Mitsubishi Electric MELSEC-Q Series User Manual page 214

2) CPU resets and errors occurred before power-off are recorded in the "Error
History" window.
[Diagnostics] [System Monitor]
In the single "Error History" window, the error history of CPU modules and
intelligent function modules (including the Simple Motion module) can be
viewed.
3) If data link cannot be performed even after the above operation is performed,
perform the following:
• Checking for error using CC-Link IE Field Network diagnostics (Refer to
Chapter 9.)
• Checking the LEDs (Refer to Section 12.3.)
• Troubleshooting by symptom (Refer to Section 12.4.)
[System Error History] button
12 - 4
Chapter 12 TROUBLESHOOTING