Sc Express Considerations; Sc Express Clock And Trigger Signals; Pxie_Clk100; Pxie_Sync100 - National Instruments PXIe-4340 User Manual

SC Express Considerations

This chapter details the clock and trigger functionality available through the PXI Express
chassis.

SC Express Clock and Trigger Signals

PXIe_CLK100

PXIe_CLK100 is a common, low-skew 100 MHz reference clock used for synchronization of
multiple modules in a PXI Express measurement or control system. The PXI Express backplane
is responsible for generating PXIe_CLK100 independently to each peripheral slot in a
PXI Express chassis. For more information, refer to the PXI Express Specification at
www.pxisa.org
.

PXIe_SYNC100

PXIe_SYNC100 is a common, low-skew 10 MHz reference clock with a 10% duty cycle for
synchronization of multiple modules in a PXI Express measurement or control system. The
PXI Express backplane is responsible for generating PXIe_SYNC100 independently to each
peripheral slot in a PXI Express chassis. PXIe_SYNC100 allows modules using PXIe_CLK100
as their reference to recreate the timing of the PXI_CLK10 signal while taking advantage of the
lower skew of PXIe_CLK100. For more information, refer to the PXI Express Specification at
www.pxisa.org
.

PXI_CLK10

PXI_CLK10 is a common, low-skew 10 MHz reference clock for synchronization of multiple
modules in a PXI measurement or control system. The PXI backplane is responsible for
generating PXI_CLK10 independently to each peripheral slot in a PXI chassis. In PXI Express
chassis, the PXI_CLK10 signal is in phase with PXIe_CLK100.
PXI_CLK10 cannot be used as a reference clock for SC Express modules.
Note

PXI Triggers

A PXI/PXI Express chassis provides eight bused trigger lines to each module in a system.
Triggers may be passed from one module to another, allowing precisely timed responses to
asynchronous external events that are being monitored or controlled. Triggers can be used to
synchronize the operation of several different PXI peripheral modules.
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