Protection Level Request From Programmer; The Oem Protection Feature - GE VersaMax PLC User Manual

102 GFK-1503E
For public disclosure

7.7.1 Protection Level Request from Programmer

Upon connection to the CPU, the programming software automatically requests the CPU
to move to the highest unprotected level. That gives the programmer access to the highest
unprotected level without having to specifically request a particular level. A privilege
change may be to a lower level or to a higher level. The privilege level is changed from
the programmer by entering the new level and the correct password for that level. If the
wrong password is entered, the change is denied and a fault is logged in the PLC fault
table. A request to change to a privilege level that is not password-protected is made by
supplying the new level and an empty password.
7.7.1.1 Notes on Using Passwords
• To re-enable passwords after passwords have been disabled, the PLC must be
power-cycled with the battery removed for long enough to completely discharge the
super-capacitor and erase the PLC's memory
• If the passwords prevent changing the run/stop mode, firmware upgrades cannot be
performed if the PLC is in run mode.
• The Run/Stop switch (if configured) will place the PLC in run or stop mode
regardless of the passwords.

7.7.2 The OEM Protection Feature

The OEM protection feature is similar to the passwords and privilege levels and provides
an even higher level of security. The feature is enabled or disabled using a 1 to 7 character
password called the OEM key. When OEM protection is enabled, no write-access to the
PLC program and configuration is permitted. Reading the configuration from the PLC is
permitted. In this mode, no user flash operations are allowed. When the OEM key
password has been created, the OEM key can be locked in two ways: by choosing the
locked setting from the programming software or by power-cycling the PLC. (The OEM
key locked status does not change when PLC communications are suspended.)
7.7.2.1 Clearing Logic/Configuration, and References
It is possible to clear logic, configuration, and references from the programmer with the
CPU at any privilege level, even with the OEM key locked. Operators can clear logic,
configuration, and references, and store a new application program to the CPU without
knowing passwords. If passwords and/or the OEM key have been set and written to flash,
a read from flash updates the protection level. In this case, it is not necessary to reenter
the password to gain access to a particular level. A Clear All does not clear user flash.
VersaMax PLC User Manual