What causes Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT fault AL 0x0030?

1. DC operating mode not supported with the selected process data or cycle time: Compare the DC tab setting and the task cycle time with what the device documentation allows. 2. Cycle time outside the device’s supported range: Check the minimum/maximum cycle time of the device. 3. Reference clock set manually to a device without DC support: Check the reference clock selection in the master’s DC settings.

EtherCAT AL Status 0x0030 Invalid DC SYNC Configuration

Beckhoff: the distributed clock configuration is invalid due to application requirements. Raised on P→S, S→O or in OP; resulting state PREOP + error or SAFEOP + error.

Diagnose this with AI

Upload a keypad photo, the fault history or a parameter export from your Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT. InduQT compares the evidence and suggests the next useful checks.

Try Free PLC Fault Diagnostic

When it happens

At startup on PREOP to SAFEOP or SAFEOP to OP
After changing the task cycle time or the DC operating mode of a drive or terminal

Likely causes and checks

1DC operating mode not supported with the selected process data or cycle time

Points to it: Fault after changing the DC mode (e.g. FreeRun/SM-synchron/DC) or the task cycle.
Check: Compare the DC tab setting and the task cycle time with what the device documentation allows.

2Cycle time outside the device’s supported range

Points to it: Related codes 0x0035 (DC invalid sync cycle time) or 0x0036 (Sync0 cycle time) appear on other devices.
Check: Check the minimum/maximum cycle time of the device.

3Reference clock set manually to a device without DC support

Points to it: Beckhoff: slaves will not switch to OP and report PREOP_ERR; logger "is reference clock device, but does not support dc!".
Check: Check the reference clock selection in the master’s DC settings.

Telling it apart

0x0030 is a configuration refusal at startup; 0x001A and 0x002C are sync losses in operation.
0x0035/0x0036 point specifically to the cycle time.

Relevant parameters

Parameter	Name	Why it matters
Slave DC tab	Operation mode (FreeRun / SM-synchron / DC)	Must be a mode the device supports with the selected PDOs.
Task cycle time	Sync task cycle	Must lie within the device’s supported range.

Evidence to collect

DC tab of the slave and DC settings of the master
Task cycle time
Logger export (reference clock and "DC not synchronized" messages)
Device documentation of supported DC modes

Work on fuel trains, burners, pressure vessels and electrical equipment must be done by qualified personnel following the manufacturer’s documentation and local codes. Never bypass a safety device or interlock.