NI-XNET Port LED Blinks Red

Updated Mar 29, 2019

Reported In


  • USB-8501
  • USB-8502
  • USB-8506
  • PCI-8511
  • PCI-8512
  • PCI-8513
  • PCI-8516
  • PCI-8517
  • PCIe-8510
  • PXI-8511
  • PXI-8512
  • PXI-8513
  • PXI-8516
  • PXI-8517
  • PXIe-8510
  • TRC-8542
  • TRC-8543
  • TRC-8546
  • NI-9861
  • NI-9862
  • NI-9866


  • LabVIEW
  • VeriStand



Issue Details

The port LED on my XNET device when I start the communication blinks red. 


The port LED blinks red if a NI-XNET catastrophic error occurs as indicated in the NI-XNET manual.

There are several reason for this issue:
  1. Verify that the cabling is working properly.​
  2. Check the termination resistors section in the device Getting Started Guide to verify that the termination resistors match the nominal impedance of the CAN cable. The termination resistance may become out of tolerance to support both devices.
  3. Use bus monitor to look at the activity on the bus while this behavior occurs and check for error frames.
  4. Verify that you are writing the right XNET messages.
  5. Perform a loop-back test by using the Loopback, located in the NI Example Finder. Follow the file path: Hardware Input and Output >> CAN >> NI-XNET >> Loopback Test to verify correct cabling.
  6. If addressing the cabling, termination resistors, and performing these two troubleshooting steps do not lead to a solution, contact NI Support.