BI Intregation With ECC

Hi,

I have installed ECC with BI in single stak (single system).

I have configured 800 client as well. i know if BI & ECC are different systems then we create source system with RFC

But here for BI has already has source system, where as ECC does not have.

when i try to create source system for SAP in rsa1 T-code it is saying source system is already exist, but i dont find any RFC under SAP. i can find RFC under BI.

What is process in this case. how do i get the data from ECC, how do i test the ECC data in BI system.

it is really appriciate the help.

Thanks,

Sreeni.