Using Pfi Terminals As Timing Input Signals; Exporting Timing Output Signals Using Pfi Terminals; Figure 2-13. Pfi Circuitry - National Instruments SC Express PXIe-4309 User Manual

Chapter 2 Using the PXIe-4309
Figure 2-13 shows the PFI circuitry.
PFIx
Protection
PFI GND
On the I/O connector, each terminal is labeled PFIx.
Refer to the PXIe-4309 Specifications for the PFI input and output specifications.

Using PFI Terminals as Timing Input Signals

Use PFI terminals to route external timing signals to different functions of the PXIe 4309. Each
PFI input can be routed to any of the following signals:
• AI Sample Clock (ai/SampleClock)
• AI Start Trigger (ai/StartTrigger)
• AI Reference Trigger (ai/ReferenceTrigger)
• AI Pause Trigger (ai/PauseTrigger)
• AI Sample Clock Timebase (ai/SampleClockTimebase)
The polarity of PFI inputs is configurable for most functions.
Note
Pause triggers are only sensitive to the level of the source, not the edge.
Note

Exporting Timing Output Signals Using PFI Terminals

You can route any of the following timing signals to any PFI terminal configured as an output:
• AI Reference Trigger (ai/ReferenceTrigger)
• AI Sample Clock (ai/SampleClock)
• AI Start Trigger (ai/StartTrigger)
• AI Pause Trigger (ai/PauseTrigger)
• PXI_STAR
• PXI_Trig <0..7>
2-18 | ni.com

Figure 2-13. PFI Circuitry

Output
Enable
10 kΩ
Debouncing
Filters
Timing
Signals
Input Timing
Signal Selectors
PFI Circuitry (1 of 2)