[?]: unprotect Logix CPU Security

al29a · Post by **al29a** » Wed Jul 29, 2009 6:42 am

Hi everybody,

One very kind person has secured Logix5550 PLC using Logix CPU Security.
Now I can not upload and download program to it.

Is it any way to upload curent program or download new program to the PLC, or unsecure the PCL?

marshjhm · Post by **marshjhm** » Tue Aug 18, 2009 7:54 pm

If you just want to reuse the processor you could unplug the battery and wait.
The memory will be erased and the processor will be returned to the default state.
Then you can download a new program to it.
If you want the program in it, well that is another problem altogether.