[Discuss-gnuradio] Calling usrp_source block function from other block

Hi all,

I'm looking for the best way to retune the USRP from another block in a running flowgraph. I've seen the tune callback method used by bin_statistics_f, but I was wondering if there are other ways to do it. I took a look at message passing (http://gnuradio.org/doc/doxygen/page_msg_passing.html), but I'm not sure how to bind usrp_source's set_center_freq to handle a freq passed by message, etc.

Are there any examples of doing this laying around or is bin_statistics_f's tune callback still the best way to do it?

-Doug