Error -52018 on a cRIO-906x Running an XNET Session in LabVIEW

Issue Details

I use a NI-XNET compatible module with cRIO-906x.

• Running the CAN examples for NI-XNET devices results in an error -52018.
• When I run the NI-XNET application, I get the following error:

Error -52018 occurred at XNET Write (Signal Single-point).vi
Possible reason(s):
A hardware failure has occurred. The operation could not be completed as specified.

When CAN communication is enabled via the NI-XNET modules, the system intermittently throws the following errors in the Distributed System Manager:

-65512 (The data transfer for some I/O variables on this target could not be completed in the allotted time, and the updates for some values may have been delayed. Increase the Scan Period to avoid this problem.)

-66460 (The I/O scan time exceeded the NI Scan Engine period you specified on the Scan Engine page of the target properties dialog box.)

-66461 (The I/O scan was repeatedly late, and the NI Scan Engine terminated to ensure controller stability. Correct the source of lateness and clear all major faults to restart the scan engine.

Solution

This is a known issue (#:1100525) for cRIO-906x controllers using NI-XNET (reported since NI-XNET 20.0).
A CPU spike on a cRIO-906x controller running an NI-XNET session can cause the error "A hardware error has occurred" to appear and leave the XNET module in an unrecoverable state that requires a reboot of the controller.

To address this issue, consider the following troubleshooting steps and workarounds:

• Reduce CPU load on the CompactRIO controller:
  • Identify CPU usage peaks and their potential causes.
  • Manually assign specific tasks to dedicated CPU cores (core affinity).
• Replace NI-986x modules with NI-985x series modules, which process traffic differently and do not exhibit this CPU overhead behavior (Note that you would need to switch to FPGA in this case: NI 9853 and 9852 with CompactRIO FAQ)
• Upgrade or switch to a higher-performance compatible controller other than cRIO-906x.
• Migrate CAN communication to an FPGA-based architecture
  • Note: This may require additional development and might not fully replicate NI-XNET feature set/functionality for your use case.
• Isolate module hardware conflicts through incremental testing. It was reported that only some module combinations contribute to the CPU spiking.
  • Start with a single NI-9862 module, then add remaining modules one by one.
  • Pinpoint exactly when the issue recurs to identify compatible hardware combinations or alternative module arrangements.

Additional Information

The issue only occurs when the cRIO contains an XNET module and another module on the Scan Engine. There are no errors if only the XNET module is deployed to the chassis.