How do I save and recall persistent variables? Where is this data stored?

Codesys & I/O Q&A
How do I save and recall persistent variables? Where is this data stored? https://forum.weintekusa.com/uploads/db0776/optimized/1X/b179351d1e5e97c8a24271b3c5677a384cf4858e_2_1024x535.jpeg
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Just trying to understand the sequence. For reference, we know that ‘Download’ and ‘Login with online changes’ are two different functions. Also, we’ll assume data from a program was previously stored in the HMI as PersistentVars. Therefore,

  1. When a program ‘Download’ is required, is the data previously stored in the Weintek memory deleted? Or is it kept and loaded into the newly downloaded program?
  2. When a ‘Login with online changes’ occurs, same question as above, previous data deleted or loaded into program?
  3. In both cases above, if previous data is loaded into the program after ‘Download’ or ‘Login with online changes’, when does that occur?
How to backup CODESYS persistent variables between project downloads