This chapter describes causes which may lead to incorrect output. The facts listed here have already been mentioned before in various chapters of this manual, but are consolidated here for convenience.
You may restart preview generation from HELIOS Admin at any time. If you have e.g. solved a specific problem and wish to restart a job that ended up in the error queue, just drag this job from the error queue’s job window to the preview queue’s job window again.
If you specify a hold queue when defining a preview queue the program will adopt the PPD file and the fonts from the hold queue as soon as you save the preview queue’s settings. If you do not specify a hold queue the program will ask you to select a PPD file. Always choose the same PPD file that has been defined for your final output device.
You can check the contents and names of the PPD files that are
currently defined for your existing printer queues by clicking
on the Edit PPD
"<Name of PPD>" button.
Note that you can even edit the contents of the PPD files in this window, provided that you have sufficient privileges. However, this requires some experience with the structure of PPD files.
The required temporary disk space for preview generation is calculated as follows:
Resolution of preview file
x page size (in inches)
x number of plates
x number of pages that have been printed
= required disk space in bytes
A one-page A4 document with a 72 dpi preview with 4 separation plates and the composite result:
72 x 72 (dpi) x 11.7 x 8.3 (inches) x 4 (number of gray separation plates) x 2 (for the CMYK composite preview) x 1 (number of pages in the original document) = 3.8 MB.
The selected preview resolution has the most significant influence on the disk space needed in the spool directory. If you double the resolution (e.g. from 72 to 144 dpi) this would quadruple the disk space requirements.
If you do not specify any compression the program will need about twice as much temporary disk space during preview generation. The maximum size of the new PDF file will be identical to the temporary disk space needed for its generation (in case you do not activate compression).
We recommend to use for your preview queue a spool directory on a file system with much more free disk space than the ones you use for your standard printer queues.
For security reasons, access rights to the preview files are pre-defined: you can only access a preview file – i.e. open, save, move or delete it – if you are the owner, “root”, or member of the printer administration group (includes members of “PrnAdm”, “QueueAdm”, and “SysAdm”). If you have top-secret print jobs that run through a preview queue, you have to set up the mentioned administration groups carefully.
Each page of a PDF preview file is an image. The elements of a page are not accessible separately. Even if you are using Adobe Acrobat you will not be able to edit text or other elements.
Usually, PrintPreview recognizes the page size of the document you have printed. If this is impossible – because the application sends incompatible page size information – the default page size is A4.
Usually, PrintPreview generates only one preview for each document page you have printed, even if you have specified a higher number of copies in the print dialog. If you move the job from the preview or hold queue to a “real-printing” queue after checking the preview, the number of copies will be recognized again, meaning that if you have specified e.g. 4 copies you will get 4 printouts of each document page.
If your preview file already contains more than one preview of each document page this indicates that your application prints each page several times instead of printing it once and specifying the number of copies you have entered in the PostScript file.
From an application, you can only print either composite or separations. In a preview file, however, you can have both, the composite preview and the separation plates – independent of whether you have printed composite or separations. That means that PrintPreview has to derive one of the previews on its own: If you have printed separations, the composite preview has to be calculated by PrintPreview, and if you have printed composite, the separation plates have to be calculated by PrintPreview. For these calculations, PrintPreview must rely on the information that is sent by the application. In case the information is not ADSC-compliant, the calculations may fail and this may lead to corrupt (or missing) composite or separation previews in a preview file. This does not affect real printing.
So, if your PrintPreview software delivers a warning in the printer log file, and if your preview files contain fewer or more separations than expected or a corrupt composite preview, you should check A “How applications cooperate with PrintPreview” for more information on this issue.
If you use PDF HandShake, and only use PDF HandShake fonts (PostScript 3 fonts) for document creation the fonts in the preview files will always be correct and identical to those used on the final printing device. Else, if you use other fonts, you have to make sure that they are available on your final output device, and that they are also installed on your server. Otherwise, printing to a preview queue and printing to the printer may lead to different results.
Users who run PDF HandShake and PrintPreview in demo
mode will notice that access to the PDF HandShake fonts is
restricted. Preview generation will work, but the fonts will
not be available for printing to a physical device. OPI users
have to switch off Check Fonts if PDF HandShake runs in
demo mode. Otherwise, even preview generation may fail.
If you receive a PostScript error when printing to a preview queue you should test whether the print job runs without problems when it is sent to a “real-printing” printer queue. If so, please contact our technical support department and send us an error report. This may help us locate potential problems on our preview queues.
Your report should contain:
Contents of the error message you have received
PPD file that has been selected for the preview queue
Contents of the HELIOS Admin Versions file
All preview queue settings
Name and version of the application you have used for printing
Send your report to the e-mail address support@helios.de