Beckhoff TwinCAT 3 EtherCAT AL Status 0x001A: what to check first?
I'm getting an EtherCAT AL Status 0x001A Synchronization Error on my Beckhoff TwinCAT 3 system. It happens in OP mode after running for a while, or sometimes when transitioning from SAFEOP to OP for DC-synchronized drives. What should I check first?
The EtherCAT AL Status 0x001A Synchronization Error indicates that process data or synchronization events are arriving too late or out of step, causing the slave to return to SAFEOP. This fault is often seen in OP mode or during the SAFEOP to OP transition for DC-synchronized devices. It suggests issues with data integrity, controller timing, or incorrect Distributed Clock (DC) settings.
Likely causes and checks
1Process data arriving too late or missing
- Points to it
- Lost frames, CRC errors, or poor cabling can cause process data to be delayed or lost, leading to synchronization issues. This is indicated by rising LostFrames or CRC counters, or the 'DC not in sync' bit.
- Check
- Read CRC and lost frame counters per port in the online view. Thoroughly check all cabling, connectors, and shielding according to ETG.1600 standards.
2Task timing issues on the controller
- Points to it
- Real-time jitter or cycle overruns on the Beckhoff TwinCAT 3 controller can disrupt the precise timing required for EtherCAT synchronization. This is often accompanied by an increasing task exceed counter.
- Check
- Trace the exceed counter and task execution time in Scope View. Review and adjust task priorities as needed.
3Manual Distributed Clock (DC) settings changes
- Points to it
- Incorrect manual adjustments to DC settings, such as shift times or reference clock configurations, can misalign SYNC pulses and cause synchronization errors. This is particularly relevant if the problem started after a configuration change.
- Check
- Compare current DC settings with the system defaults and the device documentation to identify any manual changes. Beckhoff warns against manual DC settings.
Next check: Start by checking the EtherCAT online view for rising CRC and lost frame counters on the affected segment, and visually inspect the cabling for any issues.
Related questions
Describe the fault or upload a photo, and InduQT checks it against the manufacturer manuals. Share the result here when it helps someone else.