CL3 Module Stuck in Pre-Operational and Delayed Startup with B&R CANopen Master

Dear B&R Community,

We are experiencing an unusual issue with a Nanotec CL3 module (Node-ID 19) in a machine that uses a B&R CANopen Master. The machine takes approximately 1 minute and 30 seconds longer to reach the RUN state when the CL3 module is connected to the CANopen network. Without the CL3 module, this delay does not occur, and the system starts as expected.

Observed Behavior

  1. Boot-Up:
  • The CL3 module sends the Boot-Up message correctly after powering on.
  • The B&R Master sends an NMT Start command (0x01) to transition all nodes to the Operational state.
  1. Issue:
  • While other nodes transition to Operational as expected, the CL3 module remains in Pre-Operational for a prolonged time.
  • Occasionally, the module transitions to Operational after a repeated NMT Start command, but this behavior is inconsistent.
  1. Additional Findings:
  • EMCY messages such as “Life guard error or heartbeat error” are observed in the CAN trace.
  • After the error occurs, a reset (“Error reset or no error”) is logged, and the module resumes operation, but the delay persists.

Configuration Details

  • B&R Master: Standard-compliant CANopen settings (CiA 301).
  • Baudrate: 500 kbit/s.
  • CL3 Firmware Version: FIR-v19 39-B697429.
  • Heartbeat Monitoring: Enabled, using standard settings.

Steps Taken

  1. We’ve reviewed the EDS file of the CL3 module, but no specific issues were identified.
  2. The NMT Startup (1F80h) parameter on the CL3 is set to 0x00 (default), requiring an explicit NMT Start command to transition into Operational.
  3. The Error Behavior (1029h) configuration was also analyzed, and both Subindex 01h and 02h are at their default settings (0x00).

Questions for the Community

  1. Has anyone experienced similar behavior with a CL3 module or other devices in a B&R CANopen setup?
  2. Could there be specific compatibility issues or timing problems between the CL3 module and the B&R Master?
  3. Are there recommended adjustments to the B&R Master configuration or the CL3 module settings to resolve this issue?

Additional Information

I have attached the following supporting materials:

  1. Screenshots of the CAN trace taken using Vector CANalyzer, which show the observed delays.
  2. A screenshot from the B&R Logger on start up

These materials should provide further context for understanding the issue.

Thank you in advance for your insights! Any suggestions or experiences would be greatly appreciated.

Best regards,
Andreas Sporer

Hello and welcome to our community !

The logger of the PLC shows a lot of SDO errors which would basically indicate that the used EDS file does not match the device or in other words the EDS file defines Objects which are not available on the device

Hi and thank you for your response Oliver!

Yes, I’ve noticed that as well. However, I am using the EDS file provided by the manufacturer.

I also tried deactivating the objects mentioned in the errors, and those log entries disappeared, but the long startup time remains. Currently, I am using the exact EDS file and the default settings as specified by the manufacturer.

Okay - at least your test showed that the objects defined by the EDS do not exist on the device which means the EDS is “wrong” (even if it is provided by the manufacturer)

When the device starts up and sends the “bootup” message the master should start to send SDOs to configure the device - do you see this SDOs on the trace ?
Depending on the device it could take a while to download all of the SDOs
I have seen devices where the download took almost a minute until the master sends a NMT to send the slave in “OP”

Hi Oliver,

Thanks again for your support! I wanted to share an update on the issue with the CL3 module staying in Pre-Operational mode and the delayed startup.

The problem was caused by the EDS file not matching the firmware version on the CL3 module. After updating the firmware (provided by Nanotec), the module now transitions correctly to Operational mode after the NMT Start command, and the startup delay is resolved. The SDO errors have also disappeared, and communication is stable now.

If anyone experiences similar issues, I recommend checking that the firmware and EDS file are compatible.

Best regards,
Andreas

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Thanks for the feedback !

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