Mitsubishi Electric MELSEC iQ-R Series Configuration Manual page 153

Setting for firmware update prohibition
The firmware update can be prohibited by writing a firmware update prohibition file to the CPU module and setting a file
password.
1.
Using an engineering tool, write the firmware update prohibition file (FWUPDP.SYU) to the "$MELPRJ$" folder in the
data memory of the CPU module. The firmware update prohibition file (FWUPDP.SYU) is included in the firmware update
information obtained for the preparation. ( Page 149 Preparation)
[Online]  [User Data]  [Write]
2.
Using the engineering tool, set a file password to the firmware update prohibition file.
[Project]  [Security]  [File Password Setting]
For details on the operation method, refer to the following.
 GX Works3 Operating Manual
Appendix 1 Checking Production Information and Firmware Version
A
APPX
151