Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT fault AL 0x0024: Invalid input mapping
Beckhoff: process data are described by PDO configuration (variables, usually 0x6nnn inputs) and PDO assignment (0x1C13 lists the input PDOs 0x1Amm). If the mapping set on the Process Data tab and the mapping the slave expects do not match, the slave returns 0x0024 on P→S and stays in PREOP + error.
Diagnose this with AI
Try Free PLC Fault Diagnostic 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.
When it happens
- At EtherCAT startup on the transition PREOP to SAFEOP
Likely causes and checks
1PDO selection not supported by this device or revision
- Points to it
- Fault after changing PDOs, or after replacing the device with another revision.
- Check
- Compare the PDO assignment (0x1C13) in the project with the ESI and the device documentation for that revision.
2Bus coupler / modular device whose connected modules differ from the configuration
- Points to it
- Beckhoff example for outputs: terminals connected to a coupler differ from those configured.
- Check
- Compare the physical modules with the configured ones via an online scan.
3Startup (CoE) list writes a conflicting mapping
- Points to it
- Fault persists with a correct Process Data tab; custom startup entries exist.
- Check
- Review the Startup tab for 0x1A0x / 0x1C13 entries.
Telling it apart
- 0x0024 is the input PDO mapping; 0x0025 is the output PDO mapping; 0x001E is the input SyncManager configuration.
- 0x0024 stops the slave in PREOP; 0x001D/0x001E leave it in SAFEOP + error.
Evidence to collect
- Process Data tab screenshot (PDO assignment and content)
- Startup tab entries
- Online scan result and device revision
- Logger export with the AL status code
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.
Related
- Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT AL 0x001D: Invalid output configuration
- Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT AL 0x001E: Invalid input configuration
- Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT Slave not in OP: EtherCAT slave stuck in INIT, PREOP or SAFEOP
- All Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT fault codes