Do I need to do anything different when using DayBack Online with a separated system?
No. The admin settings page in DayBack Online (where you configure your FileMaker calendar sources) asks for a File name and a Layout name. In a separated system these can be either in the interface file or in the data file, but they need to be from the same file.
There is one other consideration around access. You'll need to grant XML web publishing privileges to your data file in any case: if you use a layout in you interface file you'll need to grant XML web publishing privileges to both the interface file and the data file. And the FileMaker account name and password you put in the PHPrelay file will also need to work in the data file for sure, but in both the data file and the interface file if you use a layout from interface.
If you have more questions about this, please don't hesitate to contact us.