National Instruments PCI-8331 - Manual (Page 26)

Chapter 3 Hardware and Software Overview
MXI-4 Series User Manual 3-6 ni.com
MXI-4 Linked Chassis Status
When your PXI system contains a chassis connected through MXI-4, MAX
can show additional information about the chassis status depending on the
state of the MXI-4 link. If there is a problem with the link or the chassis is
not connected, MAX will display the chassis with a yellow exclamation
point indicating a warning (refer to Figure 3-4).
Figure 3-4. Chassis Status Indication in Configuration Tree