To detect errors, right-click the CAN node in the diagram and select Error Terminals. The resulting Error In and Error Out terminals provide the standard LabVIEW error cluster for error handling.

NI recommends using Error Terminals for CAN development. For some CAN nodes, the error terminals are essential. For example, you need to evaluate Error Out from a CAN Input node to determine if a CAN frame was received within the specified Input Timeout (ms). The only cost of using error terminals is slight FPGA gate usage, not performance.

When an error occurs, use the LabVIEW Explain Error Help dialog box for a description of the error code. Right-click an error cluster and select Explain Error from the shortcut menu for more information about the error. You also can select Explain Error and enter the returned error code into the dialog box.

The error descriptions in the Explain Error dialog box are generic to all CompactRIO (C Series) modules. The following sections provide information specific to the CAN module.

Module Communication Error

Error Code: 65536

This error occurs when there is a catastrophic error with communication to the CAN module. Catastrophic errors can result when the following events occur:

  • Unplug the CAN module.
  • Invoke a CAN node while the CompactRIO Sleep line is asserted. This error does not occur for the Sleep feature of the CAN transceiver (Transceiver Mode property).
  • Invoke a CAN node before the CAN module has reconfigured itself after the CompactRIO Sleep line deasserts (approximately 1 second).
  • An invalid data transfer between LabVIEW FPGA and the CAN module.

Incorrect Module Error

Error Code: 65537

This error occurs if the user plugs in another CompactRIO module into a slot configured for a CAN module.

Timeout Error

Error Code: 65538

This error occurs when:

  • CAN Input does not receive a valid CAN frame within the specified Input Timeout (ms).
  • CAN Output does not detect an available element in the output FIFO within the specified Output Timeout (ms).
  • An I/O Method or I/O Property node does not detect an available element in the output FIFO within the specified Output Timeout (ms). Refer to Arbitration for more information.

This error is not returned when a Wait or Abort Transmit method times out. Those methods indicate a timeout in the Timed Out? terminal.

Data Overflow Error

Error Code 65539

This error occurs from the CAN Input node. This indicates that you did not invoke CAN Input fast enough, and one or more CAN frames were lost. Since LabVIEW FPGA executes at a much faster rate than CAN frames are received, this can only happen when you introduce artificial delays in your FPGA VI. Invoke CAN Input at least once every 50 microseconds to avoid this error.

Not Run Mode Error

Error Code: 65540

This error occurs when communication is stopped and you use a CAN feature that requires communication to be started first. Refer to the preceding documentation to determine which features require running communication.

Start communication on the CAN port before using the feature (CAN Output, I/O Method, or I/O Property node). Start communication with one of the following methods:
  • enable Auto Start in the Module Configuration.
  • Invoke the Start method.

Run Mode Error

Error Code 65541

This error occurs when communication is started and you use a CAN feature that requires communication to be stopped. Refer to the preceding documentation to determine which feature cannot be used while communication is running.

Stop communication on the CAN port before using the feature (usually writing a property). To set initial properties, disable Auto Start in the Module Configuration, then set the desired properties, invoke the Start method, and proceed with your remaining application. To set properties in your main application loop, invoke the Stop method, set the relevant properties, then invoke the Start method.

Feature Not Supported Error

Error Code 65546

This error is returned by the CAN Property node when a property selected for reading or writing is not supported on the specified module.

Too Many Error Frames Warning

Error Code 65547

This warning occurs when a serious fault is detected on the node, resulting in a burst of error frames. This warning indicates that one or more error frames may not be reported to LabVIEW FPGA. All valid CAN data frames are reported.

Verify that cabling, baud rate, and termination of all nodes on the network are correct, and that proper bus power is supplied.