code: public static Srp withService(final int familyId, final int familyVersion) {
  		return new Srp(Type.SelectByService, true, (byte) familyId, (byte) familyVersion);
  	}
docs: Creates a search request parameter block to limit the extended search request to KNXnet/IP router
  or server devices with the given service family and corresponding family version. The mandatory flag
  of the SRP is not set.
  
  @param familyId the family ID used in the in the search request parameter block
  @param familyVersion the family version used in the in the search request parameter block
  @return search request parameter block for devices with a given service family and version