Et200s and proface via profibus

Hi fellas,
As I said I need to interface et200s Siemens plc with proface htb unit as a slave. Had files has been uploaded. But what is the concept of addressing profibus external device. If CPU recognizes profi device as a io unit. Then what happens if the same io numbers configure in master plc inputs, output module.

it would help if you specify the exact type no's of the equipment in question.

But generally, the IO addresses in a Profibus system is defined in the master, not the slave. In the configuration of the master, it will not be possible to assign the same addresses twice.