Using PSF to control job separation

Q: IPDS print jobs are not being separated properly when printing through ExcelliPrint®.

A: IPDS is a page-based protocol. ExcelliPrint never receives any information about when a print job starts or ends as it is not supplied by the host system.

The Print Services Facility (PSF) provides a method to separate the print job into separate files. On IBM mainframes, the JES parameter is CKPTPAGE. On the iSeries, the PSFCFG option is Acknowledgment frequency (ACKFRQ).

ExcelliPrint will create a new job or file if the number of pages in the spool file exceeds this setting. PSF supports a maximum of 32767 in this parameter.

For example, if you set this parameter to 100 and the print job is only 25 pages, the job will be split at page 25 successfully. If the number of pages in the next print job is 120, ExcelliPrint will separate the first 100 pages into one print job and the last 20 pages in a new print job.

The host system also uses this setting when handling problems.

• If you have a 60,000-page print job, and you set this parameter to 32767, ExcelliPrint will create only two separate print jobs. If an error occurs on page 60,000, the host system must resend all pages from 32,768 through 60,000 again.
• If 10 was configured in the CKPTPAGE parameter, ExcelliPrint would separate the job into 6,000 smaller print jobs. If an error occurred on page 60,000, the host system would need to resend only pages 59,991 through 60,000, significantly reducing the amount of recovery time and host system processor utilization.

Setting this parameter to a low value will cause slower printing.

We suggest testing this to find the value that works best in your environment.