<s>
A	O
cyclic	B-Operating_System
executive	I-Operating_System
is	O
an	O
alternative	O
to	O
a	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
.	O
</s>
<s>
It	O
is	O
a	O
form	O
of	O
cooperative	B-Operating_System
multitasking	I-Operating_System
,	O
in	O
which	O
there	O
is	O
only	O
one	O
task	B-General_Concept
.	O
</s>
<s>
The	O
sole	O
task	B-General_Concept
is	O
typically	O
realized	O
as	O
an	O
infinite	O
loop	O
in	O
main( )	O
,	O
e.g.	O
</s>
<s>
in	O
C	B-Language
.	O
</s>
<s>
The	O
basic	O
scheme	O
is	O
to	O
cycle	O
through	O
a	O
repeating	O
sequence	O
of	O
activities	O
,	O
at	O
a	O
set	O
frequency	O
(	O
AKA	O
time-triggered	O
cyclic	B-Operating_System
executive	I-Operating_System
)	O
.	O
</s>
<s>
For	O
example	O
,	O
consider	O
the	O
example	O
of	O
an	O
embedded	B-Architecture
system	I-Architecture
designed	O
to	O
monitor	O
a	O
temperature	O
sensor	O
and	O
update	O
an	O
LCD	B-Device
display	I-Device
.	O
</s>
<s>
The	O
LCD	B-Device
may	O
need	O
to	O
be	O
written	O
twenty	O
times	O
a	O
second	O
(	O
i.e.	O
,	O
every	O
50	O
ms	O
)	O
.	O
</s>
