[pluggo] Pluggo Rotor Effect?

I'm using both Pluggo and Mode with Logic Audio (Light), and I'm trying to get a "Rotor Effect," where the volume of a track is automatically raised and lowered at a given frequency (every 1/2 second, for instance).

This seems like a pretty basic effect but I've never found an automatic way to do this. Pluggo's Ring Modulator does this sort of thing, but I can't set it to a low enough frequency (let alone fine-tune it). It would be nice to be able to "shape" the rotor wave too, but I can do without it.

Is there any way to do this with any of the Pluggo or Mode plug-ins? Thanks in advance for any suggestions!

Muffy
http://www.dangermuff.com