SDAA410 June   2026 AM2611 , AM2612 , AM2612-Q1 , AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1 , AM263P2 , AM263P2-Q1 , AM263P4 , AM263P4-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 The Challenge of Determinism in Robotics
    2. 1.2 Why standard ethernet fails for real-time communication
      1. 1.2.1 Head-of-Line Blocking
      2. 1.2.2 Lack of Time Synchronization
      3. 1.2.3 No Traffic Scheduling
    3. 1.3 Time-Sensitive Networking (TSN) based proposed solution
      1. 1.3.1 What is TSN?
      2. 1.3.2 IEEE 1588 (802.1AS gPTP - generalized Precision Time Protocol)
      3. 1.3.3 IEEE 802.1Q (VLAN)
      4. 1.3.4 IEEE 802.1Qbu/Qbr (IET - Interspersing Express Traffic / Frame Preemption)
      5. 1.3.5 IEEE 802.1Qbv (EST - Enhancements for Scheduled Traffic)
      6. 1.3.6 CPSW Specific hardware features
  5. 2Sample Use Cases: Distributed Motion Control in Robotics
    1. 2.1 Representative scenario
    2. 2.2 Network Topology Requirements
      1. 2.2.1 Why Daisy-Chain?
      2. 2.2.2 Real world applications of daisy chain ethernet solutions
    3. 2.3 Communication Requirements
    4. 2.4 Test Implementation
  6. 3System Overview and Architecture
    1. 3.1 Hardware Architecture
      1. 3.1.1 AM261x LaunchPad
      2. 3.1.2 CPSW Sub-System overview:
    2. 3.2 Software architecture
  7. 4Sample Implementation
    1. 4.1 Standard Ethernet + CPSW InterVLAN routing
      1. 4.1.1 What is Inter-VLAN Routing
      2. 4.1.2 How This Implementation leverages Inter-VLAN Routing:
      3. 4.1.3 Test-1 Benchmarks
    2. 4.2 Integrating gPTP Time Synchronization (IEEE802.1AS)
      1. 4.2.1 What is PTP time synchronization?
      2. 4.2.2 How this implementation uses GPTP time synchronization
      3. 4.2.3 Test-2 Benchmarks
    3. 4.3 Integrating VLAN (IEEE802.1Q)
      1. 4.3.1 What is VLAN?
      2. 4.3.2 How this implementation leverages VLAN
      3. 4.3.3 Test-3 benchmarks
    4. 4.4 Integrating IET Frame Preemption (IEEE802.1Qbu/Qbr)
      1. 4.4.1 What is IET (Interspersed Express Traffic)?
      2. 4.4.2 How this implementation leverages IET
      3. 4.4.3 Test-4 Benchmarks
    5. 4.5 Integrating EST scheduling (IEEE802.1Qbv)
      1. 4.5.1 What is EST?
  8. 5Conclusion
  9. 6Challenges and Debug considerations
    1. 6.1 Network Topology Verification
    2. 6.2 Traffic Flow Analysis
    3. 6.3 Host Port Traffic Monitoring
    4. 6.4 PHY Link Management
    5. 6.5 Packets not forwarded to next node
    6. 6.6 Error Handling and Retries
    7. 6.7 High latency or Jitter for high priority packets
    8. 6.8 gPTP not synchronizing
  10. 7References

2.1 Representative scenario

Consider an industrial robot arm with each joint containing:

  • Brushless DC motors with encoder (position feedback)
  • Torque sensor (force feedback for compliant motion)
  • Brake actuator (safety function)
  • Local controller (joint-level motion interpolation)

A central motion controller generates trajectory commands at 1 kHz (1 millisecond cycle time) and requires position feedback from all joints to compute the next control output. Requirements dictate that if any joint fails to respond within the cycle deadline, all joints must enter a safe braking state. This needs a strong reliable and deterministic communication backbone, in this case implemented over standard ethernet.