Revision OR Amendment in PO

Hi,

My requirement is to bring the revision no in the PO Output.We do not use version management.

Once the PO is released after that whatever value changes happens in the PO should show as version in PO output.

My query is how to capture the value changes?from which tables?

I have checked CDHDR & CDPOS but doesn't look to be helpful.

Any logic to get the revision if the total value changes in the PO

KN