<s>
Instrument	B-Application
Neutral	I-Application
Distributed	I-Application
Interface	I-Application
(	O
INDI	O
)	O
is	O
a	O
distributed	O
control	O
system	O
(	O
DCS	O
)	O
protocol	O
to	O
enable	O
control	O
,	O
data	O
acquisition	O
and	O
exchange	O
among	O
hardware	O
devices	O
and	O
software	O
front	O
ends	O
,	O
emphasizing	O
astronomical	O
instrumentation	O
.	O
</s>
<s>
INDI	O
is	O
a	O
simple	O
protocol	O
modeled	O
on	O
Extensible	B-Protocol
Markup	I-Protocol
Language	I-Protocol
(	O
XML	B-Protocol
)	O
,	O
described	O
for	O
interactive	O
and	O
automated	O
remote	O
control	O
of	O
diverse	O
instruments	O
.	O
</s>
<s>
Each	O
Property	O
is	O
a	O
vector	O
of	O
one	O
or	O
more	O
named	O
members	O
,	O
and	O
has	O
a	O
current	O
value	O
vector	O
;	O
a	O
target	O
value	O
vector	O
;	O
provides	O
information	O
about	O
how	O
it	O
should	O
be	O
sequenced	O
with	O
respect	O
to	O
other	O
Properties	O
to	O
accomplish	O
one	O
coordinated	O
unit	O
of	O
observation	O
;	O
and	O
provides	O
hints	O
as	O
to	O
how	O
it	O
might	O
be	O
displayed	O
for	O
interactive	O
manipulation	O
in	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
.	O
</s>
<s>
The	O
INDI	O
protocol	O
can	O
be	O
nested	O
within	O
other	O
XML	B-Protocol
elements	O
such	O
as	O
Remote	O
Telescope	O
Markup	O
Language	O
(	O
RTML	O
)	O
to	O
add	O
constraints	O
for	O
automatic	O
scheduling	O
and	O
execution	O
.	O
</s>
<s>
This	O
is	O
accomplished	O
by	O
using	O
XML	B-Protocol
to	O
describe	O
a	O
generic	O
hierarchy	O
that	O
can	O
represent	O
both	O
canonical	O
and	O
non-canonical	O
devices	O
.	O
</s>
<s>
INDI	O
Library	O
is	O
an	O
implementation	O
of	O
the	O
INDI	O
wire	O
protocol	O
for	O
Unix-like	B-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
It	O
supports	O
a	O
wide	O
variety	O
of	O
astronomical	O
instruments	O
including	O
telescopes	O
,	O
charge-coupled	B-Algorithm
devices	I-Algorithm
(	O
CCDs	O
)	O
,	O
focusers	O
,	O
filters	O
,	O
and	O
video	O
capture	O
devices	O
.	O
</s>
<s>
The	O
INDI	O
Library	O
is	O
licensed	O
under	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
(	O
LGPL	B-Application
)	O
.	O
</s>
<s>
Generic	O
GUI	B-Application
clients	O
like	O
KStars	B-Language
,	O
XEphem	B-Application
,	O
AstroImager	O
,	O
or	O
AstroTelescope	O
.	O
</s>
<s>
Such	O
clients	O
generate	O
a	O
dynamic	O
GUI	B-Application
to	O
offer	O
users	O
a	O
control	O
panel	O
to	O
control	O
the	O
device	O
.	O
</s>
<s>
The	O
Internet	O
Assigned	O
Numbers	O
Authority	O
(	O
IANA	O
)	O
has	O
assigned	O
TCP/UDP	O
port	O
7624	O
(	O
Transmission	B-Protocol
Control	I-Protocol
Protocol	I-Protocol
and	O
User	B-Protocol
Datagram	I-Protocol
Protocol	I-Protocol
)	O
for	O
use	O
by	O
INDI	O
.	O
</s>
<s>
See	O
List	B-Protocol
of	I-Protocol
TCP	I-Protocol
and	I-Protocol
UDP	I-Protocol
port	I-Protocol
numbers	I-Protocol
.	O
</s>
