Mitsubishi Electric MELSEC iQ-RJ71EN71 User Manual page 334

End Error details and causes
code
63H In communications using the fixed buffer, the remote password of the
port for the destination Ethernet module is in the lock status.
3 TROUBLESHOOTING
332
3.8 End Codes Returned to an External Device During Data Communications
Action
• After unlocking the remote password using the SLMP, perform
communications using the fixed buffer.
• Exclude ports used for communications using the fixed buffer from the
targets of the remote password check.