10 CPU Unit Functions
Enabling and Disabling Program Overwriting
Overview
In addition to using the DIP switch as described above, the program (or selected tasks) can also be
write-protected if the write protection option is selected from the CX-Programmer when a password is
being registered for the entire program or those selected tasks. The write protection setting can prevent
unauthorized or accidental overwriting of the program.
CX-Programmer
When a password is being registered for the entire user
program or selected tasks, program write-protection can be
Password?
enabled/disabled with an option setting.
The user program cannot be overwritten.
CPU Unit
The user program cannot be overwritten.
• If the selected tasks or program are write-protected by selecting this option when registering a pass-
word, only the tasks (program) that are password-protected will be protected from overwriting. It will
still be possible to overwrite other tasks or programs with operations such as online editing and task
downloading.
• All tasks (programs) can be overwritten when program read protection is not enabled.
• The setting to enable/disable creating program files will not take effect unless the program is trans-
ferred to the CPU Unit. Always transfer the program after changing this setting.
Operating Procedure
1
To register a password in the UM read protection Box or Task read protection Box, select the
Prohibit from overwriting to a protected program Option in the Protection Tab Page in the PLC
Properties Dialog Box of the CX-Programmer.
2
Either select PLC - Transfer - To PLC to transfer the program or select PLC - Protection - Set
Password and click the OK button.
10-54
Overwriting can be prohibited with password protection,
regardless of the DIP switch setting.
Memory Card
Properties
CJ2 CPU Unit Software User's Manual