October 2014
22
B
OARDS
& M
ODULES
Rugged embedded standards-based
solutions that deliver on SWaP(-C)
By Jeff Munch,
ADLINK
Small form factor design trends
are paradoxical. Form factor size
decreases while required functionality
increases. More processing power
is demanded while lower power
consumption and thermal output are
expected. Ruggedness against the
shock, vibration, humidity,
temperature extremes and variance
inherent in mobile and outdoor
applications is also needed, facing
designers with a very complex soup.
Yes, designing for rugged applications pres-
ents its share of challenges, but there are form
factors and manufacturing techniques that
accommodate most requirements for either
general or application-specific design. Mobil-
ity and environmental extremes are critical
considerations for rugged board design in
military, transportation, industrial and sur-
veillance applications, to name a few. And
with today’s emphasis on SWaP(-C) in embed-
ded system design, it’s critical for embedded
designers to follow industry standards, and
equally critical for industry standards to con-
tinue evolving to maintain relevance.
Embedded board eXpandable (EBX) and
PC/104 are good format options for designs
that can handle slightly larger single board
computer (SBC) form factors. With just 46
square inches of surface area (8“ x 5.75“), EBX
balances size and functionality with a bolt-
down SBC format supporting rugged embed-
ded designs with higher-performance central
processing units (CPUs), such as those using
multi-core technology for networking, digital
signal processing (DSP), and graphics-heavy
applications, and generous on-board input/
output (I/O) functions to support every-
thing from large data exchange to video. The
PC/104 embedded computing format has no
backplane, instead allowing modules to stack
together like building blocks more rugged
than typical bus connections in PCs (such as
PCI or PCI Express slot cards). PC/104 deliv-
ers high performance combined with low
power, stackable configurations and adher-
ence to MIL-STD, and it meets key industrial
and transportation standards for electromag-
netic interface/compatibility (EMI/EMC), e.g.
EN50121, EN50155, EN610000-x, etc. The
ability to build stacks of PC/104 modules cre-
ates opportunities for developing a diversity of
complex, often mobile, applications that range
across industrial, transportation, and defense
environments where robust and reliable capa-
bilities of PC/104 are required. In addition,
PC/104 transition into vision and visual secu-
rity monitoring systems is benefitted by PCI
Express, as it has the capacity to directly meet
the bandwidth needed to support multiple
data streams.
Though the number of stacks included in
PC/104 systems has been decreasing, the
form factor continues its warm relationship
with industries requiring rugged applications
with high resistance to shock and vibration.
In defense and transportation, legacy devices
and ISA-BUS interface requirements are still
plentiful. With high-speed serial I/O inter-
faces, such as PCI Express, supported in cur-
rent PC/104-based standards, PC/104 boards
are keeping pace with the movement toward
consolidating workload on expansion mod-
ules, requiring fewer layers to fulfill applica-
tion requirements. The ability to withstand
temperature extremes often associated with
remote environments still allows PC/104
to excel in off-grid computing (e.g. defense
apps). Stackable, mix-and-match modularity
and the intrinsically rugged design of PC/104
is ideal for many of the technology upgrade
programs nowadays looking for commercial
off-the-shelf (COTS) options — especially
those that value SWaP(-C). In addition to
ruggedness, users of PC/104 have come to
expect long lifecycle support. When consid-
ering shrinking DoD budgets, the robustness,
longevity and compatibility of the PC/104
ecosystem ensure strong system support and
minimized costs.
While PC/104 allows flexibility by combining
cards to meet application requirements, the
PC/104 format becomes less attractive when
very high computing speed and network
throughput is required — situations where
VPX or CompactPCI (cPCI) formats are bet-
ter suited. In cases where an application design
requires very specific I/O or physical size/
shape restrictions, then a computer-on-mod-
ule (COM) approach would provide better
results. COMs are complete embedded com-
puters built on a single circuit board for use
in small or specialized applications requiring
low power consumption or small physical
Rugged military systems using
small form factor COTS design
and industry-standards, are
required to meet the requirements
for SWaP(-C).
