FSSDEF (Functional Subsystem Definition)

Use the FSSDEF statement to define the characteristics of a functional subsystem (FSS) which operates in its own address space. Use a FSSDEF statement for either of the following:

To define one or more C/I FSSs.
To define one or more output writer FSSs for printers that you define to run in FSS mode (through the DEVICE initialization statement). You can define more than one printer to run under the control of a single output writer FSS. If you do not define an output writer FSS for each printer that requires one, JES3 creates an FSS using default values.

For guidelines on how to choose values for the FSSDEF statement parameters, see “Configuring C/I Processing” in z/OS JES3 Initialization and Tuning Guide and C/I FSSs and “Defining an Output Writer FSS” in z/OS JES3 Initialization and Tuning Guide.