The issue is resolved.
Unfortunately the documentation for the PixHawk requires a programming knowledge base that includes the magic decoder ring, because the 3DR folk won't answer email, and unless you are part of the development team it would appear that you are not worthy to have the specific details of what triggers what in the device.
It's really good to know that companies out there value customer questions, and that everybody is an expert at the product without documentation. If my organization treated customers this way, we wouldn't have many. If any. I'm not so sure this device was a good purchase.