<s>
ESMexpress	B-Device
is	O
a	O
very	O
compact	O
computer-on-module	B-Application
(	O
COM	O
)	O
standard	O
.	O
</s>
<s>
This	O
fixed	O
pin	O
mapping	O
ensures	O
that	O
different	O
ESMexpress	B-Device
modules	O
can	O
be	O
exchanged	O
more	O
easily	O
.	O
</s>
<s>
Consequently	O
,	O
ESMexpress	B-Device
typically	O
does	O
not	O
have	O
an	O
onboard	O
FPGA	O
.	O
</s>
<s>
The	O
idea	O
behind	O
this	O
is	O
to	O
implement	O
very	O
specialized	O
functions	O
in	O
an	O
FPGA	O
on	O
the	O
COM	O
's	O
carrier	O
board	O
to	O
ease	O
upgrades	O
of	O
the	O
system	O
CPU	O
through	O
exchange	O
of	O
the	O
ESMexpress	B-Device
module	O
.	O
</s>
<s>
The	O
ESMexpress	B-Device
standard	O
includes	O
only	O
one	O
form	O
factor	O
:	O
95	O
x	O
125	O
mm	O
.	O
</s>
<s>
The	O
most	O
important	O
specialty	O
of	O
this	O
computer-on-module	B-Application
is	O
its	O
surrounding	O
mechanical	O
concept	O
,	O
which	O
was	O
designed	O
for	O
especially	O
severe	O
environmental	O
conditions	O
,	O
for	O
example	O
in	O
railway	O
or	O
avionics	O
,	O
or	O
in	O
the	O
automation	O
industry	O
.	O
</s>
<s>
ESMexpress	B-Device
was	O
undergoing	O
a	O
standardization	O
process	O
managed	O
by	O
the	O
VITA	O
organization	O
to	O
become	O
a	O
standard	O
called	O
'	O
ANSI/VITA	O
59	O
RSE	O
Rugged	O
System-On-Module	B-Application
Express	O
 '	O
.	O
</s>
<s>
For	O
companies	O
that	O
need	O
robust	O
electronic	O
products	O
,	O
both	O
the	O
reduction	O
of	O
development	O
times	O
and	O
a	O
long-term	O
availability	O
of	O
more	O
than	O
10	O
or	O
15	O
years	O
are	O
significant	O
factors	O
for	O
a	O
new	O
computer-on-module	B-Application
standard	O
like	O
ESMexpress	B-Device
.	O
</s>
<s>
However	O
,	O
ESMexpress	B-Device
had	O
been	O
based	O
on	O
the	O
existing	O
,	O
popular	O
COM	B-Device
Express	I-Device
,	O
and	O
during	O
the	O
standardization	O
process	O
the	O
work	O
group	O
decided	O
to	O
make	O
better	O
use	O
of	O
this	O
industry	O
popularity	O
.	O
</s>
<s>
In	O
2013	O
the	O
standard	O
's	O
designation	O
was	O
changed	O
into	O
'	O
VITA	O
59.00	O
Rugged	O
COM	B-Device
Express	I-Device
(	O
RCE	O
)	O
'	O
.	O
</s>
<s>
The	O
specification	O
was	O
completely	O
reviewed	O
but	O
kept	O
the	O
mechanical	O
framework	O
of	O
ESMexpress	B-Device
.	O
</s>
<s>
The	O
concept	O
now	O
defines	O
the	O
mechanical	O
design	O
to	O
convert	O
standard	O
PICMG	O
COM.0	O
COM	B-Device
Express	I-Device
CPU	O
boards	O
into	O
VITA	O
59	O
Rugged	O
COM	B-Device
Express	I-Device
boards	O
.	O
</s>
<s>
Although	O
not	O
becoming	O
an	O
official	O
standard	O
,	O
the	O
concept	O
of	O
ESMexpress	B-Device
remains	O
as	O
originally	O
specified	O
and	O
can	O
be	O
regarded	O
a	O
more	O
robust	O
variety	O
of	O
Rugged	O
COM	B-Device
Express	I-Device
,	O
primarily	O
because	O
of	O
the	O
rugged	O
board-to-board	O
connectors	O
.	O
</s>
<s>
ESMini	O
is	O
a	O
derivative	O
of	O
ESMexpress	B-Device
.	O
</s>
<s>
It	O
is	O
based	O
on	O
the	O
same	O
mechanical	O
concept	O
:	O
the	O
computer	O
board	O
is	O
also	O
embedded	O
into	O
an	O
aluminum	O
frame	O
and	O
cover	O
for	O
conduction	O
cooling	O
and	O
EMC	O
protection	O
,	O
and	O
its	O
board-to-board	O
connector	O
types	O
are	O
identical	O
with	O
ESMexpress	B-Device
.	O
</s>
<s>
The	O
most	O
important	O
difference	O
to	O
ESMexpress	B-Device
is	O
its	O
small	O
size	O
:	O
it	O
is	O
only	O
95	O
by	O
55	O
mm	O
.	O
</s>
<s>
Another	O
difference	O
is	O
that	O
it	O
allows	O
greater	O
variations	O
and	O
design	O
flexibility	O
than	O
ESMexpress	B-Device
.	O
</s>
