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- Impedance Matched Layouts
- Multi-Layer for Low Noise
- Buffered PCI slots
- PCI-Express
- PCI-X
- 32 & 64-Bit PCI/ISA
- Segmented
- Custom Designs Available
- Matched SBC's
for Reliable Performance
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All
Chassis Plans backplanes are made in the US for
superior support, reliability and long availability. |
BPX-6467 18-Slot PCI-X &
PCI-Express Backplane
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Because of all the different variations in backplanes
that can be configured, please call us at 858-571-4330
or e-mail
us to discuss your requirement.
Please see the Backplane
Primer at the bottom of this page if you have questions
about passive backplane useage.
The Backplane
Reference Manual and PCI
Express Backplane Reference Manual can be downloaded
with complete technical information for all our backplanes.
Chassis Plans Passive and Active Backplanes allow for
more than 8 slots (up to 20), a large mix of ISA, PCI,
PCI-X and PCI Express slots, and easy processor card
access. For full PC functionality with the benefit of
increased I/O expandability, Chassis Plans' full line
of ISA, PCI, PCI X and PCI Express back planes are the
perfect solution. Available in 4 to 20-Slot options,
from ISA to PCI Express PICMG Bus and Passive , Active
and Segmentable systems, these unique backplanes combine
with Chassis Plans' complete line of Single
Board Computers and Industrial
Chassis products to create a rugged, reliable platform
for hostile operating environments. Chassis Plans passive
back planes are widely used in industries that require
I/O expandability, including telecom, instrumentation
and process control.
Backplane Primer
If you are unfamiliar with passive
backplanes, this short primer should offer some clarification.
Why Use a Passive Backplane?
Why would you use a passive backplane
and Single Board Computer? The three primary reasons
are more expansion slots, need for ISA slots, and much
lower MTTR (Mean Time To Repair).
Motherboards are limited to 8 slots
maximum - at the most. It's getting hard to find even
that many. Passive Backplanes can provide up to 20 slots.
20 is the most that will fit within a 17" wide
rack mount chassis. You can build a backplane with more
than 20 if your chassis is wide enough to accommodate
the board. Also, with a smaller backplane, you can get
a more narrow system using an SBC.
Intel and Microsoft decreed some
time ago that ISA slots will no longer be supported.
New motherboards only provide PCI slots. If you have
an application that is served by a plug-in I/O which
is only available in ISA form factor, you are limited
to looking for used or old stock motherboards or switching
to a passive backplane. A passive backplane can provide
up to 20 ISA slots. However, 1 or 2 of those slots would
be occupied by the SBC leaving 18 available ISA card
slots.
An SBC can be removed from the
system by unplugging the cables, removing one screw,
and pulling the card. None of the I/O cards need to
be removed. A motherboard is buried under everything
else requiring a total system deintegration (disintegration?)
to remove the motherboard. All I/O cards have to be
removed and all the screws holding the motherboard removed.
If your application requires low MTTR, the only option
is a total system replacement if you have a motherboard
installed, or use an SBC installed in a passive backplane.
A fourth reason would be continued
availability of a stable design. Motherboards are consumer
commodity items with limited availability. There is
no guarantee how long you will be able to continue to
source a motherboard. Single Board Computers and Passive
Backplanes have much longer product life cycles. For
example, in the medical field, FDA approval is expensive.
Every time you change a component such as the motherboard,
you have to resubmit for approval.
The one negative regarding a passive
backplane and SBC is cost. Motherboards are made by
the gazillion and are very cheap. Passive backplanes
and SBCs are made in much smaller quantities and cost
considerably more than a motherboard.
Structure
A Passive Backplane provides the
slots, but not the smarts of a motherboard. Various
motherboards provide for 1 to 8 I/O card expansion slots.
The motherboard also provides the processor, processor
support chip sets, memory, I/O, etc. A passive backplane
needs the smarts provided by a plug-in Single Board
Computer (SBC) to function. A passive backplane with
an SBC installed it totally equivalent to a motherboard.
As with motherboards, passive backplanes
provide a mix of I/O slots. These can be all ISA, a
combination of ISA and PCI, or all PCI. Because of signal
loading requirements, backplanes with PCI slots will
also provide bridge chips. So, in the true sense of
the word, these are not "passive" backplanes,
but "active". For simplicity, they are all
grouped as "passive" backplanes.
Single
Board Computers can be selected with a wide variety
of features including processor type and speed, available
memory, video, I/O, etc. With regards to a passive backplane,
the only concern will be the connection between the
SBC and the backplane. An SBC looks like any other plug-in
card. Hanging from the bottom will be an ISA connector
and maybe a PCI and PICMG connectors if the board supports
PCI.
Note that a PCI SBC will work in an all ISA slot backplane.
An ISA-only SBC will work in an ISA/PCI backplane but
will not provide any PCI support (PCI slots will not
be active). The ISA signals are carried on the ISA edge
connectors and the PCI signals are carried and controlled
by the PICMG edge connectors.
It should be noted the PCI Express
bus structure is entirely new with regards to the CPU
connectors. The PCI Express SHB boards such as the NLT
and NLI will only fit in a PCI Express backplane. It's
not that you loose functionality - they simply will
not fit in the connectors.
PCI Express can be described as
parallel serial. Each channel provides packets of data
serially, but in parallel data streams. The more channels
to a connector, such as x8 or x16, the higher the available
bandwidth to that connector. The SHB has a limited number
of channels, some of which are used internally, some
to external PCI Express slots, and others to bridge
chips for driving PCI and PCI-X slots. See the PCI
Express Backplane Reference Manual for a complete
explanation of PCI Express backplane structure and use.
An ISA-only backplane can have
the SBC installed in any slot. A PCI and PCI-Express
backplane will provide dedicated SBC slot(s) and the
SBC must be installed in one of these for the system
to work.
Segmented Backplanes
Segmented or split backplanes provide
for multiple independent SBCs  to
be used in the same backplane. Each SBC has a group
of slots dedicated to it. Only power and mechanical
support are shared. In theory (and practice), a 20-slot
backplane could be split into 10 segments allowing 10
SBCs and 10 I/O cards to be installed in a single 4U
chassis. Because the SBCs share power, each SBC cannot
be individually turned on/off. However, each SBC can
be provided with its own reset switch. Imagine the processing
power available with ten 3GHz dual-Xeon SBC's in a single
4U enclosure!
Custom Backplanes
As with our Custom Chassis, Chassis
Plans can provide you with custom backplanes with any
slot  mix,
any number of segments or special mechanical features.
It is possible to add circuitry to the backplane to
provide functionality not available in a plug-in card
or to conserve I/O slots. There is a 50 piece minimum
order for custom backplanes and NRE charges will apply.
We have over 30 custom designs available with no NRE
charges applicable. Contact the Chassis Plans sales
department with your custom requirements for a quotation. | 
