Importing and Exporting External Signals To and From a FlexRIO FPGA

Updated Oct 25, 2023

Reported In


  • PXI FlexRIO Digitizer
  • PXI FlexRIO Coprocessor Module
  • PXIe-7915
  • PXIe-7911
  • PXIe-7912
  • PXI FlexRIO Signal Generator
  • PXIe-5763
  • PXIe-5764
  • PXIe-5775
  • PXIe-5785
  • PXIe-5745


  • LabVIEW
  • LabVIEW FPGA Module


  • FlexRIO

Issue Details

I am using a FlexRIO device and I know I can use the Configure Digital Edge Start Trigger VI to import a Start Trigger, but I want to import an external trigger I can access in LVFPGA, or export a signal from the FPGA to use it elsewhere, other than a start trigger. My device does not provide access to the PXI Trigger Lines as FPGA IO Channels and I do not have a timing card to use the DStar Lines.


You can use the FlexRIO Route Signal VI to create routes between the 32 source and 32 destination logical routing resources in the FlexRIO device's FPGA and the PXI triggers, the SMB trigger in the controller (controller dependent) and the chassis PFIs when using a PXIe chassis with the timing and synchronization option like a PXIe-1095 or PXIe-1092.

Use PXI_Trig0 to PXI_Trig7 to connect the PXI Trigger Lines, /PXIChassis1/PFI0 to /PXIChassis1/PFI3 to connect to the chassis' PFIs, or /<controller's name>/TRIG_SMB to connect to the controller's SMB trigger connector.



Additional Information

In the example below, the FlexRIO Route Signal VI is added to the host VI to import an external trigger coming from the chassis' PFI0 into Destination0.

Figure 1. FlexRIO Route Signal (import).

Then, the signal can be received in the FPGA using an FPGA IO Node pointing to Routing\Destination0.

Figure 2. FlexRIO FPGA VI (Destination).

Likewise, Routing\Source0 can be routed to the PXI triggers, controller SMB trigger or chassis PFI to export a signal from the FPGA.

Figure 3. FlexRIO FPGA VI (Source).

Figure 4. FlexRIO Route Signal (import).

If your FlexRIO device returns an error when trying to connect directly to the controller's SMB or chassis' PFI trigger lines, refer to the related links for workarounds to achieve the same task.