National Instruments NI PXI-1050 User Manual

National Instruments NI PXI-1050 User Manual Manual pdf 19 page image

Chapter 1 IntroductionNI PXI-1050 User Manual 1-10 ni.comSystem Controller SlotThe System Controller slot is located in Slot 1 of the chassis as defined bythe PXI specification. It has three controller expansion slots, which areused for system controller modules wider than one slot. As defined in thePXI specification, these slots allow the controller to expand to the left so itdoes not use up peripheral slots.Peripheral SlotsThe PXI-1050 has seven peripheral slots located in Slots 2 through 8. Youcan use PXI modules in peripheral slots to add functionality to the PXIsubsystem not already provided by the system controller. Examples of PXIperipheral modules are multifunction I/O, digital I/O, and instrumentmodules. Some peripheral slots also have special capabilities, such as theStar Trigger slot and the SCXI Control slot, which are explained in thefollowing sections.Star Trigger SlotThe Star Trigger slot is located at Slot 2. This slot has a dedicated triggerline between each peripheral slot (refer to Figure 1-4) and is intended formodules with Star Trigger functionality to provide individual triggers to allother peripherals. However, if you do not require advanced triggerfunctionality, you can install any standard peripheral module into this slot.Local BusThe PXI backplane local bus is a daisy-chained bus that connects eachperipheral slot with its adjacent left and right peripheral slots, as shown inFigure 1-4.For example, a given peripheral slot’s right local bus connects to theadjacent slot’s left local bus and so on. Each local bus is 13 lines wide andcan pass analog signals between modules or provide a high-speedside-band communication path that does not affect the PXI bandwidth.Local bus signals may range from high-speed TTL signals to analog signalsas high as 42 V. Initialization software keys adjacent modules to prohibitthe use of incompatible devices. This software uses the configurationinformation specific to each peripheral module to evaluate compatibility.This method is a flexible way to define local bus functionality that is notlimited by keying hardware.