Solution
Some drivers like NI-DAQmx, NI-DCPower or FlexRIO allow pointing directly to the PFI lines in the chassis to trigger the card, as shown in the code snippet below.

If your are working with a card that uses a driver that returns an error when attempting this, or does not have an option to point directly to the PFI lines in the chassis (like NI-DMM or NI-Scope, as of November 2019), you can use the method shown below to connect the PFI lines in the chassis to the PXI Trigger Lines in the chassis backplane and point the card's trigger to the chosen PXI Trigger Line instead..
Note: the pictures in this article are code snippets. To use them, download them and drag then into a blank LabVIEW VI block diagram. The shown code will be automatically created.