There's no Hardware configuration like a S7.

You can't add expansions modules in network view. In network view you can only add base modules as masters, base modules as slaves, TDEs, HMI etc.. All what have a ethernet port.

In LOGO! program you use only the number of inputs and outputs. Der first DI on the first digital expansions module is I9, the second I10 and so on. Der first DO on the first digital expansions module is Q5, the second Q6 and so on.

A LOGO! 0BA8 can manage the following:
DI = 24
DO = 20
AI = 8
AO = 8

This means you can connect on to a LOGO! 0BA8 base module max. two DM16 24Rs.
Base module = 8 DI and 4 DO
2 x DM16 24R = 16 DI and 16 DO
In sum, that are 24 DI and 20.

Since you have not written which base module it is, I write to you the following:
You can not directly connect the DM16 24R to a 230VAC base module. You must set an analog expansion module between the 230VAC base module and the first DM16 24R.

Follow the link.....

http://w3.siemens.com/mcms/topics/en/simatic/tia-selection-tool/Pages/tab.aspx