I have a AF-5600, Dynon autopilot, Dynon transponder, Dynon Com and audio panel. No external navigator. I can setup flight plans and crossing altitudes, but nothing I've tried will cause the autopilot to descend to the crossing altitudes. Arming VNAV looks good, but it happily flies the altitude bug right past TOD. VFPL displays TOD and BOD, but won't command the pitch down. I can adjust the bug to the crossing altitude (manually) but I haven't figured out the command sequence to get it to automatically fly the descent.
Can someone tell me how to get this thing to fly to the crossing altitudes without me changing the bug each time?

Thanks,

Bill