CAN diagnostic and solutions

15 Jul 2025

CANcheck, canAnalyser, PCAN-Diag FD & Co: Diagnosing and resolving physical faults on the CAN bus to prevent system failures.

 

APPLICABLE PRODUCTS

canAnalyser, CANcheck, PCAN-Diag FD, PCAN-Diag 2, PCAN-MiniDiag FD.

 

ISSUE / QUESTION / SYMPTOM

Problem – Why take action? CAN bus issues are costly:

  • Delayed commissioning
  • Returns and complaints
  • Sporadic system failures
  • Production downtimes
  • Safety risks and accidents.
     

POSSIBLE CAUSES / ANSWER

Typical Causes – What’s Behind It? Physical Causes of CAN Errors:
 

Wiring & Cabling:

  • Incorrect cable (e.g. not 120 Ohm impedance, too small cross-section, not twisted)
  • Incorrect wiring (CAN_H, CAN_L, CAN_GND, CAN_Shield)
  • Poor grounding (e.g. missing reference point, potential differences, CAN_Shield not grounded on one side)

Topology Errors:

  • Faulty CAN topology (e.g. long stubs)
  • Incorrect CAN bus termination (resistor values, placement)

Signal Quality:

  • Reflections (e.g. due to open line ends)
  • Poor signal edge steepness (e.g. due to capacitive load)
  • Poor signal levels
  • Electrical interference (e.g. EMC, induced disturbances)

Defective Hardware:

  • Faulty CAN transceivers

ADDITIONAL INFO

Analysis & Diagnosis – How to Identify the Problem?

Products for Preventive CAN Diagnosis:

  • USB-to-CAN V2 (PCIe-CAN Interface Cards):
    Robust interface for PC-based CAN communication and CAN diagnostics.
  • canAnalyser V3 mini (free):
    Entry-level tool for CAN monitoring and detection of CAN error frames.
    Note: CAN error frames always indicate a physical issue on the CAN bus.
  • canAnalyser V3 Lite / Standard:
    Advanced analysis features (filters, signal module, replay modules, CANopen modules).
  • CANcheck:
    Testing of wiring, termination, CAN signal levels, and CAN error frames.
  • PCAN Diag:
    In-depth analysis of CAN bus issues.

Optimization & Improvement – How to Fix the Problem?

Products for Signal Enhancement & Bus Stabilization:

  • CAN Repeater & FO-CAN Repeater:
    CAN signal improvement, galvanic isolation, star topology support, distribution of capacitive load.
  • CANbridge NT:
    CAN signal improvement, galvanic isolation, star topology, capacitive load distribution, CAN bus extension, message filtering, message routing.
  • CAN@net NT:
    CAN signal improvement, galvanic isolation, star topology, capacitive load distribution, CAN bus extension, message filtering, message routing, monitoring.

Service & Support – Who Can Help?

  • Technical consulting & support
  • On-site diagnostics & training
  • Assistance with commissioning & troubleshooting

Customer Benefits – What’s in It for Me?

  • Avoidance of failures
  • Faster commissioning
  • Increased system availability
  • Long-term reliability
  • Cost savings through prevention

Next Steps – What’s Next?

  • Free consultation
  • On-site or remote CAN bus check
  • Customized offer for devices & support

 

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