First of all, please refer to this page
to make sure whether the digital logic levels can be changed on your R series boards. You can follow the following steps to adjust logic levels on the PXIe or PCIe R series Board.
1. In LabVIEW project, right-click on the FPGA Target
and select Change I/O Configuration...
to open the Configure R Series I/O
2. In the Configure R Series I/O
dialog box, select the Digital Connectors
that you would like to change the logic levels for. Use the Shift
keys to select multiple channels at once.
3. Select the logic level you would like to use from the Logic Family
4. Click OK
FPGA PXIe R Series cards do not support programmatically changing the logic family with the FPGA property nodes.