Timing And Triggering; Sample Clock Timebase; External Clock; Digital Triggering - National Instruments SC Express PXIe-4309 User Manual

Use the DAQmx Channel Property Node (Analog Input»General Properties»Advanced»
High Accuracy Settings»Chop»Enable) to enable or disable chopping. For a LabVIEW
example to enable chopping, refer to
Chopping, Auto Zero Once, and Auto Zero Every Sample are mutually
Note
exclusive configurations.

Timing and Triggering

This section contains information about timing and triggering for the PXIe-4309.

Sample Clock Timebase

The PXIe-4309 sample clock is derived from the onboard 100 MHz clock, which can be locked
to the PXIe backplane 100 MHz clock to synchronize multiple modules.

External Clock

The PXIe-4309 sample clock can be driven from external sources by either PXI_TRIG<0..7>,
PFI<0..1>, PXI_STAR, or PXIe_DSTAR<A,B>.
When using the external sample clock, the PXIe-4309 does not support
Note
averaging, auto zero, or chopping.

Digital Triggering

The PXIe-4309 supports acquisition start in response to a digital trigger signal from one of the
PXI Express backplane trigger lines or the PFI from the front connector. The trigger circuit can
respond either to a rising or a falling edge.

PFI

Each PFI can be individually configured as the following:
• A timing input signal for AI.
• A timing output signal from AI.
Each PFI input has a programmable debouncing filter.
and enter the Info Code
ni.com/info
PXIe-4309 User Manual
chopexp
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