PC System resources
Check Task Manager
Too many open programs may have implications on available system resources such as memory and CPU availability and may cause poor performance of the tool:
- Open Task Manager and look for heavy users of system resources and shut down unneeded applications.
- Ensure a minimum of 8GB of RAM is installed on the target PC
Wiring and Hardware setup
Check wiring
If the dongle is connected properly to the SLSS CANAnalyser and there is no Incoming data, it may be caused by a wiring issue or a USB cable issue.
- Verify proper pinout for interfacing to the DB9 connector in the section titled “Connector Pinouts”.
- Look for any loose, shorted or damaged wiring, especially in long buses.
- Verify that the ground is shared between all CAN nodes.
- Ensure that the USB cable is a USB 2.0 or USB 3.0 data capable cable.
- Ensure the bus is properly terminated with 120-ohm resistors at both ends of the bus.
If the dongle has no LEDs lit up at all then the dongle is either not receiving proper power or the dongle is defective.
- Ensure USB cable is tested as a good cable.
- If using the DB9 to power the dongle on Storage CAN or Lab CAN, verify >7VDC is applied to pin 9.
Noise issues
If the dongle is connected properly to the SLSS CANAnalyser and there are erroneous or unexpected or missing data showing, there may be a noise issue.
- If the bus is too long or not shielded properly, it may pick up noise.
- Implement twisted pair wiring for High and Low pins per channel to reduce noise.
Matching bus types
If the dongle is connected properly to the SLSS CANAnalyser and there is no Incoming data or only partial CAN 2.0 data, it may be caused by a mixture or mismatch of CAN 2.0 and CAN FD nodes.
- Ensure all nodes are using either CAN 2.0 or CAN FD-compliant nodes, as mixing CAN 2.0 and CAN FD nodes may cause unexpected results.
- IF CAN FD is required, ensure all nodes’ controllers are CAN FD-compatible. CAN 2.0 controllers may misinterpret CAN FD messages, leading to errors.
- CAN 2.0 nodes are not compatible with CAN FD higher data rates
Dongle Hardware Configuration
A bus with CAN 2.0 only nodes is very forgiving on the hardware connection configuration settings, however a bus with CAN FD and especially with bit rate switch is extremely sensitive to precise configuration so please verify the settings carefully! |
Check arbitration bitrate setup
- Ensure that all nodes on the bus are configured to use the same nominal arbitration bit rate.
- Typical rates: 500 kbit/s or 1 Mbit/s.
Check data bit rate setup (CAN FD only)
- Verify that the bit rate setting matches the target bus configuration
- Ensure that the data bit rate multiplier is properly configured (usually a multiple of the nominal bit rate).
Verify if manual settings are required or not (CAN FD only)
- When not using the manual settings, set the multiplier to provide the correct data bitrate. Eg. Arbitration bitrate of 500 kbit/s with a multiplier of x8 equals 4000 kbit/s data bitrate
- When not using the manual settings, note that the sample point percentage is a default of 75%. Use manual settings if another sample point is required.
Synchronize timing segments (CAN FD only when activating the manual settings)
- For both arbitration and data bitrates, adjust prescalers, PSEG1, PSEG2, SJW and TDC to optimize bus performance based on network size and wire length.
- Check sample point settings to avoid improper sampling of the signal.
- Setting these improperly may cause unexpected problems and may even cause the bus to crash or go into bus off mode
Specific other hardware configuration issues
Other causes of data not being seen in the Incoming CAN Data tab may be caused by one of these settings
- If bus interaction mode is set to off
- Incorrectly configuring the configurable termination resistor setting. A bus must be properly terminated with 120-ohm resistors at both ends of the bus so if interfacing to an existing terminated bus, set them to disabled, otherwise ensure they are enabled. CAN FD buses are more sensitive to this setting so be cognizant of this setting
If trying to send messages in the Send CAN Messages tab does not produce the actual messages being sent on to the bus, it may be disabled in the hardware configuration
- Ensure that the Send CAN messages are enabled.
Bit Rate Switch (BRS) Issues
If interfacing to a CAN FD bus that used bit rate switch messages, extra care is required to avoid bus crash issues and missed messages.Mixed BRS modes on the same bus
- Ensure that all nodes are set to either use or not use BRS. Mixing nodes with BRS enabled and disabled can cause arbitration issues.
- Do not add send messages with the same ID having CAN FD bit rate switch and without bit rate switch
Diagnosing Specific Issues
Bus Off Errors
- This occurs when a node repeatedly fails to transmit or receive messages. If this occurs, try to reconnect the dongle to see if the dongle settings were the cause. If this does not work then the bus off error is caused by another node on the bus.