where to find Release notes for DIA versions ?

[b]Using Connect port X4,
Where our old application is running on DIA 1.1.16 and python 2.4.3 environment.

We need to upgrade it to DIA with Python 2.4.3

So, I am searching for the changes made on DIA from
version 1.1.16 to version 2.3.07.

Where can i get the documents related to the changes ?[/b]

The only file available in digi site is ftp://ftp1.digi.com/support/developmentsoftware/93000647_G.txt
I think you need to contact Digi people for this.