Here is a simple how to guide with screen shots on configuring RFC in BI7 for connecting to ECC6 Server.

1. T-code SM59
2. Use SAP standard connection for RFC under ABAP:
3. Go to T90CLNT090 which is standard RFC connection and exists both in BI7 as well as in ECC6 IDES.
4. Double click to edit settings for this RFC connection. You need to specify the IP for the ECC6 server and create a password for the default USER “Connector” for both ECC6 server and in BI7 server. Usually, in ECC6 server, the user “Connector” is already created by default and is locked. You need to unlock it and give it the same password as given in BI7. Enter the description, Target host, System number. Press Enter to confirm your entries and save.
5. Go to Logon and Security Tab and enter a password for user “Connector”. Remember to enter the same password in ECC6 server for user “Connector” under T-code SU01 (and unlock the user “Connector” in ECC6 server also, if locked).
   Let’s say you have entered “sap12345” as password in the screen below for user “Connector”.
6. Save your settings in this BI7 server, logon to your ECC6 server and enter T-code SU01. First make sure that the user “Connector” is unlocked.
7. Enter the same password as selected in previous screen 5 “sap12345” using the “change password” button on the top of screen below.
8. Save and exit from ECC6 server. Return to your BI7 server screen where you left it previously i.e. at the RFC destination screen in step 5. Press button “Connection Test” to test your connection settings.
9. You will see following screen if your connection settings are successful.
10. Press Back button. Now test if user “Connector” can logon to ECC6 server for data extraction. Click on “Remote Logon” button on top of the RFC connection screen.
11. If your settings are correct, you should be able to logon to your ECC6 server from this screen directly.
12. You have successfully logged on to SAP ECC6 server from SAP BI7 using User “Connector”. The two systems are now connected successfully.

To do the same steps with screen shots, Refer the Configuration Document.