How do I set intermittent backups correctly?

Been doing a lot of trial and error trying to get this right.

What I am trying to do is create an incremental backup job that is weekly and then purges to create a new backup. Do the settings below look right?

On the menu for image backups:

  1. Interval for incremental image backups - 7 days
  2. Interval for full image backups - Disabled
  3. Maximal number of incremental image backups - 7
  4. Minimal number of incremental image backups - 6
  5. Maximal number of full image backups - 1
  6. Minimal number of full image backups - 1

I am assuming that it needs to have a full image (steps 5 and 6) and that it will purge these when it creates a new one weekly? I am not sure how to configure it correctly.