Mitsubishi QD75P1N User Manual page 796

APPENDICES
MELSEC-Q
[2] Error history, warning history
Sixteen error history logs and sixteen warning history logs can be monitored. When the
number of logs exceeds 16, the latest log overwrites the oldest log so that the latest 16
logs can be monitored all the time.
To monitor the error history and warning history, register the QD75 to the "Intelligent
Function Module Monitor Window".
For details on the registration method and monitoring method, refer to the following.
GX Works2 Version1 Operating Manual (Intelligent Function Module)
Appendix - 110