This is function is used for development in order to speed up the testing and save paper. But it can also be used for PreView the print results in any printing process. The function is only available for W-ELP.

There are two keys in the Miscellaneous section available:

PreView and PreView_NoPrint

PreView_NoPrint does erase the output data stream and nothing is printed.

Both keys convert the outgoing data stream into a PDF document. If the key PDF_ARGUMENTS (normally only present if Archiving is used) in found the ELP config file (e.g. c:\ProgramData\Welp\convert.ini) the PDF conversion settings are used from that parameter. If they key PDF_ARGUMENTS is missing then these are the default PDF conversion settings: dVersion:14 -z -*c -*d -*e -*f -q -g

The generated PDF will be stored in the c:\ProgramData\Welp\Debug\<QUEUENAME> folder. ELP starts automatically the default PDF reader simply by calling the PDF file name. Therefore it is important to assign the file extension PDF to a program on your PC. Especially for a server OS where normally no PDF reader is installed you might want to use Sumatra PDF which is a nice and tiny portable app and needs no installation.


  1. If the PreView function starts the PDF reader, then ELP waits until the reader is closed. To avoid that, it is recommended to start the viewer first, as then Windows just generates a new instance and ELP will directly continue and end the print job.
  2. The preview is shown on the server/PC where ELP is installed, and not on the PC generating the print job. So you might need to logon to the server. Another method is using the archive keys and then check the stored files in the W-ELP Control Center Archive Tab.
  3. The PDF files will remain in the c:\ProgramData\Welp\Debug\<QUEUENAME> folder. If there´s a log mode enabled then ELP will delete the PDF files automatically after 4 days. If there´s no logging active the PDF remains there. So it is recommended to delete them regularly/after testing is finished.
    You can also delete the files automatically by using this command:

    call=cmd /c del /Q #ELP_FORMS_PATH#Debug\#PRINTERNAME#\*.pdf;OFF

If  you really want to have a preview function in your application, you need to print either using the key PreView_NoPrint and then let the user decide in your application, if he want to print this. There are 2 ways to achieve this:

  • Use the print function of your PDF viewer to another queue, which does not preview.
  • Ask if every thing is OK in your application and reprint the data. In order to teach ELP that it is a PreView print or not, you either can print to another queue, which does not perform that PreView function, or even nicer, use/don't a special trigger word in the data stream