Code 31 in Windows Device Manager While Using a MXI Connection

Updated Jul 28, 2023

Reported In


  • MXI Cable


  • PXI Platform Services

Issue Details

I can't see my chassis in MAX, but am seeing code 31 in Windows Device manager on the Upstream or Downstream PXI Switch port. The link light on my PXI(e) card might also be green.
Figure 1: Error example


Figure 2: Example Root Bus Partition
  • In the above example, the PCIe card is on Root Bus Partition 2 since the PCIe bus is using 43, and 43 is between 20 (32) and 2b (43), but since this partition only has 10 resources, a 20 resource setup can't be used, which can be estimated here.
  • Try ALL slots with and without the BIOS compatibility (including graphics card slots) to get on a different partition. These partitions often can't be changed or reallocated.
  • Consult with the motherboard manufacturer to check if there's a BIOS setting that could change the root bus partitions and which PCIe slots correspond to which partitions in the different configurations.