Chapter 1
Getting Started
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National Instruments Corporation
1-7
NI PXI-1042 Series User Manual
Star Trigger Slot
The Star Trigger (ST) slot is Slot 2. This slot has dedicated equal-length
trigger lines between Slot 2 and each remaining peripheral slot (refer to
Figure 1-4). This slot is intended for modules with ST functionality that can
provide individual triggers to all other peripheral modules. However, if you
do not require advanced trigger functionality, you can install any standard
peripheral module in this slot.
Peripheral Slots
There are seven peripheral slots including the Star Trigger slot.
Local Bus
The PXI backplane local bus is a daisy-chained bus that connects each
peripheral slot with adjacent peripheral slots to the left and right, as shown
in Figure 1-4.
The left local bus signals on Slot 2 are used for Star Trigger and do not
connect to Slot 1. The right local bus signals on Slot 8 are not routed
anywhere.
For example, a given peripheral slot’s right local bus connects to the
adjacent slot’s left local bus, and so on. Each local bus is 13 lines wide and
can pass analog signals between cards or provide a high-speed side-band
digital communication path that does not reduce the PXI bus bandwidth.
Local bus signals may range from high-speed TTL signals to analog signals
as high as 42 V.
Initialization software uses the configuration information specific to each
adjacent peripheral module to evaluate local bus compatibility.
