Automatic Debit position/Manual debit position

Hi Friends,

Please let me know the use of automatic debit position and manual debit position.

How can I achieve below scenario throught two-step procedure:

Interest due: need to post by FWSO

Entry: Dr Interest receivable 1000

          Cr Interest Income  1000

Interest Payment: Need topost by FWZE

Entry: Dr Cash/bank  1000

           Cr Interest receivable 1000

Kindly suggest me what configuration steps required to achieve this one.

Thanks,

Naga