...
The
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FAC-2100
...
has
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two
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analog
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outputs
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capable
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of
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providing
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0
...
to
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20mA,
...
4
...
to
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20mA,
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0
...
to
...
5V,
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or
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0
...
to
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10V
...
(all
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modes
...
are
...
software
...
configured).
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When
...
outputting
...
current
...
each
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channel
...
also
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has
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the
...
option
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to
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be
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wired
...
in
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source
...
or
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sink
...
mode.
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Two
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common
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questions
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arise
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when
...
using
...
the
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analog
...
outputs.
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First,
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what
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is
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the
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difference
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between
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wiring
...
the
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output
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as
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a
...
current
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source
...
versus
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a
...
current
...
sink?
...
The
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difference
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between
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the
...
two
...
is
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the
...
position
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of
...
the
...
load
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relative
...
to
...
the
...
A
...
OUT
...
+
...
and
...
A
...
OUT
...
-
...
pins.
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In
...
a
...
current
...
sink
...
scheme,
...
the
...
load
...
is
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attached
...
to
...
the
...
A
...
OUT
...
+
...
pin.
...
In
...
a
...
current
...
source
...
scheme,
...
the
...
load
...
is
...
attached
...
to
...
the
...
A
...
OUT
...
-
...
pin.
...
See
...
the
...
...
...
...
(Sink
...
and
...
Source)
...
examples.
...
More
...
importantly,
...
as
...
shown
...
the
...
Current
...
Sink
...
Mode
...
and
...
Current
...
Source
...
Mode
...
examples,
...
the
...
position
...
of
...
the
...
grounding
...
point
...
is
...
different.
...
Notice
...
that
...
if
...
a
...
current
...
source
...
is
...
used,
...
the
...
load
...
is
...
attached
...
directly
...
to
...
the
...
circuit
...
ground.
...
This
...
is
...
important
...
if
...
you
...
wish
...
to
...
transmit
...
an
...
analog
...
signal,
...
for
...
example,
...
from
...
a
...
sending
...
controller
...
to
...
multiple
...
receiving
...
controllers.
...
By
...
attaching
...
the
...
load
...
(in
...
this
...
case
...
the
...
load
...
is
...
the
...
analog
...
inputs
...
of
...
the
...
receiving
...
controllers)
...
to
...
ground,
...
the
...
entire
...
circuit
...
can
...
have
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a
...
common
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ground
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reference
...
point.
...
This
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common
...
ground
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can
...
become
...
important
...
if
...
a
...
single
...
source
...
is
...
providing
...
power
...
to
...
all
...
the
...
controllers,
...
sensors,
...
and
...
actuators
...
in
...
the
...
system.
...
The
...
second
...
common
...
question
...
is
...
when
...
should
...
the
...
circuit
...
be
...
wired
...
as
...
a
...
current
...
source
...
rather
...
than
...
a
...
current
...
sink?
...
In
...
general,
...
wire
...
the
...
circuit
...
using
...
the
...
current
...
sink
...
configuration.
...
If
...
you
...
need
...
to
...
transmit
...
an
...
analog
...
signal
...
between
...
controllers,
...
use
...
the
...
current
...
source
...
configuration.
...
The
...
main
...
reason
...
for
...
this
...
preference
...
is
...
that
...
the
...
analog
...
output
...
circuitry
...
in
...
the
...
controller
...
will
...
sink
...
current
...
over
...
a
...
wider
...
range
...
of
...
load
...
conditions
...
in
...
comparison
...
to
...
a
...
current
...
source
...
configuration.
...
Note
...
that
...
a
...
voltage
...
source
...
from
...
4
...
to
...
32
...
V
...
DC
...
is
...
required
...
for
...
the
...
analog
...
outputs
...
to
...
work
...
correctly
...
(see
...
the
...
Installation
...
section
...
of
...
this
...
bulletin
...
for
...
additional
...
information).
...
Care
...
must
...
be
...
taken
...
when
...
selecting
...
the
...
source
...
to
...
ensure
...
that
...
grounding
...
loops
...
or
...
unwanted
...
grounding
...
shorts
...
do
...
not
...
occur.
...
Also,
...
the
...
voltage
...
for
...
this
...
analog
...
output
...
source
...
cannot
...
exceed
...
the
...
auxiliary
...
output
...
source.
...
In
...
general,
...
it
...
is
...
recommended
...
that
...
the
...
FAC-2100's
...
internal
...
auxiliary
...
output
...
source
...
be
...
used
...
to
...
power
...
the
...
analog
...
outputs
...
.
...