All data structures used by the JES device information SSI are mapped by the IAZSSJD macro. The names of data structures and fields referenced below can be found in this macro, unless otherwise indicated.

The primary data structure used for communication with the JES device information interface is a parameter list (SSJD structure). Fields in the parameter list are differentiated as input and output fields. Input fields are used by an application program to provide detailed information upon request, such as options and device selection filters. On return from the call to the JES device information SSI, output fields of the parameter list contain the information that allows access to device data returned by the interface. Actual data structures, which contain device information, are located in the storage areas managed by the interface.