I used to do some projects with Touch Designer, unfortunately it can't export SVG. For a better understanding of your plotter you should read about the difference of pixel graphics and vector graphics. That should clear some things, espacially what your plotter demands. However you have the possibilty to convert pixel data to vector data through tracing, but I would not recommend that route.

about realtime drawing I believe is hard to do it

Yes, I'd go so far and say it is just not possible with that setup for reasons stated above. :)

Have fun, in any case this is a fun project.