Mitsubishi Electric · MELSEC System Q/L Series
The device memory in the CPU module is faulty. This can also occur if a device address outside the valid range is accessed due to indexing, potentially overwriting system device memory. This diagnostic occurs at power ON, after a reset, or upon execution of an END instruction (for specific Qn(H) series models).
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Implement noise reduction measures for the control system environment.
When indexing is performed, check the value of the index register to ensure it is within the valid device range.
Reset the CPU module and attempt to RUN it again.
If the same error is displayed again after resetting, diagnose for a CPU module hardware fault.