<s>
A	O
warehouse	B-Application
control	I-Application
system	I-Application
(	O
WCS	O
)	O
is	O
a	O
software	O
application	O
that	O
directs	O
the	O
real-time	O
activities	O
within	O
warehouses	O
and	O
distribution	O
centers	O
(	O
DC	O
)	O
.	O
</s>
<s>
Operational	O
screens	O
(	O
graphical	B-Application
user	I-Application
interface	I-Application
)	O
and	O
functions	O
to	O
facilitate	O
efficient	O
control	O
and	O
management	O
of	O
the	O
distribution	O
warehouse	O
.	O
</s>
<s>
The	O
upper	O
most	O
level	O
of	O
the	O
control	O
hierarchy	O
is	O
the	O
warehouse	B-Device
management	I-Device
system	I-Device
(	O
WMS	O
)	O
,	O
or	O
host	O
.	O
</s>
<s>
Coordinating	O
the	O
activities	O
of	O
the	O
various	O
material	O
handling	O
sub-systems	O
is	O
the	O
role	O
of	O
the	O
warehouse	B-Application
control	I-Application
system	I-Application
(	O
WCS	O
)	O
.	O
</s>
<s>
These	O
controllers	O
are	O
typically	O
some	O
form	O
of	O
a	O
programmable	B-Architecture
logic	I-Architecture
controller	I-Architecture
(	O
PLC	O
)	O
or	O
a	O
dedicated	O
,	O
real-time	O
PC	B-Device
control	O
system	O
.	O
</s>
<s>
They	O
interface	O
to	O
peripheral	O
Input/Output	B-General_Concept
(	O
I/O	B-General_Concept
)	O
devices	O
such	O
as	O
photo-eyes	O
scanners	O
,	O
motors	O
,	O
etc	O
.	O
</s>
<s>
as	O
well	O
as	O
data	O
collection	O
devices	O
such	O
as	O
bar	B-Device
code	I-Device
scanners	I-Device
(	O
barcode	B-Device
reader	I-Device
)	O
and	O
weigh	O
scales	O
and	O
are	O
responsible	O
for	O
the	O
physical	O
operation	O
of	O
the	O
material	O
handling	O
equipment	O
.	O
</s>
