Xerox DocuPrint 92C NPS Troubleshooting Manual page 53

Job #94 start, ftpadmin, rxlb300-ps2.ps, November 14, 1998 9:54:44 am PST
Printing simplex, 300 spi, 210 x 297 mm, 43 buf, black, red [r: 0.88, g:
0.00, b: 0.00]
Job #94 stop, ftpadmin, rxlb300-ps2.ps, November 14, 1998 9:55:20 am PST
pages: 30, decomp: 10.83, elapsed: 35.39
XEROX DOCUPRINT 92C NPS TROUBLESHOOTING GUIDE
ADJUSTING PRINT QUALITY AND PERFORMANCE
Note: If you experience delays due to empty paper trays or
paper jams, repeat steps 1-5 until the jobs complete without
delays.
6. Calculate the elapsed time by subtracting the stop time of the
last job from the start time of the first job.
7. Add up the total number of pages for all jobs.
8. Calculate throughput using the formula:
PPM = 60 x pages/elapsed time in seconds
Here is the calculation for the example of the sequencer log above:
The start time was: 9:44:00 am
The stop time was: 9:47:30 am
(This gives an elapsed time of 3 minutes and 30 seconds, or 210
seconds)
PPM = 60 x 300/210 = 85.8 pages per minute
This example illustrates the problem with calculating the elapsed
time from the first job, since this job was actually printing at the
maximum rate of the DocuPrint 92 ppm printer. The start-up latency
made the printer appear to be printing at a rate 6.2 ppm lower than
the maximum rate.
To verify the assumption that the sustained throughput of the job
prints at the rated speed of a DocuPrint 92 ppm printer, a calculation
of the rate based on the decomposition time is recommended. The
decomposition time gives the theoretical maximum that the
DocuPrint can print this job. Since the DocuPrint usually
decomposes more than one job at a time, the jobs are time-shared
on the one processor and this will cause the decomposition time to
be larger than if the DocuPrint decomposed once by itself. In the
sample log, there are always 3 jobs printing at the same time and the
decomposition times reported vary from 11.45 to 17.71. After
submitting this job by itself, the decomposition time reported is:
PPM = 60 x 30/10.83 = 166.2 pages per minute
This is considerably higher than the maximum speed of the printer,
so it is very likely that this job prints at rated speed.
6-5