Wrong User Data
ABB · AC500
What does 8449 mean?
The user-defined program or configuration data stored in the Safety PLC is incorrect, corrupted, or incompatible. This prevents the PLC from executing its intended safety logic or loading its correct parameters, posing a direct risk to machine operation and safety functions. The PLC cannot operate as programmed.
Common Causes
- The safety program (user data) downloaded to the safety PLC is incompatible with the PLC's firmware version or hardware revision.
- Corrupted user program stored in the PLC's memory due to power failure during download or memory write errors.
- Attempted download of a non-safety program to the safety partition of the PLC, or a standard program with incorrect safety-related flags.
- Mismatched compiler settings or project configuration (e.g., safety profile version) between the engineering software and the target PLC.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Compare the firmware version of the safety PLC (e.g., visible in TIA Portal online diagnostics) with the firmware version specified in the engineering project.
- 2
Perform a memory reset (e.g., "MRES" or "Clear all") on the safety PLC to erase corrupted user data, then attempt a full project download.
- 3
Ensure the correct safety program (F-program) is selected for download and that no compilation errors were present during the last build.
- 4
Verify that the safety configuration parameters (e.g., F-CPU ID, checksum settings) in the engineering project match the target PLC's requirements.
- 5
Download a known good, previously validated safety project to the safety PLC.
- 6
If the issue persists, consider replacing the safety PLC module, as it might have internal memory defects.