Reading data from a HR InfoObject master data

Hello All,

R/3 has 2 custom HR tables. I am pulling this data using a custom infoObject (table fields as its time dependent attributes) using Z datasources.

I want to read this data in the update rules.

For EG: To read monthly salary I would read the Employee details in the Start routine and monthly salary details using the custom InfoObject and its attributes.

I tried using the FM RSAU_READ_MASTER_DATA, but am not sure how this works. ( I tired debuggin the Code for this FM but no success).

Kinly inform how can i read the data as a lookup in update rules using Custom InfoObjects.

Regards,

KK