Mitsubishi MELSEC L Series, User Manual, Page: 114 / 124

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9.4
Detection of Unauthorized Access and Actions
When the remote password mismatch count reaches the upper limit in unlock processing, "REMOTE PASS FAIL"
(error code: 2700) is detected.
If this occurs, unauthorized access from the outside of the system can be considered as a cause of the error.
Take the following actions as needed.
1.
Monitor the Remote password count (SD979 to SD999) and identify the connection of which
remote mismatch count has reached the upper limit in unlock processing.
2.
Stop the communication by disabling the connection as shown below.
• Select the connection in the "Ethernet diagnostics" dialog box, and force it to be deactivated.
( GX Works2 Version1 Operating Manual (Common))
[Diagnostics] [Ethernet Diagnostics] "Status of Each Connection"
• Turn on the force deactivation flag of the connection in the special register (SD1276, SD1277).
3.
Clear the "REMOTE PASS FAIL" error (error code: 2700).
The remote password count (SD979 to SD999) is also cleared.
4.
Inform your system administrator that the number of unlock processing failures exceeded the
limit, and take appropriate actions.
If the error is detected due to frequent incorrect typing by authorized users, prevent this by the following operations.
• Enable "Clear Mismatch Count when Remote Password Matches" in the "Remote Password Detail Setting" dialog
box.
• Clear the accumulated count of remote password mismatches using the special relay (SM1273).