Mitsubishi Electric · MELSEC System Q/L Series
This error indicates a lack of response from a target CPU module during the initial communication stage within a multiple CPU system. This diagnostic occurs at power ON or reset. If this error persists after basic troubleshooting, it suggests a potential hardware fault within one of the CPU modules. The system will stop.
Click steps to track your progress.
Reset the CPU module and attempt to transition it to RUN mode again.
Verify the power supply and physical mounting of all CPU modules within the multiple CPU system.
Inspect the tracking cable connections for damage or incorrect seating if applicable to the system configuration.