Network Print Facility processing is illustrated in Figure 1, which contains numbered boxes that correlate to the numbered items in the list below.

Figure 1. Flow of Network Print Facility processing

The system administrator creates routing and options files using the macros provided by Network Print Facility. These files can be modified through the use of the ISPF interface, after the initial loading. The macros and the ISPF panel interface, or both, can also be used to add data to the files.

The operator starts the Network Print Facility JES or VTAM® capture point application and starts the queue manager.

For each print job, the Network Print Facility receives output through either the JES or VTAM capture point application.

The Network Print Facility obtains the necessary routing and options file information for the output. The routing can be to a single printer (a normal routing) or to multiple printers of the same type (a specific broadcast routing). Users can supply general routing or specific routing exits to alter the routing of print output.

The Network Print Facility creates a sequential print data set from the output received. Users can supply an input record exit to alter the print output before it is queued in this data set.

The Network Print Facility adds a record to the queue file for each location at which the print data set is to be printed. The queue file record contains information from the routing and options files in addition to the name and status of the print data set.

If multiple print jobs are waiting to go to the same printer, the NPF queue manager processes them in FIFO (First In, First Out) order. When it is time to send a particular print job, the queue manager uses information from the queue file to forward the queued data set to LPD services for printing.

Based on the return code from LPD and information in the queue file record, the NPF queue manager handles the queue record in one of the following ways:

• Keeps it to force the retry of an unsuccessful transmission.
• Keeps it for a user-specified retain time after a successful transmission or after all retries have been exhausted for an unsuccessful transmission.
• Erases it if no retry or retain time is indicated.

The NPF queue manager deletes the print data set after the last queue file record referring to it has been erased. For more details about queue manager processing, see Managing the print queues.