Mitsubishi Electric FX5 User Manual page 54

Firmware update prohibited setting
Updating of the firmware can be prohibited by writing the firmware update prohibited file into the CPU module.
1.
Using the engineering tool, select the folder containing the firmware update prohibited file (FWUPDP.SYU) as the write
target file, and select the CPU built-in memory for the write target. The firmware update prohibited file is stored in the
firmware update information downloaded during the preliminary preparations. (Page 50 Firmware update method)
[Online]  [User Data]  [Write]
2.
Using the engineering tool, set a file password for the firmware update prohibited file.
[Project]  [Security]  [File Password Setting]
For details on operation, refer to the following.
GX Works3 Operating Manual
*1 Refer to  Page 478 Added and Enhanced Functions for the versions that support file password setting for the firmware update
prohibited file.
The firmware update permit/prohibit state can be confirmed with the special relay (SM912).
5 FIRMWARE UPDATE FUNCTION
52
*1