Solution
If you are using MAX 2.x or earlier, PXI Chassis, themselves, will not show up unless you are using a Combo Chassis, in which case there is an SCXI portion that you can add manually. If you are using MAX 3.x or later, then your chassis should show up under
PXI System within Devices and Interfaces.
You may need to right-click on the PXI System and choose to
Identify as >> External PC to select your particular controller and chassis. After doing this, you may need to reboot your computer and then Windows should find the devices automatically. This only applies to PXI specific chassis, not PXI Express chassis.