FSS writers control the processing of JES logical printers.The number of NPF FSS writers and the number of logical printers associated with each NPF FSS writer is installation-dependent. Each FSA subtask under the FSS writer acts as a logical printer dedicated to processing the output in its defined class or classes. The steps to define FSS writers and their logical printers vary depending on the version and release of JES.

Because each FSA subtask acts as a logical printer, after the FSA subtask has been defined, each instance of a writer can be started and stopped like any printer. The FSS writer can be started by JES commands or through the JES initialization definition. Commands and initialization statements to start the FSS writer in various environments can be found in Table 1.