Mitsubishi Electric Melsec-QS Series Safety Application Manual page 38

4
PRECAUTIONS FOR USE OF SAFETY PLC
(3) Operation mode while a safety PLC is in operation
(4) ROM information management of a safety CPU
(5) Password management
4
4.4 Precautions for Safety Functions Maintenance
- 11
Set the operation mode of the safety PLC to SAFETY MODE when the PLC is in
operation.
Confirm the ROM information at regular intervals whether the programs and
parameters in the safety CPU module are illegally rewritten.
1) When writing a project file to ROM, check the ROM information using GX
Developer, and separately save the information.
2) With reference to the ROM information of GX Developer at regular intervals,
confirm whether the information is illegally rewritten.
3) When the information is illegally rewritten, stop the operation.
Then, recover the project using the backup project file.
For confirming the ROM information, refer to the following manual.
GX Developer Version 8 Operating Manual (Safety PLC)
The project files for GX Developer and safety CPU module are protected by
password.
Manage the registered password properly and do not leak the password except
authorized person in order to prevent the unauthorized access.