National Instruments PXI-6683 Series User Manual

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Chapter 3 Hardware Overview
Figure 3-5 provides an overview of the PXI synchronization architecture.
Figure 3-5. PXI Synchronization Architecture
The PXI trigger Bus, PXI star triggers, and PXI_CLK10 are PXI features that enhance
synchronization. The PXI trigger bus is a multi-drop 8-line bus that goes to every slot. The PXI star
trigger bus is a set of up to 13 point-to-point matched-length connections between the system
timing slot and every slot starting with slot 3 and up to slot 15. The propagation delay between the
system timing slot and each destination slot is matched to within 1ns to achieve low-skew
triggering. PXI_CLK10 is a high quality 10 MHz clock that is distributed with low skew to each
PXI slot. This 10 MHz signal can be sourced from the native PXI backplane oscillator or from the
system timing slot Controller Module installed in the system timing slot (such as the NI PXI-6683).
The following sections describe in more detail the use of PXI triggers and PXI star triggers with
the NI PXI-6683 series.
Using the PXI Triggers
The PXI trigger bus is a set of 8 electrical lines that go to every slot in a segment of a PXI chassis
(multi-drop up to 8 slots). Only one PXI module should drive a particular PXI_Trigger line at a
given time. The signal is then received by modules in all other PXI slots. This feature makes the
PXI triggers convenient in situations where you want, for instance, to trigger several devices,
because all modules will receive the same trigger.
Star Trigger Bus
System
Conrtroller
Star Trigger
Controller (Slot 2)
Module Module Module
132 Mbytes/s, 33 MHz, 32-bit PCI Bus
PXI Trigger Bus (8 lines)
10 MHz
Clock

National Instruments PXI-6683 Series Specifications

General

Brand	National Instruments
Model	PXI-6683 Series
Category	Control Unit
Language	English