Fair enough.
There are no such things as dumb questions.
(except for questions that ignore previously given advice).
If you need help with the Siemens PLC, then we can also help, if you state the exact type no of the CPU.
I just happened to think of one important stumplestone:
Both the AB PLC and the Siemens PLC may be password protected.
If that is the case, then it may still be possible to perform a backup. However, I wont discuss how to bypass passwords, and advice others that read this to refrain from the same.
So, in the end it may require help from either AB or Siemens or both.
What is the 'history' of the machines ?