<s>
Network	B-Device
isolators	I-Device
are	O
installed	O
as	O
part	O
of	O
a	O
wired	B-Protocol
Ethernet	I-Protocol
system	O
as	O
galvanic	O
isolators	O
to	O
reduce	O
the	O
potential	O
for	O
electrical	O
injury	O
and	O
limit	O
the	O
extent	O
of	O
damage	O
due	O
to	O
lightning	B-Architecture
strikes	O
.	O
</s>
<s>
Through	O
the	O
applied	O
principle	O
of	O
electromagnetic	O
induction	O
,	O
network	O
data	B-General_Concept
is	O
transmitted	O
across	O
an	O
electrically	O
non-conducting	O
barrier	O
.	O
</s>
<s>
High	O
frequency	O
AC	O
voltages	O
conveying	O
data	B-General_Concept
are	O
induced	B-Algorithm
across	O
an	O
isolating	O
gap	O
.	O
</s>
<s>
The	O
network	B-Device
isolator	I-Device
is	O
a	O
passive	O
device	O
,	O
and	O
functions	O
without	O
any	O
requirement	O
of	O
an	O
external	O
power	O
supply	O
.	O
</s>
<s>
A	O
functional	O
equivalent	O
to	O
network	B-Device
isolators	I-Device
is	O
Ethernet	O
over	O
a	O
small	O
stretch	O
of	O
optical	B-Architecture
fibre	I-Architecture
,	O
using	O
media	O
converters	O
or	O
Ethernet	O
switches/network	O
cards	O
with	O
fiber	O
connections	O
on	O
each	O
end	O
.	O
</s>
<s>
Network	B-Device
isolators	I-Device
have	O
many	O
other	O
applications	O
in	O
overcoming	O
the	O
problems	O
of	O
differing	O
ground	O
potentials	O
across	O
networks	O
,	O
or	O
between	O
network	O
components	O
.	O
</s>
<s>
For	O
private	O
or	O
commercial	O
networks	O
,	O
where	O
inherent	O
potential	O
differences	O
within	O
a	O
building	O
,	O
or	O
between	O
buildings	O
,	O
become	O
problematic	O
,	O
and	O
a	O
fibre-optic	B-Application
solution	O
is	O
not	O
economically	O
viable	O
;	O
</s>
<s>
Network	B-Device
isolators	I-Device
are	O
used	O
in	O
medical	O
devices	O
to	O
protect	O
patients	O
against	O
leakage	O
currents	O
.	O
</s>
<s>
Network	O
connections	O
between	O
medical	O
devices	O
and	O
Ethernet	O
networks	O
(	O
and	O
other	O
non-medical	O
devices	O
,	O
such	O
as	O
personal	B-Device
computers	I-Device
)	O
must	O
be	O
in	O
accordance	O
with	O
the	O
IEC	O
60601-1	O
standard	O
.	O
</s>
<s>
Network	B-Device
isolators	I-Device
work	O
to	O
remove	O
this	O
hazard	O
,	O
by	O
electrically	O
disconnecting	O
medical	O
devices	O
from	O
a	O
network	O
.	O
</s>
<s>
As	O
they	O
serve	O
no	O
therapeutic	O
or	O
diagnostic	O
purpose	O
,	O
network	B-Device
isolators	I-Device
themselves	O
are	O
not	O
classed	O
as	O
medical	O
electronic	O
equipment	O
according	O
to	O
the	O
IEC	O
60601-1	O
standard	O
,	O
nor	O
do	O
they	O
fall	O
within	O
the	O
scope	O
of	O
the	O
Medical	O
Devices	O
Directive	O
93/42/EEC	O
.	O
</s>
<s>
They	O
are	O
often	O
installed	O
in	O
the	O
medical	O
field	O
in	O
conjunction	O
with	O
isolation	O
transformers	B-Algorithm
,	O
which	O
serve	O
to	O
protect	O
the	O
patient	O
from	O
other	O
electrical	O
faults	O
.	O
</s>
<s>
A	O
network	B-Device
isolator	I-Device
can	O
be	O
constructed	O
to	O
provide	O
one	O
or	O
both	O
required	O
MOPPs	O
.	O
</s>
<s>
The	O
number	O
of	O
MOPPs	O
a	O
network	B-Device
isolator	I-Device
provides	O
will	O
be	O
stated	O
in	O
the	O
certification	O
of	O
the	O
device	O
.	O
</s>
<s>
However	O
,	O
this	O
fails	O
to	O
provide	O
sufficient	O
protection	O
in	O
the	O
scope	O
of	O
IEC	O
60601-1	O
,	O
as	O
the	O
data	B-General_Concept
lines	O
themselves	O
are	O
not	O
isolated	O
,	O
and	O
may	O
be	O
floating	O
at	O
dangerous	O
voltage	O
potentials	O
.	O
</s>
<s>
Network	B-Protocol
cards	I-Protocol
and	O
other	O
active	O
network	O
components	O
which	O
are	O
designed	O
to	O
meet	O
IEC	O
60950	O
(	O
Safety	O
of	O
Information	O
Technology	O
Equipment	O
)	O
,	O
will	O
usually	O
not	O
comply	O
with	O
the	O
more	O
demanding	O
isolation	O
requirements	O
of	O
IEC	O
60601-1	O
(	O
Medical	O
Electrical	O
Equipment	O
)	O
,	O
and	O
therefore	O
require	O
additional	O
isolation	O
before	O
being	O
used	O
in	O
medical	O
applications	O
.	O
</s>
<s>
The	O
transmission	O
quality	O
of	O
a	O
network	B-Device
isolator	I-Device
can	O
be	O
determined	O
by	O
measuring	O
the	O
industry	O
standard	O
parameters	O
or	O
characteristics	O
,	O
for	O
example	O
,	O
insertion	O
loss	O
,	O
return	O
loss	O
,	O
and	O
near-end	O
crosstalk	O
.	O
</s>
<s>
By	O
definition	O
,	O
a	O
network	B-Device
isolator	I-Device
completely	O
eliminates	O
each	O
and	O
every	O
direct	O
electrical	O
connection	O
between	O
devices	O
connected	O
through	O
a	O
network	O
connection	O
-	O
specifically	O
all	O
the	O
data	B-General_Concept
lines	O
,	O
and	O
the	O
cable	O
shield	O
.	O
</s>
<s>
Network	B-Device
isolators	I-Device
are	O
commercially	O
available	O
in	O
various	O
designs	O
,	O
to	O
suit	O
customers’	O
requirements	O
:	O
</s>
