MATLAB XPC TARGET 4 - IO Uživatelský manuál stáhnout pdf (Strana 37)

CompactPCI

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A CompactPCI is a good alternative to the desktop PC or rack-mount PC when

• Space is limited — CompactPCI systems are usually smaller than desktop

and rack-mount PCs.

• A high degree of maintainability is very important — I/O has to be accessible

at the front of the chassis.

• The system has to be placed in a harsh environment — Examples include

increased temperature ranges, increased vibration, and mobile applications.

• The system has a high number of I/O boards — The boards need to fit within

a restricted space.

Because CompactPCI systems depend on I/O boards in the CompactPCI form

factor, you cannot reuse I/O boards that have been used in desktop or

rack-mount PCs in a CompactPCI configuration. The acquisition cost of a

CompactPCI system is higher than a desktop PC or rack-mount PC system.

This is because of its smaller market and rugged design.

Performance

The entire PC functionality is combined on a single-width or double-width

CompactPCI board that limits the CPU performance. The fastest available

boards are currently equipped with Pentium III CPUs with clock rates below

1GHz. Since CompactPCI systems could operate in harsh environments, they

usually have no cooling fans, but could operate in extended temperature

ranges. Low power or lower clocked CPUs are commonly used to meet this

requirement, and so most CompactPCI CPU boards are equipped with

Pentium I or Mobile Pentium CPUs. Therefore, a typical CompactPCI does not

reach the typical performance level of a desktop PC or rack-mount PC.

However, since CompactPCI computers are based on the PCI bus, I/O

throughput and latency are equivalent to the best desktop PCs.

I/O Expandability

CompactPCI systems usually use passive backplanes that provide up to eight

CompactPCI slots. This backplane allows six or seven PCI slots for I/O

expansion. Recently, active backplanes with PCI-to-PCI bridges and wide

chassis were introduced that offer up to 14 CompactPCI slots. You can use bus

expanders to extend the PCI bus to another CompactPCI chassis, but the

overall system may become too large for mobile or space-restricted

applications.

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MATLAB XPC TARGET 4 - IO Uživatelský manuál Strana 37