...
sources
...
above
...
30
...
VDC
...
or
...
with
...
AC
...
signals.
...