Xerox 701P21091 manual Impact of graphics on system performance, Graphics features restrictions

Using PDL commands for graphics

Except for the graphics themselves, the input stream may contain only optional IMAGE DJDE records. When the system encounters an IMAGE DJDE record, that DJDE defines the scaling and positioning parameters for subsequent graphics.

Impact of graphics on system performance

Incorporating graphics in a job can have an impact on system performance at different points in the printing process. The effect varies according to the mode of graphics transfer.

•Random (Move) mode:

Random or Move mode requires a separate disk access for processing of every graphic on a page. The more graphics on a page and the larger the graphics, the more likely it is that paper path holes are created.

NOTE: On the DP 2000 Series EPS, this condition occurs rarely, and only under extreme conditions.

•Online:

It should be noted that sending interleaved graphics across the online interface affects system performance. The time to process graphic information across the channel, block it, and write it to disk is significant. As the average density of graphic information decreases, throughput should increase.

Graphics features restrictions

Following is a summary of restrictions imposed on, and by, graphics features supported on DP 2000 Series EPS.

•Tape formats supported by interleaved graphic processing are restricted to LPS compatible fixed or variable record structures, that is, BLOCK or RECORD STRUCTURE = F, FB, V, or VB only. Undefined length record structures, such as types U and UB, are not supported. Packed data formats are not supported.

•Graphic images may be overlapped on a page with each other and with text.

•If a graphic begins off the system page, no part of the graphic is printed.

6-6 Using LCDS Print Description Language