Skip to main content

Troubleshooting

CANbus

Problem

Possible Solution

The CANbus is red in the device tree directly after the application download.

Check the status page and logger page of the CAN bus. You will find more information here.

Possible causes:

  • The driver could not be opened:

    • The network ID is set too large.

      In the CAN bus, a network ID was set for which there is no driver instance. If the controller has only two CAN interfaces, then valid values for the network ID are only 0 and 1.

    • The driver component was not loaded in the runtime.

      Check whether the CAN driver component has been loaded correctly (see the logger and the chapter "Runtime Configuration").

    • The memory is insufficient.

      Opening the CAN driver requires memory. Too little memory may be available.

  • A bus error has occurred:

The CAN bus switches between red and green or remains red in runtime mode.

Check the status page and logger page of the CAN bus. You will find more information here.

Possible causes:

  • A bus error has occurred.

    The CAN chip signals a bus error. See the chapter "Diagnosis of Hardware Failures".

The CAN bus has a red exclamation mark.

Check the status page and logger page of the CAN bus. You will find more information here.

Possible causes:

  • A bus warning is queued.

    The CAN chip signals a bus warning. The bus subscribers can send and receive messages, but this can lead to unexpected behavior because CAN telegrams could get lost.

Check the cables.

For more information, see: Diagnosis of Hardware Failures

The CAN bus has a gray exclamation mark.

Check the status page and logger page of the CAN bus. You will find more information here.

Possible causes:

  • An error occurred in the past which has already been corrected. For example, this can be a temporary short circuit between CANLow and CANHigh. The error can be confirmed on the status page by clicking the Confirm button or the command in the context menu of the CAN bus.

: