A physical access control system, PACS, (100) comprises at least one reader (103) and a method performed comprises a number of actions that begin with obtaining a first indication that the at least one reader (103) requires reader configuration information. In response to the first indication, the control unit obtains the required reader configuration information. A protocol (108, 110) with which the at least one reader (103) is capable of communicating with a control unit (101) is determined and the required reader configuration information is then interpreted into protocol specific data. Using the determined protocol, the control unit (101) then transmits the protocol specific data to the at least one reader (103).