Chapter 1
Getting Started
1-4
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PXI-1025 Backplane Overview
Interoperability with CompactPCI
The PXI-1025 MegaPAC backplane is interoperable with PXI-compatible
products and standard CompactPCI products. This is an important feature,
as many PXI-compatible systems may not require components that do not
implement PXI-specific features. For example, you may want to use a
standard CompactPCI network interface card in a PXI chassis.
The signals on the P1 connector of the backplane meet the requirements of
the CompactPCI specification for both the peripheral and system modules.
The PXI-specific signals are located on P2 and are found on only
the signals that are reserved or not used in the CompactPCI 64-bit
specification. Therefore, all modules that meet the requirements of the
CompactPCI 64-bit specification will function in the PXI-1025 MegaPAC.
System Controller Slot
The System Controller slot is Slot 1 of the chassis as defined by the PXI
specification. It has three controller expansion slots, which are used for
system controller modules that are wider than one slot. As defined in the
PXI specification, these slots allow the controller to expand to the left to
prevent the controller from using up peripheral slots.
Star Trigger Slot
The Star Trigger (ST) slot is Slot 2. This slot has a dedicated trigger line
between each peripheral slot (see Figure 1-3). This slot is intended for
modules with ST functionality that can provide individual triggers to all
other peripherals. Additionally, you can use the ST slot as a high-precision
10 MHz clock source. However, if you do not require advanced trigger
functionality, you can install any standard peripheral module into this slot.
Peripheral Slots
There are seven peripheral slots including the ST slot.
Local Bus
The PXI backplane’s local bus is a daisy-chained bus that connects each
peripheral slot with its adjacent peripheral slots to the left and right, as
shown in Figure 1-3.
