Print Organizer to PDF

There is a special Printing and Plotting Forum just to handle problems like this, and I believe I have seen this issue mentioned more than once over there. I suggest posting your question to that forum. Be sure to tell people which software package you are using, as well as the version number - it will help them anmswer your question more directly.

I will assume you are using a delivered copy of pdf.pltcfg and that you have a print style that describes your plot area and sets the print as you want.

Next create a text file (printset.txt) that contains the following Key-in commands:
mdl load bentley.printorganizer.dll
PRINTORGANIZER NEW
PRINTORGANIZER PRINTERDRIVER pdf.pltcfg
PRINTORGANIZER ADD ACTIVEFILE Multiple_Shapes
PRINTORGANIZER SUBMITAS SINGLE
PRINTORGANIZER PRINTDESTINATION $(MS_PLTFILES)$(basename(_DGNFILE)).pdf
PRINTORGANIZER PRINT ALL
PRINTORGANIZER DELETE ALL
PRINTORGANIZER EXIT

The scripts loads Print Organizer, sets printer driver to pdf.pltcfg, adds mtcoles the active file and calls “Multiple_Shapes” print style, sets print to a single .pdf file, sets the destination according to the variable MS_PLTFILES and names the output file to the design file name, prints, deletes the contents of the .pset and dismisses the Print Organizer interface.
In the Key-in window, type in the following:
@printset.txt
Note, you may have to give the path to the script file.
A description of each key-in command can be obtain by launching MicroStation Help, expand “Working with Completed Designs”, Expand “Printing”, expand “Using Print Organizer” and “Print Organizer key-ins”.

source: https://communities.bentley.com/products/microstation/microstation_printing/w/wiki/32703/print-organizer-single-key-in-to-generate-multi-page-pdf